A fatty liver leads to decreased kidney function?

Liver fat content assessed by conventional B-mode ultrasound and metabolic profile in non-diabetic patients: Implications for clinical practice

Introduction

Several studies have demonstrated a positive correlation between severe hepatic steatosis and metabolic alterations; however, few studies have addressed the potential association between different grades of steatosis and clinical patterns in a non-diabetic population.

Methods

We conducted a cross-sectional study of 223 non-diabetic individuals. The severity of steatosis was assessed using B-mode ultrasound. We analyzed lipid and glucose profiles according to the severity of hepatic steatosis. Estimated glomerular filtration rate (eGFR) values were also recorded to investigate the potential impact of steatosis on kidney function.

Results

Patients with steatosis were found to have higher insulinemia and mean values of fasting plasma glucose compared to patients without steatosis. A significant decrease in high-density lipoprotein level was observed only in patients with severe or moderate steatosis. All grades of steatosis were associated with increased triglyceride levels, which were more significant in severe steatosis. Subgroup analysis by body mass index demonstrated a significant difference between lean patients with steatosis and lean patients without steatosis for triglycerides (p = 0.002) and high-density lipoprotein levels (p = 0.019). Finally, patients diagnosed with steatosis demonstrated a higher prevalence of estimated glomerular filtration rate < 90 ml/min.

Conclusion

The degree of steatosis diagnosed at ultrasound may predict glucose or lipid metabolism disorders and a decline in kidney function in a non-diabetic population.

Mini Review: Reappraisal of Uric Acid in Chronic Kidney Disease

Hyperuricemia predicts the development of chronic kidney disease (CKD) and metabolic complications, but whether it has a causal role has been controversial. This is especially true given the 2 recently conducted randomized controlled trials that failed to show a benefit of lowering uric acid in type 1 diabetes-associated CKD and subjects with stage 3-4 CKD. While these studies suggest that use of urate-lowering drugs in unselected patients is unlikely to slow the progression of CKD, there are subsets of subjects with CKD where reducing uric acid synthesis may be beneficial. This may be the case in patients with gout, hyperuricemia (especially associated with increased production), and urate crystalluria. Here, we discuss the evidence and propose that future clinical trials targeting these specific subgroups should be performed.

Non-alcoholic fatty liver disease: A patient guideline

This patient guideline is intended for all patients at risk of or living with non-alcoholic fatty liver disease (NAFLD). NAFLD is the most frequent chronic liver disease worldwide and comes with a high disease burden. Yet, there is a lot of unawareness. Furthermore, many aspects of the disease are still to be unravelled, which has an important impact on the information that is given (or not) to patients. Its management requires a close interaction between patients and their many healthcare providers. It is important for patients to develop a full understanding of NAFLD in order to enable them to take an active role in their disease management. This guide summarises the current knowledge relevant to NAFLD and its management. It has been developed by patients, patient representatives, clinicians and scientists and is based on current scientific recommendations, intended to support patients in making informed decisions.

Non-alcoholic fatty liver disease is associated with increased risk of chronic kidney disease

BACKGROUND AND AIMS

Whether non-alcoholic fatty liver disease (NAFLD) is associated with an increased risk of incident chronic kidney disease (CKD) independent of established cardio-renal risk factors remains controversial. We aimed to provide a quantitative estimate of the association and strength between NAFLD and risk of CKD after adjustment for multiple cardio-renal risk factors.

METHODS

We searched electronic databases (PubMed, Embase, and Google Scholar) for studies published from database inception until 30 November 2020. Analysis included cohort studies that reported multivariable-adjusted risk ratios [including odds ratios, relative risks (RRs), or hazard ratios] and 95% confidence intervals (CIs) for CKD of NAFLD compared with individuals without NAFLD.

RESULTS

A total of 11 cohort studies were included comprising 1,198,242 participants (46.3% women) for analysis. The median follow-up duration was 3.7 years, with 31,922 cases of incident CKD. Compared with individuals without NAFLD, unadjusted models showed that NAFLD was associated with a higher risk of CKD (RR 1.54, 95% CI 1.38-1.71). After adjusting for multiple cardio-renal risk factors, the CKD risk was still significantly increased in patients with NAFLD (RR 1.39, 95% CI 1.27-1.52). Compared with individuals without NAFLD, the adjusted absolute risk increase in NAFLD for CKD was 5.1 (95% CI 3.5-6.8) per 1000 person-years.

