Changes in adiponectin:leptin ratio among older adults with obesity following a 12-month exercise and diet intervention

Background: Excess adiposity is characterized by alterations in adipokine secretion such that circulating leptin concentrations are increased with reductions in adiponectin. An emerging biomarker for the assessment of this adipose tissue (AT) dysfunction is the adiponectin:leptin (AL) ratio. A low AL ratio may be suggestive of dysfunctional AT and, consequently, a heightened cardiometabolic disease risk. This ancillary study investigated the relationship between the AL ratio and cardiometabolic health among community-dwelling older adults with obesity, as well as the effects of a 12-month exercise and diet intervention on changes in the AL ratio.

Methods: Participants (n = 163, 70.2 ± 4.7 years, 38.0% male) were randomized to the exercise only group, exercise + nutrient-dense weight maintenance group (exercise + weight maintenance), or exercise + nutrient-dense caloric restriction of 500 kcal/d group (exercise + intentional weight loss) (clinicaltrials.gov #NCT00955903). Total and regional adiposity as determined by magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry (DXA), anthropometrics, and cardiometabolic biomarkers were assessed at baseline and 12 months.

Results: The AL ratio was significantly (p < 0.05) inversely correlated with body mass index, waist circumference, measures of adiposity, and insulin among all participants at baseline. Among females only, significant positive and inverse correlations were also observed between this ratio and high-density lipoprotein cholesterol and the inflammatory biomarkers high sensitivity C-reactive protein and interleukin-6, respectively. While controlling for biological sex, a significant time by intervention group interaction effect (p < 0.05) was observed such that the AL ratio significantly increased from baseline to study completion among participants in the exercise + weight maintenance group and exercise + intentional weight loss group. Post hoc analysis revealed that the exercise + intentional weight loss group exhibited a significantly greater AL ratio at study completion compared to other groups (p < 0.05 all).

Conclusions: Results are in support of the AL ratio as a measure of AT dysfunction among older adults. Furthermore, results suggest that a 12-month exercise and diet intervention with intentional weight loss assists in improving the AL ratio in this population.