Insulin resistance is increased in adult patients with dermatomyositis

OBJECTIVE: To evaluate insulinemia in glucocorticoid naïve patients with dermatomyositis and to evaluate insulin resistance using the homeostatic model assessment of insulin resistance (HOMA2-IR). METHODS: This cross-sectional study included 25 dermatomyositis, non-diabetic glucocorticoid naïve patients. The control group consisted of 50 volunteers matched for age, gender, ethnicity, weight and height. The HOMA2IR index was calculated from baseline insulin and glucose data. The International Myositis Assessment & Clinical Studies Group (IMACS) parameters were used to evaluate disease status. RESULTS: Mean age of the patients was 43.5 years and these were predominantly females. Patients had low disease activity according to IMACS parameters. Higher body mass index and waist circumference were observed in the dermatomyositis group compared to the control group. Insulin level and HOMA2-IR were also higher in patients with dermatomyositis. Moreover, analyzing dermatomyositis alone, the HOMA2-IR index correlated positively with weight, body mass index and waist circumference and was independent on disease status parameters. CONCLUSIONS: Patients with dermatomyositis had higher values for basal insulinemia, insulin resistance, body mass index and waist circumference. Moreover, HOMA2-IR moderately correlated with these anthropometric parameters. These metabolic abnormalities are related to the development of metabolic syndrome, one of the main comorbidities observed in dermatomyositis.