ADT Compromises Disease Control in Patients with Diabetes

Diabetes control worsened for patients with diabetes who received or were receiving androgen deprivation therapy for prostate cancer.

The metabolic changes that occur with androgen deprivation therapy (ADT) worsen diabetes control in patients who had diabetes prior to beginning ADT for prostate cancer.

The results of a study published in the April 2014 edition of European Urology found that participants with diabetes who received ADT had higher glycated hemoglobin (HbA1C) levels after treatment, and also had an increased hazard of adding more diabetes medications to control their condition.

“Men with diabetes who start ADT should be counseled about the potential need for intensification of diabetes therapy and should have their HbA1c levels monitored during therapy, especially if they continue on long-term continuous ADT,” the authors wrote.

Researchers identified 2237 men with invasive local or regional prostate cancer who had received either a primary diagnosis of diabetes or at least 2 outpatient diabetes diagnoses, and received ADT from a Veteran’s Administration registry. All participants in the cohort had received at least 1 HbA1C test during follow-up. Participants were age- and comorbidity-matched to men who had not been treated with ADT.

Researchers assessed diabetes control over time by checking HbA1C levels from laboratory data and initiation of new diabetes medications, which could include starting a diabetes medication if a patient was not already on one, or adding a medication from a new drug class.

Results of the HbA1C tests after 1 year showed a decrease among men who did not receive ADT, which suggested an improvement in diabetes control. Participants who had received ADT, however, saw their HbA1C increase after 1 year. The researchers recorded a similar phenomenon in the 2-year cohort, they said.

“A 0.24% increase in HbA1C at 1 year could lead to up to a 2.5% increase in risk of death from diabetes and a 4.5% increase in microvascular complications, assuming that the association is linear,” the authors wrote. “Although these risks are small, with the large numbers of men treated with ADT, they could nevertheless have a substantial impact on the health of populations of diabetic men.”

Most members (82%) of both groups were taking some form of diabetes medication at baseline. Sulfonylureas were taken by 40% of participants, 27% received metformin, and 19% received insulin, the report found. Most participants, regardless of group, received diabetes monotherapy, and less than 1% received 3 or more drugs.

ADT was associated with increased hazard of adding additional diabetes medications to existing therapy, intensifying a patient’s drug regimen. Higher baseline HbA1C levels and younger age were associated with adding diabetes medications as well.

When calculating the time until initiating diabetes therapy, or starting a new diabetes drug class, the rate for participants in the ADT group was again higher than the rate for patients who did not receive ADT. Researchers also examined insulin therapy specifically, finding a higher rate of insulin therapy initiation or addition in the ADT group.