Objective: Both osteoporosis and cardiovascular disease (CVD) are diseases that comprise a growing medical and economic burden in ageing populations. They share many risk factors, including ageing, low physical activity, and possibly overweight. We aimed to study associations between individual risk factors for CVD and bone mineral density (BMD) and turnover markers (BTMs) in apparently healthy cohort.
Design: A cross-sectional assessment of 155 healthy 32-year-old adults (74 males) was performed for skeletal status, CVD risk factors and lifestyle factors.
Methods: We analysed serum osteocalcin, procollagen I aminoterminal propeptide (P1NP), collagen I carboxy-terminal telopeptide (ICTP) and urine collagen I aminoterminal telopeptide (U-NTX), as well as serum insulin, plasma glucose, triglyceride and HDL-cholesterol levels. BMD, fat and lean mass were assessed using DXA scanning. Associations were tested with partial correlations in crude and adjusted models. Bone status was compared between men with or without metabolic syndrome (defined according to the NCEP-ATPIII criteria) with multivariate analysis.
Results: Osteocalcin and P1NP correlated inversely with insulin (R = -0.243, P = 0.003 and R = -0.187, P = 0.021) and glucose (R = -0.213, P = 0.009 and R = -0.190, P = 0.019), but after controlling for fat mass and lifestyle factors, the associations attenuated with insulin (R = -0.162, P = 0.053 and R = -0.093, P = 0.266) and with glucose (R = -0.099, P = 0.240 and R = -0.133, P = 0.110), respectively. Whole body BMD associated inversely only with triglycerides in fully adjusted model. In men with metabolic syndrome, whole body BMD, osteocalcin and P1NP were lower compared to healthy men, but these findings disappeared in fully adjusted model.
Conclusions: In young adults, inverse associations between BTM/BMD and risk factors of CVD appeared in crude models, but after adjusting for fat mass, no association continued to be present. In addition to fat mass, lifestyle factors, especially physical activity, modified the associations between CVD and bone characteristics. Prospective studies are needed to specify the role of mediators and lifestyle factors in the prevention of CVD and osteoporosis.