Body mass index at age 25 and all-cause mortality in whites and African Americans: the Atherosclerosis Risk in Communities study.
OBJECTIVE
Approximately 20% of young adults in the United States are obese, and most of them gain weight between young and middle adulthood. Few studies have examined the association between elevated body mass index (BMI) in early adulthood and mortality or have examined that such effects are independent of changes in weight. To our knowledge, no such study has been conducted in African-American samples.


METHODS
We used data from 13,941 African-American and white adults who self-reported their weight at the age of 25, and had weight and height measured when they were 45-64 years of age (1987-1989). Date of death was ascertained between 1987 and 2005. Hazard ratios and hazard differences for the effects of BMI at age 25 on all-cause mortality were determined using Cox proportional hazard and additive hazard models, respectively.


RESULTS
In the combined ethnic-gender groups, the hazard ratio associated with a 5 kg/m(2) increase in BMI at age 25 was 1.28 (95% confidence interval [CI]: 1.22-1.35), and the hazard difference was 2.75 (2.01-3.50) deaths/1,000 person-years. Associations were observed in all four ethnic-gender groups. Models including weight change from age 25 to age in 1987-1989 resulted in null estimates for BMI in African-American men, whereas associations were maintained or only mildly attenuated in other ethnic-gender groups.


CONCLUSIONS
Excess weight during young adulthood should be avoided because it contributes to increases in death rates that may be independent of changes in weight experienced in later life. Further study is needed to better understand these associations in African-American men.
Department of Nutrition, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA. june_stevens@unc.edu
June
J
Stevens
Kimberly P
KP
Truesdale
Chin-Hua
CH
Wang
Jianwen
J
Cai
Eva
E
Erber
D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D000428:Alcohol Drinking / Q000453:epidemiology; D050197:Atherosclerosis / Q000453:epidemiology / Q000401:mortality* / Q000503:physiopathology; D015992:Body Mass Index; D001835:Body Weight; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D050177:Overweight / Q000453:epidemiology / Q000208:ethnology; D016016:Proportional Hazards Models; D012907:Smoking / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data*