It's an unfortunate truth of our health care system: preventing diabetes complications hasn't been as profitable as treating them. For example, according to a January 11 article in the New York Times, many insurers will reimburse a patient for only one blood-glucose test strip per day, an inadequate number by any standard. The article also reported that insurers often won't cover a $150 podiatric visit for the prevention of foot complications, although most will pay for amputation-costing about $30,000.
Yet even as diabetes prevalence has soared, diabetes centers, often struggle to stay open. For example, according to the Times, between 1999 and 2005 three of New York City's four diabetes centers had closed-"[not] because they had failed their patients . . . [but] because they had failed to make money." Prevention of serious and potentially lethal complications may therefore hinge on more rigorous control of blood glucose levels.
Intensive treatment.
New evidence shows that tight glucose control can halve one's risk of stroke and cardiovascular disease. Results from the Diabetes Control and Complications Trial (DCCT) and the follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) study, published in the December 22, 2005, issue of the New England Journal of Medicine (NEJM), revealed that intensive treatment of type 1 diabetes lowered patients' risk of any cardiovascular event by 42% and cut the risk of nonfatal myocardial infarction, stroke, or death from cardiovascular disease by 57%, compared with conventional treatment.
In the DCCT-EDIC studies, patients in the intensive treatment group strove for specific pre- and postprandial blood glucose levels and a glycosylated hemoglobin (HbAIc) level of less than 6.05%, a value close to normal. To that end, patients monitored their blood glucose at least four times daily and received insulin either by infusion pump continuously or by injection three or more times daily. In contrast, patients in the conventional treatment group had no specific blood glucose goals (other than preventing symptoms of hyper- or hypoglycemia), and injected insulin just once or twice daily.
During the initial trial period, the average HbAIc level in the intensive-treatment group was 7.2%, and it was 8.9% in the conventional-treatment group. During follow-up, patients in both groups had the option to continue or begin intensive treatment; the average HbAIc level in both groups eventually reached 8%. Yet the patients who'd been in the original intensive-treatment group still had a much lower cardiovascular disease risk. After adjusting for other factors, the researchers concluded that "differences in HbAIc values during the DCCT accounted for much of the cardiovascular benefit accompanying intensive therapy" and called for early implementation of intensive therapy in people with type 1 diabetes. (Metabolic memory, in which the effects of early and aggressive diabetes treatment continue years later, may be one reason patients with type 1 diabetes who were treated early continued to improve.)
For people with type 2 diabetes, it's not yet clear whether rigorous blood glucose control is of equal benefit. The American Diabetes Association's current guidelines recommend that all patients with type 1 or type 2 diabetes strive for specific pre- and postprandial blood glucose levels and an HbAIc goal for patients in general of 7%. A major study designed to explore intensive treatment in people with type 2 diabetes, the Action to Control Cardiovascular Risk in Diabetes trial, is currently recruiting participants.
Adherence.
In a related finding, there is new evidence supporting patient adherence, as measured in terms of appointments kept and drug regimens followed. A study by Rhee and colleagues in the March-April 2005 issue of the Diabetes Educator reported on a retrospective 10-year study involving 1,560 patients with type 2 diabetes. After adjusting for confounding factors, the authors found that "appointment keeping and medication adherence remained significant and contributed independently" to achieving and maintaining low blood glucose levels. Although the degree to which tighter glucose control might offset the risk of complications in people with type 2 diabetes isn't yet known, the strong association between poor control and the development of complications is not disputed.
Prevention.
Cardiovascular disease is the leading cause of death among people with diabetes of either type. For patients with type 1 diabetes, advocating stricter glucose control to achieve near-normal HbAIc levels seems one likely result of the new findings. Greater emphasis on preventing complications in patients with either type of diabetes may be another. According to the Centers for Disease Control and Prevention, about 21 million Americans currently have type 1 or type 2 diabetes; another 41 million have prediabetes (impaired glucose tolerance, impaired fasting glucose, or both). Between 1997 and 2004, the number of new cases of diabetes rose by 54%. As diabetes incidence and prevalence rise, in all likelihood so will the incidence and prevalence of its complications. The added direct and indirect costs will be tremendous. As an editorial in the aforementioned issue of NEJM put it, "One of the most important questions in diabetes management is whether long-term glycemic control can reduce the risk of cardiovascular disease. If the answer is yes, a reassessment of our clinical goals may be in order."