WEIGHT AND MORTALITY IN FINNISH WOMEN

Mortality in relation to body mass index (BMI) was studied in 17,159 healthy Finnish women aged 25-79 followed up for a median of 12 years. Mortality from all cases was related to BMI only in non-smokers aged 25-64, among whom the mortality pattern was "U"-shaped, with a minimum in the second quintile of BMI (the reference range), and about 1.5 times higher in quintiles I and V. Most of the excess risk of mortality among overweight women was due to cardiovascular diseases. During the first 7 years of follow-up, and high risk (relative risk (RR) = 1.7, 95% confidence interval (CI) = 1.0-2.9 for quintile V compared to quintile II) depended on the association of BMI with the initial blood pressure level, but in the later years, the relative risk of cardiovascular death, ranging from 1.6 (95% CI = 1.0-2.5) for women in quintile III up to 2.6 (95% Ci = 1.7-4.0) for those in quintile V, was largely independent of the baseline levels of the main biological risk factors. The excess mortality among thin women under the age of 65 was mainly due to non-cardiovascular diseases (RR = 1.7, 95% CI = 1.2-2.3 for quintile I compared to quintile II) and was not attributable to antecedent disease, smoking or the biological risk factors studied. Among women aged 65 and over, overall mortality varied little with BMI, but thinness seemed to predict deaths from cancers (RR = 1.6, 95% CI = 0.9-3.0). Both thinness and overweight are detrimental to the longevity of initially healthy young and middle-aged non-smoking women, but through differing disease patterns. BMI is not an important predictor of mortality in old women.