Russell and Richard B. Devereux Jennifer S. Drukteinis - CiteSeerX

Russell and Richard B. Devereux Jennifer S. Drukteinis - CiteSeerX

Cardiac and Systemic Hemodynamic Characteristics of Hypertension and Prehypertension in Adolescents and Young Adults: The Strong Heart Study Jennifer ...

371KB Sizes 0 Downloads 6 Views

Recommend Documents

Richard B. Russell Dam and Lake, Savannah River, Georgia and
Nov 30, 1989 - Richard B. Russell Project. This includes the concrete dam, earth embankments, and the powerhouse. The re

2012 Richard B. Russell Lake Hunting Map
Page 1. Richard B. Russell Lake. Hunting Map. U.S. Army Corps of Engineers-Savannah.

Richard Russell - Advisor Perspectives
Richard Russell. December 2, 2015 by Jeffrey Saut of Raymond James. A couple of weeks ago I wrote a strategy report titl

CV - Richard Russell
Richard Russell CV page 2 of 9. Russell, R., Kramer, S.S., & Jones, A.L. (In press) Facial contrast declines with age bu

Richard Russell - MIT
Richard Russell. Graduate Student [email protected] Page 2. The Problems: Which computational image similarity metrics c

Stock Guide - Richard Russell
SIZE CONVERSIONS. Metric (mm). Feet. Inches. 915 X 610. 3 X 2. 36 X 24. 915 X 915. 3 X 3. 36 X 36. 1220 X 610. 4 X 2. 48

Richard Russell - WordPress.com
Richard Russell. 2114 Lear Ln. Austin, TX 78745 (512) 299-1261. Relevant. Experience. 5 years of experience managing e-c

Richard A. Russell
Richard A. Russell is a former Senior National Intelligence Service. Executive who served in progressively responsible p

Richard Russell, Bishop of Glasgow and Galloway's
Jun 14, 2011 - Richard Russell, Bishop of Glasgow and Galloway's. 1292. Sculptor: Unknown. Town or Village. Parish. Loca

Digital Archives Processing Manual Richard B. Russell Library for
Jun 22, 2015 - Richard B. Russell Library for Political Research and Studies. University of Georgia. Page 1. Note: conta

Cardiac and Systemic Hemodynamic Characteristics of Hypertension and Prehypertension in Adolescents and Young Adults: The Strong Heart Study Jennifer S. Drukteinis, Mary J. Roman, Richard R. Fabsitz, Elisa T. Lee, Lyle G. Best, Marie Russell and Richard B. Devereux Circulation. 2007;115:221-227; originally published online January 8, 2007; doi: 10.1161/CIRCULATIONAHA.106.668921 Circulation is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Copyright © 2007 American Heart Association, Inc. All rights reserved. Print ISSN: 0009-7322. Online ISSN: 1524-4539

The online version of this article, along with updated information and services, is located on the World Wide Web at: http://circ.ahajournals.org/content/115/2/221

Permissions: Requests for permissions to reproduce figures, tables, or portions of articles originally published in Circulation can be obtained via RightsLink, a service of the Copyright Clearance Center, not the Editorial Office. Once the online version of the published article for which permission is being requested is located, click Request Permissions in the middle column of the Web page under Services. Further information about this process is available in the Permissions and Rights Question and Answer document. Reprints: Information about reprints can be found online at: http://www.lww.com/reprints Subscriptions: Information about subscribing to Circulation is online at: http://circ.ahajournals.org//subscriptions/

Downloaded from http://circ.ahajournals.org/ by guest on March 5, 2014

Cardiac and Systemic Hemodynamic Characteristics of Hypertension and Prehypertension in Adolescents and Young Adults The Strong Heart Study Jennifer S. Drukteinis, MD; Mary J. Roman, MD; Richard R. Fabsitz, PhD; Elisa T. Lee, PhD; Lyle G. Best, MD; Marie Russell, MD; Richard B. Devereux, MD Background—The epidemic of overweight is increasing the prevalence of both prehypertension and early-onset hypertension, but few population-based data exist on their impact on cardiac structure and function in adolescents and young adults. Methods and Results—We analyzed clinical characteristics, hemodynamic parameters, and left ventricular structure and function in 1940 participants, 14 to 39 years of age, in the Strong Heart Study. Hypertension occurred in 294 participants (15%), who were more often men (70% versus 30%), older (age, 31⫾7 versus 25⫾8 years), and more commonly diabetic (23% versus 4.5%; all P⬍0.001) than their normotensive counterparts. Prehypertension occurred in 675 (35%) of participants with similar trends in gender, age, and diabetes status. After adjustment for covariates, both hypertensive and prehypertensive participants had higher left ventricular wall thickness (0.83 and 0.78 versus 0.72 cm), left ventricular mass (182 and 161 versus 137 g), and relative wall thickness (0.30 and 0.29 versus 0.28 cm) and 3- and 2-fold-higher prevalences of left ventricular hypertrophy than their normotensive counterparts (all P⬍0.001). Hypertension and prehypertension also were associated with higher mean pulse pressure/stroke volume index (1.24 and 1.15 versus 1.02 mm Hg/mL · m2) and total peripheral resistance index (3027 and 2805 versus 2566 dynes · s · cm⫺5 · m2; all P⬍0.001). Conclusions—In a population with high prevalences of obesity and diabetes, hypertension and prehypertension are associated with increases in both cardiac output and peripheral resistance index. Despite the young age of participants with hypertension and prehypertension, they had prognostically adverse preclinical cardiovascular disease, including left ventricular hypertrophy and evidence of increased arterial stiffness. (Circulation. 2007;115:221-227.) Key Words: echocardiography 䡲 hemodynamics 䡲 hypertension 䡲 hypertrophy 䡲 prehypertension

I

n the United States and other industrialized countries, physical inactivity and high-calorie diets are leading to increasing prevalences of obesity and diabetes.1 Concordantly, hypertension also has become increasingly prevalent.2 Obesity and higher blood pressure have been shown to track from childhood and adolescence to adulthood and to predict adult cardiovascular risk.3,4 According to the Seventh Report of the Joint National Committee (JNC) on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-7),5 a new category based on blood pressure (BP) level, called prehypertension, requires attention and healthpromoting lifestyle modifications at an even earlier stage to prevent the progressive rise in BP and cardiovascular disease.

