Changes in the use of diabetes drugs among community-dwelling people with Alzheimer’s disease

Background Type 2 diabetes is common in persons with Alzheimer’s disease (AD). Management of diabetes in persons with AD is challenging due to changing goals of care and susceptibility to adverse drug events including hypoglycemia. The aim of this study was to investigate the prevalence of diabetes drug use from 5 years before to 5 years after the time of AD diagnosis among persons with and without AD. Methods This was a nationwide register-based study of persons with and without AD and diabetes in Finland. We analyzed data from the Medication Use and Alzheimer’s disease (MEDALZ) study that included 70,718 community-dwelling people diagnosed with AD from 2005 to 2011. The study population included 8418 persons with AD and 6666 matched persons without AD who were diagnosed with diabetes 5 years before AD diagnosis (index date). We defined the prevalence of diabetes drug use in three-month evaluation periods from 5 years before until 5 years after the index date. Results Nearly all people with diabetes (94% in both cohorts) used one or more diabetes drugs on the index date. The most prevalent drug metformin was used by 60.9% of people with AD and 59.1% of people without AD. The next most prevalent drugs were sulfonylureas and insulin. The prevalence of diabetes drug use was similar in people with and without AD but began to decline 1 year after AD diagnosis in the AD cohort compared to non-AD cohort. Conclusions The decline in diabetes drug use after AD diagnosis may be attributed to clinicians and patients seeking to avoid serious adverse drug events including hypoglycemia. In addition, the findings may reflect personalized glycemic control and unintentional weight loss in persons with AD reducing the need for diabetes drugs.