Adiponectin, leptin, interleukin-6 and HbA1c in the prediction of incident type 2 diabetes: A nested case-control study in Asian Indian men with impaired glucose tolerance

Abstract

Aims: The aims of this study were: (1) to assess the association of adiponectin, leptin and interleukin-6 (IL-6) with incidence of type 2 diabetes (T2DM) in Asian Indian men with impaired glucose tolerance (IGT) and (2) to evaluate the additional contribution of these with the well-established glycaemic marker HbA1c.

Methods: This is an ancillary analyses of a nested case-control study derived from a prospective, prevention trial in India. All the participants had IGT at baseline. For this subanalysis a total of 147 (T2DM: 71; nondiabetic: 76) participants were selected based on the final glycemic outcomes. Association of these selected adipokines with T2DM were assessed using logistic regression analyses. Clinical usefulness of adding adipokine markers with HbA1c on prediction of T2DM was assessed using the area under the curve (AUC) of the receiver operating characteristics.

Results: Baseline levels of adiponectin were lower and the levels of IL-6 were higher in T2DM cases when compared with non-diabetic cases (P<0.05). Levels of leptin were similar in both groups. In fully adjusted models, adiponectin (odds ratio (OR): 0.55 [95%CI: 0.33-0.91]; P=0.019) and IL-6 (OR: 2.27 [95%CI: 1.40-3.691]; P=0.001) were associated with diabetes. Addition of adiponectin to HbA1c improved the AUC (ΔAUC: 0.0619; P=0.0251), whereas addition of IL-6 did not improve the predictive power of HbA1c alone.

Conclusions: Adiponectin and IL-6 are independently associated with incident diabetes. However, they are unlikely to serve as simple tools to predict future risk of diabetes but may have a role in understanding the pathogenesis.

Keywords: Adiponectin; Asian Indians; Interleukin-6; Leptin; Prediction of incident type 2 diabetes.