Environmental exposures may play an important role in a number of poorly understood chronic diseases. One such disease, chronic renal failure, affects more than 50,000 individuals in the United States who require maintenance dialysis or transplant at a cost of more than $1.5 billion per year. Despite the magnitude of this health problem, chronic renal disease has received little attention in epidemiologic studies. Two case-control studies have been completed that evaluate the importance of several exposures that have been suspected to be causes of chronic renal disease: In one study, over 500 patients with newly diagnosed chronic renal disease and over 500 population controls were surveyed by telephone to obtain exposure histories. Patients with renal disease reported more use of analgesic medications for a variety of specific symptoms, and were substantially more likely than controls to report regular use of analgesics. Renal disease risk was significantly increased for regular users of analgesics containing phenacetin (OR=6.5) or acetaminophen (OR=6.9). Results were not explained by other factors associated with analgesic use, and risks increased with increasing doses of these drugs. While there was no overall association between solvent exposure and renal disease, patients with glomerulonephritis were about twice as likely as other renal disease patients or controls to report jobs involving potential exposure to a variety of solvents and were significantly more likely to report exposure to any named solvent. In preliminary analyses, these solvent-related findings do not appear to be explained by confounding by other factors. The second study explored risk factors for IgA nephropathy. Preliminary results suggest that patients with IgA disease were more likely to report frequent colds and use of antibiotics. Patients were also more likely to report use of artificial sweeteners. Analysis of both studies is ongoing.
