Abstract

Objective: The metabolic syndrome (MS) has been shown to confer an increased risk of cardiovascular disease in both the general and type 2 diabetes populations, but few studies have assessed MS in type 1 diabetes. In a type 1 diabetes cohort, we assessed the prevalence and value of MS in improving the prediction of major complication outcomes compared to its components and a surrogate measure of insulin resistance (eGDR).

Research Design and Methods: A total of 514 (78%) subjects participating in the Pittsburgh Epidemiology of Diabetes Complications Study with complete 12 year follow-up clinical data were classified by baseline MS status according to three definitions: NCEP ATP III (AHA modified), International Diabetes Federation (IDF) and the World Health Organization (WHO). The complication outcomes included Coronary Artery Disease, Renal Failure, diabetes-related death, and the aggregate of these three Major Outcomes of Diabetes (MOD).

Results: MS prevalence ranged from 8% (IDF) to 21% (WHO). All definitions showed reasonable specificity (≥83%) for each outcome, while the WHO definition had the highest sensitivity for all outcomes except Renal Failure, for which eGDR was most sensitive. However, the components of each definition predicted better than the overall syndrome. Microalbuminuria was clearly the strongest predictor of all individual measures, yielding a HR of 9 and 6 respectively for mortality and MOD.

Conclusions: Though the three MS classifications predict major complication outcomes in type 1 diabetes, their individual components predict better. Of the variables studied, including HbA1, microalbuminuria appears to be the best single predictor of MOD.