Prevalence of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis among a largely middle-aged population utilizing ultrasound and liver biopsy: a prospective study.

BACKGROUND & AIMS: Prevalence of nonalcoholic fatty liver disease (NAFLD) has not been well established. The purpose of this study was to prospectively define the prevalence of both NAFLD and nonalcoholic steatohepatitis (NASH). METHODS: Outpatients 18 to 70 years old were recruited from Brooke Army Medical Center. All patients completed a baseline questionnaire and ultrasound. If fatty liver was identified, then laboratory data and a liver biopsy were obtained. RESULTS: Four hundred patients were enrolled. Three hundred and twenty-eight patients completed the questionnaire and ultrasound. Mean age (range, 28-70 years) was 54.6 years (7.35); 62.5% Caucasian, 22% Hispanic, and 11.3% African American; 50.9% female; mean body mass index (BMI) (calculated as kg/m(2)) was 29.8 (5.64); and diabetes and hypertension prevalence 16.5% and 49.7%, respectively. Prevalence of NAFLD was 46%. NASH was confirmed in 40 patients (12.2% of total cohort, 29.9% of ultrasound positive patients). Hispanics had the highest prevalence of NAFLD (58.3%), then Caucasians (44.4%) and African Americans (35.1%). NAFLD patients were more likely to be male (58.9%), older (P = .004), hypertensive (P < .00005), and diabetic (P < .00005). They had a higher BMI (P < .0005), ate fast food more often (P = .049), and exercised less (P = 0.02) than their non-NAFLD counterparts. Hispanics had a higher prevalence of NASH compared with Caucasians (19.4% vs 9.8%; P = .03). Alanine aminotransferase, aspartate aminotransferase, BMI, insulin, Quantitative Insulin-Sensitivity Check Index, and cytokeratin-18 correlated with NASH. Among the 54 diabetic patients, NAFLD was found in 74% and NASH in 22.2%. CONCLUSION: Prevalence of NAFLD and NASH is higher than estimated previously. Hispanics and patients with diabetes are at greatest risk for both NAFLD and NASH.

External validation of a virtual reality transurethral resection of the prostate simulator.

PURPOSE: Virtual reality surgical simulation is an emerging technology that may eventually fill the gaps in surgical education created by changes in our medical system. We assessed the construct validity of a commercially available, virtual reality transurethral prostate resection simulator. MATERIALS AND METHODS: Participants performed 2, 5-minute transurethral prostate resection exercises on a standardized virtual reality prostate. Data from the first exercise were discarded. Simulator based metrics from the second exercise were tabulated, including tissue resected in gm, number of cuts, coagulation time, number of coagulation attempts, tissue per cut in gm and blood loss. Complications were recorded. Performance metrics were compared between groups based on urological training level and prior real-world experience with transurethral prostate resection. RESULTS: A total of 35 participants with varied levels of transurethral prostate resection experience completed the exercise. Several performance metrics had statistically significant correlations with urology training level and prior experience with transurethral prostate resection. There was a positive correlation of all measures of experience with mass resected, mass resected per cut and blood loss. Number of cuts correlated significantly with transurethral prostate resection experience in the previous year. Complications were present in most groups with medical students more likely to encounter external urethral sphincter and rectal injuries. CONCLUSIONS: We report the construct validity of a commercially available, virtual reality transurethral prostate resection simulator. The more experienced participants resected more tissue in a more efficient manner but with increased blood loss. Further investigations are needed before the widespread application of transurethral prostate resection simulators for training, certification and accreditation.