Left-Sided Degenerative Valvular Heart Disease in Type 1 and Type 2 Diabetes

Background: The role of diabetes in the development of valvular heart disease, and, in particular, the relation with risk factor control, has not been extensively studied. Methods: We included 715 143 patients with diabetes registered in the Swedish National Diabetes Register and compared them with 2 732 333 matched controls randomly selected from the general population. First, trends were analyzed with incidence rates and Cox regression, which was also used to assess diabetes as a risk factor compared with controls, and, second, separately in patients with diabetes according to the presence of 5 risk factors. Results: The incidence of valvular outcomes is increasing among patients with diabetes and the general population. In type 2 diabetes, systolic blood pressure, body mass index, and renal function were associated with valvular lesions. Hazard ratios for patients with type 2 diabetes who had nearly all risk factors within target ranges, compared with controls, were as follows: aortic stenosis 1.34 (95% CI, 1.31–1.38), aortic regurgitation 0.67 (95% CI, 0.64–0.70), mitral stenosis 1.95 (95% CI, 1.76–2.20), and mitral regurgitation 0.82 (95% CI, 0.79–0.85). Hazard ratios for patients with type 1 diabetes and nearly optimal risk factor control were as follows: aortic stenosis 2.01 (95% CI, 1.58–2.56), aortic regurgitation 0.63 (95% CI, 0.43–0.94), and mitral stenosis 3.47 (95% CI, 1.37–8.84). Excess risk in patients with type 2 diabetes for stenotic lesions showed hazard ratios for aortic stenosis 1.62 (95% CI, 1.59–1.65), mitral stenosis 2.28 (95% CI, 2.08–2.50), and excess risk in patients with type 1 diabetes showed hazard ratios of 2.59 (95% CI, 2.21–3.05) and 11.43 (95% CI, 6.18–21.15), respectively. Risk for aortic and mitral regurgitation was lower in type 2 diabetes: 0.81 (95% CI, 0.78–0.84) and 0.95 (95% CI, 0.92–0.98), respectively. Conclusions: Individuals with type 1 and 2 diabetes have greater risk for stenotic lesions, whereas risk for valvular regurgitation was lower in patients with type 2 diabetes. Patients with well-controlled cardiovascular risk factors continued to display higher risk for valvular stenosis, without a clear stepwise decrease in risk between various degrees of risk factor control.