Association of NAFLD/NASH, and MAFLD/MASLD with chronic kidney disease: an updated narrative review

From Liver to Kidney: The Overlooked Burden of Nonalcoholic Fatty Liver Disease in Chronic Kidney Disease

Nonalcoholic fatty liver disease (NAFLD) is increasingly recognized as a contributor to chronic kidney disease (CKD), yet its impact remains underappreciated in clinical practice. Recent studies reveal a strong association between NAFLD and CKD progression, with evidence linking hepatic dysfunction to renal impairment through metabolic and inflammatory pathways. NAFLD not only increases the risk of CKD but also accelerates its progression, leading to worse cardiovascular outcomes and higher mortality, particularly in patients with advanced fibrosis. Despite this growing evidence, NAFLD often goes undiagnosed in CKD patients and routine hepatic evaluation is rarely integrated into nephrology care. Emerging diagnostic tools, including noninvasive biomarkers and imaging techniques, offer potential for earlier detection, yet their clinical implementation remains inconsistent. Although lifestyle modifications remain the foundation of treatment, pharmacotherapeutic strategies, including SGLT2 inhibitors and GLP-1 receptor agonists, have demonstrated potential in mitigating both hepatic and renal impairment. Recognizing the interplay between NAFLD and CKD is essential for improving patient outcomes. A multidisciplinary approach, integrating hepatology and nephrology expertise, is crucial to refining screening strategies, optimizing treatment, and reducing the long-term burden of these coexisting conditions.

How 'miracle' weight-loss semaglutide promises to change medicine but can we afford the expense?

Obesity is a complex and growing global concern, affecting one in eight individuals and compromising health, quality of life and life expectancy. It carries significant metabolic, cardiovascular, oncological, hepatorenal, skeletal and psychiatric risks, imposing substantial costs on health-care systems. Traditional treatments have often been ineffective or have led to relapse after lifestyle changes. Whereas bariatric surgery is effective, it also involves risks such as mortality and hospitalisation. Semaglutide, licensed in 2018, is a synthetic analogue of glucagon-like peptide 1 which regulates glucose metabolism and gastrointestinal (GI) motility. Studies show that semaglutide, administered either weekly and subcutaneously, or daily orally, induces an average weight loss of -11.62 kg compared to placebo and reduces waist circumference by up to -9.4 cm. It also improves blood pressure, fasting glucose levels, C-reactive protein levels and lipid profiles. The most common adverse events are mild-to-moderate GI complaints occurring more frequently with daily administration than weekly doses; hypoglycaemia is more common without lifestyle intervention. Weight regain often follows semaglutide withdrawal. Furthermore, semaglutide offers cardiovascular benefits for patients with established atherosclerotic cardiovascular disease (CVD), lowers the risk of kidney outcomes and cardiovascular-related death, resolves nonalcoholic steatohepatitis in many cases, and positively impacts mental health and quality of life. In conclusion, semaglutide therapy could significantly benefit many adults regarding CVD and mortality if made widely accessible. Ethical and financial considerations must be addressed for personalised obesity treatment approaches.

PNPLA3 variation and kidney disease

Accumulating epidemiological evidence shows that the patatin-like phospholipase domain-containing protein-3 (PNPLA3) rs738409 G allele, which is the most robust genetic variant associated with greater susceptibility to metabolic dysfunction-associated steatotic liver disease (MASLD), is significantly associated with impaired kidney function in both adults and children, regardless of the presence of common renal risk factors, MASLD severity, and other potential confounders. Although some prospective studies have reported a significant association between the PNPLA3 rs738409 G allele and the increased risk of developing chronic kidney disease (CKD), the epidemiological evidence about a possible direct effect of the PNPLA3 rs738409 G allele on the risk of developing CKD is still limited. Experimentally, PNPLA3 is expressed in renal podocytes, pericytes, and proximal tubule cells, thus supporting the notion that the mutant PNPLA3 protein may play a role in developing renal steatosis and fibrosis. However, it cannot be ruled out that a part of the adverse effect of the PNPLA3 rs738409 G allele on kidney function may be driven by a direct impact of this genetic variant on the development and progression of MASLD. It is possible to hypothesize that identifying the PNPLA3 genotype might help identify individuals at higher risk of CKD and those at greater risk of advanced MASLD. In this narrative minireview, we summarize the current epidemiological data about the association between the PNPLA3 rs738409 G allele and the risk of CKD and abnormal albuminuria. We also briefly discuss the putative biological mechanisms underpinning this association and its potential and future clinical implications.

