Early Impact of Bariatric Surgery on Type II Diabetes, Hypertension, and Hyperlipidemia: A Systematic Review, Meta-Analysis and Meta-Regression on 6,587 Patients

This study aims to evaluate the 12-24-month impact of bariatric surgery on the foremost modifiable traditional risk factors of cardiovascular disease. A systematic review and meta-analysis of prospective interventional studies reporting the most commonly performed laparoscopic surgical procedures, i.e., Roux-en-Y gastric bypass (RYGB), adjustable gastric banding (AGB), and cardiovascular risk reduction after surgery. The bibliographic research conducted independently by two authors yielded 18 records. When looking at RYGB and AGB separately, we observed a relevant heterogeneity (I (2) index a parts per thousand yen87 %) when BMI reduction was considered as the main outcome. When hypertension, type II diabetes, and hyperlipidemia risk reduction was estimated, a highly significant beneficial effect was found. The risk reduction was 0.33 [0.26; 0.42] for type II diabetes, 0.52 [0.42; 0.64] for hypertension, and 0.39[0.27; 0.56] for hyperlipidemia (P < 0.0001 for all outcomes considered). When looking at surgical technique separately, a higher but not statistically significant risk reduction for all outcomes considered was found. Results from the meta-regression approach showed an inverse relation between cardiovascular risks and BMI reduction. The present study showed an overall reduction of cardiovascular risk after bariatric surgery. According to our analysis a BMI reduction of 5 after surgery corresponds to a type II diabetes reduction of 33 % (as reported by Peluso and Vanek (Nutr Clin Pract 22(1):22-28, 2007); SAS Institute Inc., (2000-2004)), a hypertension reduction of 27 % (as reported by Buchwald and Oien (Obes Surg 23(4):427-436, 2013); Valera-Mora et al. (Am J Clin Nutr 81(6):1292-1297, 2005)), and a hyperlipidemia reduction of 20 %(as reported by Adams et al. (JAMA 308(11):1122-31, 2012)); Alexandrides et al. (Obes Surg 17(2):176-184, 2007). In summary, our study showed that laparoscopic bariatric surgery is an effective therapeutic option to reduce the cardiovascular risk in severe obese patients.