Introduction
Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease encountered in hepatology departments, particularly in western countries [1,2]. Metabolic syndrome (MetS) and its individual components are associated with NAFLD pathogenesis and progression [3-5]. Abnormal fasting blood glucose levels (≥100 mg/dL) or diabetes mellitus type II (T2DM) comprise one of the components of MetS [6-8]. Several studies have shown that patients with T2DM and/or MetS are at increased risk of developing advanced stages of NAFLD [9-12], i.e., nonalcoholic steatohepatitis (NASH), advanced fibrosis/cirrhosis and hepatocellular carcinoma [13-16]. Although many trials have investigated the role of different agents in the treatment of NAFLD and NASH, none of these agents have been approved [17], and currently the only recommendation for these patients is lifestyle modification consisting of exercise and diet [18-20]. In view of the complex pathophysiology of NAFLD/NASH [21-24], combinations of treatments targeting different pathogenetic mechanisms have been studied [25-27], and several trials related to this topic are ongoing. To write this article, we reviewed the literature reporting combination treatments in NAFLD/NASH, focusing on antidiabetic medications, namely pioglitazone—a peroxisome proliferator-activated receptor (PPAR)-γ agonist—as well as the newer antidiabetic drugs, including sodium glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor (GLP-1) agonists, all of which have shown promising results in NAFLD/NASH. The recently investigated “NAFLD-specific” drugs in this field, such as selonsertib-targeting apoptosis, cilofexor-a farnesoid X receptor agonist, and the acetyl coenzyme A carboxylase inhibitor (ACCi) firsocostat, were also included. Clinical and experimental studies were reviewed.
Materials and methods
A comprehensive literature search was conducted for relevant literature using the PubMed database, in which only studies written in the English language and published until September 2022 were included. The following search terms were used: “non-alcoholic fatty liver disease” or “NAFLD” or “non-alcoholic steatohepatitis” or “NASH” or “fatty liver” AND “pioglitazone” or “sodium glucose co-transporter 2 inhibitor” or “SGLT2 inhibitors” or “glucagon-like peptide-1 receptor agonist” or “GLP-1 agonist” or “acetyl CoA carboxylase inhibitor” or “farnesoid X receptor agonist” or every drug included in the last 4 categories. In addition, we searched for the terms “combination treatment in NAFLD”, “combination treatment in NASH”, “combined in NAFLD” and “combined in NASH”. Animal and human studies involving a combination of 2 or more of the above-mentioned categories of agents were included in the present review.
NAFLD combination therapies: animal studies (Table 1)
Ipragliflozin and pioglitazone
Tahara et al [28] conducted a study to examine the effects of ipragliflozin-a SGLT-2 inhibitor, alone or in combination with pioglitazone, in high-fat diet-fed KK/Ay T2DM mice with NASH. Diabetic mice received vehicle, or ipragliflozin, or pioglitazone, or ipragliflozin in combination with pioglitazone, for 4 weeks. At week 4, hepatic lipid contents and transaminases levels were significantly reduced after ipragliflozin and combination therapy, while the ipragliflozin and pioglitazone combination increased adiponectin levels (P<0.05 vs. vehicle group).
Table 1 Animal trials concerning combinations of antidiabetic (pioglitazone, GLP-1 agonists, SGLT-2 inhibitors) and “NAFLD-specific” drugs in NAFLD/NASH
Liraglutide and ipragliflozin
Koike et al [29] evaluated the effects of liraglutide (a GLP-1 agonist) and ipragliflozin as monotherapy or in combination in mouse models with T2DM. Diet-induced obese (DIO) mice, representing an early-stage diabetes model, and leptin receptor deficient C57BL/6 +Lepr <db>/+Lepr <db> (db/db) mice, as an advanced stage diabetes model, were studied. Four groups of DIO mice were evaluated: liraglutide group, ipragliflozin group, combination group and controls (vehicles). Alanine aminotransferase (ALT) levels were significantly lower in the liraglutide (P<0.01) and combination group (P<0.05) and tended to be lower in the ipragliflozin group, compared to the control group. Ipragliflozin, liraglutide and their combination reduced the NAFLD activity score to similar degrees. All treatments also reduced liver lipid accumulation, ipragliflozin to a lesser degree than the other treatment arms. However, hepatic triglycerides were significantly lower in the liraglutide and combination groups compared to the ipragliflozin group (P<0.01).
