Use of Serum c-Peptide Level to Simplify Diabetes Treatment Regimens in Older Adults

Abstract

Background Diabetes management in older adults is challenging. Poor glycemic control and high risk of hypoglycemia are common in older patients on a complicated insulin regimen. Newer oral hypoglycemic agents have provided an opportunity to simplify regimens in patients with type-2 diabetes on insulin. Serum c-peptide is a test to assess endogenous production of insulin. We analyze the use of serum c-peptide level in simplifying diabetes regimen by decreasing or stopping insulin injection and adding oral hypoglycemic agents in older adults. Methods One hundred patients aged over 65 years with either poor glycemic control or difficulty coping with insulin regimen seen at a geriatric diabetes clinic were analyzed for this study. The data on serum c-peptide levels and A1c, along with demographic information, were obtained from medical charts. Results Sixty-five of 100 patients (aged 79 ± 14 years, duration of diabetes 21 ± 13 years) had detectable serum c-peptide levels. Forty-six of 65 patients were available for simplification of regimen. Eleven of 46 patients had other co-morbidities preventing use of oral hypoglycemic agents. In 35/65 patients, simplification was completed successfully. Nineteen of 35 patients were converted to all-oral regimens (off insulin), while 16/35 had simplification of regimen by addition of oral hypoglycemic agents and lowering the number of insulin injections from an average of 2.7 to 1.5 injections/day ( P = .001). Glycemic control improved significantly in patients with a simplified regimen (8.0% ± 1.5% vs 7.4% ± 1.5%; P < .002), and patients reported fewer hypoglycemia episodes. Conclusions Serum c-peptide level can be used to simplify insulin regimen in older adults with diabetes.