Influence of Lifestyle Aspects on the Association of Body Size and Shape with All-Cause Mortality in Middle-Aged Men and Women

Objective: Waist circumference, BMI and hip circumference are differentially associated with mortality. We investigated the potential influence of selected lifestyle aspects such as smoking, alcohol intake, sports activity and education. Method: The Danish prospective study 'Diet, Cancer and Health' recruited 27,179 men and 29,875 women from 1993 to 1997. Cox regression models were used to estimate mortality rate ratios. Results: Adjustment for smoking habits attenuated the associations between mortality and the three body size measurements in both sexes. Adjustment for sport activity and, to a lesser extent, alcohol intake weakened the associations further for the men, whereas alcohol intake slightly weakened associations for the women. In the fully adjusted models, mortality increased highly significantly with higher waist circumference and lower hip circumference, and decreased highly significantly with higher BMI for BMI below 25 kg/m(2). This pattern was seen for all levels of the selected lifestyle factor. Conclusion: A large waist circumference remained a strong risk indicator for mortality, and a large hip circumference appeared to be protective when smoking habits, alcohol intake and sport activity were accounted for. BMI below 25 kg/m(2) remained a risk factor, but not above 25 kg/m(2) once waist circumference was adjusted for.