Regarding the db/db mice model, plasma ALT levels were lower in the liraglutide (P<0.01) and combination treatment groups (P<0.001) compared with the control group. Ipragliflozin and combination therapy reduced the NAFLD activity score (P<0.001 and P<0.05 vs. control, respectively), but no significant differences between groups were observed in reductions of hepatic lipid accumulation.
“NAFLD-specific” drugs
Vijayakumar et al [30] performed 5 in vivo studies in 3 mouse models and evaluated whether enhancing hepatocyte fatty acid oxidation by combining ACCi with PPAR agonist or thyroid hormone receptor β (THRβ) agonist would result in greater liver triglyceride reduction and NASH/antifibrotic efficacy along with amelioration of ACCi-induced hypertriglyceridemia. The duration of the studies was 2-6 weeks. In high-fat diet-fed dyslipidemic rats, it was found that the addition of PPAR agonists (fenofibrate, elafibranor, lanifibranor, seladelpar or saroglitazar) or resmetirom (a THRβ agonist) to an analog of firsocostat (ACCi) prevented ACCi-induced hypertriglyceridemia, while only PPARα agonists (fenofibrate, elafibranor) and resmetirom provided additional liver triglyceride reduction. In the choline-deficient high-fat diet rat model of advanced liver fibrosis, neither PPARα (fenofibrate) nor THRβ agonist augmented the antifibrotic efficacy of ACCi.
Combination anti-diabetic therapies in NAFLD: clinical studies (Table 2A and 2B)
Pioglitazone
Exenatide and pioglitazone
Sathyanarayana et al [31] evaluated the effects of exenatide, a GLP-1 receptor agonist, in combination with pioglitazone, on hepatic fat content and levels of plasma adiponectin (the most common adipokine to be inversely linked with insulin resistance, inflammation, lipid accumulation and NAFLD) in patients with T2DM. Twenty-four diabetic patients on diet and/or metformin were enrolled, of whom 21 completed the study. Liver fat content was assessed by magnetic resonance spectroscopy (MRS). Patients were randomized to receive pioglitazone, either alone or combined with exenatide 5 μg, subcutaneously b.i.d. for 2 weeks, followed by exenatide 10 μg subcutaneously b.i.d. All patients in both arms started pioglitazone 30 mg/day for 2 weeks, followed by pioglitazone 45 mg/day for 48 weeks.
In the combination therapy, a significant reduction in hepatic fat content was observed after 12 months (12.1±1.7% at baseline vs. 4.7±1.3% at 12 months, P<0.001). This reduction was significantly greater than under pioglitazone alone (11.0±3.1% at baseline vs. 6.5±1.9% at 12 months, P<0.05). In addition, a greater improvement in ALT was observed in the combination group compared to pioglitazone alone. Interestingly, in both treatment arms adiponectin levels increased compared to baseline (pioglitazone arm: from 8.5±0.8 to 15.8±1.4 μg/mL, combination arm: from 7.9±0.9 to 23.2±2.7 μg/mL, P<0.001), but the increase was greater in the latter arm (193% vs. 86%, P<0.001).
