The combined effect of adiposity, fat distribution and age on cardiovascular risk factors and motor disability in a cohort of obese women (aged 18-83)

The study aims to evaluate the combined effect of degree of adiposity, body fat distribution and age on selected cardiovascular risk factors and functional motor disability in obese women. A multivariate analysis of variance is employed to estimate the combined impact of BMI, WHR and age on systolic and diastolic blood pressure (SBP and DBP), total and HDL cholesterol (T-CH and HDL-CH), coronary heart disease (CHD) risk, leg power output (W& ) and subjective general fatigue in a cohort of 463 obese women (BMI range: 30.2-66.7 kg/m2). High WHR and older age, but not BMI, are to a variable degree related to unfavourable values of parameters which contribute to the cardiovascular risk. WHR in the high range is associated with higher values of SBP (P<0.001) and CHD risk scores (P<0.001), and lower levels of HDL-CH (P=0.01), while older age is associated with higher SBP (P<0.001), T-CH (P<0.001) and CHD risk scores (P<0.001). A significant interaction between age and WHR was detected in the effect on DBP (P=0.01), the negative role of high WHR values being apparent in older women (age >= 51 yr.) but not in younger ones (age < 51 yr.). Although not significantly related to CHD risk scores, BMI interacted significantly with WHR in determining high risk score values (P=0.01), the negative effect of a high WHR being apparent in women with a high degree of obesity (BMI >= 40 kg/m2) but not in those with a low one (BMI < 40 kg/m2). In contrast, WHR did not significantly affect W&, which appeared to be mainly dependent on age (P<0.001) and also on BMI (P<0.001), when considered in terms of unit body mass. Subjective global fatigue, however, was unaffected by any of the factors considered. Older age and excessive abdominal fat distribution appear to be significant factors in relation to increased cardiovascular disease risk, irrespective of BMI, while older age and higher levels of overall adiposity are associated with functional motor derangement irrespective of body fat distribution. This suggests that obesity increases metabolic risk and induces motor dysfunction by means of different biological mechanisms and with a different impact within the obese female population.