body weight and mortality

Doug Skrecky (oberon@vcn.bc.ca)
Fri, 22 May 1998 02:47:59 -0700 (PDT)


Authors
Cornoni-Huntley JC. Harris TB. Everett DF. Albanes D. Micozzi MS. Miles
TP. Feldman JJ.
Institution
Epidemiology, Demography and Biometry Program, National Institute on Aging,
National Institutes of Health, Bethesda, MD 20892.
Title
An overview of body weight of older persons, including the
impact on mortality. The National Health and Nutrition
Examination Survey I--Epidemiologic Follow-up Study.
Source
Journal of Clinical Epidemiology. 44(8):743-53, 1991.
Abstract
The authors studied distributions of body weight for
height, change in body weight with age, and
the relationship between body mass index and
mortality among participants in the Epidemiologic Follow-up
Study of the first National Health and Nutrition Examination Survey (NHEFS)
(n = 14,407), a cohort study based on an representative sample of the U.S.
population. Percentiles of body weight for
height according to age and sex are presented.
Cross-sectional analyses of body weight suggest that mean
body weight increases with age until late middle age, then
plateaus and decreases for older aged persons. However, longitudinal analysis
of change in weight with age shows that younger persons in the lower quintile
at baseline tend to gain more than those in the higher quintile. Older
persons in the higher quintile at baseline have the greatest average loss in
weight. The relationship of body mass index to
mortality is a U-shaped curve, with increased risks in the
lowest and highest 15% of the distribution. Increased risk of
mortality associated with the highest 15th percentile of the
body mass index distribution, as well as the highest 15% of
the joint distribution of body mass index and skinfold
thickness, is statistically significant for white women. However, the risk
diminishes when adjusted for the presence of disease and factors related to
disease. More noteworthy is the fact that there is a statistically
significant excess risk of mortality for both race and sex
groups in the lowest 15% of the body mass index distribution
after adjusting for smoking history, and presence of disease. Those in the
lowest 15% of the joint body mass index and skinfold
thickness distribution, were also at increased risk. Risk of
mortality for both men and women who have lost 10% or more
of their maximum lifetime weight within the last 10 years is statistically
significant, even when controlling for current weight. This study has
replicated previously reported relationships, while correcting for several
methodological issues.