Table 2 (A) Clinical trials that evaluated combinations of antidiabetic (pioglitazone, GLP-1 agonists, SGLT-2 inhibitors) and “NAFLD-specific” drugs in NAFLD/NASH)
Table 2 (B) Clinical trials that evaluated combinations of antidiabetic (pioglitazone, GLP-1 agonists, SGLT-2 inhibitors) and “NAFLD-specific” drugs in NAFLD/NASH
Tofogliflozin and pioglitazone
Yoneda et al [32] conducted an open-label, prospective randomized trial in which tofogliflozin, an SGLT2 inhibitor, and pioglitazone were combined to treat hepatic steatosis in patients with T2DM and NAFLD, defined as ≥10% liver fat content on magnetic resonance imaging proton density fat fraction (MRI-PDFF). This study was actually the second half of the ToPiND trial, which investigated the effectiveness of tofogliflozin and pioglitazone monotherapy on NAFLD. Forty patients were initially assigned to receive tofogliflozin 20 mg or pioglitazone 15-30 mg q.d. for 24 weeks. In 20 patients who received tofogliflozin and 12 who received pioglitazone and met the inclusion criteria, combination treatment was administered for an additional 24 weeks.
In patients who first received pioglitazone with the later addition of tofogliflozin, combination therapy showed an additional improvement in ALT levels compared to monotherapy (P<0.01). MRI-PDFF was improved after 24 weeks of monotherapy treatment (-3.38±4.90%, P=0.0061 with tofogliflozin, and -5.56±3.92%, P<0.001 with pioglitazone), but combination treatment further improved MRI-PDFF by -2.60% and -0.42%, respectively. Interestingly, pioglitazone and combination therapy significantly reduced magnetic resonance elastography liver stiffness measurements (MRE-LSM) (-0.43±0.61 kPa, P=0.00364 and -0.40±0.54 kPa, P<0.001, respectively). Adiponectin increased from baseline in all groups (0.40±0.63 μg/mL, P=0.0107 vs. 7.21±5.12 μg/mL, P<0.001, vs. 5.45±3.90 μg/mL, P<0.001 respectively).
Combination of newer antidiabetic agents
Exenatide and dapagliflozin
Two studies investigated the effects of the combination of exenatide and dapagliflozin, a SGLT2 inhibitor, in patients with T2DM and NAFLD/NASH. The first was a post hoc analysis of the DURATION-8 study, which enrolled patients with T2DM uncontrolled by metformin monotherapy. In this study, Gastaldelli et al [33] assessed the efficacy of exenatide once weekly subcutaneously combined with dapagliflozin once daily, versus each drug alone, in lowering noninvasive biomarkers of liver steatosis and fibrosis along with liver biochemistry and insulin resistance. In total, 695 participants were randomized to receive exenatide 2 mg once weekly plus dapagliflozin 10 mg/day orally, exenatide 2 mg once weekly plus placebo or dapagliflozin 10 mg/day plus placebo for 104 weeks. The biomarkers that were evaluated at weeks 28 and 52 were fatty liver index (FLI) (based on serum triglyceride levels, γ-glutamyltranspeptidase [γ-GT], body mass index [BMI], and waist circumference), NAFLD liver fat score [NLFS] (which includes the presence of T2DM and MetS, fasting serum insulin, AST and the AST: ALT ratio) for evaluation of steatosis, as well as the fibrosis-4 index [FIB-4] (which comprises age, platelet count [PLT], AST, and ALT) and the NAFLD fibrosis score [NFS] (which is based on the presence of impaired fasting glucose or T2DM and includes age, BMI, PLT, AST: ALT ratio and albumin) for the evaluation of fibrosis. Interestingly, greater changes were observed in: a) FLI with the combination of exenatide/dapagliflozin versus dapagliflozin/placebo at week 28 (P=0.0162); and b) FLI and NLFS in the combination treatment group compared with the exenatide/placebo group at weeks 28 and 52 (P=0.008 and 0.0036 for FLI and P<0.001 and P<0.001 for NLFS, respectively). At weeks 28 and 52, similar reductions in NFS were found in all groups, whereas FIB-4 decreased only in patients under combination therapy (P=0.0135 and 0.0308, respectively). At week 28, combination treatment reduced the proportion of patients with noninvasive scores suggestive of severe fibrosis (i.e., FIB-4 ≥1.3 and NFS >0.676) by 4.1% and 2.8%, respectively.
