METHODS: For this systematic review and meta-analysis, we searched PubMed, Embase, Scopus, and the Cochrane Library from inception to May 1, 2019, for relevant original research articles without any language restrictions. The literature search and data extraction were done independently by two investigators. Primary outcomes were the prevalence of non-obese or lean people within the NAFLD group and the prevalence of non-obese or lean NAFLD in the general, non-obese, and lean populations; the incidence of NAFLD among non-obese and lean populations; and long-term outcomes of non-obese people with NAFLD. We also aimed to characterise the demographic, clinical, and histological characteristics of individuals with non-obese NAFLD.
FINDINGS: We identified 93 studies (n=10 576 383) from 24 countries or areas: 84 studies (n=10 530 308) were used for the prevalence analysis, five (n=9121) were used for the incidence analysis, and eight (n=36 954) were used for the outcomes analysis. Within the NAFLD population, 19·2% (95% CI 15·9-23·0) of people were lean and 40·8% (36·6-45·1) were non-obese. The prevalence of non-obese NAFLD in the general population varied from 25% or lower in some countries (eg, Malaysia and Pakistan) to higher than 50% in others (eg, Austria, Mexico, and Sweden). In the general population (comprising individuals with and without NAFLD), 12·1% (95% CI 9·3-15·6) of people had non-obese NAFLD and 5·1% (3·7-7·0) had lean NAFLD. The incidence of NAFLD in the non-obese population (without NAFLD at baseline) was 24·6 (95% CI 13·4-39·2) per 1000 person-years. Among people with non-obese or lean NALFD, 39·0% (95% CI 24·1-56·3) had non-alcoholic steatohepatitis, 29·2% (21·9-37·9) had significant fibrosis (stage ≥2), and 3·2% (1·5-5·7) had cirrhosis. Among the non-obese or lean NAFLD population, the incidence of all-cause mortality was 12·1 (95% CI 0·5-38·8) per 1000 person-years, that for liver-related mortality was 4·1 (1·9-7·1) per 1000 person-years, cardiovascular-related mortality was 4·0 (0·1-14·9) per 1000 person-years, new-onset diabetes was 12·6 (8·0-18·3) per 1000 person-years, new-onset cardiovascular disease was 18·7 (9·2-31·2) per 1000 person-years, and new-onset hypertension was 56·1 (38·5-77·0) per 1000 person-years. Most analyses were characterised by high heterogeneity.
INTERPRETATION: Overall, around 40% of the global NAFLD population was classified as non-obese and almost a fifth was lean. Both non-obese and lean groups had substantial long-term liver and non-liver comorbidities. These findings suggest that obesity should not be the sole criterion for NAFLD screening. Moreover, clinical trials of treatments for NAFLD should include participants across all body-mass index ranges.
FUNDING: None.
APPROACH & RESULTS: NAFLD knowledge surveys containing 54 and 59 questions covering three domains (Epidemiology/Pathogenesis, Diagnostics, and Treatment) were completed electronically by hepatologists, gastroenterologists (GEs), endocrinologists (ENDOs) and primary care physicians (PCPs) from 40 countries comprising 5 Global Burden of Disease (GBD) super-regions. Over 24 months, 2202 surveys were completed (488 hepatologists, 758 GEs, 148 ENDOs, and 808 PCPs; 50% High-Income GBD super-region, 27% from North Africa and Middle East, 12% Southeast Asia, and 5% South Asian and Latin America). Hepatologists saw the greatest number of NAFLD patients annually: median (IQR) 150 (60-300) vs. 100 (35-200) for GEs, 100 (30-200) for ENDOs, and 10 (4-50) for PCPs (all p<0.0001). The primary sources of NAFLD knowledge acquisition for hepatologists were international conferences (33% vs. 8-26%) and practice guidelines for others (39-44%). Internet was the second most common source of NAFLD knowledge for PCPs (28%). NAFLD knowledge scores were higher for hepatologists than GEs: Epidemiology 62% vs. 53%, Diagnostics 80% vs. 73%, Treatment 61% vs. 58% (p<0.0001) and ENDOs scores were higher than PCPs: Epidemiology 70% vs. 60%, Diagnostics 71% vs. 64%, Treatment 79% vs. 68% (p<0.0001). Being a hepatologist or ENDO was associated with higher knowledge scores than GE or PCP, respectively (p<0.05). Higher NAFLD knowledge scores were independently associated with greater number of NAFLD patients seen (p<0.05).
CONCLUSION: Despite the growing burden of NAFLD, significant knowledge gap remains for identification, diagnosis and management of NAFLD.
METHODS: Clinical, laboratory, and PRO data (Chronic Liver Disease Questionnaire-nonalcoholic steatohepatitis [NASH], Functional Assessment of Chronic Illness Therapy-Fatigue, and the Work Productivity and Activity Index) were collected from NAFLD patients seen in real-world practices and enrolled in the Global NAFLD/NASH Registry encompassing 18 countries in 6 global burden of disease super-regions.
