Vitamin D and nonalcoholic fatty liver disease (NAFLD): is it more than just an association?

Lipidomics reveals different therapeutic potential for natural and synthetic vitamin D formulations in hepatocyte lipotoxicity

Natural sources of vitamin D (VD), have been proposed to represent an alternative to synthetic vitamin D in nutritional interventions, also holding therapeutic potential in non-alcoholic fatty liver disease (NAFLD). In this study lipidomics was used to comparatively investigate the molecular mechanisms behind the therapeutic effects of a natural VD formulation consisting of a Shitake mushroom extracts (NVD) and a synthetic cholecalciferol formulation (SVD) in HepaRG human hepatocytes exposed to free fatty acid (FFA)-induced lipotoxicity. The results demonstrate that the two VD formulations prevent lipotoxicity with similar efficacy, but different lipidomic fingerprints. Differentially expressed lipids in NVD' in vitro therapeutic effect indicated a reduced synthesis of cellular triglycerides; combined with a marked reshaping of glycerophospholipid metabolism and characteristic changes of the chain length and number of double bonds in the phosphatidylcholine pool that were absent in SVD treatment. Bioinformatics interpretation of lipidomics data associated NVD therapeutic properties to an enhanced insulin function and glycerophospholipid metabolism, whereas SVD was primarily associated with the inflammatory signaling and death pathways of the liver cell. These differences between the two VD formulations were further highlighted matching lipidomics data with gene microarray (transcriptomics) data available from previous studies on this experimental model; the resulting multiomics data identified lipid metabolism nodes specific for the multimolecular mechanisms of the two formulations which may deserve further pre-clinical investigation in the treatment of hepatocyte lipotoxicity.

Serum 25(OH)D Levels and Risk of Nonalcoholic Fatty Liver Disease in Nonobese and Lean Individuals

PURPOSE

The impact of vitamin D deficiency on nonalcoholic fatty liver disease (NAFLD) risk in individuals without obesity or insulin resistance has not been thoroughly evaluated. We aimed to identify whether low serum levels of 25(OH)D independently contribute to NAFLD risk in nonobese or lean individuals.

MATERIALS AND METHODS

This study analyzed 241208 asymptomatic health check-up examinees who had abdominal ultrasonography. NAFLD risk was evaluated based on obesity status and serum 25(OH)D levels.

RESULTS

The overall NAFLD prevalence was 25.5%. Among the 178630 nonobese and 126909 lean participants, the prevalence rates were 13.4% and 6.7%, respectively. The multivariable adjusted odds ratios (ORs) [95% confidence intervals (CI)] for the prevalence of NAFLD, comparing serum 25(OH)D levels of 10-19 and ≥20 ng/mL with <10 ng/mL, were 0.96 (0.93-0.99) and 0.80 (0.77-0.83), respectively. Among nonobese participants, the corresponding adjusted ORs (95% CI) were 0.94 (0.90-0.99) and 0.77 (0.73-0.81), respectively. Similar results were observed among lean participants, with those having a 25(OH)D level of ≥20 ng/mL demonstrating a significantly lower odds of NAFLD (adjusted OR, 0.76; 95% CI, 0.70-0.83). Moreover, these results were consistent even among nonobese and lean individuals who showed no signs of insulin resistance.

CONCLUSION

Insufficient 25(OH)D levels independently increased the risk of NAFLD, suggesting its role in the NAFLD pathogenesis, regardless of obesity or insulin resistance status. Considering the established relationship between vitamin D deficiency and nonobese/lean NAFLD, maintaining adequate 25(OH)D levels may aid in preventing the development of NAFLD, even among nonobese or lean individuals.

Hepatic-specific vitamin D receptor downregulation alleviates aging-related metabolic dysfunction-associated steatotic liver disease

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is defined by the abnormal lipid deposition in hepatocytes. The prevalence of MASLD is significantly increased in the elderly population, suggesting that aging may be related to the occurrence of MASLD. Emerging evidences suggest that vitamin D receptor (VDR) may be implicated in the progression of MASLD. Therefore, additional researches are warranted to elucidate whether VDR plays a role in aging-related MASLD.

AIM

To investigate the relationship between aging and MASLD and explore the role and related mechanisms of VDR in aging-related MASLD.

METHODS

Cellular senescence models were established, and the senescence phenotype of telomerase RNA component knockout mice was validated. These mice were then used as a senescence model for subsequent studies. Changes in VDR expression in the livers of aging mice were examined. VDR knockdown models, including cell knockdown models and hepatic-specific VDR knockout mice, were constructed, and MASLD was established in these models. Additionally, vitamin D (VD)-supplemented models, including senescent liver cell lines and senescent mice, were constructed.

RESULTS

The steatosis in senescent liver cells was more severe than in normal cells (P < 0.05). Moreover, hepatic steatosis was significantly more pronounced in senescence model mice compared to control group when the MASLD model was successfully induced (P < 0.05). Therefore, we concluded that aging aggravated hepatic steatosis. The hepatic expression of VDR increased after aging. VDR knockdown in senescent liver cells and senescent mice alleviated hepatic steatosis (P < 0.05). When senescent liver cells were stimulated with VD, cellular steatosis was aggravated (P < 0.05). However, VD supplementation had no effect on aging mice.

