Altered taste sensation in newly-diagnosed NIDDM

To assess gustatory appreciation in newly diagnosed NIDDM patients and to determine whether it altered with the improvement of glycemic control after treatment with diet and oral hypoglycemic drugs.

Assessments of taste, peripheral and autonomic neural function, diet, and oral microbiological flora were performed in 20 patients before and after treatment of hyperglycemia, 20 matched nondiabetic control subjects, and 11 patients with long duration of diabetes and advanced peripheral neuropathy.

Median total HbA1 fell from 12.6 to 8.8% in new diabetic patients after 3-5 months of treatment. Electrical taste thresholds, detection threshold for glucose, and recognition threshold for glucose and salt were increased in newly-diagnosed NIDDM patients compared with the control subjects. The dose-response curve to glucose (using a visual analogue scale [VAS]) of newly-diagnosed NIDDM patients was significantly impaired and improved after treatment. By contrast, newly-diagnosed NIDDM patients had normal VAS taste responses to fructose, salt, and urea. Measurements of somatic and autonomic nerve function did not correlate with electrical or chemical taste function.

Newly-diagnosed NIDDM patients have a blunted taste response, which displays a degree of specificity to glucose, is partially reversed after correction of hyperglycemia, and is independent of somatic or autonomic nerve function. This taste abnormality may influence the premorbid choice of nutrients, with a preference for sweet-tasting foods, thereby exacerbating hyperglycemia.