Depression is associated with lower adherence to cardioprotective medications in adults with type 1 diabetes

To investigate the association between depression and refill adherence to cardioprotective medications in a representative cohort of type 1 diabetes adults.

This Finnish Diabetic Nephropathy (FinnDiane) sub-study included 1,588 adults with type 1 diabetes who had purchased antihypertensive or lipid-lowering drugs within ± 0.5 years from study baseline. The proportion of days covered (PDC) method was used to calculate overall refill adherence over a 10-year follow-up. Adherence was classified into good (> 80%), intermediate (≥ 50 and < 80%), and poor (< 50%). Participants were considered to have depression, if they had a diagnosis of depression or had purchased antidepressive agents at any time point from 1995 until the end of follow-up, identified from national registries. Multinomial logistic regression analysis, adjusted for age, sex, duration of diabetes, education level, HbA_1c, BMI, diabetic kidney disease, smoking, and alcohol consumption was performed.

Of the cohort 37% had depression during the study period. Those individuals with depression were more often women (P = 0.0001), and had lower adherence to cardioprotective medication (P = 0.02) than those without depression. Individuals with depression had 72% higher odds ([95% CI 1.09, 2.70], P = 0.02) of having poor versus good adherence, compare to those without depression. The results persisted after excluding antidepressants potentially used for neuropathic pain (OR 1.61 [95% CI 1.02, 2.55], P = 0.04).

Healthcare professionals should assess presence of depression and monitor medication adherence at regular consultations, and whenever needed, should implement strategies to manage the depression in order to enhance adherence, which might ultimately lead to improved cardiovascular outcomes in type 1 diabetes.