Approximately 60% of American adults have prehypertension or hypertension, with hypertension increasing by ⬇10% in the past decade.6 Recent studies in population-based samples with mean ages from 45 to 55 years at baseline have shown increased cardiovascular event rates in adults with “high-normal” BP (130 to 139/85 to 89 mm Hg)7 or prehypertension (BP, 120 to 139/80 to 89 mm Hg without antihypertensive medication).8 Although the increased prevalence of hypertension and the common occurrence of prehypertension are affecting cardiovascular mortality in middle and older age, their earlier impact on cardiac structure and function in adolescents and young adults has not been extensively characterized in large, population-based samples.

Continuing medical education (CME) credit is available for this article. Go to http://cme.ahajournals.org to take the quiz. Received February 24, 2006; accepted October 11, 2006. From the Weill Medical College of Cornell University, New York, NY (J.S.D., M.J.R., R.B.D.); National Heart, Lung, and Blood Institute, Bethesda, Md (R.R.F.); University of Oklahoma Health Sciences Center, Oklahoma City (E.T.L.); Missouri Breaks Industries Research, Inc, Timber Lake, SD (L.G.B.); and MedStar Research Institute, Washington, DC (M.R.). This manuscript presents the views of the authors and not necessarily those of the Indian Health Service. Correspondence to Richard B. Devereux, MD, Division of Cardiology, Box 222, New York Presbyterian Hospital, 525 E 68th St, New York, NY 10021. E-mail [email protected] © 2007 American Heart Association, Inc. Circulation is available at http://www.circulationaha.org

DOI: 10.1161/CIRCULATIONAHA.106.668921

221 Downloaded from http://circ.ahajournals.org/ by guest on March 5, 2014

222

Circulation

January 16, 2007

Previous studies have examined cardiac structure and function in white, black, or Hispanic populations with modest prevalences of obesity and diabetes.9,10 Accordingly, the present study was undertaken to evaluate the associations of hypertension and prehypertension with clinical characteristics, systemic hemodynamics, and cardiac structure and function in adolescent and young adult American Indian participants (age, 14 to 39 years) in the Strong Heart Study (SHS),11–13 a population in which obesity, diabetes, and hypertension are highly prevalent.

ventricular (LV) internal dimensions were measured at end diastole and end systole by American Society of Echocardiography recommendations.22,23 Aortic annular diameter was measured as previously described.24 Doppler transaortic flow was assessed by identifying the apical view in which peak flow velocity was maximal and, after calibration, tracing the black-white interface outlining the Doppler flow envelope.25 Heart rate was measured simultaneously. Prolonged isovolumic relaxation time was recognized as ⱖ92.4 ms in this population, representing the 97.5th percentile of values in 497 nondiabetic, nonobese, nonhypertensive participants in the fourth SHS examination.

Calculation of Derived Variables

Methods The SHS is a population-based survey of cardiovascular risk factors and cardiovascular disease in American Indian communities in Arizona, Oklahoma, and South and North Dakota. As previously described,12 members of 13 communities in Arizona, Oklahoma, and South and North Dakota (45 to 74 years of age) were recruited from reservations or (in Oklahoma) in defined geographic areas (overall participation rate, 62%) for an initial examination in 1989 to 1992. Two additional examinations of the initial SHS cohort to assess change over time were performed during 1993 to 1995 and during 1997 to 1999. The fourth SHS examination in July 2001 to September 2003 included 520 SHS cohort members and 3138 of their relatives in 95 large 3-generation families (Strong Heart Family Study [SHFS]).14 Standardized measurements of seated brachial BP and aspects of body habitus, including body mass index, waist-to-hip ratio, body composition by bioelectric impedance, fasting glucose, insulin and lipid concentrations, and 2-hour glucose tolerance test and glycosylated hemoglobin levels, were obtained. Brachial artery BP (first and fifth Korotkoff sounds) was measured 3 consecutive times on seated participants after they had rested 5 minutes with the use of a mercury sphygmomanometer (W.A. Baum Co, Copiague, NY). An appropriately sized cuff was placed on the right arm; pulse occlusion pressure was determined; and the cuff was inflated to 20 mm Hg above that pressure. The mean of the last 2 of these measurements was used to estimate BP. Hypertension was defined by systolic BP ⱖ140 mm Hg, diastolic pressure ⱖ90 mm Hg, or use of antihypertensive medications.15 Participants were asked to bring their medications to the clinic and to recall (with assistance from an adult for minors) additional medications. Prehypertension was defined by systolic BP of 120 to 139 mm Hg or diastolic BP of 80 to 89 mm Hg5 in the absence of antihypertensive treatment. Fat-free mass and adipose mass were estimated with an RJL impedance meter (model B14101, RJL Equipment Co, Detroit, Mich) and equations based on total body water12 that have been validated in the American Indian population.16,17 Obesity was defined by a body mass index ⱖ30 kg/m2 and central adiposity by waist circumference ⬎102 cm for men and ⬎88 cm for women.18 Diabetes was diagnosed by 1997 American Diabetes Association diagnostic criteria.19 Participants (or their parent or guardian in the case of minors) gave written informed consent under protocols approved by institutional review boards of the clinical centers.

Echocardiographic Methods Imaging and Doppler echocardiograms, performed as previously described,14,20,21 were recorded on videotape using phased-array echocardiographs with fundamental and harmonic M-mode and 2-dimensional imaging, as well as pulsed, continuous-wave, and color-flow Doppler capabilities (Sequoia, Siemens Inc, Mountain View, Calif). Participants were examined in a partial decubitus position with the head of table tilted at ⬇30°.

