A large cohort study by researchers at Kaiser Permanente found that when diabetic patients monitor their blood glucose levels according to the frequency recommended by the American Diabetes Association (ADA), better glycemic control is achieved regardless of diabetes type or therapy.
In a study by Andrew J. Karter, PhD, and associates, data collected during 1997 on 24,312 adult patients in the Northern California Kaiser Permanente Diabetes Registry were analyzed retrospectively to evaluate the effect on glycemic control of the ADA Clinical Practice Recommendations for blood glucose self-monitoring. These recommendations include a self-monitoring frequency of at least three times daily for patients with type 1 diabetes and at least once daily for those with type 2 diabetes controlled with medication.
Hemoglobin A1c (HbA1c) levels were compared between patients who adhered to the ADA guidelines and those who did not for each of four categories of diabetes:
type 1, type 2 treated with insulin, type 2 treated with oral medication only, and type 2 treated with diet or other nonpharmacologic therapy. Frequency was based on the number of glucometer strips redeemed during a 12-month period at pharmacies within the Kaiser Permanente system. HbA1c levels were measured during this same 12-month period.
After adjustment for factors such as age and income level, adherence was associated in all four patient groups with significantly lower HbA1c levels and thus better glycemic control. For the type 1 group, adherent patients achieved a decrease of 1.0% HbA1c compared with nonadherent patients (7.7% adherence vs 8.7% nonadherence, p = .0001). The difference was 0.6% (p = .0001) for both theinsulin-treated and the oral-agent–treated type 2 groups, and 0.4% (p = .0001) for the diet-controlled type 2 group.
The few studies performed to evaluate the effectiveness of the ADA guidelines on self-monitoring of blood glucose have been inconclusive, due in part to small sample size and also to flaws in study design. This, coupled with the high cost of self-monitoring, has caused the practice of frequent self-monitoring to be debated, the researchers noted. Their study is the first large retrospective study to demonstrate that the ADA guidelines for self-monitoring of blood glucose levelsimproves glycemic control, as measured by HbA1c levels.