Effects of Aerobic-Resistance Training and Nutritional Intervention on Adiponectin, Interleukin-6, and hs-CRP Concentrations in Men with Abdominal Obesity—A Randomized Controlled Trial

The objective of this study was to assess the changes in adiponectin concentrations and inflammatory markers in men with abdominal obesity following physical exercise and exercise combined with dietary intervention. This study included 44 males with abdominal obesity (mean age 34.7 ± 5.5 years, waist circumference [WC] 110.3 ± 8.5, BMI 32.0 ± 3.9), who were randomly assigned to three groups: a control group without interventions (CG, <i>n</i> = 12), an experimental group engaging in aerobic-resistance exercise (EG, <i>n</i> = 16) and a group engaging in aerobic-resistance exercise combined with an ad libitum high-protein, low-glycemic index carbohydrate diet (EDG, <i>n</i> = 16). Body composition metrics: the body fat-, fat-free mass-, and abdominal fat-to body mass (BF/BM, FFM/BM, ABD/BM) indexes and the body adiposity index (BAI), along with biochemical blood analyses-adiponectin (ADIPO), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), Castelli-II Index (CRI II) and fasting glucose-insulin (FG/I) ratio-were measured at baseline and after the intervention. The effects of the interventions on the analyzed variables across groups were assessed using mixed ANOVA tests with post hoc comparisons. Effect size (ES) was also calculated using partial eta squared (<i>η</i>p²). The exercise intervention (EG) resulted in a significant reduction in the BAI (<i>p</i> < 0.01), insulin resistance FG/I (<i>p</i> < 0.02), and IL-6 concentrations (<i>p</i> < 0.01) and initiated an increase in ADIPO secretion (<i>p</i> = 0.03). The combined intervention (EDG) reduced the insulin resistance FG/I (<i>p</i> = 0.02) and atherogenic index CRI II (<i>p</i> = 0.01), decreased inflammatory markers IL-6 (<i>p</i> = 0.01) by 48% and hs-CRP (<i>p</i> = 0.04) by 30%, and simultaneously increased the ADIPO (<i>p</i> = 0.02) concentration by 15%. These effects were accompanied by significant changes in body composition: reductions in visceral fat ABD/BM (<i>p</i> < 0.01), total fat BF/BM (<i>p</i> < 0.01), and BAI (<i>p</i> = 0.02) and an increase in FFM/BM (<i>p</i> < 0.01). A crucial role in achieving these outcomes was played by dietary modifications, i.e., the inclusion of low-glycemic index carbohydrates (<i>p</i> < 0.01), a 23% increase in protein intake (<i>p</i> < 0.01), and a 50% increase in dietary fiber intake (<i>p</i> < 0.01), which consistently deepened the energy deficit (<i>p</i> < 0.01) and reduced fat intake (<i>p</i> < 0.01). These findings underscore that short-term interventions, whether exercise alone or combined with dietary modifications, can effectively reduce inflammation and lower insulin resistance in men with visceral obesity. However, the combined intervention, involving both exercise and dietary modifications, resulted in more pronounced beneficial changes in both body composition and concentrations of adipokines, inflammatory markers, and atherogenic indices and insulin resistance.