PREVENTIVE
MEDICINE
19, 47U88 (1%)
SHORT REPORT Obesity and Overweight
in Young Adults:
The CARDIA Study’
GREGORY L. BURKE, M.D., **’ DAVID R. JACOBS, JR., PH.D.,* J. MICHAEL SPRAFKA, PH.D., M.P.H.,* PETER J. SAVAGE, M.D.,? DR. P.H.§ STEPHEN SIDNEY, M.D.S and LYNNE E. WAGENKNECHT, *Division of Epidemiology, School of Public Health, University of Minnesota, Stadium Gate 27, 611 Beacon Street Southeast, Minneapolis, Minnesota 55455; tNationa1 Heart, Lung, and Blood Institute, Bethesda, Maryland; SDivision of Research, Kaiser Permanente, Oakland, California; and §Department of General and Preventive Medicine, University of Alabama, Birmingham, Alabama
The associations of body size with age, race, sex, and education in young adults were examined in 5,115 black and white, men and women ages 18-30 years. Black women were more obese than white women with greater mean levels of body mass index (25.8 vs 23.1 kg/m’), subscapular skinfold thickness (19.9 vs 15.2 mm), and waist girth (76.7 vs 72.0 cm), all P < 0.0001. Black women were more likely to exceed 20% of ideal body weights (black women 23.7%, white women 9.1%, P < 0.0001). No similar differences were found in men. Associations of measures of body size with age and education differed among race/sex groups. Body mass index and skinfolds increased with age among white and black men and black women, but not among white women. The association of education with obesity was negative among white women and positive among black men with no significant association noted among white men and black women. These data show a complex relationship between age, sex, race, education, and obesity in young adulthood. o IWOAcademic press, IIIC.
INTRODUCTION
Obesity, especially morbid obesity, is related to increased total mortality in adults (l-3). In a cohort of 750,000 men and women followed for 13 years, a 50% increase in total mortality was noted in individuals 30-40% above ideal body weight (3). Actuarial data confirmed the detrimental impact of obesity on all-cause mortality (1, 2). Obesity has also been linked to increased cardiovascular disease mortality (4). The association between obesity and cardiovascular disease mortality may be mediated, in part, by a greater prevalence of dyslipoproteinemias, diabetes, or hypertension (5-7). Obesity is an important public health problem regardless of the etiology of its effect on mortality. The 1985 Consensus Conference on the Health Implications of Obesity concluded that more research was needed on the levels and etiology of obesity, particularly among lower socioeconomic groups and minority populations (8). Young adults are an especially interesting population for such a study. The attributable risk of hypertension, diabetes, and hypercholesterolemia from obesity ’ This study was supported by Contracts NOl-HC-48047, NOl-HC-48048, NOl-HC-48049, and NOlHC-48050 from the National Heart, Lung, and Blood Institute, National Institutes of Health. * To whom reprint requests should be addressed. 476 0091-7435190$3.00 Copyright Q 1990 by Academic Press, Inc. All rights of reproduction in any form reserved.
THE CARDIA
477
STUDY
has been noted to be greater in younger (20 to 44 years) than in older obese adults (45 to 74 years) (9). The initial onset of obesity frequently occurred during young adulthood in a cohort of 3,322 participants, followed from birth to 36 years of age (10). The increased prevalence of obesity observed in older black women may originate in late adolescence or early adulthood (11-16). The CARDIA Study, a collaborative, multicenter survey of cardiovascular disease risk factors in young adulthood, performed cross-sectional examinations in 1985-1986.This report describes the distribution of body size across race, sex, age, and education groups in 5,115 young adults seen at this visit. METHODS Population
The CARDIA population consisted of 5,115 young adults, ages 18 to 30 years, recruited primarily through telephone contact from community lists. The recruitment and examinations took place in 1985-1986in Birmingham, Alabama (N = 1,178), Chicago, Illinois (N = 1,109), Minneapolis, Minnesota (N = 1,402), and Oakland, California (N = 1,426). Table 1 shows that the number of CARDIA participants was approximately equally distributed across age, race, sex, and education groups. A more complete explanation of the CARDIA recruitment techniques has been published elsewhere (17, 18). Data Collection
Participant’s age, education, race, and sex were self-reported during the recruitment phase and validated during the clinic visit. Subjects were instructed to fast for at least 12 hr before coming to the examination. Specific methodologic details are presented only for the body size variables. Body weight (in light clothing) and height (without shoes) were measured using a balance-beam scale and a vertical ruler, respectively. Triceps, subscapular, and suprailiac skinfold thicknesseswere measured in duplicate using a Harpenden caliper. Both waist and hip girth were measured in duplicate with waist girth measured at the minimum abdominal girth and hip girth measuredanteriorly at the level of the symphysis pubis and posteriorly at the maximum protrusion of the buttocks. Elbow breadth was TABLE 1 NUMBER OF YOUNG ADULTS EXAMINED IN 19861986 BY AGE, RACE, SEX, AND EDUCATION GROUPS: THE CARDIA STUDY
Age
18-24 YEARS
Education
White Black White Black Total
men men women women
