[Carbohydrate metabolic disorders in porphyria cutanea tarda].

The frequency of diabetes mellitus was studied in all 150 registered patients suffering from porphyria cutanea tarda in Bulgaria. To 63 of the patients an oral glucose tolerance test was performed according to the criteria of the Diabetic Committee of the WHO (1979). Diabetes mellitus was found in 9 patients--6% which is considerably above the mean frequency of diabetes in this country which is about 1%. In 4 patients diabetes mellitus developed before the onset of porphyria, in 2 patients it developed after the onset of porphyria and in 3 patients the two diseases developed simultaneously. The glucose tolerance test showed lowered tolerance in 8 patients (12.7%) and 5 of them reacted with increased insulin response. 35 patients (55.5%) presented increased insulin response. The data of the study suggest that all patients suffering from porphyria cutanea tarda should be examined for disturbed carbohydrate metabolism.