Longitudinal analysis of cardiovascular parameters after gastric bypass surgery

Identifying the predictors of co-morbidity improvement after gastric bypass surgery (Roux-en-Y gastric bypass) might give insight into disease pathophysiology.

We performed an observational study of 949 patients undergoing primary RYGB from 2005 to 2010. Multivariate mixed models were used to determine the predictors of change in hemoglobin A1c (HbA1c), lipids, systemic blood pressure, and C-reactive protein.

Greater weight loss, decreased severity of initial disease, and a greater initial body mass index predicted a significantly greater likelihood of improvement in nearly all measured parameters. Male gender predicted greater improvement in diastolic blood pressure and low-density lipoprotein and triglyceride levels. Younger patients had a greater improvement in blood pressure. Improvement in the lipid profile was independent of weight loss, and improved glycemic control was strongly dependent on weight loss. Of the 949 patients, 33% had diabetes before RYGB. A mean of 388 days after RYGB, 66% of these patients had an HbA1c of <6.5, with their mean HbA1c decreasing from 8.0 to 5.9. A greater decrease in HbA1c was also seen in patients who initially were only treated with oral hypoglycemic agents compared with those receiving insulin. The low-density lipoprotein cholesterol levels decreased significantly from a mean of 108 to 87 mg/dL. High-density lipoprotein increased by a mean of 10 mg/dL in both men and women. Also, 15% of the patients had a triglyceride level of ≥ 200 mg/dL before RYGB and only 1.1% did so afterward. The mean C-reactive protein level decreased from 5.0 to 1.6 mg/dL. We measured a 20% reduction in patients with measured hypertension after RYGB.

RYGB resulted in dramatic improvement in cardiovascular risk factors, with several significant predictors of outcome.