Echocardiographic Measurements Correct orientation of planes for imaging and Doppler recordings was verified as previously described.21,22 Measurements were made with a computerized review station equipped with digitizing tablet and monitor screen overlay for calibration and measurement performance. Interventricular and posterior wall thicknesses and left

End-diastolic LV dimensions were used to calculate LV mass by an anatomically validated formula.26 Concentric LV geometry was identified by taking into account age effects on LV relative wall thickness according to the method of de Simone et al.27 Systolic fractional shortening of the LV internal dimension and end-systolic stress were calculated by standard methods.21 Aortic annular crosssectional area was calculated as follows: ␲⫻(diameter/2).2 Doppler stroke volume was calculated as annular cross-sectional area times the time-velocity integral.26 Arterial stiffness was estimated by the ratio of pulse pressure to stroke volume index.28

Measures of Myocardial Performance The primary approach to assess myocardial contractile efficiency was to examine LV midwall shortening in relation to circumferential end-systolic stress measured at the level of the LV midwall using previously described methods.20 –30 Midwall shortening calculated from echocardiographic measurements was expressed as a percentage of the value predicted from circumferential end-systolic stress using equations derived from previously studied healthy subjects30; this variable is called stress-corrected midwall shortening.31

Statistical Analysis Data, expressed as mean⫾SD for continuous variables and proportions for categorical variables, were analyzed by SPSS 12.0 software (SPSS, Chicago, Ill). Differences between 2 groups for continuous variables were assessed by t tests, with log transformation when needed to satisfy the assumption of normality, and the ␹2 statistic was used to determine differences of categorical variables. Relations between clinical and echocardiographic variables were assessed with consideration of appropriate covariates. Independence of differences from effects of covariates (age, gender, diabetes, and center location) was assessed by ANCOVA in the general linear model with the Sidak post hoc test or by logistic regression analysis for categorical variables. Two-tailed values of P⬍0.05 indicated statistical significance. The authors had full access to and take full responsibility for the integrity of the data. All authors have read and agree to the manuscript as written.

Results Characteristics Of the 3658 participants in the fourth SHS examination, 1940 relatives of members of the original SHS cohort were ⬍40 years of age. Most participants (57.5%) were women; the mean age was 26.8⫾7.7 years; 294 (15%) and 675 (35%) met JNC-7 criteria for hypertension and prehypertension, respectively. Among hypertensive participants, 45 (15%) had systolic hypertension, defined as BP ⱖ140 mm Hg; 138 (47%) had diastolic hypertension, defined as BP ⱖ90 mm Hg; 57 (19%) had both diastolic and systolic hypertension; and 54 (18%) had normal BP on antihypertensive medication. Hypertension was more prevalent in men than women and increased with age in both genders (the Figure), rising from 1.7% in women and 9.3% in men at 14 to 19 years of age

Downloaded from http://circ.ahajournals.org/ by guest on March 5, 2014

Drukteinis et al

Hypertension and Prehypertension in Young Adults

Prevalence of hypertension (vertical axis) is greater in male (solid bars) than female (striped bars) adolescent and young adult SHS participants and increases with age (horizontal axis) in both genders.

(P⬍0.001) to 6.2% of women and 16.5% of men at 20 to 24 years of age (P⫽0.007), 5.1% of women and 16.4% of men at 25 to 29 years of age (P⬍0.001), 4.5% of women and 21.0% of men at 30 to 34 years of age (P⬍0.001), and 18.0% of women and 41.6% of men at 35 to 39 years of age (P⬍0.001). Compared with the nonhypertensive group, hypertensive and prehypertensive participants were more likely to be men (70% and 52% versus 38%, respectively), to be obese (75% and 65% versus 53%, respectively), and to have diabetes (23% and 9% versus 6%, respectively) and impaired fasting glucose (10% and 6% versus 3%, respectively; all intergroup differences, P⬍0.05). Hypertension was more prevalent in Oklahoma or Arizona than in North and South Dakota (18% and 19% versus 11%, respectively; P⬍0.001). Hypertensive and prehypertensive participants were also

older (30.9⫾6.8 and 27.2⫾7.5 versus 25.2⫾7.7 years; both P⬍0.001). In analyses that adjusted for age, gender, diabetes, and center, hypertension and prehypertension were associated with higher weight, body mass index, percent body fat, body surface area, waist circumference, and adipose mass (Table 1). However, no difference was seen in ankle/brachial index between groups. According to National Institutes of Health guidelines,19 79% and 69% of hypertensive and prehypertensive participants, respectively, had central adiposity by waist circumference criteria compared with 55% in the nonhypertensive group (P⬍0.001). The hypertensive participants had higher mean urine albumin-to-creatinine ratio and higher hemoglobin A1c levels, whereas prehypertensive participants did not differ statistically from their normotensive counterparts. Both the hypertensive and prehypertensive groups had higher total cholesterol, insulin, and low-density lipoprotein cholesterol than their normotensive counterparts, with no difference between groups in plasma creatinine, triglycerides, or high-density lipoprotein cholesterol after adjustment for covariates.

