Adult-onset dermatomyositis is associated with an increased prevalence of diabetes mellitus independent of glucocorticoid use

Background Much of the evidence for a high prevalence of diabetes mellitus in dermatomyositis comes from studies of juvenile-onset dermatomyositis patients. Also, glucocorticoid therapy may confound diabetes risk. Our study evaluated the prevalence of diabetes in adult-onset dermatomyositis, independent of glucocorticoid exposure, identified associated risk factors, and compared diabetes prevalence with that of a matched control population. Methods Our institutional database was queried to identify patients with adult-onset dermatomyositis using ICD-9 and ICD-10 codes over a 15-year study period (January 1, 2007 - December 31, 2021). Retrospective chart review identified diabetes using American Diabetes Association criteria and assessed the temporal relationship among adult-onset dermatomyositis diagnosis, diabetes onset, and glucocorticoid initiation. A contemporaneous non-dermatomyositis control cohort was identified. Propensity score matching at a 1:2 ratio was performed based on age, sex, body mass index, race, smoking status, hypertension, and dyslipidemia. Diabetes risk factors were identified using logistic regression. Results The adult-onset dermatomyositis cohort included 434 patients with a median age of 64 years. Diabetes was present in 23.6% of adult-onset dermatomyositis patients compared with 10.5% of matched controls (p < 0.001). Over half of diabetes diagnoses occurred before glucocorticoid initiation. Among patients with adult-onset dermatomyositis, higher body mass index, hypertension, and dyslipidemia were significantly associated with diabetes, whereas myositis-specific and associated antibodies were not. Adult-onset dermatomyositis was independently associated with increased odds of diabetes compared with matched controls (odds ratio 1.06; p = 0.008). Conclusion Adult-onset dermatomyositis is associated with a significantly higher prevalence of diabetes independent of glucocorticoid exposure, supporting the need for early cardiometabolic screening in this population. Funding None .