Swedish adults with type 2 diabetes with five selected risk factor variables within the target range had only marginally higher risks for death, stroke and myocardial infarction vs. the overall population without diabetes, although excess risk for hospitalization for heart failure persisted, according to findings published in The New England Journal of Medicine.
“The extent to which the excess risk associated with type 2 diabetes may be mitigated, or potentially eliminated, by contemporary evidence-based treatment and multifactorial risk-factor modification is unclear,” Aidin Rawshani, MD, of the department of molecular and clinical medicine at Sahlgrenska Academy, Sweden, and colleagues wrote in the study background. “In a nationwide cohort, we evaluated the association between the excess risks of death and cardiovascular outcomes among patients with type 2 diabetes, according to the number of risk-factor variables within therapeutic guideline levels, as compared with controls who were matched for age, sex and county in Sweden.”
Rawshani and colleagues analyzed data from 271,174 adults with type 2 diabetes identified from the Swedish National Diabetes Register between 1998 and 2012 (mean age, 61 years; 49.4% women), each matched with five healthy age-, sex- and county-matched controls randomly selected from the Swedish Population Register (n = 1,355,870). Researchers stratified patients with diabetes into two groups: those without previous stroke, acute MI or amputation, no dialysis or renal transplant and a BMI of less than 18.5 kg/m², and a second cohort that additionally excluded patients with previous coronary heart disease, atrial fibrillation or heart failure. Researchers assessed death from any cause, fatal or nonfatal acute MI, fatal or nonfatal stroke and hospitalization for heart failure identified in hospital discharge records. Researchers followed patients until an event occurred or until December 2013, apart from all-cause death, for which follow-up ended in December 2014 (median follow-up, 5.7 years). Researchers used Cox regression analysis to study the excess risk for outcomes associated with smoking and the number of variables outside target ranges, as well as the relationship between various risk factors and CV outcomes.
During follow-up, researchers observed 175,345 deaths, including 37,825 patients with diabetes (13.9%) and 137,520 controls (10.1%).
In patients with type 2 diabetes, researchers observed a stepwise decrease in excess risk for outcomes for each risk factor variable that was within the target range. Patients with all five variables within target ranges had an HR of 1.06 for death from any cause (95% CI, 1-1.12), whereas HR for acute MI was 0.84 (95% CI, 0.75-0.93) and HR for stroke was 0.95 (95% CI, 0.84-1.07).
Risk for hospitalization for heart failure was higher among patients with diabetes vs. controls (HR = 1.45; 95% CI, 1.34-1.57).
The researchers found that an HbA1c outside the target range was the greatest predictor of stroke and acute MI in patients with diabetes, whereas smoking was the strongest predictor of death in these patients, according to the researchers.
“The study indicates that having all five risk-factor variables within the target ranges could theoretically eliminate the excess risk of acute myocardial infarction,” the researchers wrote. “However, there was a substantial excess risk of hospitalization for heart failure among patients who had all variables within target ranges.”
The researchers also noted that they identified a monotonic relationship among younger age, increasing number of variables not in the target range and a higher relative risk of adverse CV events.
“The results suggest that there may be greater potential gains from more aggressive treatment in younger patients with diabetes,” the researchers wrote. – by Regina Schaffer
Disclosures: The authors report no relevant financial disclosures.