Exercise-induced compensation and C-reactive protein change in adults with elevated C-reactive protein: analysis of a randomised controlled trial.

PURPOSE: Exercise can reduce C-reactive protein (CRP), but heterogeneity exists and it is unclear whether exercise-induced weight compensation occurs or relates to CRP change. We examined whether compensation occurs in adults with elevated CRP during exercise and whether compensation and compensatory behaviours are associated with CRP change. METHODS: In this 4-month randomised controlled trial, 124 sedentary adults with elevated CRP (mean ± SD: 4.3 ± 2.5 mg/L) were randomised to a control group or a supervised aerobic exercise group expending 16 kcal/kg/week. Predicted weight change was estimated, and weight compensation (weight change - predicted weight change) was calculated. CRP was measured, and energy intake and non-exercise step count were assessed using questionnaires and pedometers, respectively. RESULTS: Weight compensation was greater in the exercise group than the control group (1.3 [95% CI, 0.6, 2.1] vs. 0.1 [95% CI, -0.6, 0.9] kg; P = 0.029). In response to exercise, compensation did not differ between participants with moderately higher (≤ 3 mg/L) and higher (> 3 mg/L) CRP (P = 0.977). Exercisers who did not compensate exhibited a 1.2 (95% CI, 0.2, 2.2) mg/L reduction in CRP versus those who did compensate (P = 0.016). Higher energy intake was associated with CRP change in exercisers, with each 100 kcal/day elevation in energy intake associated with a 0.1 (95% CI, 0.0, 0.2) mg/L increase in CRP (P = 0.022). CONCLUSION: Exercise-induced weight compensation occurs in adults with elevated CRP and is associated with attenuated improvements in CRP. Increased energy intake was associated with higher CRP in exercisers, suggesting that limiting increases in energy intake may enhance exercise-induced anti-inflammatory benefits. CLINICAL TRIALS REGISTRATION: NCT00113061.