The short-term effect of bariatric surgery on non-invasive markers of artery function in patients with metabolic syndrome

BACKGROUND: An improved understanding of the vascular function, measured in non-invasive way, in constantly growing group of patients at increased risk of cardiovascular events is necessary. To evaluate the effects of metabolic syndrome in morbidly obese patients and body mass reduction secondary to gastric bypass surgery on convenient and new non-invasive markers of artery function: pulse wave velocity (PWV), flow- and nitroglycerin-mediated dilatation (FMD, NTG). METHODS: There were 40 patients included into prospective study, who were qualified for bariatric surgery (OB1) and evaluated again 6 m after surgery (OB2). A control group (CG) consisted of 15 healthy women. A second control group (CG2) consisted of 15 women with grade 1 obesity. PWV, FMD, NTG were assessed. RESULTS: The reduction of BMI (kg/m(2)) from 47.73 ± 6.18 (OB1) to 35.22 ± 5.20 (OB2) was observed. The PWV turned out to be higher before bariatric surgery (OB1 vs. OB2 8.53 ± 1.76 vs. 7.82 ± 1.49 m/s; p < 0.001), however it was no different than PWV in CG. In OB1 group PWV showed correlation with age (r = 0.492, p = 0.001), HR (r = 0.324, p = 0.04), %FM (r = 0.328; p = 0.039), NTG% (r = -0.332, p = 0.036) as well as hsCRP (r = 0.394, p = 0.014). A multivariate analysis showed that the most significant factors influencing PWV were age (p = 0.0005) and hsCRP (p = 0.0014), pseudo R(2) index 0.44365. The values of FMD differed between OB1 and OB2 groups (12.83 ± 5.15 vs. 17.52 ± 5.50 %; p < 0.0001), however, they were similar to results obtained in CG (14.45 ± 6.14 %; NS). The values of nitroglycerin-mediated dilatation differed between OB1 and OB2 groups (21.47 ± 8.31 vs. 28.54 ± 8.16 %; p < 0.0001) and were lower as compared with CG (31.42 ± 5.95 %; p = 0.0005). CONCLUSION: Body mass reduction secondary to bariatric surgery in patients with severe obesity and metabolic syndrome results in improvement of functional markers of artery function and advantageous metabolic changes. The improvement in functional markers of artery function (NTG%) was correlated with change in triglyceride blood concentration.