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Poor Glucose Control Associated with MDD

Major depressive disorder (MDD) is a common comorbidity in all patients with type 2 diabetes. Researchers from the University of California, San Francisco, published results from a longitudinal study in the March-April issue of Annals of Family Medicine that examined biologic, behavioral, and psychosocial characteristics at baseline that may predict the onset of MDD among patients with diabetes.

The study enrolled 506 patients with type 2 diabetes and identified 338 who did not have MDD. These patients were assessed 3 times during an 18-month period to ascertain common predictors of MDD. Certain indices that assess poorly controlled diabetes, such as elevated body mass index (BMI) and poor control of glycated hemoglobin (A1C), were recorded and odds ratios (ORs) were calculated.

The researchers found that indicators of poorly controlled diabetes, including elevated A1C and BMI, were independently associated with MDD. For A1C, patients with moderate negative affect at baseline but no MDD had an OR of 1.36 (95% confidence interval [CI], 1.01-1.85) at 18 months. For BMI, the OR was 1.09 (95% CI, 1.01-1.18) at 18 months. This translates to an increased risk of developing MDD when A1C and BMI are both elevated. The authors conclude these results can assist in identifying patients with diabetes who are at an increased risk of developing MDD, and that negative affect, although a significant predictor of MDD, “Does not occur in isolation from other aspects of a patient’s social and disease-related contexts.”

Lessons Learned from the ACCORD Trial

A lthough the results of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial were previously published, there are still many lessons to learn from them. The study authors’ intentions were for the ACCORD trial to study glucose control for a duration of 5 years, but they halted the study after 3.5 years due to findings that patients who were in the intensive-therapy group (achieving a target A1C of less than 6%) had a higher rate of death from any cause but fewer nonfatal myocardial infarctions (MIs) than the standard-therapy group (target A1Cof 7% to 7.9%). The intensive-therapy group was instead switched to standard therapy, and the researchers decided to follow them for an additional 17 months. They published their results in the March 3, 2011, issue of the New England Journal of Medicine.

From the follow-up period, the authors found that the former intensive-therapy group’s increased risk of death from any cause (primarily cardiovascular) and fewer nonfatal MIs persisted even after they were switched to standard therapy. The authors wrote that, therefore, a target A1C of less than 6% is not recommended for patients who have a high risk of cardiovascular disease and suboptimally controlled, long-standing diabetes.

The researchers hypothesized this increased risk of death may be due to unconventional prescription drug regimens, including those that combined 3 or more oral agents. The researchers also warned that although there is an increased risk of death when achieving an A1C of less than 6% in patients who have had diabetes for at least 10 years, this does not translate to an increased risk of death in newly diagnosed diabetic patients. A large trial studying this group of patients actually showed a reduced rate of death after 20 years when a median target A1C of 7% was achieved. PT

Late Onset of Diabetes May Not Be a CHD Risk Equivalent

A lthough diabetes mellitus is a well-known risk factor for coronary heart disease (CHD), whether diabetes alone is a CHD risk equivalent (a condition conferring an equivalent risk of a CHD event as someone who has already had one) is controversial. Some experts have suggested taking other diabetes factors into account, such as age of onset and duration.

Researchers from St. George’s at the University of London in England designed a prospective study that enrolled 4045 men aged 60 to 79 years who had either (1) no history of myocardial infarction (MI) and diabetes; (2) late-onset diabetes, defined as a diagnosis at or after age 60; (3) early-onset diabetes, defined as a diagnosis before age 60; or (4) prior MI. The researchers excluded those who had both MI and diabetes and studied the associations, if any, of onset of diabetes and CHD events (fatal and nonfatal MI).

The results were published in the March 14, 2011, issue of Archives of Internal Medicine. They showed that although both early and late onset of diabetes were associated with a significantly increased risk of major CHD events and all-cause mortality compared with nondiabetic men who had no CHD, only men with early-onset diabetes showed risk similar to those with previous MI and no diabetes. The researchers attribute this difference in risk to a longer exposure to chronic hyperglycemia in patients with a younger onset of diabetes, as well as worsening beta-cell function and much more severe insulin insufficiency.