More About the Science Behind Diabesity

Obesity is characterized by elevated fasting plasma insulin and an exaggerated insulin response to an oral glucose load. Overall fatness and the distribution of body fat influence glucose metabolism through independent but additive mechanisms. Increasing upper body obesity is accompanied by a progressive increase in the glucose and insulin response to an oral glucose challenge with a positive correlation being observed between increasing upper body obesity and measures of insulin resistance. Post-hepatic insulin delivery is increased in upper body obesity leading to more marked peripheral insulin concentrations that, in turn, lead to peripheral insulin resistance.

• 90% of all cases of NIDDM (Non-Insulin Dependent Diabetes Mellitus) are characterized by initial insulin resistance and hyperinsulinemia with secondary beta cell failure.
  
  
• Numerous cross-sectional and retrospective studies show that obesity is associated with NIDDM prevalence. Also, more rigorous prospective studies show consistently higher incidence of NIDDM in obese persons than in thinner persons in diverse populations, such as U.S. non-Hispanic and Hispanic whites, Israelis, Sedes, Nauruans, and Pima Indians.
  
  
• Total body adiposity has been recognized as being associated with diabetes for a very long time.
  
  
• Prospective populations studies confirm a close association between increasing body fatness and type 2 diabetes. In the Nurses Cohort Study, BMI (body mass index) was the dominant predictor of the risk of diabetes after adjustment for age. The risk of diabetes increased fivefold for those with a BMI of 25, 28-fold for those with BMI of 30, and 93-fold for those women with a BMI of 35 or greater, compared with women with a BMI of less than 21.
  
  
• The number of individuals with undiagnosed NIDDM is equal to those diagnosed. The high prevalence of undiagnosed NIDDM indicates there must be a considerable preclinical phase for the disease, although this may not be an entirely asymptomatic period. Based on extrapolation of data on the prevalence of retinopathy, it has been estimated that onset of NIDDM may occur as long as 10-12 years before clinical diagnosis.
  
  
• Undiagnosed NIDDM individuals have high risk for diabetes (50% of men and 82% of women exceeding 120% of desirable weight).