Study of Nutritional Factors in Porphyria
Study of Nutritional Factors in Porphyria
OBJECTIVES: I. Determine whether differences in dietary habits are associated with disease
 activity in patients with acute intermittent porphyria.

 II. Determine whether premenstrual porphyria attacks are associated with increased luteal
 phase energy requirements.

 III. Determine whether energy requirements are higher than intakes in men with unexplained
 frequent porphyria attacks.

 IV. Assess the nutritional status of women with acute intermittent porphyria using a
 comprehensive series of laboratory methods, including zinc and pyridoxine status.

 V. Determine whether the frequency of disease exacerbations decreases when dietary and
 nutritional abnormalities are corrected in these patients.

 VI. Evaluate the safety and efficacy of a parenteral nutrition regimen for patients with
 acute porphyria attacks.
PROTOCOL OUTLINE: Women record diet intake for at least 1 cycle (28 days), then undergo a
 comprehensive nutritional assessment at least once during the follicular and luteal phases of
 the cycle.

 Men also record diet intake for at least 1 month and undergo indirect calorimetry and other
 studies.

 All patients receive a comprehensive analysis of diet and energy metabolism. Energy
 expenditure, resting metabolic rates, and basal metabolic rates are determined with indirect
 calorimetry, including measurements taken during the follicular and luteal phases of the
 cycle. Other testing includes hormone assays, serology for nutritional studies, and a urinary
 metabolite profile. Zinc, lead, and other metals are measured by atomic absorption
 spectroscopy.

 The diagnosis of acute intermittent porphyria is confirmed by erythrocyte porphobilinogen
 deaminase; urinary aminolevulinic acid, porphobilinogen, and porphyrins; and total fecal
 porphyrins.

 Patients hospitalized for acute attacks of porphyria during the study will receive standard
 treatment, including intravenous hematin and parenteral support.
-  Acute intermittent porphyria

 -  Variegate porphyria and hereditary coproporphyria eligible but analyzed separately