J Am Coll Cardiol. 2004;43:1056-1061.
Background: High sensitivity C-reactive protein (hsCRP) is associated with abdominal adiposity and other CHD risk factors. It is also a predictor of coronary heart disease (CHD) events. Although weight reduction and statin therapy have been shown to reduce hsCRP levels, the effects of cardiac rehabilitation programs on hsCRP are not well described.
Objectives: This study aimed to assess the effect of a 3-month phase 2 cardiac rehabilitation and exercise training program on hsCRP levels in patients with CHD.
Methods: This was a study of 235 consecutive patients with CHD who completed a 3-month phase 2 cardiac rehabilitation and exercise training program. This program included dietary counseling with special emphasis on the Mediterranean diet, targeted weight loss diet plans for overweight patients, formalized thrice weekly exercise instruction, and educational classes regarding CHD risk factors. A group of 42 CHD patients who were referred to cardiac rehabilitation but dropped out before active participation served as controls. HsCRP levels as well as anthropometric and lipid data were obtained before and after cardiac rehabilitation (or 3-6 months after initial testing for the controls).
Results: Median levels of hsCRP decreased by 41% in patients enrolled in the program, whereas there was no change in the control group on follow-up testing. This decrease was seen whether or not patients were on statin therapy. There were also significant improvements in lipid profiles, abdominal girth, and %fat in the treatment cohort. The authors did not adjust the hsCRP levels for these differences, but did show that the decrease in hsCRP was seen in patients whether or not they lost or gained weight after the program. No data on smoking behavior are given.
Conclusions: This study demonstrates that therapeutic lifestyle changes effected through a formalized 3-month cardiac rehabilitation and exercise training program, result in a significant improvement in lipid and obesity parameters. With these changes, a fall in hsCRP was also seen. This decrease in hsCRP appears to be incremental to the effect of statin therapy. A decrease in hsCRP level was also seen despite the absence of significant weight loss after enrollment in the program; this may be related to the emphasis on a diet high in n-3 fatty acids as well as the known benefits of exercise beyond weight loss. These data suggest that multiple components of a cardiac rehabilitation program, including diet and weight loss/maintenance, contribute to reductions in this marker of inflammation in patients with CHD.
Comments: Among the more interesting data from this paper are found in Table 1, which showed a mean BMI for the entire cohort of 28.6, with 32% of the patients classified as obese. Recognizing that regional variations of obesity prevalence exist, these numbers are still worrisome. Following completion of the cardiac rehabilitation program, obesity prevalence decreased. HsCRP, a marker of inflammation and a predictor of future risk, also decreased in patients who completed such a program. This study was not designed to isolate the effect of physical activity on inflammatory markers; rather this study demonstrated that lifestyle modifications in a directed supervised program result in favorable changes in inflammatory markers in patients with CHD. Further studies are needed to clarify whether these reductions in hsCRP levels translate into a decrease in recurrent CHD events.