Relationship between bariatric surgery and periodontal status: a systematic review and meta-analysis

Background

The effects of bariatric surgery can reflect in the oral cavity and can cause alterations in oral health. This high prevalence of oral alterations in the pre and post-operative periods has been highlighted in different studies.

Metabolic outcomes after revisional bariatric surgery: a systematic review and meta-analysis

BackgroundIt has been well-established that primary bariatric surgery is effective in inducing improvement of diabetes and other associated co-morbidities in patients with obesity. Evidence demonstrating the influence of revisional bariatric surgery on this trajectory, however, is lacking.ObjectivesWe performed a systematic review and meta-analysis to examine the impact of revisional bariatric surgery on obesity-related metabolic outcomes.SettingUniversity Hospital, SingaporeMethodsWe examined outcomes of remission and improvement of diabetes, hypertension, hyperlipidemia, and obstructive sleep apnea. Revisional surgeries included sleeve gastrectomy, Roux-en-Y gastric bypass, pouch revision, duodenal switch, and minigastric bypass.ResultsOur search identified 33 relevant studies including a total of 1593 patients. Meta-analysis of proportions demonstrated a 92% improvement in diabetes with 50% achieving remission after revisional bariatric surgery. Of patients, 81% achieved improvement of hypertension with 33% achieving complete remission. In both groups, the highest proportion of improvement was observed after revisional duodenal switch. Although reported by fewer studies, a remission of hyperlipidemia was reported in 37% of patients and improvement of obstructive sleep apnea was seen in 86% of patients.ConclusionsRevisional bariatric surgery improves the outcomes of obesity-related co-morbidities and should be considered in patients with persistent metabolic disease after primary bariatric surgery.     

Effects of bariatric surgery on DNA methylation in adults: a systematic review and meta-analysis

BackgroundDNA methylation is an epigenetic mechanism through which environmental factors, including obesity, influence health. Obesity is a major modifiable risk factor for many common diseases, including cardiovascular diseases and cancer. Obesity-induced metabolic stress and inflammation are key mechanisms that affect disease risk and that may result from changes in methylation of metabolic and inflammatory genes.ObjectivesThis review aims to report the effects of weight loss induced by bariatric surgery (BS) on DNA methylation in adults with obesity focusing on changes in metabolic and inflammatory genes.MethodsA systematic review was performed using MEDLINE, EMBASE, and Scopus, to identify studies in adult humans that reported DNA methylation after BS.ResultsOf 15,996 screened titles, 15 intervention studies were identified, all of which reported significantly lower body mass index postsurgery. DNA methylation was assessed in 5 different tissues (blood = 7 studies, adipose tissues = 4, skeletal muscle = 2, liver, and spermatozoa). Twelve studies reported significant changes in DNA methylation after BS. Meta-analysis showed that BS increased methylation of PDK4 loci in skeletal muscle and blood in 2 studies, while the effects of BS on IL6 methylation levels in blood were inconsistent. BS had no overall effect on LINE1 or PPARGC1 methylation.ConclusionThe current evidence supports the reversibility of DNA methylation at specific loci in response to BS-induced weight loss. These changes are consistent with improved metabolic and inflammatory profiles of patients after BS. However, the evidence regarding the effects of BS on DNA methylation in humans is limited and inconsistent, which makes it difficult to combine and compare data across studies.     

Impacts of bariatric surgery on adverse liver outcomes: a systematic review and meta-analysis

BackgroundBariatric surgery has been reported to improve degeneration, inflammation, and fibrosis in nonalcoholic fatty liver disease, but the effects of bariatric surgery on the associated clinical outcomes is not known.ObjectivesThis work aimed to assess the impacts of bariatric surgery on adverse liver outcomes in people with obesity.SettingAn electronic search was performed on EMBASE, PubMed, and Cochrane Central Register of Controlled Trials (CENTRAL).MethodsThe primary outcome was the incidence of adverse liver outcomes following bariatric surgery. Liver cancer, cirrhosis, liver transplantation, liver failure, and liver-related mortality were defined as adverse hepatic outcomes.ResultsWe analyzed data from 18 studies comprising 16,800,287 post bariatric surgical patients and 10,595,752 control patients. We found that bariatric surgery reduced the risk of adverse liver outcomes in people with obesity (hazard ratio [HR] = .33, 95% confidence interval [CI] = .31–.34; I² = 98.1%). The subgroup analysis showed that bariatric surgery reduced the risk of nonalcoholic cirrhosis (HR = .07, 95% CI = .06–.08; I² = 99.3%) and liver cancer (HR = .37, 95% CI = .35–.39; I² = 97.8%), although bariatric surgery may also increase the risk of postoperative alcoholic cirrhosis (HR = 1.32, 95% CI = 1.35–1.59).ConclusionsThis systematic review and meta-analysis revealed that bariatric surgery lowered the incidence of adverse hepatic outcomes. However, bariatric surgery may also increase the risk of alcoholic cirrhosis after surgery. Future randomized controlled trials are required to further investigate the effects of bariatric surgery on liver of people with obesity.     

