Older type 2 diabetics may benefit from insulin glargine

Patients with type 2 diabetes over the age of 65 years may achieve betterhemoglobin A_1c (HbA_1c) lowering with insulin glarginetreatment added to oral hypoglycemic agents than with the combination of NPH insulinand oral agents, according to results of a study presented by Pearl Lee, MD, Universityof Michigan, Ann Arbor.

"Nearly a quarter of all Americans age 60 or older have diabetes mellitus, andhypoglycemia is a deterrent to the use of insulin in older adults with type 2diabetes," the researchers say. "We hypothesized that by treating patients poorlycontrolled on oral hypoglycemic agents alone with insulin glargine, that it would besimilarly effective as NPH insulin but safer."

Dr. Lee pooled data from 22 randomized, clinical trials in which all patientswere insulin-naive at baseline and then treated with basal insulin for 24 weeks.Data from four randomized, clinical trials comparing the safety and efficacy of theaddition of NPH insulin or insulin glargine to oral hypoglycemic agents were alsoanalyzed. Results compared HbA_1c reduction and hypoglycemic eventsdefined as self-monitored blood glucose <70 mg/dL with symptoms. Severehypoglycemia was an event with blood glucose <50 mg/dL requiring the assistanceof another person or a glucose level <56 mg/dL requiring oral carbohydrate,intravenous glucose, or glucagon administration.

Dr. Lee reports that there were no significant differences in HbA_1clowering or incidence of hypoglycemia among clinical trial patients age 65 years oryounger regardless of type of insulin treatment. However, those over age 65 hadsignificantly higher HbA_1c reductions with insulin glargine treatmentversus NPH insulin (1.21% vs 0.99%; p<0.05). Dr. Lee says significantlylower fasting glucose levels were also observed in the insulin glargine group.

There was no significant difference in either symptomatic hypoglycemic events orsevere hypoglycemic events between patients using different types of insulin.However, nocturnal hypoglycemia rates were significantly lower with insulin glargineversus NPH insulin, with 1.3 versus 2.7 average number of incidents per patient yearamong those older than 65 years (p<0.005). Dr. Lee notes that nocturnalhypoglycemia incidents were more significantly lowered with insulin glargine use inpatients under age 65 (p<0.0001).