Appearance of leptin–HSP70 correlation, in type 2 diabetes☆

In vitro and in vivo studies have shown conflicting results regarding heat shock protein (HSP) and leptin correlation. More importantly both HSP70 and leptin are correlated with C reactive proteins. The purpose of the present study was to study the correlation between serum HSP70 and leptin levels in patients with type 2 diabetes stratified according to gender. We performed a cross sectional study on the established groups of patients with type 2 diabetes defined as 1: patients with long standing diabetes for more than 3 years; and 2: patients with newly diagnosed diabetes within recent 6 months who were not on any glucose lowering treatment other than by dietary means alone and 3: healthy controls. Patients with long standing diabetes had higher HSP70, HbA1c and triglyceride than controls. Serum leptin levels were significantly lower in patients with newly diagnosed diabetes. Women with type 2 diabetes had higher leptin levels compared to men, both before and after treatment. We showed a positive correlation between leptin and HSP70 levels in women with type 2 diabetes. The correlation was strongest in women with newly diagnosed diabetes (r = 0.59) and was attenuated in women who were on treatment (r = 0.3). The significance of this correlation was only observed in women with type 2 diabetes. There was no correlation between leptin and HSP70 in men. The positive correlation between leptin and HSP is observed in chronic inflammation such as type 2 diabetes. It could be hypothesized that the observed correlation between serum HSP70 and leptin implies a higher state of chronic inflammation.