Spotlight on geriatrics

Older patients with diabetes were the focus of several recent studies, including two that compared second-line medication options.

First, a study published by Diabetes Care on Feb. 21 examined the associated between HbA1c levels and mortality among patients ages 65 years or older participating in the National Health and Nutrition Examination Survey. Out of 7,333 patients followed for a median of 8.9 years, 4,729 died. Patients with diagnosed diabetes and an HbA1c ≥8% had a significantly higher mortality risk compared to diabetics with an HbA1c <6.5% (hazard ratios, 1.6 [95% CI, 1.02 to 2.06] for HbA1c from 8.0% to 8.9% and 1.8 [95% CI, 1.3 to 2.6] for HbA1c ≥9%). The results support existing American Diabetes Association recommendations of HbA1c goals of <7.5% in healthy older adults and <8.0% in those with comorbidities, the authors said. They noted that the study results also showed differences in the risk of mortality across demographics, history of cardiovascular disease, duration of diabetes, and type of antidiabetic medication and that glycemic targets should be individualized based on such factors.

Another study, published by Diabetes, Obesity and Metabolism on Feb. 14, focused specifically on second-line medication choice and any association between drug class and mortality or cardiovascular events. The analysis included Medicare beneficiaries who had been taking metformin and added a dipeptidyl peptidase-4 (DPP-4) inhibitor, a sulfonylurea, or a thiazolidinedione between 2007 and 2013. Compared to those adding a DPP-4 inhibitor, patients taking a sulfonylurea had an increased mortality risk in the first year, a finding that needs more investigation, the study authors said. Overall, however, the study found that DPP-4 inhibitors were not associated with any increase in short-term risk of myocardial infarction, stroke, or heart failure compared to these other drug classes. The study was limited by its short follow-up, the authors acknowledged.

A similar British study, published by Diabetes, Obesity and Metabolism on Feb. 23, included 10,484 patients ages 65 years and older with type 2 diabetes who were treated with metformin monotherapy and required therapy escalation between 2008 and 2014. The most common escalation treatments were adding a sulfonylurea (42%) or switching to a sulfonylurea (28%). However, patients who added a DPP-4 inhibitor had a lower rate of major adverse cardiovascular events than those who added a sulfonylurea (hazard ratio, 0.61; 95% CI, 0.39 to 0.98). Adding a DPP-4 inhibitor was also found to be more cost-effective than either adding or substituting a sulfonylurea or adding a thiazolidinedione. The study authors concluded that the findings support consideration of alternative prescribing regimens, rather than the typical practice of adding a sulfonylurea to metformin.