ABSTRACT
BACKGROUND: Olestra is a nonabsorbable fat substitute that consists of fatty acids esterified to a sucrose molecule. OBJECTIVE: To determine the effect of olestra consumption on measurements of fecal fat excretion. DESIGN: Controlled cross-over trial. SETTING: Clinical research center and outpatient research laboratory. PARTICIPANTS: 10 healthy volunteers. INTERVENTION: On days 1 to 6 of the study, participants consumed 5 oz of conventional potato chips per day; on days 7 to 12, they consumed 5 oz of potato chips containing 40 g of olestra per day. MEASUREMENTS: Quantitative measurement of fecal fat by the van de Kamer titration, van de Kamer gravimetric, and Jeejeebhoy gravimetric methods and qualitative assessment of fecal fat by Sudan III staining. RESULTS: Excellent correlation was seen among the three quantitative assays, but the van de Kamer titration method yielded lower measurements than the two gravimetric methods. When participants consumed 40 g of olestra per day, the excretion of fecal fat increased to levels observed in patients with steatorrhea caused by the malabsorption syndrome. CONCLUSION: Consumption of olestra can cause false-positive results on tests for steatorrhea and may therefore lead to an erroneous diagnosis of the malabsorption syndrome.
Subject(s)
Celiac Disease/diagnosis , Fat Substitutes/pharmacology , Fatty Acids/pharmacology , Feces/chemistry , Lipids/analysis , Sucrose/analogs & derivatives , Coloring Agents , Defecation , Diagnostic Errors , False Positive Reactions , Humans , Statistics, Nonparametric , Sucrose/pharmacology , TitrimetryABSTRACT
OBJECTIVE: We performed a case-control study to evaluate risk factors and possible modes of transmission for hepatitis C virus (HCV) infection in patients with no history of blood transfusion or injection drug use. METHODS: Study subjects were selected from among patients seen in gastroenterology outpatient clinics at a university medical center in the southwestern United States. The study group consisted of 58 patients (12%) with chronic HCV infection who reported no history of transfusion or injection drug use, among a total of 477 patients evaluated for a positive HCV antibody test. These 58 patients were matched by age, ethnicity, and gender with 58 control patients diagnosed with gastroesophageal reflux attending the same clinics. Patients and controls were subjected to structured interviews and review of medical records. RESULTS: A variety of variables were significantly associated with increased risk of sporadic HCV infection, including a history of tattoos, needlestick exposure, a history of sexually transmitted disease, intercourse with an injection drug user, five or more lifetime sexual partners, intercourse during menses (for women), lower income, and heavy alcohol intake (>60 g/day). Multivariate analysis identified a history of sexually transmitted disease, heavy alcohol intake, and the presence of a tattoo as independent risk factors for sporadic HCV. In addition, six cases and one control had a history of needlestick exposure. Of the cases, 88% had at least one of these four risk factors, as compared with 26% of controls (odds ratio = 16.5; 95% confidence interval = 4.0-68.8). CONCLUSIONS: A history of sexually transmitted disease, heavy alcohol intake, the presence of tattoos, and a history of needlestick exposure were identified as risk factors for sporadic hepatitis C in this case-control study. If we include all patients with a history of blood transfusion or injection drug use, only 2% of the total 477 HCV patients had no identified risk factors.
