Abstract MP68: Adipokines as Mediators in the Association of Changes in Physical Activity With Diabetes: The Atherosclerosis Risk in Communities (ARIC) Study

Background: Physical activity (PA) patterns over time influence diabetes risk through incompletely understood mechanisms. Adipokines secreted by adipose tissue have myriad endocrine effects and are affected by PA. It is unknown the extent to which adipokines mediate the association between changes in PA and diabetes. Methods: We conducted a cross-sectional study of 10,908 ARIC participants (mean age 54; 55% female; 21% Black adults) who attended Visits 1 (V1; 1987-1989) and 3 (V3; 1993-1995) of the ARIC Study. We used mediation analyses to determine the extent to which the association of changes in PA from V1 to V3 and diabetes status at V3 was explained by adipokines. Analyses were stratified by obesity status. PA was defined using American Heart Association guidelines as inactive, intermediate, and recommended (150 minutes of moderate-vigorous activity/week); the intermediate group was further divided into low and moderate (below or above the median activity level). Participants were categorized by PA at V1 and V3 - (1) stable low: inactive or low at both visits; (2) increasing: higher category at V3 than V1; (3) decreasing: lower category at V3 than V1; and (4) stable high: moderate or high at both visits. Results: Increasing PA was associated with higher adiponectin and lower leptin at V3 compared to stable low PA, while decreasing PA was associated with lower adiponectin and higher leptin compared to stable high PA (p<0.01 for all comparisons). Decreasing PA was associated with 28% higher odds of diabetes compared to stable high PA (Table). Conversely, increasing PA was associated with 12% lower odds of diabetes compared to stable low PA. In mediation analyses, adjustment for leptin/adiponectin ratio explained 45% of the effect of increasing PA and 35% of the effect of decreasing PA. The directionality of associations was similar in obesity stratified analyses, but results were not statistically significant. Conclusions: The associations between changes in PA and diabetes may be mediated in part by adipokines.