oa Adipokines as mediators of components of metabolic syndrome in a Qatari population

Background and Objectives: There is a high prevalence of obesity and its co-morbidities within the Arab population, especially in Qatar. Furthermore, the younger age of onset of obesity and its preponderance amongst females have seen an increase in type 2 diabetes and cardiovascular disease in this cohort. Adipose tissue dysfunction preceding frank obesity may underlie the increased risk of metabolic syndrome (MeS). Therefore aims of this study were to characterize the relationship between components of MeS and adipokines in a Qatari population. Methods: Non-diabetic subjects were recruited from the general Qatari population and patients awaiting weight reduction surgery (Al-Emadi Hospital). Lipid profiling and liver function were determined by conventional techniques (HMC). Insulin resistance was measured by HOMA. Adipokines were measured by ELISA. Results: In the whole study population (n=56, 13 males/43 females, 30.5+/-7.5 years old, BMI of 37.5+/-11kg/m-2) significant positive correlations between plasma leptin and BMI were confirmed. However, after controlling for BMI, partial correlations showed that leptin was associated negatively with all measures of blood pressure (all p≤0.01), triglycerides, total- and LDL-cholesterol (all p≤0.01), with liver enzymes (SGPT, AST and Billirubin, p=0.009, p≤0.01 and p=0.02 respectively), and positively with HDL cholesterol (p=0.05). Furthermore, leptin, was also negatively correlated with fasting blood glucose and HOMA (p=0.03 and p=0.01 respectively). In order to investigate this further, the population was dichotomized into age-matched normal weight (n=14) and obese (n=42) sub-groups. The obese group had significantly higher SBP (p=0.006), triglycerides (p=0.03), leptin (p≤0.001) and lower HDL (p≤0.001). Obesity was also associated with deteriorating liver functions manifested as elevation in SGPT (p =0.02), ALP (p= 0.01) and AST (p =0.02). Conclusions: Leptin was elevated in obesity. After correcting for BMI, an inverse relationship between leptin and risk factors for MeS was apparent, suggesting a protective role for leptin in this population, perhaps through its vasodilatory capability. However, when dichotomized into lean and obese groups, chronic elevation in leptin appeared to be associated with increased risk of MeS and deterioration of liver function, as previously described. These novel data are currently being confirmed in a larger ethnicity matched cohort.