CONCLUSION

Aging can lead to increased hepatic steatosis, and the hepatic-specific knockdown of VDR alleviated aging-related MASLD. VDR could serve as a potential molecular target for aging-related MASLD.

Hidden in the Fat: Unpacking the Metabolic Tango Between Metabolic Dysfunction-Associated Steatotic Liver Disease and Metabolic Syndrome

Metabolic syndrome (MetS) and metabolic dysfunction-associated steatotic liver disease (MASLD) are closely related, with rapidly increasing prevalence globally, driving significant public health concerns. Both conditions share common pathophysiological mechanisms such as insulin resistance (IR), adipose tissue dysfunction, oxidative stress, and gut microbiota dysbiosis, which contribute to their co-occurrence and progression. While the clinical implications of this overlap, including increased cardiovascular, renal, and hepatic risk, are well recognized, current diagnostic and therapeutic approaches remain insufficient due to the clinical and individuals' heterogeneity and complexity of these diseases. This review aims to provide an in-depth exploration of the molecular mechanisms linking MetS and MASLD, identify critical gaps in our understanding, and highlight existing challenges in early detection and treatment. Despite advancements in biomarkers and therapeutic interventions, the need for a comprehensive, integrated approach remains. The review also discusses emerging therapies targeting specific pathways, the potential of precision medicine, and the growing role of artificial intelligence in enhancing research and clinical management. Future research is urgently needed to combine multi-omics data, precision medicine, and novel biomarkers to better understand the complex interactions between MetS and MASLD. Collaborative, multidisciplinary efforts are essential to develop more effective diagnostic tools and therapies to address these diseases on a global scale.

Potential predictive role of Non-HDL to HDL Cholesterol Ratio (NHHR) in MASLD: focus on obese and type 2 diabetic populations

INTRODUCTION

This cross-sectional study was conducted to examine the association between the ratio of non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol (NHHR) and metabolic dysfunction-associated steatotic liver disease (MASLD), particularly in populations with obesity and type 2 diabetes (T2D).

METHODS

The analysis included 3784 participants who were 20 years and older, using data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018. The prevalence of MASLD was determined using multivariable logistic regression analysis, which calculated odds ratios (ORs) and 95% confidence intervals (CIs). Conducted was an analysis employing a smooth curve fitting approach to explore the potential nonlinear association between NHHR and MASLD. Subgroup analyses were performed based on age, sex, body mass index (BMI) and T2D status to evaluate the robustness of the results, with interaction tests conducted.

RESULTS

NHHR showed a consistently positive association with MASLD across all models. In the fully adjusted model, compared with the low NHHR group, participants in the middle and high NHHR group were associated with higher prevalence of MASLD (OR = 1.51, 95%CI = 1.25-1.83, p < 0.001, OR = 1.97, 95%CI = 1.62-2.41, p < 0.001, respectively). This positive relationship was significant across all subgroups, confirming a robust association between NHHR and MASLD.

CONCLUSIONS

This cross-sectional study found a significant linear positive relationship between NHHR and MASLD, which remained significant across different age, sex, BMI and T2D groups. These findings suggest that NHHR may have the potential to serve as a predictor for screening MASLD in populations with obesity or T2D.

Bioactive metabolites: A clue to the link between MASLD and CKD?

Metabolites produced as intermediaries or end-products of microbial metabolism provide crucial signals for health and diseases, such as metabolic dysfunction-associated steatotic liver disease (MASLD). These metabolites include products of the bacterial metabolism of dietary substrates, modification of host molecules (such as bile acids [BAs], trimethylamine-N-oxide, and short-chain fatty acids), or products directly derived from bacteria. Recent studies have provided new insights into the association between MASLD and the risk of developing chronic kidney disease (CKD). Furthermore, alterations in microbiota composition and metabolite profiles, notably altered BAs, have been described in studies investigating the association between MASLD and the risk of CKD. This narrative review discusses alterations of specific classes of metabolites, BAs, fructose, vitamin D, and microbiota composition that may be implicated in the link between MASLD and CKD.

