Three recent studies investigated the association between type 2 diabetes and heart failure.
The first study, published by Diabetologia on Aug. 9, used the Swedish National Diabetes Registry to compare risk of heart failure between people with and without type 2 diabetes. More than 200,000 patients with type 2 diabetes were matched to 1.3 million controls. Among those younger than age 55 years, the risk of hospitalization for heart failure was significantly increased with diabetes (hazard ratios [HRs], 2.07 for men [95% CI, 1.73 to 2.48] and 4.59 for women [95% CI, 3.50 to 6.02]). Younger age, worse glycemic control, and deteriorating renal function were associated with higher risk of heart failure. However, patients ages 75 years and older with diabetes but no albuminuria and good glycemic control (HbA1c ≤6.9%) had similar risk of heart failure as similar-aged controls. The results reveal a marked excess risk for heart failure associated with type 2 diabetes in men and women under age 55 years, which suggests that “diabetes could contribute increasingly to the global burden of early-onset heart failure,” the authors concluded.
The second study, published by Diabetes, Obesity and Metabolism on Aug. 8, used Taiwan's National Health Insurance system to analyze the same issue: hospitalizations for heart failure were compared in 34,291 patients with type 2 diabetes and an equal number of control patients. Diabetes was associated with a significantly increased risk of heart failure (adjusted HR, 1.47; 95% CI, 1.40 to 1.54), particularly in patients under age 45 years (adjusted HRs, 2.54 for men [95% CI, 1.62 to 3.98] and 4.12 for women [95% CI, 2.35 to 7.23]). In a comparison of only those without prior coronary heart disease, diabetes was again associated with significantly increased risk of heart failure (adjusted HRs, 1.54 in men and 1.56 in women). This increase in risk was similar to that associated with a history of heart disease in patients without diabetes (adjusted HRs, 1.60 in men and 1.55 in women), which supports the idea that diabetes is an equivalent risk factor to heart disease, the authors said.
The third study, published on Sept. 5 by JACC: Heart Failure, compared the effects of classes of glucose-lowering drugs on hospitalizations for heart failure. The systematic review and meta-analysis included nine studies involving 87,162 patients with type 2 diabetes that compared glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors, or sodium-glucose cotransporter-2 (SGLT2) inhibitors to placebo. The meta-analysis found SGLT2 inhibitors to provide the greatest reduction in heart failure risk compared to placebo (relative risk [RR], 0.56; 95% CrI, 0.43 to 0.72) as well as a significantly lower risk than GLP-1 agonists (RR, 0.59; 95% CrI, 0.43 to 0.79) and DPP-4 inhibitors (RR, 0.50; 95% CrI, 0.36 to 0.70). The results show that GLP-1 agonists and DPP-4 inhibitors have a neutral effect on heart failure and that SGLT2 inhibitors would be the preferred treatment for this outcome, the study authors said. The mechanism for the effect is unknown, but it may be due to acute effects on renal function or systemic hemodynamics or direct effects on cardiovascular physiology. An accompanying editorial comment noted that there is some evidence that glycemic control early in diabetes reduces heart failure risk but that drug choice may be a more effective preventive measure for patients with more established disease.