Effects of diabetes mellitus on patients with acute intermittent porphyria

Objectives. To study the effects of diabetes mellitus in patients with acut e intermittent porphyria (AIP). Haeme deficiency in the liver of AIP patients stimulates an increase in ALA -synthase which triggers an escalating metabolic chain reaction, leading to an increase in the porphyrin content. This reaction can be reduced by trea ting AIP patients with haeme arginate or with glucose. Design. A population-based study of all patients >18 years of age having DN A-verified AIP (n = 328) living in the two most northerly counties of Swede n (Norrbotten and Vasterbotten, with 550 000 inhabitants) of whom 16 had ty pe 2 diabetes. Prevalence of diabetes was studied retrospectively in 26 AIP patients with hepatocellular carcinoma (HCC). Results. None of the patients showed symptoms of AIP after the onset of the ir diabetes. Three patients had had recurrent, severe attacks for many year s but when their diabetes became manifest, their urinary ALA and PBC levels decreased and the AIP symptoms resolved, to the relief of the patients. Am ongst the 26 AIP patients with HCC, only one with signs of diabetes was ide ntified (impaired glucose tolerance test). Conclusions. This study raises the possibility that diabetes mellitus may b e beneficial for patients with severe AIP.