Glucose-lowering therapy tied to reduced risk of depression in T2D

Exposure to several glucose-lowering drugs appears to have a protective effect on the risk of depression in individuals with type 2 diabetes (T2D), according to a population-based cohort study in Hong Kong.

Researchers used data from territory-wide medical record database of public healthcare services. They identified 808,480 patients with incident T2D (mean age 62.9 years, 52.6 percent male), of which 686,533 were exposed to any glucose-lowering agents and 121,958 were not.

In the exposed group, 592,679 patients were exposed to metformin, 379,258 to gliclazide, 55,621 to glimepiride, 60,854 to pioglitazone, 44,719 to sitagliptin, 43,331 to linagliptin, 28,484 to vildagliptin, 32,168 to empagliflozin, 17,099 to dapagliflozin, and 232,436 to insulin.

Compared with non-exposed controls, patients who were exposed to any glucose-lowering agents had a 58-percent lower risk of new-onset depression (hazard ratio [HR], 0.42, 95 percent confidence interval [CI], 0.39–0.45).

Pronounced reduction in depression risk was observed with metformin (HR, 0.61, 95 percent CI, 0.57–0.66), pioglitazone (HR, 0.25, 95 percent CI, 0.10–0.63), linagliptin (HR, 0.26, 95 percent CI, 0.13–0.52), and insulin (HR, 0.63, 0.55–0.72) relative to non-exposure.

In sensitivity analyses, metformin and insulin were associated with reduced depression risk compared with non-exposure.

More research is needed to replicate the findings and establish the mechanisms by which individual glucose-lowering drugs may contribute to depression reduction, according to the researchers.