The effect of bariatric surgery on natriuretic peptide levels in patients with obesity is unclear. The purpose of this study was to conduct a systematic review and meta-analysis to determine the effect of bariatric surgery on B-type natriuretic peptide (BNP) and aminoterminal BNP (NT-proBNP) levels. MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were searched to February 2020. Primary outcomes included change in NT-proBNP or BNP levels following bariatric surgery and change in weight and body mass index. Secondary outcomes included change in blood pressure, echocardiographic findings, and heart failure symptoms. MINORS tool was used to assess quality of evidence. Twelve studies with 622 patients were included. Most patients underwent Roux-en-Y gastric bypass (RYGB) (70.5%). Mean absolute reduction in body mass index was 23%. NT-proBNP levels increased significantly from baseline at 6 months (mean difference [MD] 53.67 pg/mL; 95% confidence interval [CI], 28.72–78.61;
P≤ 0.001, I2 = 99%; 8 studies) and 12 months (MD 51.16 pg/mL; 95% CI, 20.46–81.86; P= 0.001, I2 = 99%; 8 studies) postbariatric surgery. BNP levels also increased significantly at 6 months (MD 17.57 pg/mL; 95% CI, 7.62–27.51; P< 0.001, I2 = 95%; 4 studies). Systolic and diastolic blood pressure decreased significantly 12 months after surgery. Studies measuring echocardiographic findings saw improvement in left ventricle mass and the E/A ratio, but no significant change in ejection fraction. Bariatric surgery is associated with increased natriuretic peptide levels in the absence of deteriorating cardiac function, and may be associated with improved cardiac and metabolic function after the procedure.