The relationship between non-HDL cholesterol to HDL cholesterol ratio (NHHR) and anemia: A cross-sectional study of NHANES, 2009 to 2016

The non-HDL cholesterol to HDL cholesterol ratio (NHHR) is a newly developed metric that represents the ratio of non-HDL cholesterol to HDL cholesterol. Anemia is a prevalent public health concern affecting all age groups. Our purpose is to investigate the connection between NHHR and the prevalence of anemia, as well as to explore their potential interactions. A total of 17,019 participants were incorporated into this research. NHHR was calculated as the scale of non-HDL cholesterol to HDL cholesterol. According to WHO criteria, anemia at sea level is diagnosed with a hemoglobin level (g/dL) of <12 for women and <13 for men. This study utilized multivariate linear regression, threshold effect analysis, smooth curve fitting, multivariate logistic regression as well as subgroup analysis, to investigate the linkage between the NHHR and anemia. After complete adjustment, the model indicated a strong inverse relationship between NHHR and the prevalence of anemia (the odds ratio [OR] was 0.82 with a 95% confidence interval of 0.78-0.86), suggesting that an incremental increase in NHHR correlates with an 18% decrease in the prevalence of anemia. Segmenting NHHR into quartiles maintained this significant association. The prevalence of anemia was 51% lower among participants in the highest NHHR quartile compared to those in the lowest quartile, with an OR of 0.49 (95% CI: 0.41-0.59; P for trend < .0001). Subsequent analysis revealed a significant improvement in the threshold effect value to 4.28 for the potential relationship between NHHR and anemia. Subgroup analysis showed an inverse correlation in some subgroups. Alcohol consumption significantly affects the relationship between NHHR and anemia (interaction P < .05). Our study revealed that NHHR is inversely proportional to the prevalence of anemia in U.S. adults.

Association of non-high-density lipoprotein cholesterol-to-high-density lipoprotein cholesterol ratio (NHHR) with gout prevalence: a cross-sectional study

Background

The non-high-density lipoprotein cholesterol (non-HDL-C)-to-high-density lipoprotein cholesterol (HDL-C) ratio (NHHR) is a strong lipid marker that has been associated with atherogenic features. This study aimed to investigate the potential association between the NHHR and gout prevalence.

Methods

This study investigated the relationship between the NHHR and gout by analyzing data gathered from the National Health and Nutrition Examination Survey (NHANES), a research study conducted in the United States from 2007 to 2018. All participants in NHANES provided written informed consent prior to participation. The NHHR was calculated as the ratio of non-HDL-C to HDL-C. Total cholesterol (TC) and HDL-C levels were sourced from NHANES laboratory data. Gout was assessed using a questionnaire. Weighted logistic regression analysis, subgroup analysis, and smoothed curve fitting were performed.

Results

This study included 30,482 participants. The fully adjusted models showed that for each unit increase in NHHR in continuous variables, there was a 10% higher likelihood of gout prevalence (OR: 1.10, 95% CI: 1.05, 1.16). Analysis of the NHHR quartiles revealed that patients in the highest quartile had a notably greater probability of developing gout than those in the lowest quartile. (Q4 vs. Q1, OR: 1.34, 95% CI: 1.05, 1.71). Subgroup analyses yielded consistent results across categories, indicating a significant positive association between the NHHR and gout. E-value analysis suggested robustness to unmeasured confounding. Interaction tests showed that the race, education level, marital relationship, poverty-income ratio (PIR), hypertension, smoking habits, estimated glomerular filtration rate (eGFR), lipid-lowering therapy, and diabetes had no discernible effects on this association. The p-values for all the interactions were > 0.05. Nevertheless, the relationship between the NHHR and gout was significantly affected by the age and sex of the participants (interaction p < 0.05).

Conclusion

Among adults in the United States, elevated NHHR levels are correlated with increased odds of gout prevalence.

Efficacy of Adding Sitagliptin to Ongoing Metformin on Metabolic Profile, Triglyceride-Glucose Index, Vitamin D3, and Liver Tests in Patients Type 2 Diabetes Mellitus and Nonalcoholic Fatty Liver Disease: A Double-Blind Randomized Clinical Trial

Background

Dipeptidyl peptidase-4 inhibitors provide potent antidiabetic effects in patients with type 2 diabetes mellitus (T2DM), but their role in the presence of nonalcoholic fatty liver disease (NAFLD) is not well-known.

Objective

The aim of this clinical trial was to evaluate the effects of sitagliptin on the metabolic profile and liver test results in metformin-treated patients with T2DM and NAFLD.

Methods

This was a prospective, 12-week, single-center, comparative randomized clinical trial enrolling 66 adult patients with T2DM and NAFLD (diagnosed by ultrasound). Patients were randomly assigned to either metformin (2000 mg/d, n = 33) or sitagliptin + metformin (100 and 2000 mg/d, respectively, n = 33), administered orally. Certain metabolic parameters, that is, fasting blood sugar (FBS), glycosylated hemoglobin, triglycerides (TGs), total cholesterol (TC), low-density lipoprotein cholesterol, vitamin D3 (vitD3), alkaline phosphatase, alanine aminotransferase (SGPT), and aspartate aminotransferase, were measured at baseline and after 12 weeks. Triglyceride-glucose (TG-G) index was also calculated.

Results

All biochemical variables decreased by a greater extent in the sitagliptin + metformin group than in the metformin group, with differences in FBS (P = 0.030), TC (P = 0.017), TG (P = 0.008), SGPT (P = 0.018), and vitD3 (P = 0.001) reaching statistical significance. Furthermore, the mean reduction of the TG-G index was significantly greater in the sitagliptin + metformin group than in the metformin group (0.67 vs 0.21, respectively; P = 0.017).

