BREATH-ACETONE AND BLOOD-SUGAR MEASUREMENTS IN DIABETES

The concentration of breath acetone has been found to correlate with the β-hydroxybutyrate concentration of venous blood in fasting obese patients. Overnight fasting levels of both breath acetone and blood-sugar were measured in 251 diabetics, after which the patients were grouped for analysis by the type of diabetic management and the fasting blood-sugar found. Amongst the subgroups with near-normal fasting blood-sugar (<120 mg. per 100 ml.) the mean breath acetone was normal only in the group whose diabetes was controlled by a non-reducing diet ( > 100 g. carbohydrate per day); it was raised in similarly well-controlled patients receiving either reducing diets (< 100 g. carbohydrate per day) or hypoglycæmic tablets or insulin. Among those with higher simultaneous blood-sugar levels the mean acetone concentration was abnormal and rose progressively with the blood-sugar. In insulin-dependent diabetics similar measurements made before meals showed a progressive decrease in mean acetone levels during the day (for the same simultaneous blood-sugar), lowest levels being attained in the late afternoon. This mild ketosis, present in 40–50% of diabetics apparently well controlled on hypoglyæmic tablets or insulin, was not relatable to diet, degree of obesity, or the occurrence of hypoglycæmia. In such patients, measurement of the breath acetone can detect inadequacies of control not revealed by measure- ment of the blood-sugar alone.