Background: Gastric bypass (GB) and sleeve gastrectomy (SG) are two common types of bariatric surgery that carry many potential complications. Among these complications, bone metabolism-related diseases have attracted substantial attention; however, no meta-analysis of them has been performed to date.
Methods: We searched PubMed, Web of Science, The Cochrane Library, and Embase to identify relevant studies published before January 2019. The following indicators were evaluated: serum parathyroid hormone (PTH), calcium, phosphorus and 25-hydroxyvitamin D levels, body mass index (BMI), and bone mineral density (BMD).
Results: Thirteen studies met our inclusion criteria. Overall results showed that patients undergoing GB had lower levels of 25-hydroxyvitamin D (MD = - 1.85, 95% CI (- 3.32, - 0.39) P = 0.01) and calcium (MD = - 0.15, 95% CI (- 0.24, - 0.07) P = 0.0006) as well as higher levels of PTH (MD = 3.58, 95% CI (0.61, 7.09) P = 0.02) and phosphorus (MD = 0.22, 95% CI (0.10, 0.35) P = 0.0005). The results of BMI and BMD were comparable in each group.
Conclusion: Our meta-analysis suggested that obese patients undergoing GB had lower levels of serum calcium and 25-hydroxyvitamin D as well as higher levels of serum phosphorus and PTH. To prevent postoperative bone metabolism-related diseases, appropriate postoperative interventions should be undertaken for particular surgical procedures.
Keywords: Bone metabolism; Bone mineral density; Gastric bypass; Meta-analysis; Sleeve gastrectomy.