The association of uncoupling proteins 1, 2, and 3 with weight loss variability after bariatric surgery: a systematic review

BackgroundBariatric surgery is currently the most effective treatment for patients with severe obesity. Uncoupling proteins (UCP) 1, 2, and 3 play key roles in the regulation of energy balance and weight. Previous studies have suggested that changes in UCP1–3 genes could influence weight loss after bariatric surgery. However, it is still unclear if these UCPs are indeed involved in weight loss variability after surgery. Therefore, we performed a systematic review aiming to summarize the results of studies on this subject.MethodsA literature search was performed for all studies that evaluated associations of UCP1–3 expressions and their polymorphisms with obesity-related outcomes after bariatric surgery.ResultsTwenty-six studies were eligible for inclusion in this systematic review. Among them, 18 evaluated UCP1–3 expressions while 8 studies investigated the association between UCP1–3 polymorphisms and weight loss after bariatric surgery. In general, UCP2 and UCP3 expressions in adipose tissue and skeletal muscle seem to be affected by metabolic changes of bariatric surgery, which might be influenced by the surgery type. Data on UCP1 expression in adipose tissue is still inconclusive. Only few studies investigated the association between polymorphisms in UCP1–3 genes and weight loss after bariatric surgery, with contradictory results.ConclusionAvailable studies suggest that changes caused by bariatric surgery could influence UCP2 and UCP3 expressions in adipose tissue and muscles, consequently affecting weight loss. However, because of the reduced number of studies, further studies are needed to confirm whether these UCPs and their polymorphisms are indeed involved in weight loss after bariatric surgery.     

Weight loss after bariatric surgery in obese adolescents: a systematic review and meta-analysis

Of adolescents in the United States, 20% have obesity and current treatment options prioritize intensive lifestyle interventions that are largely ineffective. Bariatric surgery is increasingly being offered to obese adolescent patients; however, large-scale effectiveness data is lacking. We used MEDLINE, Embase, and Cochrane databases, and a manual search of references to conduct a systematic review and meta-analysis on overall weight loss after gastric band, gastric sleeve, and gastric bypass in obese adolescent patients (age ≤19) and young adults (age ≤21) in separate analyses. We provided estimates of absolute change in body mass index (BMI, kg/m²) and percent excess weight loss across 4 postoperative time points (6, 12, 24, and 36 mo) for each surgical subgroup. Study quality was assessed using a 10 category scoring system. Data were extracted from 24 studies with 4 having multiple surgical subgroups (1 with 3, and 3 with 2 subgroups), totaling 29 surgical subgroup populations (gastric band: 16, gastric sleeve: 5, gastric bypass: 8), and 1928 patients (gastric band: 1010, gastric sleeve: 139, gastric bypass: 779). Mean preoperative BMI (kg/m²) was 45.5 (95% confidence interval [CI]: 44.7, 46.3) in gastric band, 48.8 (95%CI: 44.9, 52.8) in gastric sleeve, and 53.3 (95%CI: 50.2, 56.4) in gastric bypass patients. The short-term weight loss, measured as mean (95%CI) absolute change in BMI (kg/m²) at 6 months, was –5.4 (?3.0, ?7.8) after gastric band, ?11.5 (?8.8, ?14.2) after gastric sleeve, and ?18.8 (?10.9, ?26.6) after gastric bypass. Weight loss at 36 months, measured as mean (95%CI) absolute change in BMI (kg/m²) was ?10.3 (?7.0, ?13.7) after gastric band, ?13.0 (?11.0, ?15.0) after gastric sleeve, and ?15.0 (?13.5, ?16.5) after gastric bypass. Bariatric surgery in obese adolescent patients is effective in achieving short-term and sustained weight loss at 36 months; however, long-term data remains necessary to better understand its long-term efficacy.     