Conclusions

Sitagliptin + metformin therapy led to significantly greater improvements in FBS, TC, TG, SGPT, vitD3, and TG-G compared with the metformin monotherapy group. Other biomarkers also decreased more in the sitagliptin + metformin group than in the metformin group, but these differences did not reach statistical significance. The present findings should be interpreted with caution, although they suggest certain metabolic benefits after sitagliptin addition in metformin-treated patients with T2DM and NAFLD. Further studies are required to elucidate these effects and provide strong evidence for safe conclusions.

The non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) is associated with thyroid hormones and thyroid hormone sensitivity indices: a cross-sectional study

BACKGROUND

Lipids and thyroid hormones (TH) are closely interrelated. However, previous studies have not mentioned the linkage encompassing the non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) alongside TH level, as well as sensitivity indices.

METHODS

This cross-sectional study leverages expansive datasets from the National Health and Nutrition Examination Survey (NHANES) spanning 2007 to 2012. Weighted multivariate linear regression, smoothed curve fitting and sensitivity analyses were used to investigate the associations of the NHHR with the thyroid. Subgroup analyses and interaction tests were conducted to determine the robustness of the findings across diverse segments of the population, ensuring the consistency and generalizability of the observed associations.

RESULTS

The NHHR was significantly positively correlated with free triiodothyronine (FT3) levels, thyroid-stimulating hormone (TSH) levels, the FT3 to FT4 ratio (FT3/FT4), and the quantile-based thyroid feedback index for FT3 (TFQIFT3) and negatively correlated with free thyroxin (FT4) levels [0.17(0.07-0.27), P = 0.001; 0.60 (0.03-1.17), P = 0.040; 0.06 (0.04-0.08), P < 0.0001; 0.23 (0.16-0.30), P < 0.0001; and -0.65 (-1.05--0.24), P = 0.002]. Smoothed curve fitting revealed nonlinear correlations of the NHHR with thyroid function and thyroid hormone sensitivity indices. In subgroup analyses, interaction tests, and smoothed curve fitting analyses, different populations presented largely consistent statistical differences.

CONCLUSION

Among American adults, the NHHR was significantly positively correlated with FT3 levels, TSH levels, the FT3/FT4 and the TFQIFT3. Conversely, a negative association was noted between the NHHR and FT4 levels.

Association of 28-day mortality with non-high-density lipoprotein cholesterol and the high-density lipoprotein cholesterol ratio (NHHR) in patients with sepsis: Results of MIMIC-IV database analysis

BACKGROUND

The correlation between lipid profiles and sepsis has received increasing attention. The ratio of non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol (NHHR) is one of the key lipid profiles. However, in-depth exploration of the correlation between NHHR and the mortality risk of patients with sepsis is limited.

METHODS

Data from the MIMIC-IV (v2.2) database, we review the NHHR relevance and the sepsis severity index using Spearman's correlation analysis. Additionally, we research NHHR associated with sepsis patients' survival rate of 28 days using Cox regression analyses of continuous and categorical models. To further validate our findings, we conducted subgroup and sensitivity analyses.

RESULTS

The study involved 3,142 patients diagnosed with sepsis, according to 28 days after in-hospital survival condition, divided into two groups. In this study, 2932 patients were in the survival group and 210 patients died within 28 days (mortality group). Of note, the mean NHHR of patients in the mortality group exceeded that of the survival group (3.5 vs. 2.9). Additionally, NHHR was positively correlated with the severity index. After adjusting for demographic and laboratory data, an increased NHHR was positively correlated with higher sepsis mortality risk (OR = 1.06; 95% CI: 1.02-1.11; P = 0.013). Subgroup analysis shown the same results. Contributors were be categorized into two groups based on NHHR levels, with a threshold of 2.61. Contrast the mortality risk between low-NHHR group and high-NHHR group, high-NHHR show greater mortality risk on 28-day, 60-day, 90-day, in ICU, and in hospital.

CONCLUSION

Elevated NHHR is to be correlated with an increased risk of mortality in patients with sepsis. Further research on NHHR may contribute to advancements in sepsis prevention and treatment.

Association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) and kidney stone: evidence from NHANES 2007-2018

BACKGROUND

As an innovative lipid parameter, NHHR (the ratio of non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol) can serve as a valuable tool for assessing cardiovascular disease risk. Nevertheless, the relationship between NHHR and the risk of kidney stones remains unexplored.

METHODS

A cross-sectional survey utilized data from the National Health and Population Survey (NHANES) database in the United States spanning from 2007 to 2018. Distinct statistical analyses were applied, including weighted logistic regression, stratified and interaction analysis and restricted cubic spline curve (RCS) models, to examine the correlation between NHHR and the incidence of kidney stones.

