The deleterious effects of physical inactivity on elements of insulin resistance and metabolic syndrome in Central Africans at high cardiovascular risk

Aim: We aimed to describe the physical activity and to investigate the association between classical hypertension, obesity, diabetes, and new inflammation, IDF-defined metabolic syndrome, insulin resistance CV risk factors.

Design: This was a cross-sectional study based on interviews and physical and biochemistry measurements among Central African patients.

Measurements: Waist circumference (WC), blood pressure, weight and height to calculate body mass index (BMI), fasting glucose, CRP, ERS, uric acid, cholesterol (C), LDL-C, HDL-C, triglycerides, elements of homeostatic model assessment (HOMA) including insulin, HOMA index, QUICKI, insulin sensitivity (%S), beta-cell function (%β) and insulin resistance (IR).

Findings: Of the 60 patients included, 30 (50%) were physically inactive versus 30 (50%) active. In pooled analyses, in men and in women, there was significant and positive correlation between WC and seating/laying down position (WC=92.41+1.49 seating time in hours, R(2)=0.11; P<0.0001). The mean value of CRP and ERS were higher and those of all indices of HOMA were lower in inactive patients. The discriminant function for physical activity was Z (score=barycentre)=-7.36+1.013 HOMA index where -1.4 was the barycentre for active and +1.4 for inactive. HOMA index >2.42 was the optimal cut-off value to detect physically inactive patients: sensitivity=93.3%, specificity=100%, area under ROC=0.991±0.01 95%=0.975-1.0; P<0.0001.

Conclusion: The association between low-grade inflammation markers, insulin resistance and physical inactivity favours the hypothesis that a low-grade inflammatory status and enhanced insulin, sensitivity may constitute a part of the CV benefits from physical activity.