The effects of bariatric surgery on cognition in patients with obesity: a systematic review and meta-analysis

Obesity impairs cognition. Bariatric surgery can result in substantial weight loss in patients with severe obesity; however, the impact of bariatric surgery on cognitive function remains controversial. To quantify the effect of bariatric surgery on cognition in patients with severe obesity, we performed a meta-analysis of 20 studies retrieved from PubMed, Cochrane, and Embase. Of these, 6 cohort studies found that Roux-en-Y gastric bypass leads to better performance for immediate verbal memory function (standardized mean difference [SMD] = .56; 95% confidence interval [CI]: .30–.82, P < .0001; I2 = 0%) and delayed memory function (SMD = .64; 95% CI: .38–.90, P < .00001; I² = 0%) during in the short term. Similarly, positive impacts on immediate verbal memory function (SMD = .46; 95% CI: .09–.83, P < .00001) and delayed memory function (SMD = .84; 95% CI: .46–1.22, P < .0001) were identified during a long-term follow-up. The Roux-en-Y gastric bypass group showed no improvements in attention, cognitive speed, and executive function compared with the control obese group. In 14 longitudinal studies (12 single-arm pre-post comparison studies and 2 cohort studies whose control group had no follow-up cognitive data), patients performed better postoperatively than preoperatively in all cognitive domains during repeated assessments. The analysis for the 20 operative groups showed that individuals treated with bariatric surgery had higher scores after repeated assessment of most neuropsychological tests except for animal fluency and letter fluency than baseline scores. These findings suggest that patients with severe obesity may obtain immediate verbal and delayed memory function benefits from Roux-en-Y gastric bypass.     

Efficacy of probiotics in patients with morbid obesity undergoing bariatric surgery: a systematic review and meta-analysis

Bariatric surgery is considered effective for morbid obesity, and probiotic supplementation might provide some benefits. We aimed to revise the evidence regarding probiotic supplementation in patients with morbid obesity undergoing bariatric surgery. MEDLINE, Embase, Web of Science, CENTRAL, and trial registers were searched up to April 1, 2020. We included randomized controlled trials and controlled clinical trials, and outcomes of interest were weight change, quality of life, gastrointestinal symptoms, and adverse events. All stages of the review were done by 2 authors independently and we followed Cochrane Handbook guidance. We screened 2541 references and included 5 studies. Probiotics may have minor to no effect regarding percentage excess weight loss (%EWL) at 6 weeks (mean difference [MD], .28; 95% CI, −9.53 to 10.09; 44 participants, 2 studies), 3 months (MD, 5.47; 95% CI, −3.22 to 14.17; 165 participants, 3 studies), 6 months (MD, .46; 95% CI, −8.14 to 9.07; 115 participants, 2 studies), and 12 months post surgery (MD, .35; 95% CI, −8.66 to 9.37; 123 participants, 2 studies). We observed short-term improvement in gastrointestinal symptoms. There was no important effect on quality of life and no meaningful adverse events. Because probiotic supplementation might provide some benefit with respect to weight loss, might alleviate some gastrointestinal symptoms, and is associated with minor or no adverse events, continuous supplementation might be worth considering in certain individuals. Our findings are based on the body of evidence of very low certainty, and further well-designed randomized controlled trials are required to elucidate the effect and strengthen the certainty in the estimates.     

The effect of omentectomy added to bariatric surgery on metabolic outcomes: a systematic review and meta-analysis of randomized controlled trials

Background

Excess visceral adipose tissue has been identified as an important risk factor for obesity-related co-morbidities. Conflicting information exists on whether omentectomy added to bariatric surgery is beneficial to metabolic variables.

Hypothyroidism and levothyroxine therapy following bariatric surgery: a systematic review,meta-analysis,network meta-analysis,and meta-regression