Harreiter et al [34] investigated the effects of combined exenatide and dapagliflozin versus dapagliflozin and placebo on hepatocellular lipid (HCL) concentrations in patients with T2DM under metformin therapy. Subjects were randomized and stratified by BMI to receive either exenatide 2 mg subcutaneously once a week and dapagliflozin 10 mg/day orally, or dapagliflozin 10 mg/day and placebo for 24 weeks. A hepatic triglyceride threshold of ≥5.56% was used to determine hepatic steatosis.
HCL, assessed by MRS, decreased similarly in both treatment groups compared to baseline. As regards liver enzymes, after 24 weeks of treatment, ALT levels were lower in the combination treatment group compared to baseline (P<0.01). The authors did not detect any differences between the 2 arms regarding FIB-4 score or FLI. Both therapeutic approaches reduced FLI (P=0.002 for both), whereas FIB-4 score was lower under dapagliflozin treatment (P=0.028) compared to baseline.
Combination of “NAFLD-specific” with or without antidiabetic agents
Selonsertib, cilofexor, and firsocostat
Loomba et al [35] evaluated the effects of selonsertib (an apoptosis signal-regulating kinase 1), cilofexor (a farnesoid X receptor agonist) and firsocostat (an ACCi), alone or in 2-drug combinations, in patients with biopsy-proven NASH-related bridging fibrosis or compensated cirrhosis. However, 20% of the controls were enrolled based on noninvasive markers consistent with advanced fibrosis: vibration-controlled transient elastography ≥14.4 kPa and enhanced liver fibrosis test ≥9.8. Patients were randomized to 7 groups: placebo, or selonsertib 18 mg, or cilofexor 30 mg, or firsocostat 20 mg, or combination treatment with either cilofexor/selonsertib or firsocostat/selonsertib or cilofexor/firsocostat. The regimens were administered orally once daily for 48 weeks. Liver biopsies were also performed at week 48 and were evaluated post hoc by a machine learning (ML) approach validated for the assessment of NASH pathology. A weighted average of the proportionate areas of each fibrosis stage pattern was calculated (ML NASH Clinical Research Network [CRN] fibrosis score).
Differences in the primary endpoint (i.e., a ≥1-stage improvement in fibrosis without worsening of NASH) did not reach statistical significance between groups. However, combination treatment with cilofexor/firsocostat was more likely to achieve a ≥2-point improvement in NAFLD activity score compared to placebo (35% vs. 11%, P=0.002) and ≥1-grade improvements in steatosis (26% vs. 6%, P=0.009), ballooning (29% vs. 13%, P=0.04), and lobular inflammation (57% vs. 29%, P=0.004), while progression to cirrhosis was less frequent in patients treated with the combination of cilofexor/selonsertib than in those receiving placebo (8% vs. 41%, P=0.018).
With firsocostat monotherapy, steatosis based on MRI-PDFF and liver histology was decreased compared to baseline (P=0.033 and P=0.017 vs. placebo at week 48, respectively), while steatosis according to MRI-PDFF was also reduced in all combination treatments compared to placebo at week 48. Interestingly, compared with placebo, cilofexor/firsocostat significantly decreased ML NASH CRN fibrosis score (P=0.04) Finally, all combination groups reduced the proportionate area of steatosis compared to placebo (P-values always <0.05).
Semaglutide, cilofexor, and firsocostat
A phase II open-label, randomized proof-of-concept trial [36] evaluated the safety and tolerability of subcutaneous semaglutide (a GLP-1 agonist) alone or in combination with cilofexor and/or firsocostat in NASH patients with mild-to-moderate fibrosis (F2-F3) on biopsy or fat fraction ≥10% on MRI-PDFF and liver stiffness ≥7 kPa on transient elastography). Patients were randomized to receive semaglutide alone once a week (at a starting dose of 0.24 mg and increased monthly to 0.5 mg, 1.0 mg and 1.7 mg and to 2.4 mg after week 17). or combined with cilofexor 30 mg/day or cilofexor 100 mg/day or firsocostat 20 mg/day or cilofexor 30 mg and firsocostat 20 mg for 24 weeks.
