Are general obesity and visceral adiposity in men linked to reduced bone mineral content resulting from normal ageing? A population-based study

Associations between fat accumulation and distribution and bone mineral status in men have not been comprehensively established, and available results are inconsistent. The aims of this study were as follows: (1) to evaluate relationships between anthropometric parameters of general obesity (body mass index, ME) and fat distribution (waist/hip ratio, WHR) and bone mineral content (BMC), and (2) to compare BMC (a) between obese men (BMI greater than or equal to 27) and nonobese men and (b) between abdominally obese men (WHR greater than or equal to 0.95) and men without visceral adiposity, in a population-based sample of Polish men. The sample comprised a group of 272 men, aged 20-60, randomly selected from healthy and occupationally active inhabitants of Wroclaw, Lower Silesia, Poland. Trabecular. cortical and total BMC at the ultra-distal radius of the nondominant hand were assessed by pQCT using the Stratec 960 apparatus. BMI and WHR were used as parameters of general obesity and fat distribution, respectively. The relationships among the analysed variables were established using a multiple linear regression. The differences in BMC depending on BMI and WHR values were tested using an analysis of covariance (ANCOVA). BMI was positively related only to trabecular BMC (r=0.17; P=0.03). Only trabecular BMC was higher in men with BMI greater than or equal to 27 compared to nonoverweight subjects (F=5.38; P=0.02). WHR was inversely related to trabecular (r=-0.30; P < 0.001), cortical (r=-0.30, P < 0.001) and total BMC (r=-0.34; P < 0.001). All densitometric parameters were lower in males with WHR greater than or equal to 0.95 than in normal men (results Of ANCOVA: for trabecular BMC. F=6.33, P=0.01, for cortical BMC, F=5.52, P=0.02, and for total BMC, F=7.73, P=0.006). In the healthy Polish male population, BMI was of minor significance as a predictor of BMC at the ultra-distal radius, whereas visceral adiposity (assessed by WHR) was significantly linked to reduced bone mass in men.