Systemic Hemodynamics Heart rate and cardiac output were higher in both hypertensive and prehypertensive participants than in normotensive participants in absolute terms and after adjustment for age, gender, diabetes, and center location (Table 2). Total peripheral resistance was higher in both the hypertensive and prehypertensive groups; however, after adjustment for covariates, the difference remained significant in only the hypertensive group. Peripheral resistance index and pulse pressure/

TABLE 1. Clinical Characteristics of Normotensive, Prehypertensive, and Hypertensive Adolescent and Young Adult SHS Participants BP

P*

NT (N⫽971)

PH (N⫽675)

HT (N⫽294)

HT vs PH

PH vs HT

NT vs HT

Systolic BP, mm Hg

108.0⫾7.0

123.2⫾7.5

134.9⫾14.7

䡠䡠䡠

䡠䡠䡠

䡠䡠䡠

Diastolic BP, mm Hg

68.1⫾7.2

78.7⫾7.7

89.6⫾10.8

Body mass index, kg/m2

30.0⫾8.2

33.8⫾8.3

36.6⫾9.2

䡠䡠䡠 ⬍0.001

䡠䡠䡠 0.003

䡠䡠䡠 ⬍0.001

Weight, kg

82.5⫾22.6

97.5⫾24.6

108.8⫾28.2

⬍0.001

⬍0.001

⬍0.001

Body surface area, m2

1.89⫾0.24

2.07⫾0.25

2.19⫾0.27

⬍0.001

0.001

⬍0.001

Body fat, %

36.8⫾11.6

37.9⫾10.8

38.2⫾9.5

⬍0.001

0.087

⬍0.001

Adipose mass, kg

32.3⫾17.5

38.1⫾17.9

43.2⫾20.0

⬍0.001

0.007

⬍0.001

Waist circumference, cm

96.5⫾18.5

106.2⫾18.1

114.3⫾19.1

⬍0.001

0.001

⬍0.001

Ankle/arm index

1.10⫾0.11

1.11⫾0.11

1.11⫾0.11

0.757

0.494

0.170

Plasma creatinine, mg/dL

0.77⫾0.16

0.81⫾0.16

0.83⫾0.28

0.995

0.973

0.931

Log urinary albumin/creatinine

2.08⫾0.10

2.18⫾1.1

2.53⫾1.5

0.932

0.010

0.003

Total cholesterol, mg/dL

165⫾33.1

181⫾38.3

190⫾42.7

⬍0.001

0.986

0.003

HDL cholesterol, mg/dL

50.3⫾13.0

48.3⫾12.7

50.0⫾15.0

0.074

0.101

0.954

LDL cholesterol, mg/dL

89.5⫾25.0

101⫾29.6

105⫾33.0

⬍0.001

0.623

0.030

Triglycerides, mg/dL

130⫾121

172.5⫾236

211.4⫾305

0.121

0.990

0.555

Insulin, ␮U/mL

15.6⫾14.7

19.5⫾20.5

22.4⫾26.6

⬍0.001

0.043

⬍0.001

5.9⫾1.9

6.3⫾2.1

7.0⫾2.3

0.992

0.949

0.882

Hemoglobin A1C, %

223

NT indicates normotensive; PH, prehypertensive; HT, hypertensive; HDL, high-density lipoprotein; and LDL, low-density lipoprotein. Values are mean⫾SD unless otherwise indicated. *Adjusted for age, gender, diabetes, and center location.

Downloaded from http://circ.ahajournals.org/ by guest on March 5, 2014

224 TABLE 2.

Circulation

January 16, 2007

Systemic Hemodynamics of Normotensive and Hypertensive Adolescent and Young Adult SHS Participants BP

Heart rate, bpm

P*

NT

PH

HT

NT vs PH

PH vs HT

NT vs HT

65⫾10

68⫾11

71⫾12

⬍0.001

0.020

⬍0.001

Cardiac output, mL/min

5037⫾987

5624⫾1175

6111⫾1390

⬍0.001

0.014

⬍0.001

Cardiac output/body surface area, mL 䡠 min 䡠 m⫺2

2683⫾511

2736⫾544

2790⫾541

0.172

0.793

0.095

Total peripheral resistance, dyne 䡠 cm 䡠 s⫺5

1365⫾278

1369⫾283

1398⫾311

0.866

0.257

0.097

Pulse pressure/stroke index, mm Hg/mL 䡠 m2

1.02⫾0.26

1.15⫾0.30

1.24⫾0.35

0.034

0.074

⬍0.001

Peripheral resistance⫻body surface area, dyne 䡠 cm 䡠 s⫺5 䡠 m2

2566⫾552

2805⫾569

3027⫾631

⬍0.001

⬍0.001

⬍0.001

Abbreviations as in Table 1. Values are mean⫾SD unless otherwise indicated. *Adjusted for age, gender, diabetes status, and center location.

stroke index were higher in both the hypertensive and prehypertensive groups.

LV Systolic Function LV endocardial fractional shortening and ejection fraction from linear LV dimension or 2-dimensional wall motion scores were not statistically different among groups (Table 3). Hypertensive and prehypertensive participants had lower midwall shortening than the nonhypertensive group. Stresscorrected midwall shortening was not statistically different among groups. Circumferential end-systolic stress was significantly elevated in both the hypertensive and prehypertensive groups. The circumferential end-systolic stress/end-systolic volume index, a load-adjusted measure of chamber contractility, did not differ among groups after adjustment for age, gender, diabetes, and center.

LV Diastolic Filling Isovolumic relaxation time was longer and the mean E velocity was slightly lower in hypertensive and prehypertensive participants, but the differences were not significant after adjustment for covariates (Table 4). More participants had prolonged isovolumic relaxation time in both the hypertensive and prehypertensive groups; however, after adjustment for covariates, the difference remained significant only in the hypertensive group. Mean mitral A velocity and atrial filling fraction were higher and the mean mitral E/A ratio was lower in both hypertensive and prehypertensive participants, even

after covariate adjustment. Mitral deceleration time was slightly higher in hypertensive and prehypertensive participants, although this difference did not remain significant after covariate adjustment.

LV Geometry Hypertensive and prehypertensive patients had, on average, thicker interventricular septal and LV posterior walls than normotensive participants (Table 5). Both LV chamber diameter and relative wall thickness were increased in the hypertensive and prehypertensive groups. As a result, LV mass in absolute terms or indexed for body surface area and height to its allometric power was higher in both the hypertensive and prehypertensive groups. The prevalence of LV hypertrophy was ⬎3-fold higher in hypertensive and 2-fold higher in prehypertensive participants than in their normotensive counterparts. Classification of LV geometry, using age-adjusted relative wall thickness27 and LV mass/height2.7 partition values of 46.9 g/m2.7 in women and 49.2 g/m2.7 in men, shows minimally higher prevalence of concentric remodeling and 3-fold- and 2-fold-higher prevalences of eccentric LV hypertrophy in the hypertensive and prehypertensive groups, respectively. Concentric LV hypertrophy was rare (n⫽6, 0.4%) in the present study population.

