Treating prediabetes does not affect progression

Clinical Question

Does treatment of postprandial hyperglycemia in patients with early, asymptomatic diabetes delay progression to frank fasting hyperglycemia?

Bottom Line

The jury is still out regarding the identification and treatment of patients with prediabetes. According to this study, a similar percentage of patients with early diabetes will develop frank diabetes whether or not they receive therapy to lower postprandial glucose levels. A larger, though shorter, study has shown a difference, but it looks like early benefit is lost over time. (LOE = 1b-)


Kirkman MS, Shankar RR, Shankar S. Treating postprandial hyperglycemia does not appear to delay progression of early type 2 diabetes. Diabetes Care 2006;29:2095-2101.  [PMID:16936159]

Study Design

Randomized controlled trial (nonblinded)


Industry + govt




Outpatient (specialty)


Researchers conducting this US-based study enrolled 219 adults with obesity, a history of gestational diabetes, or a family history of diabetes. The patients did not have a diagnosis of diabetes but had a fasting plasma glucose level between 105 mg/dL and 140 mg/dL (5.5 mmol/L - 7.8 mmol/L) and a 2-hour postload of plasma glucose of at least 200 mg/dL (11.1 mmol/L). After a 2-day admission for extensive testing, patients were randomly assigned, concealed allocation uncertain, to receive either placebo or acarbose (Precose) titrated to a maximum dose of 100 mg 3 times daily. The maximum dose was achieved by 91% of patients. The patients had their fasting glucose level measured every 3 months for up to 5 years. Approximately 43% of the patients did not complete the study. Since the dropout rates were similar in both groups, it is likely that the patients represent a highly motivated group of people. Additionally, given the frequent side effects of acarbose, patients receiving placebo were probably aware of that fact and may have been more rigorous with nondrug efforts to reduce the risk of diabetes. This increased effort might be responsible for the lower than expected development of diabetes in the placebo-treated patients. Though postprandial glucose levels were decreased by acarbose, over the 5 years of the study a similar proportion of patients in both groups developed frank fasting hyperglycemia, approximately 30% in both groups (29% vs 34%). The study was small and the results would only be significant if the treatment decreased the development of diabetes by half as compared with typical rates of development. The results conflict with the shorter-duration STOP-NIDDM study which found, after an average 3 years, that 32% of treated patients had diabetes as compared with 42% of placebo-treated patients (Lancet 2002;359:2072-2077). A nonsignificant difference in diabetes also occurred at 3 years in the current study, though the difference was lost by the end of the study.