Alessandro Mor, MD, Philip Omotosho, MD, Alfonso Torquati, MD. Department of Surgery, Duke University.
INTRODUCTION – Roux-en-Y Gastric Bypass (RYGB) has been proven effective in reducing most of the obesity-related comorbidities that concur to increase the cardiovascular risk in obesity. The Framingham Risk Score (FRS) is designed to be independent of weight and estimates the 10-year risk for coronary heart disease (CHD), myocardial infarction, stroke, cardiovascular disease (CVD), and death from CHD and from CVD. For the first time, we prospectively studied two obese populations with type 2 diabetes (T2DM) matched by weight and most of the risk factors that mainly impact the FRS (age, gender, blood pressure, serum cholesterol and smoking status). Our aim was to evaluate the RYGB effectiveness on improving cardiovascular risk when compared to a control medical group not participating in designed weight-loss intervention. We hypothesize that obese diabetic patients who undergo RYGB will significantly reduce their FRS compared to matched diabetic subjects who undergo Diabetes Support and Education program (DSE).
METHODS – In a prospective cohort study, we evaluated preoperatively and at 12-month sixty-one morbidly obese subjects (BMI 41.7±0.6 kg/m2) with T2DM. 30 patients underwent laparoscopic RYGB and 31 patients received 1-year of DSE, consisting of educational sessions on diet/nutrition, exercise and living with diabetes. The two groups were matched according to gender, age, weight, waist circumferences, systolic blood pressure, serum cholesterol and triglyceride levels, and menopausal status. The cardiovascular risk was assessed at baseline and at 1-year follow-up in both groups using the strict gender-specific Framingham Risk Score which is based on age, total cholesterol, HDL cholesterol, blood pressure, ECG evidence of left ventricular hypertrophy and smoking and diabetes status. Pre- and postoperative variables were compared using a paired sample t-test. The independent t-test was used to determine differences between the two groups.
RESULTS – Change in BMI was -12.20±0.8 Kg/m2 in the RYGB group and 0.3±0.4 Kg/m2 in the DSE group (respectively, P<0.001 and P=0.446). As shown in Table1, the two groups were matched for baseline FRS. After 12 months of intervention, RYGB experienced a significant decrease in all the FRS, whereas control subjects did not show this significant decrease for the 10-year risk for CHD, CVD and death from CVD. The between-group differences for the changes from baseline to 12-month in all the FRS were significant. No Spreaman’s correlations between reduction in FRS and %EWL were found in the RYGB surgery.
Table1. Outcomes calculated using the gender-specific FRS. Data are presented with mean±SEM. CHD, coronary hearth disease; MI, Myocardial infarction; CVD, Cardiovascular disease; CHD-death, death from CHD; CVD-death, death from CVD.
CONCLUSIONS – In a population of diabetic obese patients, the RYGB’s benefits on FRS has never been prospectively compared to the effects of a diabetes support and education program in a matched control group who did not undergo bariatric surgery. As expected, the long-term effects of RYGB surgery on FRS are independent on weight loss and, as we hypothesized, a significant improvement of the cardiovascular risk is observed in morbidly obese patients with diabetes who underwent RYGB, but not in those who were offered DSE.