RESUMO
Obesity and physically inactive lifestyles are associated with an increased risk for developing insulin resistance. It has been confirmed that insulin resistance is a common feature in many inflammatory diseases and can be recognized with overproduced levels of markers such as IL-6, IL-18 and CRP. The aim of this study was to determine whether obesity or inactivity are stronger factors in the develop mental insulin resistance, considering insulin resistance markers such as IL-6, IL-18 and CRP. Thirty-two healthy, male students participated in the present study, age 24. 8 +/- 2.52 years, height 175.47 +/- 6.7, and weight 81.64 +/- 20.14]. Weight and body fat were measured with the body composition set and levels of exercise was determined with the PA-Rscore questionnaire. All subjects based on body fat and levels of exercise were divided into 4 groups: Active obese [n=8], active, non-obese[n=8], inactive, obese [n=8] and inactive, non obese[n=8]. To determine fasting values of IL-6, IL-18, CRP, glucose and insulin blood samples were obtained at 8 a.m. Obese subjects had higher resting levels of IL-6, IL18, CRP and insulin than lean subjects, with no significant difference between active lean and inactive lean subjects at resting levels of inflammatory markers. However there was a significant difference in the resting levels of IL-18 between active and inactive obese subjects [t=-2.51 p=0.031], and also a significant difference in resting levels of IL-6, IL18, CRP, insulin and HOMA between inactive obese with active and inactive lean subjects, IL-18 having the strongest relationship with HOMA [r=0.54 p=0.001]. Results indicated that obesity is a stronger factor than inactivity for development of insulin resistance. On the other hand, activity has anti-inflammatory effects, and hence can decrease the effects of obesity, in the development of insulin resistance