Relationship Between Circadian Rhythm of Blood Pressure and Bone Mineral Density in Postmenopausal Women

OBJECTIVE: The prevalence of atherosclerosis and osteoporosis increase with age. An association has been demonstrated between cardiovascular diseases and low bone mineral density. We aimed to investigate the association between bone mineral density and nondipping pattern in postmenopausal women.

MATERIAL and METHODS: Eighty-four patients aged lower than 65 and and menopausal for more than a year were included in the study. Ambulatory blood pressures were recorded for 24 hours, and lumbar spine and femoral neck bone mineral density were measured by DEXA in all patients.

RESULTS: According to ambulatory blood pressure measurement results, 29 patients (34.5%) were dipper and 55 patients (65.5%) were nondipper. The mean vertebral T-scores were significantly lower in nondipper patients compared to dipper patients (-1.67±0.96 vs -1.06±1.1, p=0.02). However, the mean femur T-scores were not significantly different between the groups, although it was lower in the nondipper group (-1.22±0.81 vs -0.65±1.16, p=0.05). The mean vertebral and femoral Z-scores were similar in the groups (vertebral Z-score; dipper group; -0.31 ± 0.95, nondipper group; -0.39±1.18, p> 0.05, femur Z-score; dipper group; 0.38±1,27, nondipper group; 0.17±1.03, p> 0.05).

CONCLUSION: We showed a significant association between decreased bone mineral density and blunted nighttime blood pressure decrease, which is one of the earliest markers of atherosclerosis. Further studies are warranted to explain this association.