Myocardial extracellular volume expansion in type 2 diabetes is associated with ischemic heart disease, autonomic neuropathy, and active smoking

OBJECTIVE Myocardial interstitial fibrosis expands the extracellular volume (ECV) and is in patients with type 2 diabetes implicated in the development of heart failure. ECV can be determined with gadolinium-contrast magnetic resonance imaging. We investigated which known risk factors for cardiovascular disease were associated with increased ECV in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS 296 patients with type 2 diabetes and 25 sex and age-matched controls were included in a cross-sectional magnetic resonance imaging study. The influence of risk factors on ECV was investigated by multiple regression analysis.

RESULTS Controls and patients with type 2 diabetes without complications had similar ECV (27.4±2.1% vs 27.9±2.6%, p=0.4). Compared to patients without, ECV was significantly increased in patients with 1≥ complication (29.0±3.3%, p=0.02). Both in univariable analysis and after multivariable adjustment, ischemic heart disease, autonomic neuropathy, and active smoking were associated with increased levels of ECV. Active smoking exhibited the largest effect size (ß=2.0%-point 95% CI 0.7 to 3.3). Former smokers had similar ECV as never-smokers. Albuminuria and systolic blood pressure were inversely associated with ECV in multivariable analysis, but after adjustment for medication suspected to affect ECV, the association with albuminuria was no longer significant (p=0.1). SGLT2i treatment was not significantly associated with reduced ECV (-0.8% 95%CI -1.7 to 0.06, p=0.067).

CONCLUSION Patients with complications of diabetes have increased ECV not seen in patients without complications. Ischemic heart disease, autonomic neuropathy, and active but not former smoking was highly associated with increased ECV.