The effect of weight loss after gastric bypass on C-reactive protein levels

Abstract

Background Recent studies have shown a direct correlation between C-reactive protein (CRP) level and obesity. There has also been increasing evidence that elevated CRP level is a significant risk factor for cardiac events and stroke. We wanted to evaluate whether CRP is altered by gastric bypass surgery. In addition, we wanted to investigate whether there was any correlation between reduced body mass index (BMI) and decreased CRP level. Methods CRP levels were obtained at 1 week preoperatively and then at 3 and 6 months postoperatively. Measurements of weight (kg), height (cm), and waist and hip circumferences (cm) were also measured at these time points. The BMI and CRP mean levels at the 3 time points were compared using a nonparametric Kruskal-Wallis 1-way analysis of variance test, with post hoc Z tests used for comparisons between the individual time periods. In addition, a linear regression analysis was performed at each time period to determine whether a significant correlation existed between the CRP level and the change in BMI. Results Twenty subjects (19 females and 1 male) have been studied to date. There were significant decreases in BMI between the preoperative and 3-month periods, with a further significant decrease at 6 months (44.5 ± 4.7, 35.7 ± 5.1, and 31.5 ± 4.3, respectively; P < .05). CRP level decreased significantly between the preoperative and 3-month periods (1.02 ± 0.7 to 0.49 ± 0.09, respectively; P < .05). (Normal CRP level is < 0.5 mg/dL.) There was a tendency toward a further decrease in CRP level from 3 to 6 months, although this did not reach statistical significance (6-month mean, 0.39 ± 0.10; P > .05). There was no statistically significant correlation between the change in BMI and CRP levels at any of the time periods. Conclusion There were significant reductions in BMI and CRP levels after gastric bypass surgery. However, there was no statistically significant correlation between the decrease in BMI and the decrease in CRP levels.