Five-Year Follow-Up of Diabetic Complications and Geriatric Alterations in French Older Patients with Type 2 Diabetes According to Treatment Modalities: The Observational Prospective GERODIAB Cohort

Little is known about clinical events occurring in older patients with type 2 diabetes mellitus according to their therapeutic modalities based on the prescription of insulin and/or oral antidiabetic drugs.

The aim of this study was to compare the complications of diabetes and geriatric alterations that occurred according to three therapeutic modalities prescribed over 5 years.

A total of 616 patients from the GERODIAB cohort (mean age 77.1 years) were divided into three groups: an insulin-only group (n = 200), a group receiving insulin and one or more oral antidiabetic drug (n = 169), and an oral antidiabetic drug group without insulin (n = 247). We compared the diabetic complications and geriatric alterations that occurred over 5 years in patients without these pre-existing complications.

At inclusion, there was a significant difference between glycosylated hemoglobin values, and between the frequencies of most diabetic complications and geriatric alterations, with higher frequencies in the insulin group and lower frequencies in the oral antidiabetic drug group. At the end of the follow-up, there was still a significant difference between the mean glycosylated hemoglobin of the three groups (mean for all patients 7.4 ± 0.8%). The frequencies of new clinical events were high and they were generally higher in the insulin group. They were not significantly different between the three groups, with the exception of four events: heart failure, retinopathy, transfer to a nursing home (more frequent in the insulin group), and hypoglycemia (more frequent in the insulin + oral antidiabetic drug group). Some frequencies of the total diabetic complications (including complications at inclusion and at the follow-up) in the oral antidiabetic drug group were close to those in the insulin group, although only at inclusion. Mortality was higher in the insulin group and lower in the oral antidiabetic drug group.

The increased frequency of hypoglycemia in the insulin + oral antidiabetic drug group raises doubts about the value of continuing a secretagogue drug when insulin is introduced. As the vast majority of patients were not yet receiving antidiabetic drugs with cardiovascular action, our results on heart failure could help in conducting specific studies on these drugs in older patients with type 2 diabetes.