ROLE OF BODY-MASS INDEX IN THE PREDICTION OF ALL-CAUSE MORTALITY IN OVER 62000 MEN AND WOMEN - THE ITALIAN RIFLE POOLING PROJECT

Study objective-To evaluate the relation of body mass index (BMI) to s hort-term mortality in a large Italian population sample. Design-Withi n the Italian RIFLE pooling project, BMI was measured in 47 population samples made of 32 741 men and 30 305 women aged 20-69 years (young 2 0-44, mature 45-69). Data on mortality were collected for the next six years. Main outcome measures-Age adjusted death rates in quintile cla sses of BMI and Cox proportional hazards models with six year all caus es mortality as end point, BMI as covariate and age, smoking, systolic blood pressure as possible confounders were computed. Multivariate an alysis was tested in all subjects and after the exclusion of smokers, early (first two years) deaths, and both categories. Results-The univa riate analysis failed to demonstrate in all cases a U or inverse J sha ped relation. The Cox coefficients for the Linear and quadratic terms of BMI proved significant for both young and mature women. The minimum of the curve was located at 27.0 (24.0, 30.0, 95% confidence limits, CL) and 31.8 (25.5, 38.2, 95% CL) units of BMI, for young and mature w omen respectively. Similar findings were obtained even when exclusion were performed. No relation was found for young men while for mature a dult men only the model for all subjects retained significant curvilin ear relation (minimum 29.3; 22.4, 36.2, 95% CL). Conclusion-These unco mmon high values of BMI carrying the minimum risk of death seems to be in contrast with weight Rome, Italy guidelines. A confirmation of the se findings in other population groups might induce the consideration of changes in the suggested healthy values of BMI.