BOSTON (Reuters) - Long-acting insulin works better than other types of injections for people who need more than pills for their type 2 diabetes, researchers reported on on Thursday.

Long-acting Levemir insulin, given at bedtime, and NovoRapid insulin injections, given three times a day before meals, controlled insulin levels best in patients not doing well with the daily pills alone, the study found.

They were compared to results with twice-daily injections of NovoMix 30 in diabetes patients taking the pills metformin and sulfonylurea.

Drugmaker Novo Nordisk sponsored the trial of diabetes patients in Britain and Ireland and made all the insulin products tested.

The goal was to bring glycated hemoglobin levels — a measure known as a1c — down to 6.5 percent. This gives doctors an idea of insulin levels over the long term.

Dr Rury Holman of the Oxford Centre for Diabetes, Endocrinology and Metabolism in Britain and colleagues watched their 708 patients for three years.

Most did need extra insulin to control their diabetes — ultimately, 68 percent to 82 percent of the patients needed to added a second type of insulin to keep their blood sugar low.

The long-acting insulin helped about 45 percent of the patients, while only 32 percent of those who got twice-daily shots of NovoMix 30 controlled their insulin well, the researchers reported in the New England Journal of Medicine.

But the patients who got the three insulin injections a day were more likely to gain weight and more than three times as likely to have an episode where their blood sugar dipped too low, compared to those who took the long-acting insulin, the researchers found.

Potentially dangerous hypoglycemia incidents were nearly doubled among patients who received the twice-daily injections.