CONCLUSION

NAFLD is associated with an increased risk of incident CKD independent of established cardio-renal risk factors.

Role of non-alcoholic fatty liver disease in the evolution of renal function in patients with diabetes mellitus

BACKGROUND

Increasing prevalence in type 2 diabetes mellitus (T2DM) have influenced in an increasing prevalence of chronic kidney disease (CKD). Little is known about the influence of non-alcoholic fatty liver disease (NAFLD) on progression of CKD. The aim of this study was to analyse the role of NAFLD and its severity in the progression of renal function in patients with T2DM.

METHODS

Retrospective and observational study, including patients with T2DM and estimated glomerular filtration rate (eGFR) >30 ml/min/1,73m2. NAFLD was defined with presence of compatible ultrasonography and/or presence of fibrosis using NAFLD score. Patients were classified in three groups according to the NAFLD score; group 1 <-1.85, group 2 -1.85 to 0.18, and group 3 > 0.18.

RESULTS

A total of 102 patients were included (67.6% males, median age 59 [53-64] years), with median time of T2DM evolution was 70 [39-131] months. Group 3 had lower eGFR (84.8  ±  40.4 vs 71.4  ±  30.6 ml/min/1.73m2; p = 0.03) and higher proteinuria at baseline (0.56  ±  0.77 vs 1.59  ±  2.70 g/24h; p = 0.05). After a follow-up time of 75.8  ±  23.9 months, group 3 had a significant decrease in eGFR (66.6  ±  33.3 vs 36.8  ±  23.1 ml/min/1.73m2; p = <0.01), and higher risk of CKD progression (OR 7.50; CI 95% 2.76-20.35; p = <0.001) defined as decrease in > 50% eGFR.

CONCLUSIONS

The presence of NAFLD with high-risk fibrosis confers higher risk of CKD progression in patients with T2DM. Therefore, NAFLD should be a risk factor evaluated in these patients to optimise treatment.

Pharmacological Treatment for Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has become the most frequently encountered chronic liver disease. NAFLD is associated with increased liver-related morbidity and mortality, but also contributes to cardiovascular disease, diabetes and non-liver-related malignancy. Non-alcoholic steatohepatitis (NASH) is considered the more severe subtype of NAFLD that drives most of these adverse outcomes. Lifestyle modification and associated weight loss can improve NASH but are not always sufficient and sustained results are difficult to obtain. There is hence an urgent need for pharmacological treatment. In this review we discuss some of the concepts and challenges in the development of pharmacological treatment. We also briefly summarise what can be achieved with some of the drugs that are currently available for other indications but have demonstrated benefit in the treatment of NASH. Finally we present an overview of some of the main drugs or types of drugs, mainly based on their mode of action, that are now being developed specifically to treat NASH and that might soon result in the availability of drugs licensed for NASH.

Intracellular lipids are an independent cause of liver injury and chronic kidney disease in non alcoholic fatty liver disease-like context

Objective

Ectopic lipid accumulation in the liver and kidneys is a hallmark of metabolic diseases leading to non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD). Moreover, recent data have highlighted a strong correlation between NAFLD and CKD incidences. In this study, we use two mouse models of hepatic steatosis or CKD, each initiated independently of the other upon the suppression of glucose production specifically in the liver or kidneys, to elucidate the mechanisms underlying the development of CKD in the context of NAFLD-like pathology.

Methods

Mice with a deletion of G6pc, encoding glucose-6 phosphatase catalytic subunit, specifically in the liver (L.G6pc^−/− mice) or the kidneys (K.G6pc^−/− mice), were fed with either a standard diet or a high fat/high sucrose (HF/HS) diet during 9 months. These mice represent two original models of a rare metabolic disease named Glycogen Storage Disease Type Ia (GSDIa) that is characterized by both NAFLD-like pathology and CKD. Two other groups of L.G6pc^−/− and K.G6pc^−/− mice were fed a standard diet for 6 months and then treated with fenofibrate for 3 months. Lipid and glucose metabolisms were characterized, and NAFLD-like and CKD damages were evaluated.

