Background: In women, bariatric surgery (BS) leads to a decline in bone mineral density (BMD) and may ultimately lead to premature osteoporosis. The impact in men is largely unknown.
Objective: To assess the effect of BS on bone metabolism in males.
Setting: Single-center prospective cohort study.
Methods: Twenty-four male BS candidates were prospectively enrolled. Anthropometric characteristics, serum gonadal hormones, markers of bone metabolism, and BMD were measured at baseline, 6-, 12- and 36-months postoperatively.
Results: Roux-en-Y gastric bypass (RYGB) and adjustable gastric banding (AGB) were performed in 15 and 9 patients, respectively. Nineteen patients completed the 3-year follow-up. At 3 years, BMD of the right and left femur had decreased by 9.1 ± 7.2% and 9.4 ± 5.8% for RYGB and by 6.7 ± 3.9% and 4.5 ± 2.8% for AGB. Radius BMD had decreased by 14.0 ± 5.6% for RYGB and 5.9 ± 4.1% for AGB, i.e., significantly stronger for RYGB (P = .006). Serum parathyroid hormone increased in both groups and 13 of 19 patients developed Vitamin D deficiency. A significant increase of the bone resorption marker was seen only during the first year despite continuation of bone loss. Four patients developed de novo osteopenia or osteoporosis. No fractures were observed.
Conclusion: There are strong indications that male bone metabolism response after BS differs from female metabolism. The most affected site is the radius. In males, the cause of this BMD loss seems multifactorial, including mechanical unloading, hyperparathyroidism, and hypogonadism. However, clinical relevance remains unknown and therefore studies with longer-term follow-up are necessary.
Keywords: Adjustable gastric banding; Bariatric surgery; Bone metabolism; Bone mineral density; Roux-en-Y gastric bypass.
Copyright © 2020 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.