Long-term maintenance of glucose control in veterans with type 2 diabetes mellitus using oral agents

The aim of this study was to evaluate long-term glycemic control in individuals with type 2 diabetes mellitus on oral hypoglycemic agents.

We identified the cohort of veterans prescribed hypoglycemic agents every year from July, 1992, through June, 2007 (n=191). Glycosylated hemoglobin (HbA1c) was used to assess glycemic control. Data are expressed as mean±standard deviation (SD); statistics are expressed by t-test and chi-squared. P<0.05 was considered significant.

In the first year, 96 of the select group of 191 veterans identified above received oral agents only (OAO), 74 insulin only, and 21 both insulin and oral agents. Fifteen years later, 59 were OAO, 78 insulin only, and 54 both. Six patients receiving insulin in 1992-1993 were OAO-treated in 2006-2007. In the subgroup on OAO both at baseline and at the end (n=53), HbA1c decreased from 7.89±1.21 to 7.09±1.13 (P<0.001). These veterans were older at baseline (62.4±6.2) and leaner at the 15-year follow-up [body mass index (BMI) 28.1±4.9] than those who received insulin in 2006-2007 (n=43; age=57.9±9.6; BMI=32.3±7.9; P<0.05 and 0.005, respectively). Patients in the stable OAO group (n=53) were 74.0% Caucasian, compared to 51.2% in former-OAO [n=43; P<0.05 (chi-squared)].

Over half (n=53; 55%) of patients originally in the OAO group remained so 15 years later. These stable patients were in better glycemic control, both at baseline and follow-up, less obese, older, and more likely to be Caucasian, than those who eventually received insulin. Currently used oral agents often maintain, or even improve, glucose control, over 2 decades after diagnosis of diabetes mellitus.