Copper and liver fibrosis in MASLD: the two-edged sword of copper deficiency and toxicity

Copper is a trace metal whose absence or deficiency can cause structural and functional alterations that can be corrected by copper administration. Copper excess is associated with significant liver toxicity, such as that seen in Wilson’s disease, which often exhibits liver steatosis and can be managed by copper sequestrants. Copper, due to its ability to either accept or donate electrons, is a cofactor in many physiological redox reactions, playing an essential role in cell energy homeostasis, detoxification of reactive oxygen species, and hepatic immunometabolism. Given these facts, it is reasonable to speculate that copper might be involved in the pathogenesis of liver fibrosis in the setting of metabolic dysfunction-associated fatty liver disease (MASLD). To address this research question, a narrative review of published studies was conducted, spanning from the needs, sources, and toxicity of copper to Menkes and Wilson’s disease. Most epidemiological studies have demonstrated that MASLD is associated with copper deficiency. However, several studies show that MASLD is associated with copper excess and very few conclude that copper is not associated with MASLD. Therefore, the putative pathomechanisms associating both copper excess and deficiency with MASLD development and progression are reviewed. In conclusion, epidemiological and pathogenic data support the notion that well-balanced copper homeostasis is a prerequisite for liver health. Accordingly, both copper excess and deficiency may potentially predispose to liver fibrosis via the development of MASLD. Therefore, studies aimed at restoring normal bodily stores of copper should be tailored according to precision medicine approaches based on the specific features of copper metabolism in individual MASLD patients.

Soft drink consumption and increased risk of nonalcoholic fatty liver disease: Results from the health workers cohort study

INTRODUCTION AND OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is a common clinical condition and an important public health problem. Some epidemiological studies have suggested that soft drinks (SD) intake is associated with NAFLD. However, the evidence is inconsistent. Our objective was to assess the association between SD consumption and the risk of NAFLD in a Mexican adult population.

MATERIALS AND METHODS

A total of 1,759 participants from the Health Workers Cohort Study (HWCS) were included in the analyses. SD intake was measured using a validated food frequency questionnaire. We classified SD consumption as follows: a) less than 1 serving per week, b) 1 to less than 3.5 servings per week, and c) 3.5 or more servings per week. Hepatic steatosis index (HSI) was calculated based on sex, BMI, and blood transaminase levels, and was categorized as NAFLD ≥ 36. To assess the relation between SD and NAFLD, we followed two approaches: fixed effects logistic regression and generalized estimating equations.

RESULTS

After adjusting for demographic characteristics, lifestyle factors, and dietary intake, the odds ratio (OR) and 95 % confidence interval (95 % CI) for NAFLD were 1.26 (95 % CI: 1.08, 1.48) for 1 to less than 3.5 servings per week and 1.42 (95 % CI: 1.19, 1.69) for ≥3.5 servings/week category in both sexes. When stratifying the analysis by sex, we observed that the association tended to be greater in men than in women.

CONCLUSIONS

The results from our prospective study indicate that SD consumption is associated with an increased risk of NAFLD.

Perspective article: determinants and assessment of cardiovascular risk in steatotic liver disease owing to metabolic dysfunction-addressing the challenge

Metabolic dysfunction-associated steatotic liver disease (MASLD) stands as an independent risk factor for cardiovascular disease (CVD), which is the leading cause of mortality among MASLD patients. The diverse spectrum of cardio-nephro-metabolic and vascular manifestations inherent in MASLD highlights the complex profile of CVD risk associated with this condition. However, current approaches to assessing CVD risk in MASLD lack specificity, predominantly relying on traditional markers. Although it is widely accepted that patients with advanced fibrosis are more prone to CVD risk, recent evidence suggests that this isolated focus may overlook the remarkable phenotypic variability of this CVD risk across the entire MASLD population. Emerging data indicate a progressive escalation of CVD risk in parallel with the severity of MASLD, highlighting the need for precise disease staging to inform accurate risk assessment. To address this challenge, we propose a novel sequential approach to CVD risk assessment in MASLD. While traditional CVD risk factors remain essential, incorporating liver-specific parameters enhances risk stratification and guides targeted interventions to mitigate the substantial burden of cardiovascular disease in this vulnerable population. This approach involves initial screening using FIB-4 and NAFLD fibrosis score, followed by assessment of liver fibrosis with imaging-based non-invasive techniques in individuals at intermediate-high risk for advanced fibrosis and liver fat quantification in low-risk individuals. Future prospective investigations should focus on the simultaneous use of liver biomarkers and imaging modalities to evaluate, in a sex-specific manner, the efficacy of the proposed approach and to determine optimal thresholds of liver fibrosis and steatosis for optimal CVD risk assessment.