Overweight and obesity are major risk factors for many chronic diseases, with the prevalence of overweight/obesity among Chinese adults reaching 50.7% in 2018. Bariatric surgery is one currently available treatment for obesity, but whether it increases the risk of fracture is still controversial.

To analyze whether weight-loss surgery will increase the risk of fracture.

PubMed, Embase, and Cochrane Library databases were searched for studies (cohort studies, case-control studies, and randomized controlled trial) about the risk of fracture and bariatric surgery published between January 2010 and November 2021. The Newcastle-Ottawa scale (NOS) and Jadad scale were used to evaluate the methodological quality of the studies. RevMan 5.3 and Stata 12.0 were used for data analysis. The Begg's test and Egger's test were conducted to assessing the potential publication bias. Compare the association of bariatric surgery with risk of fracture by comparing risk of fracture between patients with and without bariatric surgery.

A total of 15 studies were included, including 12 cohort studies, two case-control studies, and one randomized controlled trial, all of which were of high quality. Twelve studies compared the risk of fracture between patients with bariatric surgery and those without, 10 of which enrolled patients with bariatric surgery (surgery group, n=137 239) and obese patients without bariatric surgery (obesity group, n=159 066) with no differences in baseline BMI, showing large heterogeneity (P<0.01, I²=94%). Meta-analysis using a random-effects model showed that there was no significant intergroup difference in fracture risk between the two groups〔RR (95%CI) =1.21 (1.00, 1.46), P=0.05〕. Four studies enrolled patients with bariatric surgery (n=14 796) and non-obese patients without bariatric surgery (n=132 124) with significant differences in baseline BMI, showing slight heterogeneity (P=0.26, I²=25%), and a higher risk of fracture was found in those with bariatric surgery revealed by meta-analysis using a fixed effects model〔RR (95%CI) =1.73 (1.59, 1.89), P<0.01〕. The level of heterogeneity decreased significantly after removing 4 of the 10 studies with high heterogeneity with no intergroup difference in baseline BMI (P=0.24, I²=25%), and a higher risk of fracture was found in patients with bariatric surgery indicated by meta-analysis using a fixed effects model〔RR (95%CI) =1.38 (1.31, 1.46), P<0.01〕. Subgroup analysis showed that the risk of fracture was similar in the surgery group and the obesity group within two years〔RR (95%CI) =1.05 (0.89, 1.24), P=0.56〕 and during two to five years〔RR (95%CI) =1.16 (1.00, 1.35), P=0.05〕, but it was higher in the former group five years after surgery〔RR (95%CI) =1.50 (1.23, 1.84), P<0.001〕. The risk of fracture was higher in patients with Roux-en-Y gastric bypass than that of those with adjustable gastric banding〔RR (95%CI) =1.31 (1.15, 1.50), P<0.01〕 or with sleeve gastrectomy〔RR (95%CI) =1.77 (1.55, 2.02), P<0.01〕. The risk of fracture was lower in patients with gastric banding than that of those with gastric bypass〔RR (95%CI) =0.54 (0.41, 0.71), P<0.01〕. Both Begg's test and Egger's test showed that publication bias was less likely in the studies (P=0.631, 0.720) .

Fracture risk is increased by bariatric surgery, which is not influenced by obesity. High risk of fracture did not appear until five years after the operation, with Roux-en-Y gastric bypass and gastric bypass were associated with higher fracture risk.

超重和肥胖是多种慢性病的主要危险因素，2018年，我国成年人超重/肥胖患病率高达50.7%。目前减肥手术是肥胖患者的治疗方式之一，但其是否会增加骨折发生风险尚存在争议。

分析减肥手术是否会增加骨折发生风险。

检索PubMed、Embase和Cochrane Library数据库，收集2010年1月至2021年11月发表的相关研究（队列研究、病例对照研究、随机对照试验），使用纽卡斯尔-渥太华量表（NOS）及Jadad量表进行文献质量评价，采用RevMan 5.3、Stata 12.0软件进行数据分析，使用Begg's和Egger's检验评估研究的潜在发表偏倚。比较接受减肥手术患者与未接受减肥手术患者的骨折发生风险。

共纳入15篇文献，包括12篇队列研究、2篇病例对照研究和1篇随机对照试验，文献质量均较高。纳入的12篇文献均设有接受减肥手术组（手术组，）和未接受减肥手术组（肥胖组+非肥胖组），其中10篇文献组间基线体质指数（BMI）无差异，分为手术组（137 239例）与肥胖组（159 066例），异质性较大（P<0.01，I²=94%），采用随机效应模型进行Meta分析，结果显示手术组与肥胖组骨折发生风险比较，差异无统计学意义〔RR（95%CI）=1.21（1.00，1.46），P=0.05〕；4篇文献组间基线BMI有差异，分为手术组（14 796例）与非肥胖组（132 124例），有轻度异质性（P=0.26，I²=25%），采用固定效应模型进行Meta分析，结果显示手术组骨折发生风险较非肥胖组高〔RR（95%CI）=1.73（1.59，1.89），P<0.01〕。将组间基线BMI无差异的10篇文献中去除异质性较大的4篇文献后异质性明显下降（P=0.24，I²=25%），采用固定效应模型进行Meta分析，结果显示手术组骨折发生风险高于肥胖组〔RR（95%CI）=1.38（1.31，1.46），P<0.01〕。亚组分析显示，手术组和肥胖组术后2年内〔RR（95%CI）=1.05（0.89，1.24），P=0.56〕及术后2~5年〔RR（95%CI）=1.16（1.00，1.35），P=0.05〕的骨折发生风险无差异，手术组术后5年后骨折发生风险高于肥胖组〔RR（95%CI）=1.50（1.23，1.84），P<0.001〕。胃旁路术（RYGB）术式骨折发生风险高于可调节胃束带术（AGB）术式〔RR（95%CI）=1.31（1.15，1.50），P<0.01〕和袖状胃切除术（SG）术式〔RR（95%CI）=1.77（1.55，2.02），P<0.01〕，胃束带术（GB）术式骨折发生风险低于胃转流术（GBP）术式〔RR（95%CI）=0.54（0.41，0.71），P<0.01〕。Begg's和Egger's检验结果显示存在发表偏倚可能性较小（Begg's检验：P=0.631，Egger's检验：P=0.720）。

减肥手术会增加骨折发生风险，但该风险不受BMI的影响。高骨折发生风险在术后5年得到显现，其中RYGB、GBP术式骨折发生风险相对较高。