Background:
Although low levels of cardiorespiratory fitness (CRF) and obesity are often associated with a deteriorated cardiometabolic risk profile including low-grade inflammation, the respective contributions of specific indices of body fat distribution and CRF to variation of inflammatory markers remains uncertain. We therefore sought to determine the respective contributions of visceral adipose tissue (VAT) accumulation and CRF to variation of inflammatory markers in middle-aged men and women.
Methods and Results:
A complete lipoprotein-lipid profile and circulating levels of inflammatory markers such as C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and adiponectin were obtained and in a sample of healthy men (n=120) and women (n=152) covering a wide range of obesity values. VAT accumulation was measured by computed tomography and CRF levels were measured by a progressive submaximal physical working capacity test. In both men and women, VAT was positively associated with CRP and IL-6 levels (r≥0.35, p<0.0001), negatively associated with adiponectin (r≤ −0.29, p≤0.0003), after adjusting for CRF. After adjusting for VAT, CRF was not associated with variation in inflammatory markers in women and only with adiponectin in men (r= −0.20, p=0.03). An inflammation score was developed based on the sex-specific 50
th
percentile values of each inflammatory marker (0 or 1) which yielded a score ranging from 0 (low) to 4 (high). Participants who scored 0, 1 or 2 were considered as having a low score and participants who scored 3 or 4 had an elevated inflammation score. In participants with low VAT (<130cm
2
for men and <100cm
2
for women), the prevalence of participants with an elevated inflammation score was of 23.9% and of 28.0%, respectively for participants with high and low CRF, whereas in participants with an elevated VAT accumulation, the prevalence of an elevated inflammation score was of 60.0% and of 61.7%, respectively for high and low CRF.
Conclusions:
These results suggest that the inflammatory state associated with low CRF is largely attributable to the increased VAT accumulation often observed in poorly fit individuals.
Comparative effects of single-mode vs. duration-matched concurrent exercise training on body composition, low-grade inflammation, and glucose regulation in sedentary, overweight, middle-aged men
