Long-Term Metabolic Outcomes Following Bariatric Surgery: A Systematic Review, Meta-Analysis, and Meta-Regression
In brief
Bariatric surgery cuts fasting glucose by up to 45 mg/dL after 5 years
A meta-analysis of 54 studies involving nearly 38 000 patients showed that bariatric procedures produced lasting reductions in all metabolic-syndrome components after at least five years, including a 23-45 mg/dL drop in fasting glucose, a 10-12 mg/dL rise in HDL, and a 55 mg/dL fall in triglycerides. Benefits were strongest after Roux-en-Y gastric bypass, and data on sleeve gastrectomy remain sparse, highlighting a need for longer-term studies of newer techniques.
- Journal
- Obesity reviews : an official journal of the International Association for the Study of Obesity (Q1)
- Published
- 19 August 2026
- Study design
- Systematic review / meta-analysis of RCTs
- Evidence level
- Level 1, High (CEBM 1a)
- Authors
- Bernardo Paz Barboza, Pietro Ferrara, Lisa Ye, Lorenzo Losa, Gianluca Perseghin, Giovanni Cesana, et al.
- PMID
- 42615579
- DOI
- 10.1111/obr.70211
Why clinicians should know about it
- Picked for Bariatric and Metabolic Surgery (top studies of the week, 23 August 2026): Long-term bariatric surgery outcomes meta-analysis
Abstract
Bariatric surgery (BS) has short- and medium-term benefits in improving metabolic syndrome (MetS) components, but its long-term impact remains incompletely characterized. This systematic review and meta-analysis aimed to quantify the long-term effects of BS (≥ 5 years) on fasting blood glucose (FBG), HDL cholesterol, triglycerides (TG), waist circumference (WC), and systolic and diastolic blood pressure (SBP and DBP). A comprehensive literature search was conducted across relevant databases. Eligible studies included randomized controlled trials and observational cohorts reporting pre- and postsurgical metabolic outcomes after at least 5 years of follow-up. Random-effects meta-analyses and meta-regressions were performed. Fifty-four articles (49 cohorts and five RCTs), including 37,840 baseline participants, were analyzed. BS was associated with significant improvements across all outcomes, with effect sizes varying by study design. Pooled estimates ranged from -22.97 to -44.68 mg/dL for FBG, +10.25 to +11.94 mg/dL for HDL, -54.11 to -59.59 mg/dL for TG, -20.55 cm for WC, -7.82 to -9.76 mmHg for SBP, and -4.80 to -6.48 mmHg for DBP. Meta-regression showed stronger effects in patients with higher baseline values. BS provides sustained, long-term improvements in all major MetS components. However, these findings are primarily driven by studies on Roux-en-Y gastric bypass, whereas long-term data on sleeve gastrectomy remain limited. High-quality longitudinal evidence on sleeve gastrectomy is needed to improve the generalizability of these results to contemporary surgical practice.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.