MEDICINE
19, 47U88 (1%)
SHORT REPORT Obesity and Overweight
in Young Adults:
The CARDIA Study’
GREGORY L. BURKE, M.D., **’ DAVID R. JACOBS, JR., PH.D.,* J. MICHAEL SPRAFKA, PH.D., M.P.H.,* PETER J. SAVAGE, M.D.,? DR. P.H.§ STEPHEN SIDNEY, M.D.S and LYNNE E. WAGENKNECHT, *Division of Epidemiology, School of Public Health, University of Minnesota, Stadium Gate 27, 611 Beacon Street Southeast, Minneapolis, Minnesota 55455; tNationa1 Heart, Lung, and Blood Institute, Bethesda, Maryland; SDivision of Research, Kaiser Permanente, Oakland, California; and §Department of General and Preventive Medicine, University of Alabama, Birmingham, Alabama
The associations of body size with age, race, sex, and education in young adults were examined in 5,115 black and white, men and women ages 18-30 years. Black women were more obese than white women with greater mean levels of body mass index (25.8 vs 23.1 kg/m’), subscapular skinfold thickness (19.9 vs 15.2 mm), and waist girth (76.7 vs 72.0 cm), all P < 0.0001. Black women were more likely to exceed 20% of ideal body weights (black women 23.7%, white women 9.1%, P < 0.0001). No similar differences were found in men. Associations of measures of body size with age and education differed among race/sex groups. Body mass index and skinfolds increased with age among white and black men and black women, but not among white women. The association of education with obesity was negative among white women and positive among black men with no significant association noted among white men and black women. These data show a complex relationship between age, sex, race, education, and obesity in young adulthood. o IWOAcademic press, IIIC.
INTRODUCTION
Obesity, especially morbid obesity, is related to increased total mortality in adults (l-3). In a cohort of 750,000 men and women followed for 13 years, a 50% increase in total mortality was noted in individuals 30-40% above ideal body weight (3). Actuarial data confirmed the detrimental impact of obesity on all-cause mortality (1, 2). Obesity has also been linked to increased cardiovascular disease mortality (4). The association between obesity and cardiovascular disease mortality may be mediated, in part, by a greater prevalence of dyslipoproteinemias, diabetes, or hypertension (5-7). Obesity is an important public health problem regardless of the etiology of its effect on mortality. The 1985 Consensus Conference on the Health Implications of Obesity concluded that more research was needed on the levels and etiology of obesity, particularly among lower socioeconomic groups and minority populations (8). Young adults are an especially interesting population for such a study. The attributable risk of hypertension, diabetes, and hypercholesterolemia from obesity ’ This study was supported by Contracts NOl-HC-48047, NOl-HC-48048, NOl-HC-48049, and NOlHC-48050 from the National Heart, Lung, and Blood Institute, National Institutes of Health. * To whom reprint requests should be addressed. 476 0091-7435190$3.00 Copyright Q 1990 by Academic Press, Inc. All rights of reproduction in any form reserved.
THE CARDIA
477
STUDY
has been noted to be greater in younger (20 to 44 years) than in older obese adults (45 to 74 years) (9). The initial onset of obesity frequently occurred during young adulthood in a cohort of 3,322 participants, followed from birth to 36 years of age (10). The increased prevalence of obesity observed in older black women may originate in late adolescence or early adulthood (11-16). The CARDIA Study, a collaborative, multicenter survey of cardiovascular disease risk factors in young adulthood, performed cross-sectional examinations in 1985-1986.This report describes the distribution of body size across race, sex, age, and education groups in 5,115 young adults seen at this visit. METHODS Population
The CARDIA population consisted of 5,115 young adults, ages 18 to 30 years, recruited primarily through telephone contact from community lists. The recruitment and examinations took place in 1985-1986in Birmingham, Alabama (N = 1,178), Chicago, Illinois (N = 1,109), Minneapolis, Minnesota (N = 1,402), and Oakland, California (N = 1,426). Table 1 shows that the number of CARDIA participants was approximately equally distributed across age, race, sex, and education groups. A more complete explanation of the CARDIA recruitment techniques has been published elsewhere (17, 18). Data Collection
Participant’s age, education, race, and sex were self-reported during the recruitment phase and validated during the clinic visit. Subjects were instructed to fast for at least 12 hr before coming to the examination. Specific methodologic details are presented only for the body size variables. Body weight (in light clothing) and height (without shoes) were measured using a balance-beam scale and a vertical ruler, respectively. Triceps, subscapular, and suprailiac skinfold thicknesseswere measured in duplicate using a Harpenden caliper. Both waist and hip girth were measured in duplicate with waist girth measured at the minimum abdominal girth and hip girth measuredanteriorly at the level of the symphysis pubis and posteriorly at the maximum protrusion of the buttocks. Elbow breadth was TABLE 1 NUMBER OF YOUNG ADULTS EXAMINED IN 19861986 BY AGE, RACE, SEX, AND EDUCATION GROUPS: THE CARDIA STUDY
Age
18-24 YEARS
Education
White Black White Black Total
men men women women
