Infective endocarditis according to type 2 diabetes mellitus status: an observational study in Spain, 2001–2015

The main aims of this study were to describe trends and outcomes during admission for infective endocarditis (IE) in people ≥ 40 years old with or without type 2 diabetes distributed in five time-periods (2001–2003; 2004–2006; 2007–2009; 2010–2012 and 2013–2015), using Spanish national hospital discharge data.

We estimated admission rates by diabetes status. We analyzed comorbidity, therapeutic procedures, and outcomes. We built Poisson regression models to compare the adjusted time-trends in admission rates. Type 2 diabetes cases were matched with controls using propensity score matching (PSM). We tested in-hospital mortality (IHM) in logistic regression analyses.

We identified 16,626 hospitalizations in patients aged ≥ 40 years for IE in Spain, 2001–2015. The incidence of IE increased significantly from 6.0/100,000 per year to 13.1/100,000 per year (p < 0.001) in the population with type 2 diabetes, and from 3.9/100,000 per year to 5.5/100,000 per year (p < 0.001) in the population without diabetes, over the study period. The adjusted incidence of IE was 2.2-times higher among patients with diabetes than among those without diabetes (IRR = 2.2; 95% CI 2.1–2.3). People with type 2 diabetes less often underwent heart valve surgery than people without diabetes (13.9% vs. 17.3%; p < 0.001). Although IHM decreased significantly in both groups over time, it represented 20.8% of IE cases among diabetes patients and 19.9% among PSM matched controls (p = 0.337). Type 2 diabetes was not associated with a higher IHM in people admitted to the hospital for IE (OR = 1.1; 95% CI 0.9–1.2).

Incidence rates of IE in Spain, among those with and without T2DM, have increased during the period 2001–2015 with significantly higher incidence rates in the T2DM population. In our population based study and after PSM we found that T2DM was not a predictor of IHM in IE.