Discussion The present study documents high prevalences of hypertension (15%) and prehypertension (35%) in a large population-

TABLE 3. Left Ventricular Systolic Function of Normotensive and Hypertensive Adolescent and Young Adult SHFS Participants BP

P*

NT

PH

HT

NT vs PH

PH vs HT

NT vs HT

Ejection fraction, %

60.4⫾5.0

59.6⫾5.0

2-Dimensional ejection fraction, %

62.5⫾2.5

62.4⫾2.7

59.5⫾5.2

0.150

0.863

0.867

62.3⫾3.3

1.00

1.00

Endocardial fractional shortening, %

32.5⫾3.4

1.00

32.1⫾3.5

32.1⫾3.6

0.306

0.809

0.981

Midwall shortening, % Stress-corrected midwall shortening, %

18.7⫾1.6

18.1⫾1.6

17.8⫾1.6

⬍0.001

0.871

⬍0.001

1139⫾10

112⫾10

112⫾10

0.852

0.371

Circumferential end-systolic stress, kdyne/cm2

0.736

158⫾25

175⫾28

190⫾35

⬍0.001

⬍0.001

⬍0.001

Circumferential end-systolic stress/end-systolic volume index, ⫻10 kdynes 䡠 cm⫺2 䡠 m⫺2

1.12⫾0.31

1.05⫾0.27

1.04⫾0.27

0.053

0.903

0.634

Abbreviations as in Table 1. Values are mean⫾SD unless otherwise indicated. *Adjusted for age, gender, diabetes status, and center location.

Downloaded from http://circ.ahajournals.org/ by guest on March 5, 2014

Drukteinis et al

Hypertension and Prehypertension in Young Adults

225

TABLE 4. Diastolic Function of Normotensive and Hypertensive Adolescent and Young Adult SHFS Participants BP

IVRT, ms

P*

NT

PH

HT

75.3⫾10.4

77.3⫾10.4

80.0⫾11.8

NT vs PH 0.631

PH vs HT 0.923

NT vs HT 0.463 ⬍0.001

IVRT ⬎92 ms, n (%)

44 (4.6)

43 (6.5)

38 (13.3)

0.375

0.001

Mitral E velocity, cm/s

73.3⫾13.2

70.3⫾13.8

68.4⫾16.3

0.943

0.893

0.992

Mitral A velocity, cm/s

48.9⫾11.3

52.1⫾11.7

58.5⫾14.5

⬍0.001

0.004

⬍0.001

Mitral E/A ratio

1.84⫾0.55

1.69⫾0.53

1.47⫾0.38

⬍0.001

0.001

⬍0.001

166.2⫾36.1

169.5⫾35.4

177.0⫾37.4

25

28

32

Mitral deceleration time, ms Atrial filling fraction, %

0.840

0.799

0.455

⬍0.001

0.003

⬍0.001

IVRT indicates isovolumic relaxation time. Other abbreviations as in Table 1. Values are mean⫾SD unless otherwise indicated. *Adjusted for age, gender, diabetes status, and center location.

based sample of adolescent and young adult American Indians (mean age, 29 years) who are particularly affected by the epidemic of obesity that is engulfing industrialized nations. Twice as many participants in this population and age range had diastolic hypertension than systolic hypertension. The higher prevalence of diastolic hypertension in this younger age group is consistent with previous data that arterial elasticity decreases with age, consequently increasing systolic hypertension, and is an independent risk factor for cardiovascular disease.31,32 The presence of systolic hypertension in 102 participants and increased pulse pressure/ stroke index in the entire group of hypertensive participants identifies an early prevalence of increased arterial stiffness with multiple features related to insulin resistance, as suggested by the Bogalusa Heart Study.33 In the present study population, hypertension was more prevalent in obese than nonobese participants (21% versus 9%), particularly those with central adiposity (19% versus 9%), and in those with TABLE 5.

than without diabetes (24% versus 6%), consistent with evidence implicating these factors in precipitating hypertension in middle-aged to elderly adults.34 Previous data in hypertensive adults indicated that lower stress-corrected midwall shortening predicts a higher rate of cardiovascular events.35 Our population did not exhibit a difference in circumferential end-systolic stress/end-systolic volume index or stress-corrected midwall shortening between groups. The lack of difference in these contractility indexes between young normotensive and hypertensive SHS participants indicates that myocardial function has not yet been compromised despite LV geometric abnormalities at this early and relatively mild stage of hypertension. The percentage of patients with prolonged isovolumic relaxation time was higher in the hypertensive and prehypertensive groups, which also had higher peak mitral A velocity and atrial filling fractions. Hypertensive and prehypertensive participants had significantly lower mean mitral E/A ratios, suggesting

LV Geometry of Normotensive and Hypertensive Adolescent and Young Adult SHFS Participants BP

IVSd, cm

P*

NT

PH

HT

NT vs PH

PH vs HT

NT vs HT

0.79⫾0.10

0.86⫾0.11

0.91⫾0.11

⬍0.001

0.005

⬍0.001

LVIDd, cm

5.2⫾0.38

5.4⫾0.44

5.5⫾0.47

⬍0.001

0.485

⬍0.001

PWTd, cm

0.72⫾0.10

0.78⫾0.10

0.83⫾0.10

⬍0.001

0.018

⬍0.001

LVIDs, cm

3.5⫾0.35

3.7⫾0.40

3.8⫾0.45

⬍0.001

0.974

⬍0.001

136.5⫾31.8

161.1⫾37.4

181.9⫾42.4

⬍0.001

0.014

⬍0.001

LV mass, g LV mass/BSA, g/m

71.9⫾12.9

77.7⫾14.3

82.9⫾15.2

⬍0.001

0.346

⬍0.001

LV mass/height2.7, g/m2.7

34.7⫾7.7

38.4⫾7.9

41.4⫾8.6

⬍0.001

0.100

⬍0.001

RWTd, cm

0.28⫾0.04

0.29⫾0.04

0.30⫾0.04

⬍0.001

0.145

⬍0.001

62 (6.5)

