Background: Surgically treated patients with NFA often present with secondary hypogonadism. Hypogonadism is a well known risk factor for osteopenia or osteoporosis. The aim of this study was to assess (a) the frequency of osteopenia/osteoporosis in a single centre Swiss cohort of patients with operated NFA and (b) whether gender or hypogonadism impacts on bone density at follow up.
Methods: Data of patients with NFAs diagnosed between 1967 and 2005 were analysed. Clinical and endocrinological parameters were recorded before, immediately after surgery and at last follow-up. Bone densitometry (DEXA) was performed during follow up. Data were analyzed using Fishers Exact Test for calculating relative risks (RR) and p-values.
Results: 121 patients with NFA were included (71% male and 29% female). Mean age at diagnosis was 55.2±14.7 years. 74% of male and 25% of female patients had secondary hypogonadism at follow up, 57% (20) of female were menopausal prior to surgery. DEXA was performed in 68% (n=82) of all patients. Overall, DEXA showed a normal bone density (T-score ≧−1) in 26%, in 30% signs of osteopenia (T-score between −1 and −2.5) and in 12% signs of osteoporosis (T-score ≤−2.5). The relative risk (RR) for osteopenia/osteoporosis in all patients with secondary hypogonadism at follow up compared to patients with normal gonadale function at follow up was 0.84 (95% CI 0.611.16; P=0.36) [men: 1.19 (0.592.40; 0.74), women: 1.50 (0.673.34;P=0.37)]. The RR for osteopenia/osteoporosis in female patients with hypogonadism (incl. menopausal females) compared to men with hypogonadism at follow up was 1.57 (95% CI 1.162.14; P=0.013).
Conclusions: (1) Osteopenia and Osteoporosis is a common problem in patients with NFA. (2) A diminished bone density is not only related to impaired gonadale axis in patients with NFA. (3) The influence of gender on bone density appears to be critical.