BackgroundMany health benefits of bariatric surgery are known and well-studied, but there is scarce data on the benefits of bariatric surgery on the thyroid function.ObjectiveWe aimed to make a meta-analysis regarding the impact of bariatric surgery on thyroid-stimulating hormone (TSH) levels, levothyroxine dose, and the status of subclinical hypothyroidism.SettingSystematic review and meta-analysis.MethodsPubMed, EMBASE, and Cochrane Library were searched up to December 2020 for relevant clinical studies. Random-effects model was used to pool results. Network meta-analysis was performed, incorporating direct and indirect comparisons among different types of bariatric surgery. Meta-regression analysis was performed to evaluate the impact of moderator variables on TSH levels and required levothyroxine dose after surgery. We followed the PRISMA guidelines for data selection and extraction. PROSPERO registry number: CRD42018105739.ResultsA total of 28 studies involving 1284 patients were included. There was a statistically significant decrease in TSH levels after bariatric surgery (mean difference = ?1.66 mU/L, 95%CI [?2.29, ?1.03], P < .0001). In meta-regression analysis, we found that the following moderator variables: length of follow-up, mean age, baseline TSH, and preoperative thyroid function, could explain 1%, 43%, 68%, and 88% of the between-study variance, respectively. Furthermore, subclinical hypothyroidism was completely resolved in 87% of patients following bariatric surgery. In addition, there was a statistically significant decrease of levothyroxine dose in frank hypothyroid patients following bariatric surgery (mean difference = ?13.20 mcg/d, 95%CI [?19.69, ?6.71]). In network meta-analysis, we found that discontinuing or decreasing levothyroxine dose was significant following Roux-en-Y gastric bypass, 1 anastomosis gastric bypass, and sleeve gastrectomy, (OR = 31.02, 95%CI [10.34, 93.08]), (OR = 41.73, 95%CI [2.04, 854.69]), (OR = 104.03, 95%CI [35.79, 302.38]), respectively.ConclusionsBased on our meta-analysis, bariatric surgery is associated with the resolution of subclinical hypothyroidism, a decrease in TSH levels, and a decrease in levothyroxine dose.     

Measurement of adherence in bariatric surgery: a systematic review

After bariatric surgery, rates of adherence to behavioral recommendations, including attending regular appointments and following specific dietary, physical activity, and vitamin use recommendations, tend to be highly variable across studies. Lack of consistency in measurement of adherence is a likely contributor to this variability, making it challenging to determine the prevalence and impact of nonadherence in this population. PubMed was searched for articles measuring behavioral adherence or compliance in patients after bariatric surgery, resulting in 85 articles. Articles were reviewed for the definition and measurement of adherence in each area (appointment attendance, as well as dietary, physical activity, and vitamin use adherence), and on the use and reporting of recommended adherence measurement strategies. Over half of the articles measured adherence to appointment attendance. Significant variability was found across adherence definitions and measurement methods, and use of recommended adherence measurement strategies was poor. Adherence was mostly commonly measured via self-report (either verbal or written) using cutoffs for adherent versus nonadherent behavior. Over half of studies assessed adherence up to ≥2 years postsurgery. Recommendations for ways to improve adherence measurement in patients who have had bariatric surgery are outlined.     

Impact of bariatric surgery on breastfeeding: a systematic review

Metabolic and bariatric surgery helps women achieve a healthier weight, reduce co-morbid conditions, increase fertility rates, and improve pregnancy outcomes compared with counterparts who are obese. Breastfeeding is known to provide both infant and maternal health benefits as well. Less is known about the impact of bariatric surgery on breastfeeding. The objective of this study was to review the impact of bariatric surgery on breastfeeding following the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. PubMed and Medline databases were searched using terms such as “bariatric surgery,” “postnatal care,” “lactation,” and “breastfeeding.” Reference lists were also used to find relevant articles. A total of 49 records were identified. Abstracts were screened, and 11 observational studies were identified after meeting inclusion criteria, which included the use of original research on breastfeeding and women who have had bariatric surgery. The available research shows that breast milk after bariatric surgery is adequate in nutrients and that no long-term effects were reported in cases studies when nutrient deficiencies were corrected. Limitations include observational study design and small sample sizes. This systematic review suggests that breastfeeding after bariatric surgery should be recommended along with monitoring and micronutrient supplementation. However, additional research and increased sample sizes are needed to further examine the relationship, and such studies should be conducted to strengthen the evidence and explore ways to improve breastfeeding rates in this population.     

