Changes in bone mineral density after bariatric surgery in patients of different ages or patients with different postoperative periods: a systematic review and meta-analysis

To assess changes in bone mineral density (BMD) following bariatric surgery (BS) in patients with different bone sites, postoperative periods and ages. Twenty-two studies were included. Femoral neck (FN) BMD decreased after surgery (MD, − 0.05 g/cm(2), CI − 0.10 to − 0.01, P = 0.03). Postoperative BMD decreased more in the FN and lumbar spine (LS) of patients older than 40 (FNBMD, − 0.07 g/cm(2), CI − 0.13 to − 0.00, P = 0.04; LSBMD, − 0.03 g/cm(2), CI − 0.05 to − 0.00, P = 0.02) or patients with a postoperative time of greater than 12 months (FNBMD, − 0.06 g/cm(2), CI − 0.12 to − 0.01, P = 0.03; LSMD, − 0.04 g/cm(2), CI − 0.09 to 0.01, P = 0.12); therefore, post-BS bone loss should be monitored among patients in these groups. Longer follow-ups are needed to determine whether BMD changes or stabilizes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40001-022-00774-0.