Results

Lipid depot exacerbation upon high-calorie diet strongly accelerated hepatic and renal pathologies induced by the G6pc-deficiency. In L.G6pc^−/− mice, HF/HS diet increased liver injuries, characterized by higher levels of plasmatic transaminases and increased hepatic tumor incidence. In K.G6pc^−/− mice, HF/HS diet increased urinary albumin and lipocalin 2 excretion and aggravated renal fibrosis. In both cases, the worsening of NAFLD-like injuries and CKD was independent of glycogen content. Furthermore, fenofibrate, via the activation of lipid oxidation significantly decreased the hepatic or renal lipid accumulations and prevented liver or kidney damages in L.G6pc^−/− and K.G6pc^−/− mice, respectively. Finally, we show that L.G6pc^−/− mice and K.G6pc^−/− mice developed NAFLD-like pathology and CKD independently.

Conclusions

This study highlights the crucial role that lipids play in the independent development of both NAFLD and CKD and demonstrates the importance of lipid-lowering treatments in various metabolic diseases featured by lipid load, from the “rare” GSDIa to the “epidemic” morbid obesity or type 2 diabetes.

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Exacerbating lipid accumulation aggravates liver/kidney injury in GSDI.

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Fenofibrate-mediated PPARα activation induces hepatic and renal lipid turnover.

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Increased lipid turnover prevents glycogen synthesis and accumulation.

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PPARα–mediated metabolic reprograming prevents hepatic and renal GSDI complications.

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NAFLD and CKD develop independently.

Inflammatory Biomarkers of Cardiometabolic Risk in Obese Egyptian Type 2 Diabetics

Inflammatory biomarkers provide a minimally invasive means for early detection and specific treatment of metabolic syndrome and related disorders. The objective of this work was to search for inflammatory biomarkers of cardiometabolic risk in obese type 2 diabetics. The study was performed on 165 persons attending the medical outpatient clinic of Ismailia General Hospital. Their mean age was (50.69 ± 10.15) years. They were divided into three groups. The control group was composed of 55 non-obese, non-diabetic healthy volunteers, 32 males and 23 females. Two study groups were included in this study: group 2 was composed of 55 obese, non-diabetic subjects, 25 males and 30 females matched for age and gender. All patients including the control were subjected to clinical history taking, a clinical examination for the measurement of body mass index (BMI). Investigations were carried out for fasting blood glucose, fasting serum insulin, insulin resistance (IR), the lipid profile, lipoprotein band lipoprotein phospholipase A2, and non-high-density lipoprotein cholesterol (non-HDL-C). Urea, albumin and creatinine analysis and liver function tests were performed, and a complete blood count (CBC) was taken. Hemoglobin A1C (HbA1C), serum high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were tested. There were statistically significant differences among the studied groups in terms of total cholesterol, non-HDL-C, high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), lipoprotein-associated phospholipase A2 and apolipoprotein B. The inflammatory biomarkers hs-CRP, IL-6 and TNF-α were significantly statistically increased in the study groups by (1.62 ± 0.99, 2.32 ± 1.11), (1.73 ± 1.14, 2.53 ± 1.34), and (1.87 ± 1.09, 2.17 ± 0.89) respectively, where p < 0.01. Significant positive correlation was found between Homeostatic Model Assessment (HOMA)-IR, hs-CRP and IL-6. There was a significant positive correlation between non-HDL and hs-CRP, IL-6 and TNF-α and triglycerides and hs-CRP. In conclusion, in this study, CRP, IL-6, and TNF-α were significantly elevated in obese Egyptian type 2 diabetics and were positively correlated with insulin resistance, non-HDL and triglycerides. These inflammatory biomarkers could help in the premature identification of obese type 2 diabetic patients at high cardiometabolic risk. Additionally, these biomarkers are critical for providing prognostics and the validity of future potential anti-inflammatory therapeutic modalities.