Effect of bariatric surgery on endogenous sex hormones and sex hormone-binding globulin levels: a systematic review and meta-analysis

BackgroundMost studies have shown beneficial effect of bariatric surgery (BS) on serum levels of sex hormones.ObjectiveA systematic review and meta-analysis was conducted to examine the magnitude of possible changes in levels of sex hormones following BS.SettingsElectronic databases were searched, including PubMed, Scopus, Web of Science, and Embase, for relevant studies.MethodsThe heterogeneity of the studies was examined by χ² tests and the degree of heterogeneity was estimated using I² statistic.ResultsThe results of pooled analyses revealed that BS caused a significant increase in luteinizing hormone (LH), follicular stimulating hormone (FSH), total testosterone (TT), and sex hormone binding globulin (SHBG) levels and conversely, decreased dehydroepiandrosterone (DHEA) and estradiol (E2) levels in males. For females, BS significantly increased LH, FSH, and SHBG levels and conversely, decreased androstenedione (AE), E2 and TT levels. Additionally, the level of progesterone (P), prolactin (PRL), free testosterone (FT) and dehydroepiandrosterone sulfate (DHEA-S) showed no significant changes in patients who had undergone BS.ConclusionBS changed most sex hormones levels including LH, FSH, TT, SHBG, AE, DHEA, and E2. It seems that BS is able to exert substantial impacts on sex hormones levels and as well as sexual function, however, larger, and more precise trials are required to specifically focus on these claims.     

The risk of kidney stones following bariatric surgery: a systematic review and meta-analysis

Background With rising prevalence of morbid obesity, the number of bariatric surgeries performed each year has been increasing worldwide. The objective of this meta-analysis was to assess the risk of kidney stones following bariatric surgery. Methods A literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from inception through July 2015. Only studies reporting relative risks, odd ratios or hazard ratios (HRs) to compare risk of kidney stones in patients who underwent bariatric surgery versus no surgery were included. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method. Results Four studies (One randomized controlled trial and three cohort studies) with 11,348 patients were included in analysis to assess the risk of kidney stones following bariatric surgery. The pooled RR of kidney stones in patients undergoing bariatric surgery was 1.22 (95% CI, 0.63–2.35). The type of bariatric surgery subgroup analysis demonstrated an increased risk of kidney stones in patients following Roux-en-Y gastric bypass (RYGB) with the pooled RR of 1.73 (95% CI, 1.30–2.30) and a decreased risk of kidney stones in patients following restrictive procedures including laparoscopic banding or sleeve gastrectomy with the pooled RR of 0.37 (95% CI, 0.16–0.85). Conclusions Our meta-analysis demonstrates an association between RYGB and increased risk of kidney stones. Restrictive bariatric surgery, on the other hand, may decrease kidney stone risk. Future study with long-term follow-up data is needed to confirm this potential benefit of restrictive bariatric surgery.     

Effect of bariatric surgery on long-term cardiovascular outcomes: a systematic review and meta-analysis of population-based cohort studies

This meta-analysis aimed to compare the effects of bariatric surgery and nonsurgery on cardiovascular outcomes in patients with obesity. A systematic literature search of the Medline (via PubMed), Embase, and Cochrane Central Register of Controlled Trials databases was performed until August 18th, 2021. Population-based cohort studies comparing long-term cardiovascular outcomes for patients with obesity undergoing bariatric surgery or not were included. A meta-analysis of relative risks (RRs) was performed for all outcomes. We conducted subgroup analyses and meta-regression to explore sources of heterogeneity and the stability of the results. Twenty-one population-based cohort studies involving 2,857,016 participants were identified. The major adverse cardiovascular event (MACE) RR in the bariatric surgery group was .53 (95% confidence interval [CI] = .45–.62, P < .001) relative to the nonsurgical group. Relative to the nonsurgical group, the risk of myocardial infarction (MI) (RR = .40, 95% CI = .30–.52, P < .001), stroke (RR = .60, 95% CI = .46–.79, P < .001), cardiovascular death (RR = .43, 95% CI = .35–.54, P < .001), and all-cause death (RR = .44, 95% CI = .32–.59, P < .001) was significantly reduced for patients who underwent bariatric surgery. In subgroup analyses, as the proportion of patients with diabetes mellitus increased, lower RRs for MACE, MI, and stroke were observed in the surgery group relative to the nonsurgical group. The decreased risk of MACE was also observed in the subgroup with median follow-up duration ≥5 years.Bariatric surgery improves cardiovascular outcomes in patients with obesity, especially providing long-term benefits, and this effect is more pronounced in patients with comorbid diabetes.     

