Patients with Diabetes Face Higher Risk for Left-sided Valvular Stenotic Lesions

Patients with diabetes face a significantly increased risk of disease in left-sided heart valves compared to controls without diabetes, according to a new comprehensive register study published in the journal Circulation.

“This study adds to the notion that cardiovascular disease epidemiology is shifting with less cardiovascular disease and more valvular heart disease,” wrote study authors led by Aidin Rawshani, MD, PhD, of the University of Gothenburg in Sweden. “Patients with diabetes are at higher risk than those without diabetes for left sided valvular stenosis, whereas risk for valvular regurgitation was lower, compared with matched controls.”

Rawshani and colleagues aimed to examine the long-term trends (between 2001 and 2019) for left-sided degenerative valvular heart disease, in a large cohort of patients with type 1 diabetes (T1D, n=36 211) and type 2 diabetes (T2D, n=678 932) from the Swedish National Diabetes Registry, compared with 2 732 333 controls from the general population matched on age, sex and county of residence. The mean age of patients with T1D was 32 years and 64 years for those with T2D.

Investigators analyzed trends with incidence rates and Cox regression, which was also used to assess diabetes as a risk factor compared to controls, and second, separately in patients with diabetes according to the presence of the following 5 risk factors:

  • HbA1c (≥7.0%)
  • Systolic and diastolic blood pressure (either ≥130 mmHg systolic or ≥80 mmHg diastolic)
  • Albuminuria (presence of microalbuminuria or macroalbuminuria)
  • Smoking (being a “current smoker” at baseline)
  • LDL-C (≥2.5 mmol/L)

Results showed that patients with T1D and T2D were at an increased risk of developing valve disease, and for those with T2D, the risk of aortic stenosis was 1.62-times higher than for controls and risk of mitral stenosis was 2.3-times higher.

For patients with T1D, the risk of aortic stenosis and mitral stenosis was 2.59-times and 11.43-times higher, respectivley, than for controls.

Risk of mitral regurgitation among participants with T1D vs controls was found to be 1.38-times higher. Among patients with T2D, however, the risks of aortic- and mitral regurgitation were 19% and 5% lower, respectively, compared with controls. While this finding could be interpreted as a protective effect, Rawshani warned it is presumably not.

“The lower risk of primary regurgitation, or leakage, in type 2 diabetes is also caused by the presumed process of hardening and calcification that’s started by, for instance, high blood pressure, impaired blood-sugar metabolism, and factors linked to obesity. As we age, the hardening process in the heart occurs in all of us — even in individuals without diabetes — but we assume that diabetes accelerates it,” said Rawshani in a university press release.

Patients with diabetes vs controls with values for most of the 5 risk factors within guideline target ranges continued to display higher risk of stenotic lesions. The team also found that systolic blood pressure, body mass index, and renal function were strongly associated with increased prevalence of valvular lesions.

“In general, diabetes was associated with higher risk for left-sided valvular stenotic lesions, but significantly lower risk for valvular regurgitation, warranting further clinical and basic research,” stated Rawshani et al.