RESULTS: Across the global burden of disease super-regions, NAFLD patients (n = 5691) were oldest in Latin America and Eastern Europe and youngest in South Asia. Most men were enrolled at the Southeast and South Asia sites. Latin America and South Asia had the highest employment rates (>60%). Rates of cirrhosis varied (12%-21%), and were highest in North Africa/Middle East and Eastern Europe. Rates of metabolic syndrome components varied: 20% to 25% in South Asia and 60% to 80% in Eastern Europe. Chronic Liver Disease Questionnaire-NASH and Functional Assessment of Chronic Illness Therapy-Fatigue PRO scores were lower in NAFLD patients than general population norms (all P < .001). Across the super-regions, the lowest PRO scores were seen in Eastern Europe and North Africa/Middle East. In multivariate analysis adjusted for enrollment region, independent predictors of lower PRO scores included younger age, women, and nonhepatic comorbidities including fatigue (P < .01). Patients whose fatigue scores improved over time experienced a substantial PRO improvement. Nearly 8% of Global NAFLD/NASH Registry patients had a lean body mass index, with fewer metabolic syndrome components, fewer comorbidities, less cirrhosis, and significantly better PRO scores (P < .01).
CONCLUSIONS: NAFLD patients seen in real-world practices in different countries experience a high comorbidity burden and impaired quality of life. Future research using global data will enable more precise management and treatment strategies for these patients.
METHODS: Members of the Global NASH Council created two surveys about experiences/attitudes toward NAFLD and related diagnostic terms: a 68-item patient and a 41-item provider survey.
RESULTS: Surveys were completed by 1,976 patients with NAFLD across 23 countries (51% Middle East/North Africa [MENA], 19% Europe, 17% USA, 8% Southeast Asia, 5% South Asia) and 825 healthcare providers (67% gastroenterologists/hepatologists) across 25 countries (39% MENA, 28% Southeast Asia, 22% USA, 6% South Asia, 3% Europe). Of all patients, 48% ever disclosed having NAFLD/NASH to family/friends; the most commonly used term was "fatty liver" (88% at least sometimes); "metabolic disease" or "MAFLD" were rarely used (never by >84%). Regarding various perceptions of diagnostic terms by patients, there were no substantial differences between "NAFLD", "fatty liver disease (FLD)", "NASH", or "MAFLD". The most popular response was being neither comfortable nor uncomfortable with either term (56%-71%), with slightly greater discomfort with "FLD" among the US and South Asian patients (47-52% uncomfortable). Although 26% of patients reported stigma related to overweight/obesity, only 8% reported a history of stigmatization or discrimination due to NAFLD. Among providers, 38% believed that the term "fatty" was stigmatizing, while 34% believed that "nonalcoholic" was stigmatizing, more commonly in MENA (43%); 42% providers (gastroenterologists/hepatologists 45% vs. 37% other specialties, p = 0.03) believed that the name change to metabolic dysfunction-associated steatotic liver disease (or MASLD) might reduce stigma. Regarding the new nomenclature, the percentage of providers reporting "steatotic liver disease" as stigmatizing was low (14%).
CONCLUSIONS: The perception of NAFLD stigma varies among patients, providers, geographic locations and sub-specialties.
IMPACT AND IMPLICATIONS: Over the past decades, efforts have been made to change the nomenclature of nonalcoholic fatty liver disease (NAFLD) to better align with its underlying pathogenetic pathways and remove any potential stigma associated with the name. Given the paucity of data related to stigma in NAFLD, we undertook this global comprehensive survey to assess stigma in NAFLD among patients and providers from around the world. We found there is a disconnect between physicians and patients related to stigma and related nomenclature. With this knowledge, educational programs can be developed to better target stigma in NAFLD among all stakeholders and to provide a better opportunity for the new nomenclature to address the issues of stigma.
METHODS: Members of the Global NASH Council created a survey about disease burden in NAFLD. Participants completed a 35-item questionnaire to assess liver disease burden (LDB) (seven domains), the 36-item CLDQ-NASH (six domains) survey to assess HRQL and reported their experience with stigmatization and discrimination.
RESULTS: A total of 2,117 patients with NAFLD from 24 countries completed the LDB survey (48% Middle East and North Africa, 18% Europe, 16% USA, 18% Asia) and 778 competed CLDQ-NASH. Of the study group, 9% reported stigma due to NAFLD and 26% due to obesity. Participants who reported stigmatization due to NAFLD had substantially lower CLDQ-NASH scores (all p <0.0001). In multivariate analyses, experience with stigmatization or discrimination due to NAFLD was the strongest independent predictor of lower HRQL scores (beta from -5% to -8% of score range size, p <0.02). Experience with stigmatization due to obesity was associated with lower Activity, Emotional Health, Fatigue, and Worry domain scores, and being uncomfortable with the term "fatty liver disease" with lower Emotional Health scores (all p <0.05). In addition to stigma, the greatest disease burden as assessed by LDB was related to patients' self-blame for their liver disease.
CONCLUSIONS: Stigmatization of patients with NAFLD, whether it is caused by obesity or NAFLD, is strongly and independently associated with a substantial impairment of their HRQL. Self-blame is an important part of disease burden among patients with NAFLD.
IMPACT AND IMPLICATIONS: Patients with nonalcoholic fatty liver disease (NAFLD), recently renamed metabolic dysfunction-associated steatotic liver disease (MASLD), may experience impaired health-related quality of life and stigmatization. Using a specifically designed survey, we found that stigmatization of patients with NAFLD, whether it is caused by obesity or the liver disease per se, is strongly and independently associated with a substantial impairment of their quality of life. Physicians treating patients with NAFLD should be aware of the profound implications of stigma, the high prevalence of self-blame in the context of this disease burden, and that providers' perception may not adequately reflect patients' perspective and experience with the disease.