Impact of Fibrosis-4 Index Prior to COVID-19 on Outcomes in Patients at Risk of Non-alcoholic Fatty Liver Disease.

BACKGROUND: Severity of disease and outcomes in patient with COVID-19 has been associated with several risk factors tied to the metabolic syndrome. AIMS: We conducted a study with the objective of describing the association between the baseline Fibrosis-4 (FIB-4) index prior to SARS-CoV-2 infection and the severity of COVID-19 among patients at risk of non-alcoholic fatty liver disease (NAFLD). METHODS: This was a retrospective cohort study of patients with at least two risk factors for metabolic syndrome diagnosed with COVID-19. The main exposure of interest was FIB-4 index prior to infection, categorized into three previously validated age-specific levels. The main outcomes of interest were disease requiring hospitalization and in-hospital mortality. RESULTS: We included 373 patients [median age, 62 years; 194 male (52%); median number of metabolic syndrome risk factors, 3]. The median FIB-4 index was 1.10 (interquartile range 0.78-1.61). In models adjusting for diabetes mellitus and chronic kidney disease, patients with intermediate FIB-4 index had 67% higher odds of hospitalization compared to those in the low category {odds ratio (OR) 1.67 [(95% CI 1.06-2.64); p = 0.03]} and patients with high FIB-4 index had higher odds of mortality compared to intermediate and low category with an OR 2.22 (95% CI 1.20-4.12; p = 0.01). However, when we evaluated components of FIB-4 (age and AST/ALT ratio), we found that age alone was the best predictor of hospitalization and mortality. CONCLUSIONS: Among patients at risk of NAFLD with COVID-19 infection, elevated pre-infection FIB-4 index was associated with worsened clinical outcomes, but age was the strongest predictor.

Prospective comparison of longitudinal change in hepatic proton density fat fraction (PDFF) estimated by magnitude-based MRI (MRI-M) and complex-based MRI (MRI-C).

PURPOSE: To compare longitudinal hepatic proton density fat fraction (PDFF) changes estimated by magnitude- vs. complex-based chemical-shift-encoded MRI during a weight loss surgery (WLS) program in severely obese adults with biopsy-proven nonalcoholic fatty liver disease (NAFLD). METHODS: This was a secondary analysis of a prospective dual-center longitudinal study of 54 adults (44 women; mean age 52 years; range 27-70 years) with obesity, biopsy-proven NAFLD, and baseline PDFF ≥ 5%, enrolled in a WLS program. PDFF was estimated by confounder-corrected chemical-shift-encoded MRI using magnitude (MRI-M)- and complex (MRI-C)-based techniques at baseline (visit 1), after a 2- to 4-week very low-calorie diet (visit 2), and at 1, 3, and 6 months (visits 3 to 5) after surgery. At each visit, PDFF values estimated by MRI-M and MRI-C were compared by a paired t test. Rates of PDFF change estimated by MRI-M and MRI-C for visits 1 to 3, and for visits 3 to 5 were assessed by Bland-Altman analysis and intraclass correlation coefficients (ICCs). RESULTS: MRI-M PDFF estimates were lower by 0.5-0.7% compared with those of MRI-C at all visits (p < 0.001). There was high agreement and no difference between PDFF change rates estimated by MRI-M vs. MRI-C for visits 1 to 3 (ICC 0.983, 95% CI 0.971, 0.99; bias = - 0.13%, p = 0.22), or visits 3 to 5 (ICC 0.956, 95% CI 0.919-0.977%; bias = 0.03%, p = 0.36). CONCLUSION: Although MRI-M underestimates PDFF compared with MRI-C cross-sectionally, this bias is consistent and MRI-M and MRI-C agree in estimating the rate of hepatic PDFF change longitudinally. KEY POINTS: • MRI-M demonstrates a significant but small and consistent bias (0.5-0.7%; p < 0.001) towards underestimation of PDFF compared with MRI-C at 3 T. • Rates of PDFF change estimated by MRI-M and MRI-C agree closely (ICC 0.96-0.98) in adults with severe obesity and biopsy- proven NAFLD enrolled in a weight loss surgery program. • Our findings support the use of either MRI technique (MRI-M or MRI-C) for clinical care or by individual sites or for multi-center trials that include PDFF change as an endpoint. However, since there is a bias in their measurements, the same technique should be used in any given patient for longitudinal follow-up.

Measurement of spleen fat on MRI-proton density fat fraction arises from reconstruction of noise.

PURPOSE: This study compares splenic proton density fat fraction (PDFF) measured using confounder-corrected chemical shift-encoded (CSE)-MRI to magnetic resonance spectroscopy (MRS) in human patients at 3T. METHODS: This was a prospectively designed ancillary study to various previously described single-center studies performed in adults and children with known or suspected nonalcoholic fatty liver disease. Patients underwent magnitude-based MRI (MRI-M), complex-based MRI (MRI-C), high signal-to-noise variants (Hi-SNR MRI-M and Hi-SNR MRI-C), and MRS at 3T for spleen PDFF estimation. PDFF from CSE-MRI methods were compared to MRS-PDFF using Wilcoxon signed-rank tests. Demographics were summarized descriptively. Spearman's rank correlations were computed pairwise between CSE-MRI methods. Individual patient measurements were plotted for qualitative assessment. A significance level of 0.05 was used. RESULTS: Forty-seven patients (20 female, 27 male) including 12 adults (median 55 years old) and 35 children (median 12 years old). Median PDFF estimated by MRS, MRI-M, Hi-SNR MRI-M, MRI-C, and Hi-SNR MRI-C was 1.0, 2.3, 1.9, 2.2, and 2.0%. The four CSE-MRI methods estimated statistically significant higher spleen PDFF values compared to MRS (p < 0.0001 for all). Pairwise associations in spleen PDFF values measured by different CSE-MRI methods were weak, with the highest Spearman's rank correlations being 0.295 between MRI-M and Hi-SNR MRI-M; none were significant after correction for multiple comparisons. No qualitative relationship was observed between PDFF measurements among the various methods. CONCLUSION: Overestimation of PDFF by CSE-MRI compared to MRS and poor agreement between related CSE-MRI methods suggest that non-zero PDFF values in human spleen are artifactual.

Can stock rotation effectively mitigate EMS medication exposure to excessive heat and cold?

The United States Pharmacopeia recently published a general chapter specifically addressing on-ambulance storage of medications, including a suggestion for stock rotation. This study describes the effectiveness of a simple stock rotation strategy in mitigating EMS medication exposure to excessive heat and cold. Previously collected on-ambulance temperature data from 5 US cities were randomly resampled to generate model exposures of 2 days to 6 months duration. The temperature measurements for every other 24-hour period were then set at 20 degrees C to model the rotation of medications into a controlled environment. For each model, we then determined consistency with the official United States Pharmacopeia definition of controlled room temperature. Without stock rotation, excessive heat occurred in 39.9% of the model exposures. With stock rotation, exposures to excessive heat occurred in less than 1% of northern city models and in 2.9% of the central US models. Stock rotation did not reduce heat exposures in the models for southern cities.