All combination treatments achieved greater reduction in liver steatosis, evaluated by MRI-PDFF, compared with semaglutide alone, but the decrease was statistically significant only in the semaglutide plus firsocostat arm (-11% vs. -8% in semaglutide alone, P=0.0353). However, in a sensitivity analysis, excluding patients with imaging data at least 1 month after the last dose of the study, the difference between semaglutide compared to semaglutide plus cilofexor plus firsocostat was also significant (-8.6% vs. -12.6%, P=0.0078). The proportion of patients who achieved a relative reduction in MRI-PDFF of ≥50%, compared to baseline, was greater for the combination regimens than for semaglutide alone (58.8-76.2% vs. 38.9%, respectively, always P>0.05). Interestingly, 29.4% of the patients who received semaglutide alone achieved normalization of liver fat content by MRI-PDFF (i.e., liver fat <5%), compared to 38.1-41.2% of patients under combination regimens (always P>0.05). Treatment with semaglutide plus firsocostat and semaglutide plus cilofexor 30 mg significantly reduced liver steatosis assessed by the controlled attenuation parameter (CAP), compared to semaglutide monotherapy (P=0.0034 and 0.0379, respectively). Liver stiffness measured by magnetic resonance elastography (MRE) did not change from baseline to the end of study and no differences were observed between groups.
Discussion
The highly heterogenous pathogenesis of NAFLD/NASH implies that an individualized approach would be a reasonable option to treat and control the consequences of the disease [37,38]. Combining medications that have the same or, preferably, different targets would appear to be an interesting approach with many potential benefits. The concomitant use of drugs may have synergistic effects, enhancing the efficacy of the regimen. Additionally, this strategy allows the use of lower doses of each drug, increasing the tolerability and attenuating the possible side-effects [27]. Table 3 summarizes the combinations of drugs in these categories that have been studied so far. Several trials that investigated the efficacy of combination therapies in NAFLD/NASH are ongoing, and antidiabetic drugs, including pioglitazone or the newer classes of antidiabetic regimens, as well as “NAFLD-specific” drugs, are part of them (Table 4). Interestingly, newer antidiabetic drugs with more than one way of action—such as tirzepatide, a dual glucose-dependent insulinotropic polypeptide and GLP-1 receptor agonist, and cotadutide, a dual glucagon-like protein-1 receptor and glucagon receptor agonist—seem promising agents for the therapy of NAFLD/NASH [39,40].
Table 3 Summary of the combinations of antidiabetic (pioglitazone, GLP-1 agonists, SGLT-2 inhibitors) and “NAFLD-specific” drugs in NAFLD/NASH
Table 4 Ongoing trials evaluating combinations of antidiabetic (pioglitazone, GLP-1 agonists, SGLT-2 inhibitors) and “NAFLD specific” drugs in NAFLD/NASH
So far, animal studies regarding this topic have shown encouraging results. In the study of Tahara et al [28], a combination of ipragliflozin and pioglitazone significantly and additively improved liver fibrosis in T2DM mice compared to monotherapy. However, in 5 in vivo studies using preclinical models of NASH and fibrosis [30], the combination of ACCi with hepatic lipid modulating agents did not augment antifibrotic efficacy. In a study by Koike et al [29], pancreatic insulin content and β cell area were further increased in db/db mice under combination therapy with liraglutide plus ipragliflozin, compared to ipragliflozin monotherapy, leading to better glycemic control. On the other hand, liraglutide and/or ipragliflozin reduced hepatic lipid accumulation similarly in DIO mice. However, no evaluation of fibrosis parameters was performed in this study, although fibrosis is considered to be an optimal target for these therapies.
