Endocrine Abstracts

JOINT641

Background: Hypertension is associated with increased bone fragility. However, the underlying mechanisms remain partly obscure. Evidence on the association of hypertension with bone mineral density (BMD) is conflicting, and changes in BMD are insufficient to justify the observed increase in fracture risk. Data on bone microarchitectural quality in hypertensive patients are scarce. The in vivo effects of anti-hypertensive medications on bone quality are poorly explored.

Objective: The primary aim of this study was to evaluate whether trabecular bone microarchitecture, non-invasively assessed by trabecular bone score (TBS), is altered in hypertensive patients. The association between anti-hypertensive medications and TBS was also evaluated as a secondary endpoint.

Methods: We conducted a cross-sectional analysis on 7053 subjects extracted from the 2005-2008 cycles of the National Health and Nutrition Examination Survey (NHANES), in which lumbar spine dual-energy X-ray absorptiometry (DXA) scans were acquired. TBS values were calculated from DXA images using dedicated software. The association between hypertension, anti-hypertensive medications and bone outcomes was assessed by regression analyses. Generalized additive models with spline smoothing were used to evaluate systolic and diastolic blood pressure as continuous predictors. All analyses were adjusted for relevant confounders.

Results: Hypertension was independently associated with lower TBS values (adjusted β = –0.010, 95%CI: [–0.016, –0.003], P = 0.008); on the contrary, no association was observed between hypertension and BMD T-scores at lumbar spine (adjusted β = +0.04, 95%CI: [–0.05, +0.13], P = 0.362), total hip (adjusted β = –0.03, 95%CI: [–0.10, +0.05], P = 0.474), or femoral neck (adjusted β = –0.03, 95%CI: [–0.10, +0.03], P = 0.294). When evaluating blood pressure as a quantitative measure, a significant inverse relationship was observed between systolic blood pressure and TBS values (P < 0.001); conversely, no correlation was found for diastolic blood pressure (P = 0.616). No class of anti-hypertensive medications was significantly associated with TBS. Thiazide diuretics and angiotensin receptor blockers were associated with higher BMD values, whereas loop diuretics and non-dihydropyridine calcium channel blockers with lower BMD values.

Conclusion: Hypertension is associated with degraded bone microarchitecture, while no association is observed with bone mass. No significant relationships between anti-hypertensive medications and TBS were found. Associations between anti-hypertensive medications and BMD were consistent with previous reports. Overall, these results provide further insight into the relationship between hypertension and bone health. The specific degradation of bone microarchitecture may offer a plausible explanation for the increased fracture risk observed in hypertensive patients, independent of BMD.