Abstract EP48: Long Term Improvement In Cardiorespiratory Fitness Ameliorates Insulin Sensitivity Beyond The Response Of Visceral/Ectopic Fat In Viscerally Obese Men

Introduction: The SYNERGIE study has documented the effects on the cardiometabolic risk (CMR) profile of a 1-year lifestyle intervention targeting physical activity (PA) and diet followed by an additional 2-year maintenance period in a sample of 144 men with visceral obesity and an atherogenic dyslipidemia. Previously published results, following the 1-year intervention, had reported significant improvements in CMR markers and a decrease in intramuscular lipids assessed by computed tomography (CT) using the area of low attenuation muscle (LAM) as a marker. However, following the 2-year maintenance period, a slight deterioration of CMR markers including visceral adiposity (VAT) was observed, with the exception of circulating insulin levels. Hypothesis: In this secondary analysis, we tested the hypothesis that variations in cardiorespiratory fitness (CRF) and LAM could explain the long-term improvement in insulin sensitivity indices. Methods: Anthropometric measurements and an oral glucose tolerance test were performed at 0, 1 and 3 years, as well as a submaximal exercise test to assess CRF. Areas and volume of VAT and areas of LAM at mid-thigh and L4-L5 (psoas and core) were measured by CT. Participants were classified into two groups based on CRF changes observed during the 2-year maintenance period: CRF increased (CRF+) and CRF decreased (CRF-). Results: Complete data were available in a subsample of 72 men (52±8 years). Mean annual PA decreased from 143 min/week during the intervention to 103 min/week after the 2-year maintenance period (p<0.05). CRF changes during the maintenance period were negatively correlated with changes in psoas LAM area (r=-0.31; p<0.01) and core LAM area (r=-0.30; p<0.05). Changes in psoas LAM area (r=0.29; p<0.05) and core LAM area (r=0.35; p<0.01) were also correlated with changes in insulin resistance (HOMA-IR). The CRF+ group showed a greater decrease in HOMA-IR than the CRF- group (p<0.05). CRF was found to limit the deterioration of the CMR profile observed during the 2-year maintenance period (smaller gain in BMI, waist circumference, VAT volume, and LAM at the psoas; p<0.05). Conclusion: Despite some gain in VAT observed during the 2-year maintenance period following the initial 1-year lifestyle intervention, participants who were able to maintain or even increase their CRF during the 2-year maintenance period were those whose insulin sensitivity continued to improve, regardless of the changes in LAM. In conclusion, these results are consistent with the importance of targeting CRF for the long-term management of CMR in men with visceral obesity.