Regarding the clinical studies published so far, 2 randomized controlled trials evaluated the combination of pioglitazone with either a GLP-1 receptor agonist or an SGLT-2 inhibitor. Sathyanarayana et al [31] found that, in patients with T2DM, combination treatment with pioglitazone and exenatide resulted in a greater reduction of ALT as well as hepatic fat content, compared to pioglitazone alone, although no significant change in body weight was observed. However, the effects of combined treatment on liver fibrosis were not evaluated in this study. In another study from Japan [32], the combination of pioglitazone and tofogliflozin improved ALT levels, liver steatosis and stiffness compared to tofogliflozin alone, in patients with T2DM and NAFLD. Interestingly, the combination treatment also resulted in an improvement of lipidemic profile and increased adiponectin levels.
Regarding the newer antidiabetic agents, the combination of exenatide and dapagliflozin has been studied in 2 trials, with contradictory results. In the first study [33], the combination treatment improved markers of liver steatosis and fibrosis in patients with T2DM, uncontrolled by metformin; however, in the second study [34], which was a small pilot study, combination therapy had no additive effects on the reduction of hepatocellular lipids in patients with T2DM, despite better glycemic control.
As for the use of “NAFLD-specific” drugs, in a phase 2b trial [35], which enrolled patients with bridging fibrosis or compensated cirrhosis attributable to NASH, steatosis was reduced in all studied combination treatments (cilofexor/firsocostat, cilofexor/selonsertib and firsocostat/selonsertib) versus placebo. However, only the combination of cilofexor/firsocostat was found to improve NASH activity, and there were indications that it may also exert an antifibrotic effect, so this combination regimen seems to be a better option for this category of patients. In another phase 2 trial [36], which studied the combinations of semaglutide/cilofexor, semaglutide/firsocostat and semaglutide/cilofexor/firsocostat in patients with mild to moderate fibrosis due to NASH, only semaglutide/firsocostat significantly reduced liver steatosis measured by MRI-PDFF or CAP, whereas semaglutide plus cilofexor 30 mg reduced only steatosis evaluated by CAP, compared to monotherapy with semaglutide. However, no differences in liver stiffness were observed between groups. Interestingly, compared to semaglutide monotherapy, the FAST score, which incorporates liver stiffness, liver steatosis and AST levels, was reduced in all combination regimens except for semaglutide plus cilofexor 100 mg.
Concluding remarks
Combining new antidiabetic medicines as well as new “NAFLD-specific” drugs is a promising approach to the treatment of NAFLD/NASH, and many trials are ongoing in this area (Table 4). As no treatment is currently approved for this entity, further research is needed to specify the categories of patients that could benefit more from this strategy, focusing on patients with or without T2DM/MetS and taking into account the complexity of NASH pathophysiology.
References
1. Younossi ZM, Koenig AB, Abdelatif D, Fazel Y, Henry L, Wymer M. Global epidemiology of nonalcoholic fatty liver disease-Meta-analytic assessment of prevalence, incidence, and outcomes. Hepatology 2016;64:73-84.
2. Vernon G, Baranova A, Younossi ZM. Systematic review:the epidemiology and natural history of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in adults. Aliment Pharmacol Ther 2011;34:274-285.
3. Jinjuvadia R, Antaki F, Lohia P, Liangpunsakul S. The association between nonalcoholic fatty liver disease and metabolic abnormalities in the United States population. J Clin Gastroenterol 2017;51:160-166.
4. Saklayen MG. The global epidemic of the metabolic syndrome. Curr Hypertens Rep 2018;20:12.
5. Kim D, Chung GE, Kwak MS, et al. Body fat distribution and risk of incident and regressed nonalcoholic fatty liver disease. Clin Gastroenterol Hepatol 2016;14:132-138.e4.