RESULTS

This analysis encompassed 24,664 participants, with 9.63% reporting incidents of kidney stones. Following multivariate logistic regression and comprehensive adjustments, participants in NHHR quartile 4 (OR 1.34; 95% CI 1.12, 1.60, P < 0.01) exhibited a significantly increased risk of kidney stones compared to those in NHHR quartile 1 (Q1). The RCS result further illustrated a non-linear correlation between NHHR and the incidence of kidney stones. The result of subgroup analysis manifested that participants without diabetes had a higher risk of kidney stones when measured high NHHR levels compared those with diabetes (p for interaction < 0.05).

CONCLUSION

Elevated NHHR levels were found to be associated with an increased risk of kidney stones. Based on these findings, NHHR appears to be a promising predictive indicator for the occurrence of kidney stones.

Low vitamin D levels are linked with increased cardiovascular disease risk in young adults: a sub-study and secondary analyses from the ACTIBATE randomized controlled trial

PURPOSE

Vitamin D deficiency is related to metabolic disturbances. Indeed, a poor vitamin D status has been usually detected in patients with cardiovascular disease (CVD). However, the relationship between vitamin D and CVD risk factors in young adults remains controversial at present. This study aimed to examine the association between circulating 25-hydroxivitamin D (25(OH)D) and CVD risk factors in young adults.

METHODS

The present cross-sectional study included a cohort of 177 young adults aged 18-25 years old (65% women). 25(OH)D serum concentrations were assessed using a competitive chemiluminescence immunoassay. Fasting CVD risk factors (i.e., body composition, blood pressure, glucose metabolism, lipid profile, liver, and inflammatory markers) were determined by routine methods. A panel of 63 oxylipins and endocannabinoids (eCBs) was also analyzed by targeted metabolomics.

RESULTS

Circulating 25(OH)D concentrations were inversely associated with a wide range of CVD risk factors including anthropometrical (all P ≤ 0.005), body composition (all P ≤ 0.038), glucose metabolism (all P ≤ 0.029), lipid profile (all P < 0.035), liver (all P ≤ 0.011), and pro-inflammatory biomarkers (all P ≤ 0.030). No associations of serum 25(OH)D concentrations were found with pro-inflammatory markers (all P ≥ 0.104), omega-6 and omega-3 oxylipins, nor eCBs concentrations or their analogs (all P ≥ 0.05).

CONCLUSION

The present findings support the idea that 25(OH)D could be a useful predictor of CVD risk in young individuals.

Association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) and sleep disorders in US adults: NHANES 2005 to 2016

NHHR (non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio) is a novel lipid parameter. However, the association between NHHR and sleep disorders remains unknown.; A cross-sectional analysis was conducted using data from the National Health and Nutrition Examination Survey (NHANES) 2005 to 2016. The association between NHHR and sleep disorders was explored using weighted multivariate logistic regression and generalized summation models. Subgroup analyses were employed to verify the robustness of this association. The prevalence of sleep disorders was 25.83% in a total of 22,221 participants. Compared to the lowest quartile of NHHR, participants in the top quartile had a 14% higher odds of sleep disorders prevalence in fully adjusted model (OR: 1.14, 95% CI: 1.06-1.23). After subgroup analyses and interaction tests, sex, race, marital status, education level, body mass index (BMI), person income ratio (PIR), alcohol consumption, smoking status, hypertension, and diabetes mellitus were not significantly associated with this positive association (P for interaction > 0.05). The NHHR is positively associated with sleep disorders in US adults. The management and monitoring of NHHR may have a potential role in improving sleep disorders.

The association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) and kidney stones: a cross-sectional study

BACKGROUND

The relationship between the NHHR and kidney stone risk remains unknown. The purpose of this study was to evaluate the association between adult NHHR and kidney stone occurrence in USA.

METHODS

This study used a variety of statistical techniques such as threshold effects, subgroup analysis, smooth curve fitting, multivariate logistic regression, and data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2014. We aimed to clarify the relationship between the NHHR and kidney stone risk.

RESULTS

The average age of the 21,058 individuals in this research was 49.70 ± 17.64 years. The mean NHHR was 3.00 ± 1.47, and the overall prevalence of kidney stone occurrence was 9.05%. The prevalence within the quartile ranges (Q1-Q4) was 7.01%, 8.71%, 9.98%, and 10.49%, respectively. The overall average recurrence rate of kidney stones was 3.05%, demonstrating a significant increase with increasing NHHR (Q1: 1.92%, Q2: 2.92%, Q3: 3.35%, Q4: 4.00%, P < 0.01). The occurrence of kidney stones increased by 4% (95% CI: 1.00-1.08, P = 0.0373) and the chance of recurrence increased by 9% (95% CI: 1.03-1.14, P < 0.01) with each unit increase in NHHR. The interaction analysis results demonstrated that the relationship between the NHHR and the risk of kidney stones was not significantly impacted by the following factors: sex, body mass index, poverty income ratio, diabetes, or hypertension. Curve fitting and threshold effect analysis also demonstrated a non-linear association, with a breakpoint found at 3.17, between the NHHR and the risk of kidney stones.

