Forty-five subjects with a rising, progressively improving (RPI) audiometric pattern were considered for a 5-hour oral glucose tolerance test. Results revealed that 2 nondiabetic subjects (4%) had a plasma glucose nadir of 49 mg/dl or lower and 7 nondiabetic subjects had a nadir between 50 and 57 mg/dl. A total of 21% of 42 subjects with data indicated abnormally low readings. An additional 7 subjects were found to be diabetic; 5 subjects had impaired glucose tolerance, and 9 other subjects had nondiagnostic glucose intolerance, totalling 47% of 45 subjects in the study with abnormally elevated plasma glucose levels. Therefore a total of approximately 68% of all subjects in our study indicated metabolic dysfunction based specifically on a RPI pattern.