6. Eslam M, Sanyal AJ, George J;International Consensus Panel. MAFLD:a consensus-driven proposed nomenclature for metabolic associated fatty liver disease. Gastroenterology 2020;158:1999-2014.
7. Eslam M, Newsome PN, Sarin SK, et al. A new definition for metabolic dysfunction-associated fatty liver disease:an international expert consensus statement. J Hepatol 2020;73:202-209.
8. Polyzos SA, Mantzoros CS. Making progress in nonalcoholic fatty liver disease (NAFLD) as we are transitioning from the era of NAFLD to dys-metabolism associated fatty liver disease (DAFLD). Metabolism 2020;111S:154318.
9. Cusi K. Time to include nonalcoholic steatohepatitis in the management of patients with type 2 diabetes. Diabetes Care 2020;43:275-279.
10. Younossi ZM, Golabi P, de Avila L, et al. The global epidemiology of NAFLD and NASH in patients with type 2 diabetes:a systematic review and meta-analysis. J Hepatol 2019;71:793-801.
11. Dai W, Ye L, Liu A, et al. Prevalence of nonalcoholic fatty liver disease in patients with type 2 diabetes mellitus:a meta-analysis. Medicine (Baltimore) 2017;96:e8179.
12. Hazlehurst JM, Woods C, Marjot T, Cobbold JF, Tomlinson JW. Non-alcoholic fatty liver disease and diabetes. Metabolism 2016;65:1096-1108.
13. Angulo P. Long-term mortality in nonalcoholic fatty liver disease:is liver histology of any prognostic significance?Hepatology 2010;51:373-375.
14. Wree A, Broderick L, Canbay A, Hoffman HM, Feldstein AE. From NAFLD to NASH to cirrhosis-new insights into disease mechanisms. Nat Rev Gastroenterol Hepatol 2013;10:627-636.
15. Shetty K, Chen J, Shin JH, Jogunoori W, Mishra L. Pathogenesis of hepatocellular carcinoma development in non alcoholic fatty liver disease. Curr Hepatol Rep 2015;14:119-127.
16. Wainwright P, Scorletti E, Byrne CD. Type 2 diabetes and hepatocellular carcinoma:risk factors and pathogenesis. Curr Diab Rep 2017;17:20.
17. Kenneally S, Sier JH, Moore JB. Efficacy of dietary and physical activity intervention in non-alcoholic fatty liver disease:a systematic review. BMJ Open Gastroenterol 2017;4:e000139.
18. Hallsworth K, Adams LA. Lifestyle modification in NAFLD/NASH:Facts and figures. JHEP Rep 2019;1:468-479.
19. Vilar-Gomez E, Martinez-Perez Y, Calzadilla-Bertot L, et al. Weight loss through lifestyle modification significantly reduces features of nonalcoholic steatohepatitis. Gastroenterology 2015;149:367-378.e5.
20. Romero-Gómez M, Zelber-Sagi S, Trenell M. Treatment of NAFLD with diet, physical activity and exercise. J Hepatol 2017;67:829-846.
21. Buzzetti E, Pinzani M, Tsochatzis EA. The multiple-hit pathogenesis of non-alcoholic fatty liver disease (NAFLD). Metabolism 2016;65:1038-1048.
22. Polyzos SA, Kountouras J, Mantzoros CS. Obesity and nonalcoholic fatty liver disease:From pathophysiology to therapeutics. Metabolism 2019;92:82-97.
23. Bedossa P. Pathology of non-alcoholic fatty liver disease. Liver Int 2017;37(Suppl 1):85-89.
24. Makri E, Goulas A, Polyzos SA. Epidemiology, pathogenesis, diagnosis and emerging treatment of nonalcoholic fatty liver disease. Arch Med Res 2021;52:25-37.
25. Polyzos SA, Kang ES, Boutari C, Rhee EJ, Mantzoros CS. Current and emerging pharmacological options for the treatment of nonalcoholic steatohepatitis. Metabolism 2020;111S:154203.
