Bone health in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED): findings in 25 adults

OBJECTIVE: Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is characterized by chronic mucocutaneous candidiasis and autoimmune destruction of endocrine organs. The resulting endocrinopathies and their treatment may impact bone health. The purpose of our study was to assess bone health and its correlates in adult patients with APECED. PATIENTS AND METHODS: Twenty-five adults (12 males) with APECED were prospectively assessed. Data on their previous medical history were collected from hospital records. Areal bone mineral density (aBMD) for the lumbar spine (L1-L4), femoral neck and whole body as well as volumetric BMD (vBMD) for the lumbar spine (L2-L4) were measured with dual-energy X-ray absorptiometry (DXA). RESULTS: Mean age was 34 years (range 21-59 years). All patients had 1-4 autoimmune endocrinopathies, the most common being adrenocortical failure (20 patients) and hypoparathyroidism (18 patients). Osteopaenia or osteoporosis was present in 28%. The median (range) aBMD Z-scores were for the lumbar spine -0.3 (-2.3 to +3.3) and for the femoral neck, -0.1 (-2.2 to +2.0). The BMD Z-scores tended to be higher in patients with hypoparathyroidism than in patients with normal parathyroid function (at the lumbar spine +0.4 vs.-1.2, P = 0.016, and at the femoral neck +0.3 vs.-0.4, P = 0.090). Adrenocortical failure had a negative impact on BMD. Six patients had had low-impact fractures and three were diagnosed with compression fractures. CONCLUSIONS: Despite the complex endocrine problems, the overall prevalence of symptomatic osteoporosis is low in adults treated for APECED. Osteopaenia is frequently observed and warrants follow-up. Treated hypoparathyroidism may have a positive, and adrenocortical failure a negative, impact on bone health.