New for April 12, 2017
Association of Glycemic Variability in Type 1 Diabetes With Progression of Microvascular Outcomes in the Diabetes Control and Complications Trial
Diabetes can lead to a variety of complications, including microvascular complications, which affect the small blood vessels and result in damage to the eyes, kidneys and nerves. The Diabetes Control and Complications Trial (DCCT) was a clinical trial conducted from 1983 to 1993 in 1,441 patients with type 1 diabetes across the U.S. and Canada. The study randomly assigned 711 patients to intensive therapy aimed at achieving HbA1c levels as close to the non-diabetic level as safely possible, and assigned 730 patients to conventional therapy aimed at maintaining clinical well-being, with no specific glucose targets. The DCCT demonstrated the beneficial effects of intensive control of blood glucose versus standard blood glucose control on the development and progression of microvascular complications of diabetes. These beneficial effects were almost completely explained by the difference in HbA1c levels between the two treatment groups, which in turn were associated with the risk of these complications. While overall patient compliance in the DCCT was high, completion of the patient-reported 7-point blood glucose profile collections was problematic due to missing data points. A total of between 15 and 18 percent of glucose values were missing from each of the seven time points during which blood glucose should have been measured and recorded by patients. Researchers recently addressed this limitation by applying a modern computer-intensive statistical method—multiple imputation—to estimate missing blood glucose profile values based on other measurements that were observed in the study, thus increasing the statistical validity of further analyses. Using such methods, researchers recently evaluated the association of glucose variability within and between quarterly 7-point glucose profiles with microvascular outcomes in the DCCT. They concluded that overall, within-day glycemic variability, as determined from quarterly glucose profiles, does not play an apparent role in the development of microvascular complications above and beyond the influence of the mean glucose.
free online [10.2337/dc16-2426]
Early Glycemic Control and Magnitude of HbA1c Reduction Predict Cardiovascular Events and Mortality: Population-Based Cohort Study of 24,752 Metformin Initiators
People with diabetes have a significantly increased risk for cardiovascular disease. Lowering HbA1c levels to less than 7 percent in most adults with type 2 diabetes has been a recommended target in treatment guidelines for over a decade because of the documented effect in reducing microvascular complications. In contrast, it remains debated whether even tighter glucose control of less than 6.5 percent might be beneﬁcial or harmful for people with type 2 diabetes, and what the true effect of tight early glucose control is on subsequent cardiovascular disease. This study examined the effect that tight early glucose control (HbA1c less than 6.5 percent) had on subsequent cardiovascular disease in over 24,000 people in Denmark with newly diagnosed type 2 diabetes who were prescribed metformin. Using data from existing population-based medical registries from 2000 to 2012, researchers identiﬁed all patients with type 2 diabetes aged 30 or older (average age 62.5 years) living in Northern Denmark, who were prescribed glucose-lowering medications for the first time. Researchers used Cox regression analysis to examine subsequent rates of acute myocardial infarction, stroke, or death, controlling for baseline HbA1c and other confounding factors. Data indicated that a large initial HbA1c reduction and achievement of low HbA1c levels within six months after beginning metformin are associated with a lower risk of cardiovascular events and death in patients with type 2 diabetes.
free online [10.2337/dc16-2271]
Predicting and Reducing Driving Mishaps Among Drivers with Type 1 Diabetes
Some people with diabetes who drive have a higher risk of motor vehicle accidents due to blood glucose fluctuations and/or the effects of diabetes complications such as retinopathy and neuropathy. In its Position Statement on diabetes and driving, the American Diabetes Association (Association) recommends that clinicians assess people with diabetes individually, taking into account each patient's medical history as well as the potential related risks associated with driving. This series of studies developed and tested an 11-item questionnaire to assist clinicians in screening and identifying type 1 diabetes drivers for a high risk of driving mishaps, and also developed an online intervention tool to assist people with diabetes who were identified as high risk drivers. The research demonstrated that some drivers with type 1 diabetes are at greater risk of driving mishaps, and that those higher risk drivers can be identified with the Risk Assessment of Diabetic Drivers (RADD) scale—a brief, psychometrically sound questionnaire which the Association will feature on its website. Additionally, the studies showed that the incidence of future driving mishaps among higher risk drivers can be reduced via the online intervention tool, which helps drivers with type 1 diabetes to better anticipate and prevent hypoglycemia right before driving, and to detect and treat hypoglycemia while driving.
free online [10.2337/dc16-0995]