26. Dufour JF, Caussy C, Loomba R. Combination therapy for non-alcoholic steatohepatitis:rationale, opportunities and challenges. Gut 2020;69:1877-1884.
27. Makri ES, Makri E, Polyzos SA. Combination therapies for nonalcoholic fatty liver disease. J Pers Med 2022;12:1166.
28. Tahara A, Takasu T. SGLT2 inhibitor ipragliflozin alone and combined with pioglitazone prevents progression of nonalcoholic steatohepatitis in a type 2 diabetes rodent model. Physiol Rep 2019;7:e14286.
29. Koike M, Saito H, Kohno G, Takubo M, Watanabe K, Ishihara H. Effects of GLP-1RA and SGLT2i, alone or in combination, on mouse models of type 2 diabetes representing different disease stages. Int J Mol Sci 2021;22:11463.
30. Vijayakumar A, Okesli-Armlovich A, Wang T, et al. Combinations of an acetyl CoA carboxylase inhibitor with hepatic lipid modulating agents do not augment antifibrotic efficacy in preclinical models of NASH and fibrosis. Hepatol Commun 2022;6:2298-2309.
31. Sathyanarayana P, Jogi M, Muthupillai R, Krishnamurthy R, Samson SL, Bajaj M. Effects of combined exenatide and pioglitazone therapy on hepatic fat content in type 2 diabetes. Obesity (Silver Spring) 2011;19:2310-2315.
32. Yoneda M, Kobayashi T, Honda Y, et al. Combination of tofogliflozin and pioglitazone for NAFLD:Extension to the ToPiND randomized controlled trial. Hepatol Commun 2022;6:2273-2285.
33. Gastaldelli A, Repetto E, Guja C, et al. Exenatide and dapagliflozin combination improves markers of liver steatosis and fibrosis in patients with type 2 diabetes. Diabetes Obes Metab 2020;22:393-403.
34. Harreiter J, Just I, Leutner M, et al. Combined exenatide and dapagliflozin has no additive effects on reduction of hepatocellular lipids despite better glycaemic control in patients with type 2 diabetes mellitus treated with metformin:EXENDA, a 24-week, prospective, randomized, placebo-controlled pilot trial. Diabetes Obes Metab 2021;23:1129-1139.
35. Loomba R, Noureddin M, Kowdley KV, et al;ATLAS Investigators. Combination therapies including cilofexor and firsocostat for bridging fibrosis and cirrhosis attributable to NASH. Hepatology 2021;73:625-643.
36. Alkhouri N, Herring R, Kabler H, et al. Safety and efficacy of combination therapy with semaglutide, cilofexor and firsocostat in patients with non-alcoholic steatohepatitis:A randomised, open-label phase II trial. J Hepatol 2022;77:607-618.
37. Polyzos SA, Kountouras J, Anastasiadis S, Doulberis M, Katsinelos P. Nonalcoholic fatty liver disease:is it time for combination treatment and a diabetes-like approach?Hepatology 2018;68:389.
38. Polyzos SA, Kountouras J, Zavos C, Deretzi G. Nonalcoholic fatty liver disease:multimodal treatment options for a pathogenetically multiple-hit disease. J Clin Gastroenterol 2012;46:272-284.
39. MuzurovićEM, Volčanšek, TomšićKZ, et al. Glucagon-like peptide-1 receptor agonists and dual glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 receptor agonists in the treatment of obesity/metabolic syndrome, prediabetes/diabetes and non-alcoholic fatty liver disease-current evidence. J Cardiovasc Pharmacol Ther 2022;27:10742484221146371.
40. Boland ML, Laker RC, Mather K, et al. Resolution of NASH and hepatic fibrosis by the GLP-1R/GcgR dual-agonist Cotadutide via modulating mitochondrial function and lipogenesis. Nat Metab 2020;2:413-431.