SUN-378 Unilateral Primary Aldosteronism as an Independent Risk Factor for Vertebral Fracture

Context: Primary aldosteronism (PA) is known to increase vertebral fracture (VF), although the detailed mechanism remains to be elucidated. PA consists of two subtypes: the unilateral and bilateral subtype. Patients with unilateral PA, who usually have a higher plasma aldosterone concentration than those with bilateral PA, exhibit a more severe clinical phenotype. We hypothesized that PA subtype affects the prevalence of VF. Objective: To evaluate whether unilateral PA is associated with the prevalence of VF. Design: Cross-sectional study in a single referral center. Patients: We identified 210 hypertensive patients whose clinical data were available for case-detection results. One hundred and fifty-two patients were diagnosed with PA using captopril challenge tests. Measurements: The prevalence of VF according to PA subtype. Results: We included 113 patients with PA who were subtype classified according to adrenal vein sampling, of whom 37 patients had unilateral PA and 76 patients had bilateral PA, whereas 58 patients had non-PA. We excluded 39 patients with PA who were not subtype classified. Patients with PA had a higher prevalence of VF (28% [32/113]) than those with non-PA (12% [7/58]; p = 0.020). Moreover, unilateral PA had a higher prevalence of VF (46% [17/37]) than bilateral PA (20% [15/76]; p = 0.021). There was no significant difference between bilateral PA and non-PA. Unilateral PA was an independent risk factor for VF after adjusting for age and sex (odds ratio, 3.16; 95% confidence interval, 1.12-8.92; p = 0.017). Among patients with unilateral PA, serum cortisol concentrations after 1 mg dexamethasone suppression test were higher in those with VF (1.32 ± 0.67 g/dl) than those without (0.96 ± 0.33 g/dl; p = 0.048). Conclusions: Unilateral PA is an independent risk factor for VF, which is associated with autonomous cortisol secretion. Thus, careful management is required to prevent the development of VF in patients with unilateral PA.