Risk Of Heart Failure In Type 2 Diabetes Has Decreased Over Time - A Danish Nationwide Cohort Study

Introduction: Although type 2 diabetes (T2DM) is one of the strongest risk factors for heart failure (HF), there is limited data on contemporary lifetime risk estimates in this segment. Incident HF appears to be decreasing in the general population, but little is known how the risk has changed over time in patients with T2DM. The increasing prevalence and rapidly evolving management of T2DM has furthered interest in the epidemiological relationship between HF and T2DM. We therefore sought to investigate the lifetime risk of HF in people with T2DM and how the long term risk of HF has changed over time in patients with T2DM. Hypothesis: We assessed the hypothesis that there would be a statistically significant reduction in the ten- year risk of HF among patients with T2DM over time in all age groups except the youngest (<50 years old), mimicking trends in the general population and that men would have a higher cumulative risk than women. Methods: We employed the Danish nationwide databases which included information on all Danish citizens’ hospitalizations, outpatient visits, and medication use since 1978 (diagnoses) and 1995 (medications). Using this data, we calculated the cumulative incidence of HF among patients with T2DM who were free from HF at age 30, 40, 50, 60, and 70 years, respectively. We censored people at time of emigration or at Dec 31, 2017 and we used Aalen-Johnsen estimators to adjust for the competing risk of death. Results: A total of 473,685 patients (47% women) had a diagnosis of T2DM between Jan 1, 1995 and Dec 31, 2017. Of those who were free from HF before T2DM onset, 21,030 were diagnosed before the age of 30; 33,786 before age 40; 55,537 before 50 years of age; 85,108 before age 60; and 98,631 before age 70. During follow-up, 48,026 (10%) were diagnosed with HF and 133,561 were censored for death. The cumulative life-time risk of developing HF among people with diabetes at age 50 was 24% (95% CI 21-27%) in females and 27% (25-29%) in men, p for difference <0.0001. Among patients aged 50 years, the 10-year risk of HF decreased from 12.2% (1995-2005) to 9.6% (2005- 2015), p<0.0001. Similar 10-year risks decreased for those free from HF at age 60 year (from 19.0% in 1995-2005 to 13.3% in 2005-2015, p<0.0001) and 70 years old (from 22.2% to 17.1% between 1995-2005 and 2005-2015, p<0.0001). Conclusion: The lifetime risk of HF among patients with T2DM exceeds 1 in 4 for both men and women. There was, however, a decrease in ten-year cumulative incidence of HF over time among patients with T2DM in all age groups.