Body Mass and 26-Year Risk of Mortality among Women Who Never Smoked: Findings from the Adventist Mortality Study

Abstract

The authors have examined the relation between the Quetelet body mass index (BMI) and 26-year risk of all-cause mortality in a population of 12,576 non-Hispanic while, Seventh-day Adventist women (ages 30-74 years) who never smoked. Mortality risk for each BMI quintile (I, < 21.3 kg/m2; II, 21.3-22.9 kg/m2; III, 23.0-24.8 kg/m2; IV, 24.9-27.4 kg/m2; and V, > 27.4 kg/m2) was determined from a proportional hazard regression with adjustment for age and other covariables. In this population, the overall BMI-mortality relation showed dependence on age, duration of follow-up, and baseline indicators of preexisting illness (weight fluctuation, history of major chronic disease, and severe physical complaints). Therefore, the analysis focused on women with no indicators of preexisting illness, and risk estimates were stratified by age at baseline and duration of follow-up. Among middle-aged women (ages 30-54 years), the authors found a weak linear relation during years 1-8 (median attained age, 51 years), a significant linear relation during years 9-14 (median attained age, 57 years), and a significant nonlinear (U-shaped) relation during years 15-26 (median attained age, 68 years). Among older women (ages 55-74 years), they found a significant nonlinear (U-shaped) relation during years 1-8 (median attained age, 71 years) and significant linear relations during years 9-14 (median attained age, 77 years) and years 15-26 (median attained age, 87 years). These findings implicate overweight as a risk factor for fatal disease among women throughout adulthood and raise the possibility that lean, apparently healthy, middle-aged women may experience a higher risk of death during old age due to their lower body weight.

Health consequences of obesity in the elderly: a review of four unresolved questions

“…However, six 48,49,53,54,59,66 out of seven showed lower mortality in subjects with lower BMI, or at least a U-shaped relation between BMI and mortality. It is important to note that none of these studies were able to distinguish between intentional and unintentional weight loss.…”

“…However, when only people who never smoked were studied, two studies out of three 48,60,63 observed linear relation between BMI and mortality among older subjects, suggesting that increased mortality associated with the lowest weights were a function of cigarette smoking, and that, among never-smokers, very low weights were associated with the greatest longevity.…”

“…[47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66] Heiat et al 67 recently reviewed all studies evaluating the relation between obesity and mortality in the elderly published, from 1966 to 1999. They searched Medline, and from 444 papers they presented data from 13 studies on the basis of the following inclusion criteria: subjects older than 65 y, age adjustment performed, inclusion of at least 100 subjects, adjustments for smoking, baseline health status, and selection of nonhospitalized subjects.…”

“…Seven [48][49][50]53,54,59,66 out of 20 studies presented in Table 2 were able to take into account weight changes in the relation between obesity and mortality. However, six 48,49,53,54,59,66 out of seven showed lower mortality in subjects with lower BMI, or at least a U-shaped relation between BMI and mortality.…”

“…83 Studies with short follow-up generally do not show associations between obesity and mortality in the elderly, while studies with longer follow-up show significant associations. The longer the follow-up, the greater the need to account for the effect of confounding factors and in particular the effect of voluntary vs involuntary weight loss: the majority of the studies reported in Table 2, with follow-up 12 y or longer, showed lower all-cause and specific mortality in subjects with BMI lower than 27 kg/m 2 , 48 9FFat distribution. Indices of fat distribution show a greater association with specific and total mortality in the elderly than BMI.…”