Ketonuria in Hospitalized Patients With Non-Insului-Dependent Diabetes Mellitus

Physicians routinely order urinary ketone testing for most patients with diabetes mellitus upon hospitalization, even in the absence of a history of diabetic ketoacidosis. To determine whether testing for urinary ketones is clinically useful in patients with non-insulin-dependent diabetes mellitus (NIDDM), a retrospective review was undertaken of 152 charts of patients admitted to the hospital during a 6-mo period with the diagnosis of diabetes mellitus. Of the 135 patients with NIDDM, 96% had routine testing performed for urinary ketones. Surprisingly, 26% of the patients with NIDDM had positive urine ketones at some time during hospitalization, and the degree of ketonuria was markedly greater than that of control NIDDM outpatients and nondiabetic hospitalized patients. However, ketonuria did not reflect diabetic ketoacidosis. Ketonuria was accompanied by significant hyperglycemia and most likely reflects relative insulinopenia. Only 23% of the episodes of ketonuria were acknowledged in the progress notes. Although NIDDM patients who had ketonuria in the hospital were more likely to be transiently treated with insulin than patients without ketonuria, in no instance did the progress notes state that a diagnostic test or change in therapy was ordered because of the presence of a positive test for urinary ketones. The primary goal for therapy of patients with NIDDM should remain good control of blood glucose. In the hospitalized patient in whom frequent blood glucose determinations are made, it is not clear that urinary ketone testing needs to be routinely done.