The long-acting insulin glargine (Lantus, Sanofi Aventis, Bridgewater, NJ) has lipid-lowering effects that investigators believe are independent of its effect on blood sugar, according to results of two trials presented at the 67th Scientific Sessions of the American Diabetes Association in Chicago.
Dr. Sherwyn Schwartz of the Diabetes and Glandular Disease Clinic of San Antonio, TX, reported on 165 type 2 diabetics assigned to glargine therapy and 182 patients to a thiazolidinediones plus pioglitazone add-on therapy for 24 weeks.
Hemoglobin A1c levels were significantly lower in the glargine group compared with the pioglitazone group.
"There was a much more favorable lipid pattern in the glargine group than in those on thiazolidinediones," Dr. Schwartz told Reuters Health. "The worse the A1c level, the better the lipid-lowering effect. The biggest changes were seen in those with baseline A1c levels above 8.7%"
Glargine's effect on triglycerides was small but slightly greater compared with pioglitazone. Patients taking thiazolidinediones had greater increases in HDL cholesterol.
"Overall, [the effect on] LDL cholesterol was where the action was," Dr. Schwartz said. "I think the effect on free fatty acids is independent of its effect on blood sugar."
Dr. Janet McGill, of Washington University School of Medicine in St. Louis, presented similar findings of the changes in lipid variables in 129 poorly controlled type 2 diabetics randomized to glargine as add-on therapy to metformin or sulfonylurea compared with 130 patients taking pioglitazone as add-on therapy.
Free fatty acids decreased an average of 0.6 mmol/l more with glargine than pioglitazone. The largest effects with glargine on free fatty acids were in patients taking a sulfonylurea, and the greatest effects were seen in the most poorly controlled diabetics at baseline. There was a drop of approximately 0.5 to 0.6 mmol/l in triglycerides.
"Metformin is pretty good at controlling lipids. Our findings lend credence to the use of insulin early in type 2 diabetes," Dr. McGill told Reuters Health.
"Insulin therapy should not be delayed. In addition to lowering blood glucose, it has a number of useful ancillary benefits, including a direct effect on lipids," she said.
"This is one more brick in the house of diabetes management."