CONCLUSIONS

In adults in the USA, there is a substantial correlation between elevated NHHR levels and a higher probability of kidney stones developing and recurring. Timely intervention and management of NHHR may effectively mitigate the occurrence and recurrence of kidney stones.

Aerobic training with moderate or high doses of vitamin D improve liver enzymes, LXRα and PGC-1α levels in rats with T2DM

Dysregulation of key transcription factors involved in hepatic energy metabolism, such as peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) and liver X receptor alpha (LXRα), has been observed in T2DM. The present study aims to investigate the effects of aerobic training and vitamin D supplementation on liver enzyme levels and the levels of PGC-1α and LXRα proteins in hepatocytes, in a rat model of T2DM. The study involved 56 male Wistar rats, divided into two groups: one was non-diabetic and acted as a control group (n = 8), and the other had induced diabetes (n = 48). The diabetic rats were then split into six subgroups: two groups received high or moderate doses of vitamin D and aerobic training (D + AT + HD and D + AT + MD); two groups received high or moderate doses of vitamin D alone (D + HD and D + MD); one group underwent aerobic training with vehicle (sesame oil; D + AT + oil), and one group was a diabetic control receiving only sesame oil (oil-receiving). The D + AT + HD and D + HD groups received 10,000 IU of vitamin D, while the D + AT + MD and D + MD groups received 5000 IU of vitamin D once a week by injection. The D + AT + oil group and the sham group received sesame oil. After eight weeks of treatment, body weight, BMI, food intake, serum insulin, glucose, 25-hydroxyvitamin D, ALT, AST, and visceral fat were measured. The levels of PGC-1α and LXRα proteins in the liver was assessed by western blotting. Statistical analysis was performed using the paired t-test, one-way analysis of variance (ANOVA), and the Tukey post hoc test at a significance level of P < 0.05. Body weight, food intake, and BMI decreased significantly in the D + AT + HD, D + AT + MD, D + AT + oil, D + HD, and D + MD groups with the highest reduction being observed in body weight and BMI in the D + AT + HD group. The D + AT + HD group exhibited the lowest levels of insulin, glucose, and HOMA-IR while the D + C group exhibited the highest levels among the diabetic groups. The D + AT + HD and D + AT + MD groups had lower levels of ALT and AST enzymes compared to the other groups with no significant difference between D + AT + HD and D + AT + MD. D + AT + HD (p = 0.001), D + AT + MD (p = 0.001), D + HD (p = 0.023), D + MD (p = 0.029), and D + AT + oil (p = 0.011) upregulated LXRα compared to D + C. Among these groups, D + AT + HD exhibited a more profound upregulation of LXRα than D + AT + MD, D + AT + oil, D + HD, and D + MD (p = 0.005; p = 0.002, p = 0.001, and p = 0.001, respectively). Similarly, D + AT + HD showed a more notable upregulation of PGC-1α compared to D + AT + oil, D + HD, and D + MD (p = 0.002; p = 0.001, and p = 0.001, respectively). Pearson correlation tests showed significant and negative correlations between serum 25-hydroxyvitamin levels and both visceral fat (r = - 0.365; p = 0.005) and HOMA-IR (r = - 0.118; p = 0.009); while positive and significant correlations between the liver-to-bodyweight ratio with both ALT and AST enzymes and also between QUICKI levels with LXRα (r = 0.578; p = 0.001) and PGC-1α (r = 0.628; p = 0.001). Combined administration of aerobic training and vitamin D supplementation potentially improves liver enzymes in type-2 diabetic rats that were simultaneous with upregulating the levels of PGC-1α and LXRα proteins in hepatocytes. These improvements were more significant when combining exercise with high-dose vitamin D supplementation. This study highlights the potential of this combination therapy as a new diabetes treatment strategy.

Associations of severe liver diseases with cataract using data from UK Biobank: a prospective cohort study

Background

Liver disease is linked to series of extrahepatic multisystem manifestations. However, little is known about the associations between liver and eye diseases, especially cataract, the global leading cause of blindness. We aimed to investigate whether severe liver diseases, including non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), viral hepatitis, and liver fibrosis and cirrhosis, were associated with an increased risk of the cataract.

Methods

A total of 326,558 participants without cataract at baseline enrolled in the UK Biobank between 2006 and 2010 were included in this prospective study. The exposures of interest were severe liver diseases (defined as hospital admission), including NAFLD, ALD, viral hepatitis and liver fibrosis and cirrhosis. The outcome was incident cataract. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs). Each liver disease was first treated as a binary time-varying variable to investigate its association with cataract, and then was treated as a ternary time-varying variable to examine the recent (liver disease within 0-5 years) vs. long-term (liver disease > 5 years) state associations with the risk of cataract.

