Bone turnover markers and the metabolic syndrome
S E Oros1, O Ianas1, D Manda1, R I Rosca1,2, O M Popa1, S Vladoiu1 & C Dumitrache1,2
Obesity was considered to be a protective condition against osteoporosis. New studies suggest that visceral obesity is associated with low BMD and a higher risk for fracture. Patients with diabetes mellitus, although they do not have a lower BMD, have a higher fracture risk, probably due to the lower bone turn over.
Aim: The aim of the study was to evaluate bone metabolism in connection with hormonal profile in postmenopausal women with metabolic syndrome compared with matched controls without metabolic syndrome.
Subjects and methods: A number of 144 postmenopausal women were enrolled and 2 groups were formed (57 subjects with metabolic syndrome, 87 controls). Fasting blood samples were taken in order to determine the biochemical and hormonal status. SPSS version 15 was used for statistical analyze. Results were expressed as mean values±S.D. and were considered to be statistically significant if the P value was ≤0.05.
Results: Significant higher mean values were found for BMI, waist circumference, blood pressure, glycemia, triglycerides and apolipoprotein B, white blood cells, lymphocytes, CRP (markers of the pro-inflammatory state), insulinemia and insulin resistance expressed by HOMA, GHBP (P<0.001) and PTH (P=0.041). Postmenopausal women with metabolic syndrome had lower HDL-cholesterol, SHBG, IGFBP1 (P=0.027) and 25OH vitamin D (P=0.025) levels. Osteocalcin correlated positively with crosslaps (P<0.001), PTH (P=0.025) and 25OH vitamin D (P=0.005); PTH correlated positively with glycemia, uric acid and negatively with IGFBP3 (P=0.048).
Conclusions: Postmenopausal women with metabolic syndrome have a modified hormonal status and different correlations between bone turn-over markers. Lower 25 OH vitamin levels, leading to higher PTH levels reinforce the importance of optimal vitamin D concentrations and its role in metabolic syndrome.