NEW YORK (Reuters Health) - When anti-diabetes pills no longer keep blood sugar levels down for people with type 2 diabetes, it is usual to add insulin therapy -- and for most this will mean using more than one type of insulin, a new study suggests.

The study involved 708 patients with hemoglobin A1c levels between 7% and 10% despite taking maximal doses of oral agents. A1c is an indicator of blood glucose levels over the long term, and should be below 7%.

The patients were assigned to receive different types of insulin in one of three regimens: biphasic insulin, which gives a rapid peak of insulin and a lower peak several hours later, injected twice daily; prandial insulin, administered with meals three times daily; or basal insulin, which gives a relatively steady background level of insulin throughout the day, administered once daily or twice if needed.

The results were released online last Friday by the New England Journal of Medicine.

Dr. Rury R. Holman, from the University of Oxford in the UK, and colleagues found that after a year the prandial insulin regimen was better than the others at achieving A1c levels of 6.5% or less. That said, fewer than 1 in 4 people treated with the regimen achieved this goal.

Moreover, this regimen was more than twice as likely as the others to cause hypoglycemia -- excessively low blood sugar -- and was associated with greater weight gain.

"Most patients are likely to need more than one type of insulin to achieve target glucose levels," the researchers state.

However, an editorial commentary says: "Deciding among the various strategies for insulin initiation is probably less important than taking steps to start insulin in patients who need it."

SOURCE: New England Journal of Medicine for October 25, online September 23, 2007.