ABSTRACT
INTRODUCTION: Given the global rise in obesity-related metabolic diseases, the upper limit of normal (ULN) alanine aminotransferase (ALT) in individuals with and without metabolic diseases may have changed. We performed a meta-analysis combined with bootstrap modelling to estimate the ALT ULN levels for individuals with and without metabolic diseases. METHODS AND RESULTS: Two separate searches of the PubMed, Embase and Cochrane databases were performed, one to identify healthy individuals which yielded 12 articles (349,367 individuals); another to include those with potential metabolic diseases but without known liver disease which yielded 35 articles (232,388 individuals). We estimated the mean ALT using a random-effects mixed model and the ULN level (95th-percentile value) via a bootstrap model with 10,000 resamples. In individuals without metabolic diseases and known liver disease, the ALT ULN levels were 32 U/L overall; 36 U/L in males and 28 U/L in females. In analyses that included individuals with metabolic diseases, the ALT ULN levels were 40 U/L among the overweight/obese (29 U/L if normal weight) and 36 U/L among those with type 2 diabetes mellitus (T2DM) (33 U/L if no T2DM). On meta-regression of study-level factors, body mass index (coefficient 1.49, 95% CI 0.11-2.86, p = 0.03), high-density lipoprotein (coefficient -0.47, 95% CI -0.85-(-0.08), p = 0.02) and triglycerides (coefficient 0.19, 95% CI 0.12-0.25, p < 0.0001) correlated with ALT. CONCLUSION: We provide expected ranges of ALT ULN levels for individuals without known liver disease without metabolic diseases and those with or without T2DM and/or are normal weight or overweight/obese. These data may have implications for clinical care and screening.
Subject(s)
Diabetes Mellitus, Type 2 , Liver Diseases , Male , Female , Humans , Overweight , Obesity , Body Mass Index , Alanine TransaminaseABSTRACT
BACKGROUND & AIMS: The increasing rates of obesity and type 2 diabetes mellitus may lead to increased prevalence of nonalcoholic fatty liver disease (NAFLD). We aimed to determine the current and recent trends on the global and regional prevalence of NAFLD. METHODS: Systematic search from inception to March 26, 2020 was performed without language restrictions. Two authors independently performed screening and data extraction. We performed meta-regression to determine trends in NAFLD prevalence. RESULTS: We identified 17,244 articles from literature search and included 245 eligible studies involving 5,399,254 individuals. The pooled global prevalence of NAFLD was 29.8% (95% confidence interval [CI], 28.6%-31.1%); of these, 82.5% of included articles used ultrasound to diagnose NAFLD, with prevalence of 30.6% (95% CI, 29.2%-32.0%). South America (3 studies, 5716 individuals) and North America (4 studies, 18,236 individuals) had the highest NAFLD prevalence at 35.7% (95% CI, 34.0%-37.5%) and 35.3% (95% CI, 25.4%-45.9%), respectively. From 1991 to 2019, trend analysis showed NAFLD increased from 21.9% to 37.3% (yearly increase of 0.7%, P < .0001), with South America showing the most rapid change of 2.7% per year, followed by Europe at 1.1%. CONCLUSIONS: Despite regional variation, the global prevalence of NAFLD is increasing overall. Policy makers must work toward reversing the current trends by increasing awareness of NAFLD and promoting healthy lifestyle environments.
