Body weight and mortality among adults who never smoked

In a 12-year prospective study, the authors examined the relation between b ody mass index (BMI) and mortality among the 20,346 middle-aged (25-54 year s) and older (55-84 years) non-Hispanic white cohort members of the Adventi st Health Study (California, 1976-1988) who had never smoked cigarettes and had no history of coronary heart disease, cancer, or stroke. In analyses t hat accounted for putative indicators (weight change relative to 17 years b efore baseline, death during early follow-up) of pre existing illness, the authors found a direct positive relation between BMI and all-cause mortalit y among middle-aged men (minimum risk at BMI (kg/m(2)) 15-22.3, older men ( minimum risk at BMI 13.5-22.3), middle-aged women (minimum risk at BMI 13.9 -20.6), and older women who had undergone postmenopausal hormone replacemen t (minimum risk at BMI 13.4-20.6). Among older women who had not undergone postmenopausal hormone replacement, the authors found a J-shaped relation ( minimum risk at BMI 20.7-27.4) in which BMI <20.7 was associated with a two fold increase in mortality risk (hazard ratio (HR) = 2.2, 95% confidence in terval (CI) 1.3, 3.5) that was primarily due to cardiovascular and respirat ory disease. These findings not only identify adiposity as a risk factor am ong adults, but also raise the possibility that very lean older women can e xperience an increased mortality risk that may be due to their tower levels of adipose tissue-derived estrogen.