76 (11.4)

56 (19.9)

⬍0.000†

⬍0.000†

⬍0.000†

2

LV hypertrophy, n (%)

889 (92.8)

579 (87.2)

220 (78.3)

⬍0.000†

⬍0.000†

⬍0.000†

Concentric remodeling, n (%)

7 (0.7)

9 (1.4)

5 (1.8)

NS†

NS†

NS†

Concentric LV hypertrophy, n (%)

4 (0.4)

2 (0.3)

0 (0)

NS†

NS†

NS†

Eccentric LV hypertrophy, n (%)

58 (6.1)

74 (11.1)

⬍0.000†

⬍0.000†

⬍0.000†

Normal LV geometry, n (%)

56 (19.9)

IVSd indicates interventricular septal thickness in diastole; LVIDd, LV internal dimension diastole; LVIDs, LVID in systole; PWTd, posterior wall thickness in diastole; BSA, body surface area; and RWTd, relative wall thickness, diastole. Other abbreviations as in Table 1. Values are mean⫾SD unless otherwise indicated. *Adjusted for age. †Unadjusted for age.

Downloaded from http://circ.ahajournals.org/ by guest on March 5, 2014

226

Circulation

January 16, 2007

slightly impaired LV relaxation that was offset by a greater atrial contribution to ventricular filling in a young, mildly hypertensive population. Our results are more marked than the marginal differences in LV diastolic function reported by Palatini et al36 in the Hypertension and Ambulatory Recording Venetia Study (HARVEST) in young adults 18 to 45 years of age with mild, stage 1 hypertension, a difference that may be due to the greater prevalence and severity of obesity in our large, population-based sample of young participants. The importance of systemic hypertension in the pathogenesis of LV hypertrophy is well established, and previous population-based studies have shown strong associations between LV mass and BP within the normal to slightly elevated range.37– 40 Even after adjustment for age, both the hypertensive and prehypertensive groups exhibited cardiac structural features associated with increased cardiovascular risk, including increased interventricular septal, posterior wall, and relative wall thicknesses and higher LV mass, LV mass/body surface area, and LV mass/height.2.7 In the Coronary Artery Risk Development in Young Adults (CARDIA) study,37,38 systolic BP was responsible for much of the increase in LV mass over a 10-year period in young, healthy black and white men and women with low prevalences of hypertension (1.6% to 3.8%). The present study differs from previous ones in population-based samples in grouping adolescents and young adults by the JNC-7 categories of normal BP, prehypertension, and hypertension and by documenting substantial prevalences of prognostically important measures of preclinical cardiovascular disease in prehypertensive and especially in hypertensive participants despite their young age. Future studies are needed to determine whether the abnormalities of LV structure that we have identified at this stage contribute to subsequent cardiovascular events. The prevalence of LV hypertrophy was elevated in hypertensive and prehypertensive SHFS participants and was similar to findings in hypertensive children and adolescents by Daniels et al.41 Approximately 20% of hypertensive participants in the present study had eccentric LV hypertrophy, but few had either concentric LV hypertrophy or concentric LV remodeling. This is in contrast to 16% of hypertensive children having concentric hypertrophy in a study by Hanevold et al,10 with especially higher prevalences among Hispanic or black subjects. The absence of concentric LVH in young SHS participants may reflect their generally mild hypertension, whereas the high prevalence of eccentric LVH may be related to the high prevalence of obesity in our population, with a larger volume of circulating plasma.42 Our study is the first large population-based study to examine specifically the cardiac and systemic hemodynamic status of the new JNC-7 category of prehypertension. A recent study by Zhang et al8 provides evidence for an increase in incident cardiovascular disease among prehypertensive adults 45 to 74 years of age at baseline and an even more striking incident among those with both prehypertension and diabetes in the SHS, suggesting a need for more vigilant monitoring of prehypertensive adults. A previous report by Toikka et al43 used borderline hypertension as a model for prehypertension before the new JNC-7 criteria and found no difference in LV mass but differences in LV geometry between borderline hypertensive young

adult men and normotensive control subjects. From our data, it appears that prehypertension represents an intermediate point between hypertension and normal BP. In ANCOVAs, prehypertensive participants differ similarly from hypertensive and the now more stringently defined normotensive participants with regard to changes in cardiac structure and function. The differences seen between prehypertensive and normotensive participants may be due in part to a “supranormalization” of normotensive control subjects. This suggests that new partition values for “normal” cardiac structural and functional measures are needed if prehypertension is documented to be a robust predictor of increased cardiovascular risk. Although our data suggest parallels between cardiovascular effects of prehypertension in adolescents and young adults and the well-known detrimental effects of hypertension, further data from longitudinal observational and therapeutic studies are needed before we can draw conclusions about the clinical implications of prehypertension.

Study Limitations The present study assessed a population-based sample of American Indians with higher prevalences of overweight and diabetes than the general US population. Although this may limit the generalizability of the present results to some populations, our findings are relevant to the increasing proportion of young adults in developed countries who suffer from overweight and/or diabetes. In addition, despite extensive efforts to standardize measurements, with the use of the same echocardiographic method as in other clinical and population-based studies, subtle differences in performance technique among sites also could have influenced results.

Conclusions Our results show that even small elevations in BP, as seen with prehypertension, can have detrimental effects on hemodynamics and cardiovascular structure and function in an adolescent and young adult American Indian population with many of the same risk factors plaguing the United States and industrialized countries around the world.

