Clinical Capsules

Risk Factors for Nighttime Heartburn

Consumption of carbonated soft drinks and the use of benzodiazepines are newly identified risk factors for nighttime heartburn, according to the largest prospective, observational study of its kind.

Of 15,314 individuals older than 40 years who responded to a question about nighttime heartburn on a survey, 25% reported heartburn that awakened them two or more times per month, reported Ronnie Fass, M.D., of the University of Arizona, Tucson, and associates (Chest 2005;127:1658–66).

Multivariate logistic regression analysis showed that carbonated soft drink intake and the use of benzodiazepines were significant predictors of heartburn during sleep, in addition to high body mass index, hypertension, and asthma, Dr. Fass reported.

Insomnia and the symptom complex of snoring and sleepiness also significantly predicted heartburn during sleep.

However, these factors may be the consequences rather than the causes of heartburn during sleep, the study investigators noted.

Metformin, Nonalcoholic Fatty Liver

Metformin appears to improve ALT levels and metabolic syndrome criteria significantly more than a prescriptive diet or vitamin E supplements in patients with nonalcoholic fatty liver disease, reported Elisabetta Bugianesi, M.D., of the University of Turin (Italy) and her associates.

In a randomized study, ALT levels dropped within the normal range of less than 40 U/L after 12 months of treatment in significantly more patients who received no more than 2,000 mg of metformin per day (31 of 55) than patients randomized to a diet with a 500 kcal deficit per day (8 of 27) or to supplementation with 400 IU of vitamin E per day (4 of 28) (Am. J. Gastroenterol. 2005;100:1082–90).

In a multivariate analysis, normal ALT at the end of the 12-month study period was significantly associated with a change in body mass index and metformin treatment. Compared with the diet and vitamin E groups together, patients on metformin had a significant trend toward improvement in fasting glucose, insulin, and insulin resistance according to the homeostasis model assessment technique.

Fluorescence Endoscopy for Barrett's

Surveillance of Barrett's esophagus with autofluorescence endoscopy performed with a videoendoscope, rather than a fiberoptic endoscope, may enhance detection of dysplasia or early cancer, reported Mohammed A. Kara, M.D., and his colleagues at the Academic Medical Center, Amsterdam.

In a randomized, crossover study of 47 patients, autofluorescence endoscopy with a fiberoptic endoscope had the same sensitivity in detecting high-grade dysplasia or early cancer (62%) as did standard white-light videoendoscopy. The sensitivities were 69% for fluorescence endoscopy and 85% for standard endoscopy when the results of random biopsy specimens with high-grade dysplasia or early cancer were included in the analysis (Gastrointest. Endosc. 2005;61:671–8).

In a separate study, Dr. Kara and his associates improved autofluorescence endoscopy by using a videoendoscope that incorporates information from reflected light and displays dysplastic or neoplastic lesions as blue or violet and nondysplastic Barrett's esophagus as green. In a high-risk referral group of 60 patients with Barrett's esophagus, 14 (23%) had high-grade dysplasia or early cancer detected with standard white-light endoscopy or autofluorescence endoscopy with a videoendoscope; the modified form of autofluorescence endoscopy detected an additional 6 patients (bringing the total detection rate to 33%). (Gastrointest. Endosc. 2005;61:679–85).

Hyperhomocysteinemia in Hepatitis C

Chronic hepatitis C patients with hyperhomocysteinemia are at high risk for steatosis and progression of liver fibrosis, according to prospective data on 116 patients.

Luigi E. Adinolfi, M.D., and his colleagues at the Second University of Naples (Italy) reported that the degree of steatosis in those patients was correlated with hyperhomocysteinemia and with the C677T polymorphism of the MTHFR gene—a mutation known to be associated with hyperhomocysteinemia. The prevalence of steatosis and of high-grade steatosis was 41% and 11%, respectively, in patients without the polymorphism; 61% and 49% in patients heterozygous for the polymorphism; and 79% and 64% in patients homozygous for the polymorphism (Hepatology 2005;41:995–1003).

In multivariate analyses, progression of liver fibrosis was independently associated with steatosis, homocysteine levels were independently associated with steatosis and the MTHFR polymorphism, and steatosis grades greater than 1 were independently associated with levels of homocysteinemia and liver fibrosis scores.