Pyrophosphate arthropathy: a study of metabolic associations and laboratory data.

105 consecutive patients with pyrophosphate arthropathy have been studied. Disease associations and metabolic abnormalities were compared with those of an age and sex matched group of 105 acute medical admissions, and with 48 patients presenting with uncomplicated osteoarthritis. Patients with pyrophosphate arthropathy had a higher incidence of hypothyroidism (10, hyperparathyroidism 92), and chronic steroid therapy (15) than did those in the comparative groups. Laboratory data showed abnormalities suggesting chronic inflammatory disease in many patients, but no other unexpected metabolic findings. Metabolic abnormalities were uncommon in pyrophosphate arthropathy, and extensive metabolic screening of patients was unrewarding.