Findings

After a median follow-up of 13.3 years (interquartile range, 12.5-14.0 years), 37,064 individuals were documented as developing cataract. Higher risk of cataract was found in those with severe NAFLD (HR, 1.47; 95% CI, 1.33-1.61), ALD (HR, 1.57; 95% CI, 1.28-1.94) and liver fibrosis and cirrhosis (HR, 1.58; 95% CI, 1.35-1.85), but not in individuals with viral hepatitis when exposure was treated as a binary time-varying variable (P = 0.13). When treating exposure as a ternary time-varying variable, an association between recently diagnosed viral hepatitis and cataract was also observed (HR, 1.55; 95% CI, 1.07-2.23). Results from the combined model suggested they were independent risk factors for incident cataract. No substantial changes were found in further sensitivity analyses.

Interpretation

Severe liver diseases, including NAFLD, ALD, liver fibrosis and cirrhosis and recently diagnosed viral hepatitis, were associated with cataract. The revelation of liver-eye connection suggests the importance of ophthalmic care in the management of liver disease, and the intervention precedence of patients with liver disease in the early screening and diagnosis of cataract.

Funding

National Natural Science Foundation of China, Science and Technology Innovation Action Plan of Shanghai Science and Technology Commission, Clinical Research Plan of Shanghai Shenkang Hospital Development Center, Shanghai Municipal Key Clinical Specialty Program, the Guangdong Basic and Applied Basic Research Foundation and Shenzhen Science and Technology Program.

The association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) and suicidal ideation in adults: a population-based study in the United States

BACKGROUND

The ratio of non-high-density lipoprotein cholesterol (non-HDL-C) to high-density lipoprotein cholesterol (HDL-C) (NHHR) serves as a reliable lipid indicator associated with atherogenic characteristics. Studies have indicated a potential connection between suicidality and lipid metabolism. This research aims to investigate any possible association between the NHHR and the emergence of suicidal ideation within the confines of the study.

METHODS

This study examined the association between NHHR levels and suicidal ideation using data from the National Health and Nutrition Examination Survey (NHANES), conducted in the United States spanning 2005 and 2016. Calculation of the NHHR corresponds to the proportion of HDL-C to Non-HDL-C. The Patient Health Questionnaire-9's ninth question was implemented for assessing suicidal ideation. Using subgroup analysis, smooth curve fitting, and multivariate logistic regression analysis, the research was conducted.

RESULTS

Encompassing a cohort of 29,288 participants, the analysis identified that 3.82% of individuals reported suicidal ideation. After using multivariable logistic regression and thorough adjustments, elevated NHHR levels were significantly and positively associated with a heightened likelihood of suicidal ideation, according to the findings (odds ratio [OR] = 1.06; 95% confidence interval [CI]: 1.02-1.11; P = 0.0048). Despite extensive adjustment for various confounding factors, this relationship remained consistent. An inverted U-shaped curve was utilized to illustrate the link between NHHR and suicidal ideation among nonsmokers; the curve's inflection point was situated at 7.80. Subgroup analysis and interaction tests (all P for interaction > 0.05) demonstrated that there was no significant influence of the following variables on this positive relationship: age, sex, race, body mass index, education level, married status, hypertension, diabetes, and smoking status.

CONCLUSION

Significantly higher NHHR levels were associated with an elevated likelihood of suicidal ideation. Based on these results, it is probable that NHHR may serve as a predictive indicator of suicidal ideation, emphasizing its potential utility in risk assessment and preventive strategies.

Serum vitamin D is associated with ultrasound-defined hepatic fibrosis

BACKGROUND

Evidences from population-based investigations on the exact relationship between vitamin D and the severity of liver fibrosis remain debated and conflicting. Here, we aim to explore the relationship between serum vitamin D and ultrasound-defined advanced hepatic fibrosis in the US participants with nonalcoholic fatty liver disease (NAFLD).

METHODS

In the retrospective study, individuals with intact information on interesting variables from the 2017-2018 National Health and Nutrition Examination Survey (NHANES) were included. NAFLD was diagnosed on the basis of controlling attenuation parameter (CAP) value≥ 274 dB/m without causes of other chronic hepatic diseases. We identified advanced fibrosis grades (F2) by liver stiffness measurement (LSM) score of ≥ 8.2 kPa in NAFLD patients. The impact of elevated serum vitamin D on the prevalence of hepatic fibrosis was assessed by multivariate logistic regression models on the basis of the NHANES recommended weights.

RESULTS

The study involved 1624 subjects with NAFLD in total, and 305 (18.28 %, weighted%) of whom were diagnosed with advanced hepatic fibrosis according to the definition based on parameters obtained from vibration controlled transient elastography (VCTE). In the multivariate logistic regression analysis, serum vitamin D presented a negative relationship to hepatic fibrosis with lower odds in patients with hepatic steatosis after being adjusted for potential confounding factors (fully adjusted: OR=0.47, 95 % CI: 0.24-0.90, p = 0.034). Our subgroup analysis revealed that the inverse relationship was still existed in males (fully adjusted: OR = 0.34, 95 % CI: 0.17-0.70, p = 0.014), non-obese subjects (fully adjusted: OR = 0.20, 95 % CI: 0.04-0.89, p = 0.042) and participants below 60 years (fully adjusted: OR = 0.43, 95 % CI: 0.21-0.90, p = 0.033), whereas in models adjusted for the potential confounding factors, no statistically significant correlation was noted in females, obese subjects or subjects with age≥ 60 years.