Acknowledgments We thank the Indian Health Service, SHS participants, and participating tribal communities for their extraordinary cooperation and involvement that made this study possible; Betty Jarvis, RN, Tauqeer Ali, MD, and Marcia O’Leary for their coordination of 3 study centers; Dawn Fishman, BA, for her data coordination and management of the database; Tauqeer Ali, MD, Rosina Briones, RDMS, Joanne Carter, RDMS, for their technical assistance; and Virginia M. Burns for her assistance in the preparation of this manuscript.

Sources of Funding This work was supported in part by grants HL41642, HL41652, HL41654, HL65521, and M10RR0047–34 (GCRC) from the National Institutes of Health, Bethesda, Md.

Disclosures None.

References 1. Mokdad AJ, Ford ES, Bowman BA, Dietz WH, Vinivor F, Bales VS, Marks JS. Prevalence of obesity, diabetes, and obesity-related health risk factors, 2001. JAMA. 2003;289:76 –79.

Downloaded from http://circ.ahajournals.org/ by guest on March 5, 2014

Drukteinis et al

Hypertension and Prehypertension in Young Adults

2. Fields LE, Burt VL, Cutler JA, Hughes J, Roccella EJ, Sorlie P. The burden of adult hypertension in the United States 1999 to 2000: a rising tide. Hypertension. 2004;44:398–404. 3. Gidding SS, Bao W, Srinivasan SR, Berenson GS. Effects of secular trends in obesity on coronary risk factors in children: the Bogalusa Heart Study. J Pediatr. 1995;127:868–874. 4. Lauer RM, Clarke WR, Mahoney LT, Witt J. Childhood predictors of adult blood pressure: the Muscatine Study. Pediatrics. 1993;40:23–40. 5. Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL Jr, Jones DW, Materson BJ, Oparil S, Wright JT Jr, Roccella EJ. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure: the JNC 7 Report. JAMA. 2003;289: 2560–2572. 6. Wang Y, Wand QJ. The prevalence of prehypertension and hypertension among US adults according to the new Joint National Committee guidelines: new challenges of the old problem. Arch Intern Med. 2004;164:2126–2134. 7. Vasan RS, Larson MG, Leip EP, Evans JC, O’Donnell CJ, Kannel WB, Levy D. Impact of high-normal blood pressure on the risk of cardiovascular disease. N Engl J Med. 2001;345:1291–1297. 8. Zhang Y, Lee ET, Devereux RB, Yeh J, Best LG, Fabsitz RR, Howard BV. Prehypertension, diabetes, and cardiovascular disease risk in a population-based sample: the Strong Heart Study. Hypertension. 2006;47:410–414. 9. Gardin JM, Wagenknecht LE, Anton-Culver H, Flack J, Gidding S, Kurosaki T, Wong ND, Manolio TA. Relationship of cardiovascular risk factors to echocardiographic left ventricular mass in healthy young black and white adult men and women: the CARDIA Study. Circulation. 1995;92:380–387. 10. Hanevold C, Waller J, Daniels S, Portman R, Sorof J. The effects of obesity, gender and ethnic group on left ventricular hypertrophy and geometry in hypertensive children: a collaborative study of the international pediatric hypertension association. Pediatrics. 2004;113:328–333. 11. Lee ET, Welty TK, Fabsitz R, Cowan LD, Le NA, Oopik AJ, Cucciara AJ, Savage PJ, Howard BV. The Strong Heart Study: a study of cardiovascular disease in American Indians: design and methods. Am J Epidemiol. 1990;132: 1141–1155. 12. Howard BV, Welty TK, Fabsitz RR, Cowan LD, Oopik AJ, Le NA, Yeh J, Savage PJ, Lee ET. Risk factors for coronary heart disease in diabetic and non-diabetic Native Americans. Diabetes. 1992;41(suppl 2):4–11. 13. Welty TK, Lee ET, Yeh JL, Cowan LD, Go O, Fabsitz RR, Le NA, Oopik AJ, Robbins DC, Howard BV. Cardiovascular disease risk factors among American Indians: the Strong Heart Study. Am J Epidemiol. 1995;142:269–287. 14. Chinali M, de Simone G, Roman MJ, Lee ET, Best LG, Howard BV, Devereux RB. Impact of obesity on cardiac geometry and function in a population of adolescents: the Strong Heart Study. J Am Coll Cardiol. 2006;47:2267–2273. 15. National Heart, Lung, and Blood Institute. The Seventh Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure. Bethesda, Md: National Institutes of Health; December 2003. NIH publication 03–5233. 16. Stolarczyk LM, Heyward VH, Hicks VL, Baumgartner RN. Predictive accuracy of bioelectric impedance in estimating body composition of American women. Am J Clin Nutr. 1994;59:964–970. 17. Rising R, Swinburn B, Larson K, Ravussin E. Body composition in Pima Indians: validation of bioelectric resistance. Am J Clin Nutr. 1991;53:594–598. 18. National Institutes of Health. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: The Evidence Report. Bethesda, Md: National Institutes of Health; September 1998. NIH publication 98–4083. 19. Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Diabetes Care. 1997;20:1183–1197. 20. Devereux RB, Roman JR, Paranicas M, O’Grady MJ, Wood EA, Howard BV, Welty TK, Lee ET, Fabsitz RR. Relations of Doppler stroke distance and aortic annular diameter to left ventricular stroke volume in normotensive and hypertensive American Indians: the Strong Heart Study. Am J Hypertens. 1997;10: 619–628. 21. Devereux RB, Roman MJ, de Simone G, O’Grady MJ, Paranicas M, Yeh J-L, Fabsitz RR, Howard BV, for the Strong Heart Study Investigators. Relations of left ventricular mass to demographic and hemodynamic variables in American Indians: the Strong Heart Study. Circulation. 1997;96:1416–1423. 22. Sahn DJ, De Maria A, Kisslo J, Weyman AE. The Committee on M-mode Standardization of the American Society of Echocardiography: recommendations regarding quantitation in M-mode echocardiography: results of a survey of echocardiographic measurements. Circulation. 1978;58:1072–1083.

