"Kidney disease is a major lethal complication for people with diabetes, particularly those with type 1 diabetes, and until now there has been no clear explanation for its cause beyond blood sugar itself," said principal investigator Trevor Orchard, M.D., professor and acting chair, department of epidemiology, GSPH. "We now suspect that reducing or preventing insulin resistance, possibly through exercise, weight loss and drugs, may help people with type 1 diabetes avoid nephropathy."
The study analyzed data from the Pittsburgh Epidemiology of Diabetes Complication Study (PEDCS), a 10-year prospective investigation based on a cohort of adults with type 1, or childhood-onset, diabetes. Of the 658 subjects in PEDCS, 485 did not have nephropathy at baseline and were followed for the current study.
Fifty-six of the 485 subjects developed nephropathy during either the first five years of follow-up, or during years 6-10. Researchers found that in all cases, strong relationships existed between nephropathy and insulin resistance throughout follow up, unlike other risk factors such as blood pressure and blood fats, which only predicted nephropathy in the short term.
To measure insulin resistance, investigators used a novel calculation based on waist-to-hip ratio, hypertension status and long-term blood sugar levels.
"Although our measure of insulin resistance is an estimate based on easier-to-measure factors, it is strongly correlated with the gold standard euglycemic clamp studies and clearly stands out as the leading p
Contact: Kathryn Duda
University of Pittsburgh Medical Center