Habitual Physical Activity is Associated with Relative Apelin Gene Expression in Adipose Tissues Among Non-Diabetic Adults

The objective of the present study was to investigate the association between the apelin gene expression and habitual physical activity among morbid obese and non-obese subjects. Visceral and subcutaneous adipose tissues were obtained from 32 morbidly obese and 32 non-obese age- and sex-matched subjects, who underwent open abdominal surgery. Physical activity was collected using a valid and reliable International Physical Activity Questionnaire (IPAQ)-long form, and the metabolic equivalent of task (MET) was calculated. The mRNA expressions of apelin gene in visceral and subcutaneous adipose tissues were analyzed by Real-Time PCR. The mean age was 39.6 years for both groups and body mass index for morbidly obese and non-obese subjects were 45.3 and 25.7 kg/m2, respectively. Apelin gene expression was more increased in morbid obese than non-obese subjects in subcutaneous (2.82 vs. 0.70,P < 0.05) adipose tissues. After controlling for potential cofounders, apelin expression in subcutaneous adipose tissue was associated with total MET in both non-obese (β = 0.589, p value = 0.001) and morbid obese participants (β = 0.395, p value = 0.038). Among non-obese participants, apelin mRNA levels in visceral fat depots were associated with the total physical activity (β = 0.487, p value = 0.010). Moreover, occupational physical activity was associated with apelin gene expression in the subcutaneous adipose tissue of non-obese and morbid obese participants. Total MET was associated with apelin gene expression in visceral and subcutaneous adipose tissue in non-obese participants and was associated with only mRNA levels in subcutaneous fat depots in morbid obese participants.