227

23. Schiller NB, Shah PM, Crawford M, De Maria A, Devereux R, Feigenbaum H, Gutgesell H, Reichek N, Sahn D, Schnittger I, Silverman NH, Tajik AJ. The American Society of Echocardiography Committee on Standards, Subcommittee on Quantitation of Two-Dimensional Echocardiograms: recommendations for quantitation of the left ventricle by two-dimensional echocardiography. J Am Soc Echocardiogr. 1989;2:358–367. 24. Roman MJ, Devereux RB, Kramer-Fox R, O’Loughlin J. Two-dimensional echocardiographic aortic root dimensions in children and adults: biologic determinants and normal limits. Am J Cardiol. 1989;64:507–512. 25. Dubin J, Wallerson DC, Cody RJ, Devereux RB. Comparative accuracy of Doppler echocardiographic methods for clinical stroke volume determinations. Am Heart J. 1990;120:116–123. 26. Devereux RB, Alonso Dr, Lutas EM, Gottlieb GJ, Campo E, Sachs I, Reichek N. Echocardiographic assessment of left ventricular hypertrophy: comparison to necropsy findings. Am J Cardiol. 1986;57:450–458. 27. de Simone G, Daniels SR, Kimball TR, Roman MJ, Romano C, Chinali M, Galderisi M, Devereux RB. Evaluation of concentric left ventricular geometry in humans, evidence for age-related systematic underestimation. Hypertension. 2005;45:64–68. 28. de Simone G, Roman MJ, Daniels SR, Mureddu G, Kimball TR, Greco R, Devereux RB. Age-related changes in total arterial capacitance from birth to maturity in a normotensive population. Hypertension. 1997;29:1213–1217. 29. de Simone G, Devereux RB, Roman MJ, Ganau A, Saba PS, Alderman MH, Laragh JH. Assessment of left ventricular function by the mid-wall fractional shortening-end-systolic stress relation in human hypertension. J Am Coll Cardiol. 1994;23–1444–1451. 30. Devereux RB, de Simone G, Pickering TG, Schwartz JE, Roman MJ. Relation of left ventricular midwall function to cardiovascular risk factors and arterial structure and function. Hypertension. 1998;31:929–936. 31. Gratzka CD, Cameron JD, Kingwell BA, Dart AM. Relation between coronary artery diseases, aortic stiffness, and left ventricular structure in a population sample. Hypertension. 1998;32:575–578. 32. Arnett DK, Evans GW, Riley WA. Arterial stiffness: a new cardiovascular risk factor? Am J Epidemiol. 1994;140:669–682. 33. Urbina EM, Srinivasan SR, Kielyka RL, Tang R, Bond MG, Chen W, Berenson GS. Correlates of carotid stiffness in young adults: the Bogalusa Heart Study. Atheroslcerosis. 2004;176:157–164. 34. de Simone G, Devereux RB, Chinali M, Roman MJ, Best LG, Welty TK, Lee ET, Howard BV, for the Strong Heart Study Investigators. Risk factors for arterial hypertension in adults with initial optimal blood pressure: the Strong Heart Study. Hypertension. 2006;47:1–7. 35. de Simone G, Devereux RB, Koren MJ, Mensah GA, Casale PN, Laragh JH. Midwall left ventricular mechanics: an independent predictor of cardiovascular risk in arterial hypertension. Circulation. 1996;93:259–265. 36. Palatini P, Visentin P, Mormino P, Pietra M, Piccolo D, Cozzutti E, Mione V, Bocca P, Perissinotto F, Pessina AC. Left ventricular performance in the early stages of systemic hypertension. Am Heart J. 2001;142:1016–1023. 37. Gardin JM, Brunner D, Schreiner PJ, Xie X, Reid CL, Ruth K, Bild DE, Gidding S. Demographics and correlates of five-year change in echocardiographic left ventricular mass in young black and white adult men and women: the Coronary Artery Risk Development in Young Adults (CARDIA) study. J Am Coll Cardiol. 2002;40:529–535. 38. Lorber R, Gidding SS, Daviglus ML, Colangelo LA, Liu K, Gardin JM. Influence of systolic blood pressure and body mass index on left ventricular structure in healthy African-American and white young adults: the CARDIA study. J Am Coll Cardiol. 2003;41:955–960. 39. Burke GL, Arcilla RA, Culpepper WS, Webber LS, Chiang YK, Berenson GS. Blood pressure and echocardiographic measures in children: the Bogalusa Heart Study. Circulation. 1987;75:106–114. 40. Urbina EM, Gidding SS, Bao W, Pickoff AS, Berdusis K, Berenson GS. Effect of body size, ponderosity, and blood pressure on left ventricular growth in children and young adults in the Bogalusa Heart Study. Circulation. 1995;91:2400–2406. 41. Daniels SR, Loggie JM, Khoury P, Kimball TR. Left ventricular geometry and severe left ventricular hypertrophy in children and adolescents with essential hypertension. Circulation. 1998;97:1907–1911. 42. Ganau A, Arru A, Saba PS, Piga G, Glorioso N, Tonolo G, Mardeddu G, Bianchi G. Stroke volume and left heart anatomy in relation to plasma volume in essential hypertension. J Hypertens. 1991;9(suppl 6):S150–S151. 43. Toikka JO, Laine H, Ahotupa M, Haapanen A, Viikari JS, Hartiala JJ, Raitakari OT. Increased arterial intima-medial thickness and in vivo LDL oxidation in young men with borderline hypertension. Hypertension. 2000;36:929–933.

Go to http://cme.ahajournals.org to take the CME quiz for this article. Downloaded from http://circ.ahajournals.org/ by guest on March 5, 2014