Vascular complications remain a major source of morbidity in people with type 2 diabetes mellitus (T2DM) when metabolic comorbidities coexist. In Diabetes Therapy, a real-world cohort study evaluated the association between metabolic dysfunction-associated steatohepatitis (MASH) and vascular complications in adults with T2DM.

Eligible adults with T2DM were identified from a large administrative health care claims database between 2016 and 2024. The presence of MASH was defined using International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis codes, requiring at least one primary inpatient or outpatient code. Patients with T2DM and MASH were matched 1:1 with patients with T2DM without MASH using propensity score matching to balance baseline characteristics. Fine-Gray models were applied to estimate subdistribution hazard ratios (sHRs) for microvascular and macrovascular complications, accounting for death as a competing risk. Stratified analyses were performed by glycated hemoglobin (HbA1c) level and age.

The analysis included 7,396 matched pairs in the microvascular complications cohort and 6,207 matched pairs in the macrovascular complications cohort. Mean follow-up was 2.8 years (standard deviation [SD], 2.0) for patients with MASH and 2.4 years (SD, 1.8) for patients without MASH. Compared with patients with T2D without MASH, those with T2DM and MASH had higher hazards of microvascular complications (sHR, 1.19; 95% confidence interval [CI], 1.12-1.26) and macrovascular complications (sHR, 1.15; 95% CI, 1.08-1.23). Similar associations were observed in subgroup analyses stratified by age and glycemic control.

These findings show that coexisting MASH was associated with a higher risk of vascular complications in patients with T2DM.