Higher prevalence of insulin resistance and non-alcoholic fatty liver disease in Asian-Indian men was linked to elevated levels of interleukin-6 (IL-6) in the plasma.
For the latest study, 482 young, lean, healthy and sedentary men and women underwent oral glucose tolerance tests.
These tests showed that insulin resistance, as defined by insulin sensitivity index (ISI), was two to three times more prevalent among Asian-Indians, at 2.38dl/min per units/ml, than other ethnic groups.
Participants also underwent magnetic resonance spectroscopy to measure intramyocellular lipid and hepatic triglyceride (HTG) levels and tests for levels of plasma IL-6.
This showed that, after adjustment for ISI, the insulin resistance in the Asian-Indian men was associated with a two-fold increase in HTG content and plasma IL-6 content. However, it remains to be determined whether or not the elevated levels of IL-6 are a cause or consequence of insulin resistance, said the researchers.
Compared with Caucasian men, Asian-Indians showed a 30 per cent higher rate of pancreatic beta-cell function.
Mark Thursz, professor of hepatology at Imperial College London, said that while Asian-Indian men are known to be at high risk of the metabolic syndrome, this study ‘is more definitive than anything we’ve had before. Fat cell metabolism and immunity are probably key in this’, he added.