Diabetes Health Center

Type 2 Diabetes: How to Start Insulin

Oct. 24, 2007 -- Do you have type 2 diabetes and need to start taking insulin? Scientists have new insights on how you should do so.

Taking insulin once daily at bedtime may be a first step, with fewer risks than other insulin-dosing strategies, a new study shows.

Those findings are preliminary, so patients should ask their doctors what they recommend.

But diabetes experts are certain of this: Get your hemoglobin A1c below 7% to cut your risk of heart attack, stroke, and other diabetes complications -- and if that means taking insulin, so be it.

What Is Hemoglobin A1c?

Your hemoglobin A1c number shows how well your blood sugar has been controlled for the past two to three months. The goal for hemoglobin A1c should be less than 7%.

If type 2 diabetes patients can't reach that goal with a healthy lifestyle and oral medications, they may need to start giving themselves insulin shots.

The new study included some 700 type 2 diabetes patients in the U.K. and Ireland.

The patients were taking the maximum dose of the oral drug metformin (sold generically and as Glucophage) and a class of diabetes pills called sulfonylureas, which include Glucotrol, Glucotrol XL, DiaBeta, Micronase, Glynase PresTab, Amaryl, Dymelor, Diabinese, Orinase, and Tolinase,

But despite taking those diabetes drugs, the patients' hemoglobin A1c levels were still too high, measuring 7% to 10%.

Insulin for Type 2 Diabetes

All of the patients started taking insulin, but they took it in one of three different ways:

• Twice daily
• Three times daily with meals
• Once daily at bedtime

After taking insulin for a year, some of the patients met their hemoglobin A1c goal.

That goal was met by 17% of the patients taking insulin twice daily, nearly a quarter of those taking insulin with meals, and 8% of those taking insulin once daily at bedtime.

Once-Daily Insulin

There was a fine line to tread with insulin to avoid dangerously low blood sugar (hypoglycemia) and weight gain.

The patients who took insulin once daily at bedtime were the least likely to gain weight or have hypoglycemia during their first year of taking insulin.

The study still has two more years to go.

But based on the first year's results, once-daily insulin may be an appropriate first step, though insulin doses may need tweaking later, according to the researchers.

They included Rury Holman, MB, ChB, FRCP, of Oxford University's Diabetes Trial Unit.

Why didn't more patients meet the hemoglobin A1c goal? A journal editorial suggests two possibilities:

• Insulin doses may not have been perfect during the study's first year.
• The patients may have needed more help in making healthy lifestyle changes.

Graham McMahon, MD, MMSc, and Robert Luhy, MD, wrote the editorial. They're editors at The New England Journal of Medicine.

The study was funded by Novo Nordisk, which also provided the insulin drugs. Holman and several colleagues report ties to drug companies including Novo Nordisk.

The editorialists note no potential conflicts of interest.