Glucose testing challenged among diabetics who don't use insulin

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Frequent self-monitoring of blood-glucose levels - which is commonplace among diabetics - actually provides little practical benefit to most patients who do not use insulin, a new study shows.

Drugs plans could save hundreds of millions of dollars by reducing coverage for glucose test strips, a second research paper suggests.

Barb Shea, acting senior vice-president of science directorates at the Canadian Agency for Drugs and Technologies in Health, summed up the findings as follows:

"From a practical point of view, most people with Type 2 diabetes don't need to test their blood as often as they do now. It's not something that is improving their health to any degree," she said. "From a systems point of view, there are a lot of resources being spent on these tests that could be better spent otherwise."

Ms. Shea, a pharmacist by training, was not directly involved in the new studies but her agency, CADTH, has published extensively on the issue of glucose monitoring.

The first research paper is a systematic review, a compilation and analysis of earlier research that compared diabetes patients who monitored their blood glucose with those who did not.

A total of 2,270 patients with Type 2 diabetes who managed their condition with oral medications or lifestyle measures were involved. (The study did not include diabetics who use injected insulin.)

The study, led by health economist Chris Cameron of the Canadian Optimal Medication Prescribing and Utilization Service of CADTH, found that patients who tested themselves frequently (more than seven times a week) reduced their hemoglobin A1c levels by a mere 0.25 per cent. (The hemoglobin A1c level represents the average amount of sugar - also called glucose - that has been in a person's blood over the past three months.)

Those who self-monitored had only marginally fewer complications than those who did not. For example, over a 40-year period, 36.5 per cent of those who did not self-monitor suffered a heart attack, compared to 36.2 per cent of those who self-monitored at least daily. The results were similar for other common complications such as stroke, amputation, blindness and kidney failure.

All told, using test strips for 40 years translates into an additional gain of about six days of life, the research showed. But that benefit comes at a substantial cost. The test strips cost about $1 each.

"There are very modest benefits in terms of glycemic control and complications and they come at a very high cost to the individual or health care system," Mr. Cameron said.

The second study, led by Muhammad Mamdani, director of the applied health research centre at St. Michael's Hospital in Toronto, examined more directly the cost of glucose test strips to public drug plans.

The research showed that between 1997 and 2008, the use of test strips increased fivefold among seniors in Ontario. (The strips, which are prescribed like drugs, are covered for diabetics over the age of 65 but not for those younger.)

In 2008 alone, 117 million test strips were dispensed to 263,513 Ontario seniors with diabetes. That is up from 24.9 million test strips dispensed to 76,320 seniors in 1995.

Only about 15 per cent of diabetics use insulin; the rest treat the condition with oral medication or lifestyle changes. "Beyond the insulin group, frequent self-monitoring is really of questionable benefit," Dr. Mamdani said.

The research shows that, by limiting test strips to diabetics with insulin, use could be cut by almost 75 million annually. Even limiting non-insulin users to one strip a day would reduce test strip use by 9.5 million.

"We're not saying that monitoring of blood is a bad thing. On the contrary, it's essential," Dr. Mamdani said. "What we're asking is: What is the value of self-monitoring above and beyond what physicians already do?"

About 2.5 million Canadians have diabetes.

There are three distinct forms of diabetes: gestational diabetes is a temporary condition that occurs during pregnancy; Type 1 diabetes, usually diagnosed in children, occurs when the pancreas is unable to produce insulin; Type 2 diabetes occurs when the pancreas does not produce enough insulin or the body does not effectively use the insulin it produces.

About 90 per cent of diabetics have the Type 2 disease, which is usually a consequence of obesity, inactivity, poor diet and aging. Diabetes is also strongly associated with poverty.