Although prediabetes is common among U.S. older adults, the natural history of prediabetes in this patient population is poorly understood. A community-based cohort study investigated the progression from normoglycemia to prediabetes or diabetes and from prediabetes to diabetes among older adults.
Prediabetes was defined as a glycated hemoglobin (HbA1c) level of 5.7% to 6.4%, a fasting glucose level of 100 to 125 mg/dL, or both. Of the 3,412 participants (mean age, 75.6 years; 60% women; 17% Black) who did not have diabetes and attended the baseline visit, 44% had prediabetes (as defined by HbA1c level), 59% had impaired fasting glucose, and 29% met both HbA1c and impaired fasting glucose criteria.
A total of 2,497 participants attended the follow-up visit or died by the end of follow-up. During the median follow-up of five years, there were 156 incident total diabetes cases, 118 incident diagnosed diabetes cases (according to a secondary analysis using just self-report of physician diagnosis and use of hypoglycemic medication), and 434 deaths. Among participants who had HbA1c levels of 5.7% to 6.4% at baseline, 59% had no change in status, 19% died, 13% regressed to normoglycemia, and 9% progressed to diabetes. Among participants with impaired fasting glucose at baseline, 44% regressed to normoglycemia, 32% had no change in status, 16% died, and 8% progressed to diabetes.
These findings suggest prediabetes may not be a robust diagnostic entity for predicting progression to diabetes in older adults, according to the authors.