NEW YORK, July 26 (Praxis Press) Regular physical activity is independently associated with a reduction in the risk of major coronary heart disease (CHD) events and type 2 diabetes. However, few prospective studies have investigated the role of insulin as a mediating factor in the relationship between physical activity and CHD or type 2 diabetes. To examine this relationship, Wannamethee and colleagues performed a prospective study of 5,159 men aged 40 to 59 years with no history of CHD, type 2 diabetes, or stroke and measured various physical, biochemical and hematological variables in these men. During an average follow-up period of 16.8 years, there were 616 cases of major CHD events (fatal and nonfatal) and 196 incident cases of type 2 diabetes. They found that the relationship between physical activity and type 2 diabetes appeared to be mediated by serum true insulin level and components of the insulin...