VIENNA — Glycemic control was maintained over 5 years using metformin, sulfonylureas, and insulin almost exclusively in a longitudinal study of cholesterol lowering in 4,900 patients with type 2 diabetes.
The findings call into question the need for new diabetes drugs, especially now that increased emphasis is being placed on the safety of these agents, Dr. James Best said at the annual meeting of the European Association for the Study of Diabetes.
The finding comes from the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study, which investigated whether fenofibrate could reduce the risk of cardiovascular disease in patients with type 2 diabetes in Finland, Australia, and New Zealand (Lancet 2005;366:1849-61). FIELD failed in its primary end point, but because its design did not involve modifying any aspect of glycemic management, it offered a real-world opportunity to see what happened over time with standard care for diabetes, mainly in primary care settings.
The results suggest that diabetes control can be effectively maintained using the three oldest and least expensive classes of diabetes drugs, and challenges the prevailing belief that new types of glucose-lowering drugs are needed. “There's this background subtext that diabetes control inexorably deteriorates despite optimal therapy and therefore we need to find new drugs to treat this disease. My message is that we don't,” Dr. Best, professor of medicine and head of the school of medicine at the University of Melbourne, said in an interview.
At baseline, the study population had a mean age of 62 years and diabetes duration of 5 years. Just over a third were women. They were reasonably well controlled at baseline, with a median hemoglobin A1c of 6.9%, even though 26% were on no diabetes medications, 60% were on oral agents only, and just 14% were using insulin. Median body weight was 86.3 kg.
Over the subsequent 5 years, the median HbA1c rose slightly (0.22 percentage points), to just over 7.0%, while body weight fell slightly, to 85.0 kg. Oral hypoglycemic medication—nearly all metformin, sulfonylureas, or both—was initiated in 56% of the 1,287 who had been taking no medications at baseline, and insulin was started in 25% of the 2,917 who had not been taking it at baseline. Thus, at 5 years, 77% of patients were on oral agents and 28% were on insulin, but only 4% were on oral agents other than sulfonylureas or metformin, Dr. Best reported.
The 0.22 percentage-point increase in HbA1c seen in FIELD is in contrast to the 1.0 percentage-point rise that occurred in the landmark U.K. Prospective Diabetes Study (UKPDS), which is often cited as evidence for the inevitable decline in glucose control in patients with type 2 diabetes (Lancet 1998;352:837-53).
The findings support the new emphasis on cardiovascular safety that regulatory bodies are now imposing on all glucose-lowering drugs, following reports of adverse cardiovascular outcomes with the thiazolidinedione (TZD) rosiglitazone, Dr. Best said.
“I see much less urgency for new therapies. We need safety outcomes for new treatments, rather than just efficacy. The TZDs are a good example. They got to market before there was really safety data, on the grounds that glycemic control deteriorates with standard treatment and therefore we needed them. Now that we've seen the safety outcomes, their use should be much more limited than was thought initially.”
Dr. Best stated that he did not have any relevant financial disclosures.