Abstract

Objective: Insulin resistance (IR) is greater in racial/ethnic minorities than in non-Hispanic whites (NHW) for those with and without type 2 diabetes. Because previous research on IR in type 1 diabetes was limited to NHW, racial/ethnic variation in an estimated measure of IR in type 1 diabetes was determined.

Research Design and Methods: The sample includes 79 type 1 diabetes individuals diagnosed <18 years old [NHW=32.9%, non-Hispanic black (NHB)=46.8%, Other/Mixed=7.6%, Hispanic=12.7%] and their families. Estimated glucose disposal rate [eGDR (mg kg⁻¹ min⁻¹); lower eGDR=greater IR] was calculated using HbA1c, waist circumference, and hypertension status.

Results: Mean current age and diabetes duration were 13.5 (range: 3.2-32.5) and 5.7 (0.1-19.9) years, respectively. eGDR was inversely associated with age. Compared to NHW, age-adjusted eGDR was significantly lower among non-whites (NHB, Other/Mixed, and Hispanic; □□−1.83, P=0.0006). Age-adjusted eGDR was negatively associated with bodyfat, triglycerides, urinary albumin/creatinine, acanthosis nigricans, parental obesity, and parental IR, and positively related to HDL and sex hormone-binding globulin. In multivariable analysis, lower eGDR was significantly associated with older age, non-white race/ethnicity, acanthosis, and lower HDL.

Conclusions: Minorities with type 1 diabetes are significantly more IR, as measured by eGDR, than NHW. Exploring potential mechanisms, including disparities in care and/or physiological variation, may contribute to preventing racial/ethnic differences in IR-associated outcomes.