Incidence and risk factors of post-metabolic and bariatric surgery hypoglycemia: a systematic review.

Objective: This study aimed to systematically review the existing literature to summarize the incidence and risk factors of post-metabolic and bariatric surgery hypoglycemia (MBSH).

Methods: We searched PubMed, Medline, Embase, and the Cochrane Library databases for the studies published from inception to August 2023. Randomized controlled trials and analytical studies that investigated the incidence or risk factors of MBSH after different surgery techniques (including Roux-en-Y gastric bypass, sleeve gastrectomy, gastric banding, duodenal switch, omega-loop gastric bypass, and vertical banded gastroplasty) were involved. The incidence and risk factors of MBSH were extracted and described separately based on different diagnostic criteria and then summarized the risk factors and their statistical findings collectively.

Results: Twenty-nine studies were reviewed with follow-up ranging from 1 to 22 years. The incidence of MBSH ranged significantly across different diagnostic methods: 2.6-66.4% (self-report), 6.6-61.8% (oral glucose tolerance test), 29.4-78.6% (mixed-meal tolerance test), and 50-75% (continuous glucose monitoring). Patients with a mean age of 49.8 years and 89.0% of them were women with a better glycemic control who undergo RYGB and achieve 86.5% of estimated weight loss from surgery should be particularly vigilant about the possibility of developing MBSH. Distinct biomarkers such as IGF-1 (OR 1.06), fasting glicentin (AUC 0.81), HbA1c (AUC 0.76), and absolute weight reduction (AUC 0.72), greater fluctuations in glucose (OR 1.98) are valuable in promptly detecting MBSH. Specifically, patients with prior cholecystectomy or antidepressant therapy should be particularly cautious.

Conclusion: The review highlights higher MBSH risk in younger women with significant weight loss after RYGB, and those with prior cholecystectomy or antidepressant use. Systematic summarization of MBSH criteria allowed us to identify the predictors for MBSH, which can aid in early diagnosis and treatment, reducing the need for prolonged monitoring.