Osteoporosis, vertebral fractures and metabolic syndrome in postmenopausal women

BACKGROUND: The combined effect of the metabolic syndrome (MS) risk factors on bone health has led to controversial results and it is still not clear whether this effect is protective or detrimental. The study aimed to examine the association between MS and bone mineral density (BMD), osteoporosis, and vertebral fractures (VFs) among ambulatory older postmenopausal women. METHODS: 270 post-menopausal women with a mean age of 61.0 years ± 7.8 (50 to 90) with no prior known diagnosis of osteoporosis were recruited. BMD and Lateral vertebral fracture assessment (VFA) images were obtained using a GE Healthcare Lunar Prodigy densitometer. VFs were defined using a combination of Genant semiquantitative approach and morphometry. RESULTS: The MS as defined by the NCEP-ATP III was present in 62 women (23.0%). According to the WHO classification, 82 had osteoporosis at any site (30.4%). VFs were identified in 116 (43.0%): 80 (29.6%) had grade 1 and 36 (13.3%) had grade 2 or 3. Women with MS had a significantly higher BMD and lower prevalence of osteoporosis (17.7% vs. 34.1%) than those without MS. No significant statistical difference was noted in prevalence of VFs (14.5 vs. 13.0%). There were significantly less women with MS among the group of osteoporotic women (13% vs. 27%; p = 0.018). Conditional regression binary analysis assessing the presence of osteoporosis as the dependent variable showed that women with a MS had a significant 71% decrease in the odds of being osteoporotic by BMD compared with women who had not MS accounting for age, BMI, number of parities and years since menopause. CONCLUSION: Women with MS had higher BMD at the hip and spine, suggesting a protective effect of MS on bone. However, the prevalence of VFs was similar between women with or without MS.