Medical Care Costs One Year After Identification of Hyperglycemia Below the Threshold for Diabetes

OBJECTIVE: To estimate the resource utilization and medical costs of patients with impaired fasting glucose (IFG), impaired glucose tolerance (IGT), or both, in a real-world clinical setting. METHODS: We used fasting and random glucose test results and a previously validated predictive equation to identify glycemic status in 26,111 nondiabetic patients, assigning them to categories of normoglycemia, isolated IFG (I-IFG), isolated IGT (I-IGT), or IFG with possible IGT (IFG/IGT). We then calculated and compared mean annual medical resource utilization and age/sex-adjusted costs over the ensuing 12-month period. RESULTS: I-IGT patients incurred significantly greater age- and sex-adjusted total costs in the observation year compared with normoglycemic and I-IFG patients (both comparisons, P < 0.001). IFG/IGT patients also had significantly greater age- and sex-adjusted total costs in the observation year compared with normoglycemic and I-IFG patients (P < 0.001, both comparisons). In both cases, the differences were driven by significantly greater inpatient costs-20.3% of patients with I-IGT and 17.1% with IFG/IGT were hospitalized during the observation year, whereas approximately 12% of normoglycemic and I-IFG patients had an admission (all comparisons, P < 0.001). CONCLUSIONS: Abnormal glucose tolerance, in particular, IGT, is associated with excess medical care costs relative to normoglycemia. Preventing progression to diabetes, when costs are known to be dramatically greater, would likely provide substantial economic benefit. More research is needed to determine the prevalence of hyperglycemia-related complications at elevated glucose levels below the diabetic threshold and the associated costs of those complications.