Use of serum c-peptide level to simplify diabetes treatment regimens in older adults.

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.