Waist and extremity circumferences shown to have opposite and independent effects on mortality
Body mass index (BMI), a widely used estimator of total adiposity, does not provide information about body composition (skeletal muscle vs fat) or fat distribution. For a given level of obesity, greater lower body circumferences seem to protect against cardiovascular disease and diabetes. This study aimed to determine the independent and shared influences of upper- and lower-body circumferences on the risk of mortality in 10,638 adults from the nationally representative 1981 Canada Fitness Survey. Waist, hip, thigh, calf and upper arm circumferences were measured by means of a flexible, non-elastic anthropometric tape. Measuring limb circumference provides a simple non-invasive estimate of subcutaneous fat and/or skeletal muscle mass. In total, 340 deaths in men and 231 in women occurred during 131,563 person-years of follow-up. Sex-specific proportional hazards regression analysis revealed that waist circumference (WC) was positively associated with mortality whereas upper arm, thigh, and calf circumferences were protective in men, and upper arm and thigh circumferences were protective in women. In conclusion, among this nationally representative Canadian population, waist and extremity circumferences seem to have opposite and independent effects on mortality, with men and women with larger extremity circumferences somatotypes having a lower risk of mortality, independent of BMI and WC.


















