Add-on sitagliptin more effective than increasing insulin dose
MedWire News: Adding sitagliptin to insulin therapy is more effective at improving glycemic control in patients with uncontrolled Type 2 diabetes than increasing insulin dose alone, report researchers.
In addition, the sitagliptin add-on regimen is associated with a lower incidence of hypoglycemia and more favorable effects on weight gain than insulin intensification, they say.
Soo Lim (Seoul National University College of Medicine, South Korea) and team conducted a 24-week study comparing the efficacy and tolerability of adding sitagliptin to insulin with that of increasing insulin dose in 124 patients with uncontrolled Type 2 diabetes (glycated hemoglobin [HbA1c] 7.5-11.0%). All patients had been receiving insulin injections for at least 3 months at a dose of at least 10 U/day and for a minimum of 4 weeks prior to enrollment.
The researchers randomly allocated the participants to receive treatment with either sitagliptin 100 mg daily or an up-to-20% increase in daily insulin dosage over a 24 week period. In addition to this 20% increase, individuals were allowed to adjust their insulin dose by 2 U every week, based on blood glucose self-monitoring. The patients were assessed at weeks 12 and 24 for changes from baseline in mean HbA1c and weight.
As reported in Diabetes, Obesity and Metabolism, the researchers found that the mean HbA1c reduction from baseline was significantly greater in the sitagliptin group than in the insulin-increasing group, decreasing by 0.52% and 0.63% versus 0.12% and 0.22% at weeks 12 and 24, respectively.
In addition, by week 24, the mean body weight and waist circumference had reduced by 0.7 kg and 0.8 cm, respectively, in the sitagliptin group, whereas they had increased in the insulin-increasing group, by 1.1 kg and 1.2 cm, respectively.
Furthermore, incidence rates of hypoglycemia and severe hypoglycemia were significantly lower in the sitagliptin group, at 7.02 and 0.88 per patient-year, respectively, than they were in the insulin-increasing group, at a corresponding14.29 and 2.81 events per patient-year.
Finally, the overall frequency of drug-related adverse events was not significantly different between the groups, reports the team.
The favorable side effect profile of sitagliptin add-on therapy as well as its beneficial effect on HbA1c compared with increased insulin therapy suggests this may be a beneficial regimen in particular individuals with uncontrolled diabetes, write Lim et al.
"This should be tested in a larger, long-term clinical trial," they conclude.
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By Sally Robertson