Hip fractures in patients with primary aldosteronism - a Swedish nationwide study

In this large population-based matched cohort study, patients with primary aldosteronism were at increased risk of hip fracture, particularly subgroups traditionally considered at higher risk of osteoporosis such as women, patients older than 56 years at diagnosis, patients with established cardiovascular disease at diagnosis, and patients treated with MRA.

Previous studies suggest that primary aldosteronism (PA) is associated with dysregulated bone homeostasis. The aim of this study was to evaluate the incidence of hip fractures in patients with PA.

We studied a nationwide cohort of 2419 patients with PA (1997-2019) and 24 187 age and sex matched controls from the general population. Hip fractures were identified by ICD codes in the Swedish National Patient Register. We estimated hazard ratios (HRs) for incident hip fractures, adjusted for prior fractures, socioeconomic factors, diabetes, osteoporosis, hyperparathyroidism, and cardiovascular disease (CVD). Pairwise subgroup comparisons were performed by age (18-56 and > 56 years), sex, CVD at baseline, and treatment for PA.

During a mean follow up of 8 ± 5 years, 64 (2.6%) patients had a hip fracture after being diagnosed with PA, compared to 401 (1.7%) controls. After adjustments, PA was associated with a 55% increased risk of hip fracture compared to controls (HR 1.55 [1.18-2.03]). HRs were increased in women (HR 1.76 [95% CI 1.24-2.52]), patients aged > 56 years (HR 1.62 [95% CI 1.21-2.17]), and patients with CVD at diagnosis (HR 2.15 [95% CI 1.37-3.37]). PA patients treated with adrenalectomy did not have higher risk than controls (HR 0.84 [95% CI 0.35-2.0]), while patients treated with mineralocorticoid receptor antagonists (MRA) retained a greater risk (HR 1.84 [95% CI 1.20-2.83]).

PA is associated with increased hip fracture risk, especially in women, patients diagnosed after the age of 56 years and patients with established CVD at diagnosis. Also, patients treated with MRA seem to have an increased risk of hip fractures, while adrenalectomy may be protective.