SAN DIEGO – Findings from a study of 12,725 new insulin users with type 2 diabetes mellitus (T2DM) show that those who did not take statins were slightly better able to control their blood sugar, but those who used the cholesterol-lowering drugs lived longer and had fewer cardiac events.
“It is clear that, in this high-risk population, the benefits of statins on cardiovascular outcomes outweigh the small adverse metabolic effects on glycemic control,” study lead author Uche Anyanwagu, MBBS, MSc, a graduate student and research fellow at the University of Nottingham (England), said in an interview about his data presented in a poster at the annual scientific sessions of the American Diabetes Association.
Uche Anyanwagu
However, “there remain great concerns about statins and their modest adverse effects on glucose and insulin metabolism in increasing the risk of new-onset diabetes or worsening glycemic control, especially in higher doses and with the more potent statins,” Dr. Anyanwagu said. “Very little is known about the relationship between statin use and glycemic control in patients with established T2DM.”
The study authors retrospectively analyzed medical records of 12,725 new insulin users with T2DM from a British primary care database. “The commencement of insulin represents a group of patients with T2DM with longer disease duration and more complex needs, many of whom have other comorbid illnesses,” Dr. Anyanwagu said.
The average age of the subjects was 58.6 years (standard deviation, 13.8), and 50% were female (P less than 0.001 for both). Their average HbA1c level was 8.7 (SD, 1.8; P = .556), and 63% were obese.
The numbers of statin users and nonstatin users were 10,682 and 2,043, respectively. Researchers found that the statin users performed better in measures of all-cause mortality, nonfatal stroke, and a composite outcome measure but not in acute myocardial infarction.
In all-cause mortality, the absolute rate over 5 years was 9.5 deaths per 1,000 person years (95% confidence interval, 8.7-10.5) for statin users and 24.9 (95% CI, 21.5-28.9) for nonusers. After adjustment for age, gender, duration of insulin use, albumin, glomerular filtration rate, lipid profile, and coronary heart disease, the hazard ratio was 1.89 (95% CI, 1.51-2.37) for nonusers, compared with a reference of 1 for users. (P less than .0001).
The absolute rate for a composite outcome – encompassing measures of all-cause mortality, nonfatal acute myocardial infarction, and nonfatal stroke – was 20.7 (95% CI, 19.3-22.1) for statin users and 30.9 (95% CI , 27-35.3) for nonusers (P less than .0001).
As for HbA1c levels, at 12 months, they’d fallen by an average of 0.29% in the statin group and 0.37% in the nonuser group (P = .021). At 36 months, there was a smaller difference (–0.31% vs. –0.35%, respectively), and it wasn’t statistically significant (P = .344).
The study was funded by the University of Nottingham. (England). Dr. Anyanwagu reports no relevant disclosures.