Adipocytokines and the expanding 'Asian Indian Phenotype'.

expenditure. 13 In addition to adipocytokines, pro-inflammatory markers like tumour necrosis factor-α [TNF-α] inhibit insulin signaling in human adipocytes, 14 enhance insulin resistance and increase the risk for diabetes. Recent reports show that Indians have low levels of adiponectin compared to their Caucasian counterparts. 15 In this issue of JAPI, Lele and Joshi 16 report on interesting new information on the relation of adipocytokines with diabetes in urban western Indians. They show that adiponectin and leptin have a reciprocal association with diabetes. In a south Indian population, we showed that low adiponectin levels are associated with hypertriglyceridemia, low HDL cholesterol, insulin resistance and other components of the metabolic syndrome. 17 As low levels of adiponectin have been demonstrated in migrant Indians, one could speculate that this could be one of the mechanisms for the increased diabetic tendency observed in Indians. It is of interest that in the study by Lele and Joshi, 16 leptin had a positive association with obesity indices but a negative association with diabetes. This has been earlier documented in Caucasians. 18 It is possible that adipocytokines secreted from different fat depots may have differential effects on diabetes. Another interesting observation in the study conducted by Lele and Joshi 16 is that proinsulin showed a positive association with diabetes and an inverse association with adiponectin. It is well known that compensatory hyperinsulinemia observed in pre-diabetic stage is followed by decreased insulin secretion. Indeed, at the time of clinical diagnosis of type 2 diabetes, only 50% of the beta cell function is present. 19 In this regard, the link between adiponectin and beta cell dysfunction shown in this study adds a new dimension to the pathophysiology of diabetes in Indians. Recent studies have shown increased levels of inflammatory markers like C-reactive protein in Indians compared to Caucasians. 20 It was also shown that in south Indians inflammatory markers are linked to diabetes and this link is probably mediated through body fat. 21 Though hsCRP, an inflammatory predictor for diabetes is associated with diabetes, TNF-α failed to show an association with diabetes in the study by Lele and Joshi. T he prevalence of diabetes in India is growing rapidly and recent studies have documented a 72% increase in the prevalence of diabetes in urban areas in the last 15 years. 1 Indeed, the number of subjects with diabetes in India is expected to double from the current figures of …