Gender effect on vascular inflammation following bariatric surgery.

Studies have shown that mortality was reduced by 31.6% in patients that underwent bariatric surgery compared with the non-operative control group. However, in most surgical series the majority of patients were women, and men had higher post-operative mortality rates and a higher postoperative morbidity, regardless of weight. Our primary end point was to study gender effects on vascular inflammation following bariatric surgery for weight loss. Methods. A prospective study evaluated vascular inflammation in obese patients before and three months after bariatric surgery. Markers of vascular inflammation were measured - before surgery and three months afterwards. Results. One hundred and two patients (73 women and 29 men, 40.5 ± 12.3 years old) underwent bariatric surgery. Correlation was found between BMI change and waist circumference change (r = 0.658, P<0.001). Three months post-surgery, BMI was significantly decreased (p<0.001) (a decrease of 8.82), waist circumference was reduced (p<0.001) (a decrease of 17.33 cm). ICAM-1 levels and hs-CRP levels were decreased (both P = 0.0001). Gender differences seem to be borderline significant with respect to the prevalence of type II diabetes mellitus (men > women; P = 0.05) and hypertension (men > women; P = 0.06). In women, following bariatric surgery, BMI was decreased (p<0.001) (a decrease of 9.25), waist circumference was reduced (p<0.001) (a decrease of 18.8cm). ICAM-1 levels were decreased (p = 0.002) and hs-CRP levels were also decreased (P = 0.0001). In men, following bariatric surgery, BMI was decreased (p = 0.001) (a decrease of 8.1), waist circumference was reduced (p<0.005) (a decrease of 14.6cm); however, although ICAM-1 levels and hs-CRP levels were decreased the decreases were non-significant (both P = 0.09). Discussion. Our study examined gender effects of bariatric surgery on vascular inflammation. Bariatric surgery had no significant effect on biochemical inflammatory markers in male patients, while females undergoing the same kind of bariatric surgery for weight loss showed a significant decrease in these markers of inflammation. These results may explain the epidemiological data that described higher morbidity and mortality among obese men undergoing bariatric operation for weight loss. This is the first study that has demonstrated a gender difference in the inflammatory responses that may affect clinical outcome, and cardiovascular morbidity and mortality.