Role of Apelin in Type II Diabetes Mellitus

Diabetes mellitus (DM) is characterised by persistent hyperglycaemia. It is associated with severe microvascular and macrovascular complications and leads to a significant decline in quality of life. Apelin is an endogenous ligand for the APJ receptor. There is some evidence in the literature that it promotes glucose uptake and improves insulin sensitivity and thus helps to control diabetes and prevent its complications in the initial stages. In later stages, however, apelin is found to aggravate the complications of diabetes by causing endothelial dysfunction and microangiopathic changes.

The aim of our study was to assess apelin levels in patients with type II DM. Our primary objective was to find an association between serum apelin levels and insulin resistance. Secondary objectives were to find an association between serum apelin levels and the control and duration of diabetes, and also the micro- and macrovascular complications of type II DM.

The study was conducted among the Indian population in view of the massive prevalence of type II DM in India. A total of 60 patients were selected after applying the inclusion and exclusion criteria. A detailed history was taken for the duration and complications of diabetes, and samples were drawn for fasting and postprandial blood sugar levels, HbA1c, LFT (liver function test) and KFT (kidney function test), lipid profile, serum fasting insulin levels, and serum apelin levels. Urine albumin assessment by dipstick and UACR (urine albumin-creatinine ratio) and fundus examination were also done.

The study found significantly high levels of serum apelin among the subjects. It also found significant associations between serum apelin levels and HOMA-IR (homeostatic model assessment for insulin resistance) and fasting blood sugar levels. Apelin levels were also found to be higher in patients with macro- and microvascular complications.