Effect of Calorie-Unrestricted Low-Carbohydrate, High-Fat Diet Versus High-Carbohydrate, Low-Fat Diet on Type 2 Diabetes and Nonalcoholic Fatty Liver Disease : A Randomized Controlled Trial.

BACKGROUND: It remains unclear if a low-carbohydrate, high-fat (LCHF) diet is a possible treatment strategy for type 2 diabetes mellitus (T2DM), and the effect on nonalcoholic fatty liver disease (NAFLD) has not been investigated. OBJECTIVE: To investigate the effect of a calorie-unrestricted LCHF diet, with no intention of weight loss, on T2DM and NAFLD compared with a high-carbohydrate, low-fat (HCLF) diet. DESIGN: 6-month randomized controlled trial with a 3-month follow-up. (ClinicalTrials.gov: NCT03068078). SETTING: Odense University Hospital in Denmark from November 2016 until June 2020. PARTICIPANTS: 165 participants with T2DM. INTERVENTION: Two calorie-unrestricted diets: LCHF diet with 50 to 60 energy percent (E%) fat, less than 20E% carbohydrates, and 25E% to 30E% proteins and HCLF diet with 50E% to 60E% carbohydrates, 20E% to 30E% fats, and 20E% to 25E% proteins. MEASUREMENTS: Glycemic control, serum lipid levels, metabolic markers, and liver biopsies to assess NAFLD. RESULTS: The mean age was 56 years (SD, 10), and 58% were women. Compared with the HCLF diet, participants on the LCHF diet had greater improvements in hemoglobin A1c (mean difference in change, -6.1 mmol/mol [95% CI, -9.2 to -3.0 mmol/mol] or -0.59% [CI, -0.87% to -0.30%]) and lost more weight (mean difference in change, -3.8 kg [CI, -6.2 to -1.4 kg]). Both groups had higher high-density lipoprotein cholesterol and lower triglycerides at 6 months. Changes in low-density lipoprotein cholesterol were less favorable in the LCHF diet group than in the HCLF diet group (mean difference in change, 0.37 mmol/L [CI, 0.17 to 0.58 mmol/L] or 14.3 mg/dL [CI, 6.6 to 22.4 mg/dL]). No statistically significant between-group changes were detected in the assessment of NAFLD. Changes were not sustained at the 9-month follow-up. LIMITATION: Open-label trial, self-reported adherence, unintended weight loss, and lack of adjustment for multiple comparisons. CONCLUSION: Persons with T2DM on a 6-month, calorie-unrestricted, LCHF diet had greater clinically meaningful improvements in glycemic control and weight compared with those on an HCLF diet, but the changes were not sustained 3 months after intervention. PRIMARY FUNDING SOURCE: Novo Nordisk Foundation.

Using the ELF test, FIB-4 and NAFLD fibrosis score to screen the population for liver disease.

BACKGROUND & AIMS: There is a need for accurate biomarkers of fibrosis for population screening of alcohol-related and non-alcoholic fatty liver disease (ALD, NAFLD). We compared the performance of the enhanced liver fibrosis (ELF) test to the fibrosis-4 index (FIB-4) and NAFLD fibrosis score (NFS), using transient elastography as the reference standard. METHODS: We prospectively included participants from the general population, and people at risk of ALD or NAFLD. Screening positive participants (TE ≥8 kPa) were offered a liver biopsy. We measured concomitant ELF, FIB-4, and NFS using validated cut-offs: ≥9.8, ≥1.3, ≥-1.45, respectively. RESULTS: We included 3,378 participants (1,973 general population, 953 at risk of ALD, 452 at risk of NAFLD), with a median age of 57 years (IQR: 51-63). Two hundred-and-forty-two were screening positive (3.4% in the general population, 12%/14% who were at-risk of ALD/NAFLD, respectively). Most participants with TE <8 kPa also had ELF <9.8 (88%) despite a poor overall correlation between ELF and TE (Spearman´s rho = 0.207). ELF was associated with significantly fewer false positives (11%) than FIB-4 and NFS (35% and 45%), while retaining a low rate of false negatives (<8%). A screening strategy of FIB-4 followed by ELF in indeterminate cases resulted in false positives in 8%, false negatives in 4% and the correct classification in 88% of cases. We performed a liver biopsy in 155/242 (64%) patients who screened positive, of whom 54 (35%) had advanced fibrosis (≥F3). ELF diagnosed advanced fibrosis with significantly better diagnostic accuracy than FIB-4 and NFS: AUROC 0.85 (95% CI 0.79-0.92) vs. 0.73 (0.64-0.81) and 0.66 (0.57-0.76), respectively. CONCLUSION: The ELF test alone or combined with FIB-4 for liver fibrosis screening in the general population and at-risk groups reduces the number of futile referrals compared to FIB-4 and NFS, without overlooking true cases. IMPACT AND IMPLICATIONS: We need referral pathways that are efficient at detecting advanced fibrosis from alcohol-related and non-alcoholic fatty liver disease in the population, but without causing futile referrals or excessive use of resources. This study indicates that a sequential test strategy of FIB-4 followed by the ELF test in indeterminate cases leads to few patients referred for confirmatory liver stiffness measurement, while retaining a high rate of detected cases, and at low direct costs. This two-step referral pathway could be used by primary care for mass, targeted, or opportunistic screening for liver fibrosis in the population. CLINICAL TRIAL NUMBER: Clinicaltrials.gov number NCT03308916.