Benefits of bariatric surgery on microvascular outcomes in adult patients with type 2 diabetes: a systematic review and meta-analysis

BackgroundMicrovascular diabetes complications impair patients’ health-related quality of life. Bariatric surgery (BS) emerged as a compelling treatment that demonstrated to have beneficial effects on patients with diabetes and obesity.ObjectiveWe aimed to synthesize the benefit of bariatric surgery on microvascular outcomes in adult patients with type 2 diabetes.Setting2011-2021.MethodsWe included both cohort studies and randomized trials that evaluated bariatric surgery added to medical therapy compared with medical therapy alone in the treatment of adult patients with type 2 diabetes. Studies must have evaluated the incidence of any microvascular complication of the disease for a period of at least 6 months. We performed our search using PubMed, Scopus, EMBASE, Web of Science, and COCHRANE Central database which was performed from inception date until March 2021. PROSPERO (CRD42021243739).ResultsA total of 25 studies (160,072 participants) were included. Pooled analysis revealed bariatric surgery to reduce the incidence of any stage of retinopathy by 71% (odds ratio [OR] .29; 95% confidence interval [CI] .10–.91), nephropathy incidence by 59% (OR .41; 95% CI 17–96), and hemodialysis/end-stage renal disease by 69% (OR .31 95% CI .20–.48). Neuropathy incidence revealed no difference between groups (OR .11; 95% CI .01–1.37). Bariatric surgery increased the odds of albuminuria regression by 15.15 (95% CI 5.96–38.52); higher odds of retinopathy regression were not observed (OR 3.73; 95% CI .29–47.71). There were no statistically significant differences between groups regarding the change in surrogate outcomes.ConclusionsBariatric surgery in adult patients with diabetes reduced the odds of any stage of retinopathy, hemodialysis/end-stage renal disease, and nephropathy composite outcome. However, its effect on many individual outcomes, both surrogates, and clinically significant, remains uncertain.     

Disordered eating following bariatric surgery: a review of measurement and conceptual considerations

Eating disorders are associated with significant medical morbidity and mortality and serious psychological impairment. Individuals seeking bariatric surgery represent a high-risk group for evidencing disordered eating and eating disorders, with some patients experiencing the persistence or onset of disordered eating postsurgery. This review synthesizes the available literature on problematic or disordered eating in the bariatric field, followed by a review of measurement and conceptual considerations related to the use of eating disorder assessment tools within the bariatric population.     

Effects of bariatric surgery on the menstruation- and reproductive-related hormones of women with obesity without polycystic ovary syndrome: a systematic review and meta-analysis

BackgroundBariatric surgery is an effective treatment for severe obesity. Several studies have been conducted on the effects of bariatric surgery on the reproductive function of women with obesity who do not have polycystic ovary syndrome (PCOS).ObjectivesTo evaluate the effects of bariatric surgery on the menstruation and reproductive related hormones of women of childbearing age with who do not have PCOS.SettingA systematic review and meta-analysis at a university hospital.MethodsOnline databases were searched for all studies reporting the efficacy of bariatric surgery for women with obesity until March 2021. The language of publication was limited to English and Chinese. Incidence of abnormal menstruation and reproductive-related hormone levels were the primary outcomes.ResultsFifteen studies comprising 725 patients were enrolled in this meta-analysis. Results showed a significantly lower incidence of abnormal menstruation (relative risk: .40, 95% confidence interval [CI]: .20–.79, P = .008) after bariatric surgery. Moreover, bariatric surgery led to a decrease in serum insulin levels (mean difference [MD] = ?13.12 mIU/L, 95% CI: ?15.03 to ?11.22, P < .00001), glucose (MD = ?.91 mmol/L, 95% CI: ?1.26 to ?.56, P < .00001), triglyceride (MD = ?.61 g/L, 95% CI: ?.76 to ?.46, P < .00001), total testosterone (MD = ?.22 ng/mL, 95% CI: ?.24 to ?.20, P < .00001), dehydroepiandrosterone (DHEA) (MD = ?25.34 μg/dL, 95% CI: ?31.19 to ?19.49, P < .00001), estradiol (MD = ?25.13 pg/mL, 95% CI: ?34.13 to ?16.13, P < .00001), and anti-Mullerian hormone (AMH) (MD = ?.40 ng/mL, 95% CI: ?.67 to ?.13, P = .003). Serum sex hormone binding globulin (SHBG) levels increased after bariatric surgery (MD = 43.99 nmol/L, 95% CI: 34.99–52.99, P < .00001).ConclusionBariatric surgery can lower fasting insulin, glucose, and triglyceride levels, reduce the incidence of abnormal menstruation, decrease total serum testosterone, DHEA, estradiol, and AMH levels, and increase SHBG level for women with obesity of childbearing age who do not have PCOS. This meta-analysis indicated that bariatric surgery could be effective in improving reproductive function for women with severe obesity.