CONCLUSIONS

This large population-based investigation indicated that elevated serum vitamin D reduced the onset of advanced fibrosis diagnosed by ultrasound in males, non-obese subjects and younger participants with NAFLD.

Serum 25-hydroxyvitamin D, type 2 diabetes, and liver-related outcomes: Secondary data analysis of a prospective recruited cohort

BACKGROUND

The association of vitamin D deficiency, which is prevalent in type 2 diabetes mellitus (T2DM), with liver disease and related mortality has not been quantified. Our study aimed to (1) investigate whether there is a synergistic association of vitamin D deficiency and T2DM with liver-related outcomes and (2) explore whether high 25-hydroxyvitamin D [25(OH)D] concentrations are associated with a lower risk of liver-related outcomes in T2DM.

METHOD

Leveraging the data from UK Biobank, we conducted 2 studies: study I assessed the joint associations of vitamin D deficiency [25(OH)D <50 nmol/L] and T2DM with liver-related outcomes among 439,276 participants, and study II explored the associations of vitamin D status with liver-related outcomes among 21,519 individuals with T2DM. Baseline T2DM was identified through medication, laboratory test, and electronic health-related records. Serum 25(OH)D was measured by direct competitive chemiluminescent immunoassay. Liver-related outcomes included 6 liver disease end points and mortality by overall liver disease, chronic liver disease, and severe liver disease.

RESULTS

During an average follow-up duration of 11.6 years, we observed a significant positive additive interaction effect (all synergy index>1.0) of T2DM and vitamin D deficiency on the risk of liver-related outcomes. Compared with participants without either T2DM or vitamin D deficiency, the multivariable-adjusted HRs of overall liver diseases were 1.29 for participants without T2DM but with vitamin D deficiency, 1.73 for participants with T2DM but without vitamin D deficiency, and 2.19 for participants with both T2DM and vitamin D deficiency. In individuals with T2DM, we observed that participants without vitamin D deficiency were inversely associated with incident liver disease and related mortality (multivariable-adjusted HRs 0.41-0.81) when compared with individuals with vitamin D deficiency.

CONCLUSIONS

There are positive synergistic associations of vitamin D deficiency and T2DM with liver-related outcomes. Inverse associations between serum 25(OH)D concentrations and liver-related outcomes were observed in individuals with T2DM.

Insights into the role of vitamin D in targeting the culprits of non-alcoholic fatty liver disease

Vitamin D (VD) is a secosteroid hormone that is renowned for its crucial role in phospho-calcium homeostasis upon binding to the nuclear vitamin D receptor (VDR). Over and above, the pleiotropic immunomodulatory, anti-inflammatory, and metabolic roles VD plays in different disease settings started to surface in the past few decades. On the other hand, a growing body of evidence suggests a correlation between non-alcoholic fatty liver disease (NAFLD) and its progressive inflammatory form non-alcoholic steatohepatitis (NASH) with vitamin D deficiency (VDD) owing to the former's ingrained link with obesity and metabolic syndrome. Accordingly, a better understanding of the contribution of disrupted VDR signalling to NAFLD incidence and progression would provide further insights into its diagnosis, treatment modalities, and prognosis. This is especially significant as, hitherto, no drug for NAFLD has been approved. This review, therefore, sought to set forth the likely contribution of VDR signalling in NAFLD and how it might influence its multiple drivers.

Metabolic health phenotype better predicts subclinical atherosclerosis than body mass index-based obesity phenotype in the non-alcoholic fatty liver disease population

Background

Non-alcoholic fatty liver disease (NAFLD), especially lean NAFLD is associated with an increased risk of atherosclerotic cardiovascular disease (CVD). It is not currently known which clinical phenotypes of NAFLD contribute most to individual subclinical atherosclerosis risk. We examined the relationship between body mass index (BMI), the metabolically healthy status, and subclinical atherosclerosis in the NAFLD population.

Methods

Data from asymptomatic NAFLD subjects who participated in a routine health check-up examination were collected. Participants were stratified by BMI (cutoff values: 24.0-27.9 kg/m2 for overweight and ≥28.0 kg/m2 for obesity) and metabolic status, which was defined by Adult Treatment Panel III criteria. Subclinical atherosclerosis was evaluated by brachial-ankle pulse wave velocity (baPWV) in 27,738 participants and by carotid plaque in 14,323 participants.

Results

Within each BMI strata, metabolically unhealthy subjects had a significantly higher prevalence of subclinical atherosclerosis than metabolically healthy subjects, whereas fewer differences were observed across subjects within the same metabolic category. When BMI and metabolic status were assessed together, a metabolically unhealthy status was the main contributor to the association of clinical phenotypes with the subclinical atherosclerosis burden (all p < 0.001). When BMI and metabolic abnormalities were assessed separately, the incidence of subclinical disease did not increase across BMI categories; however, it increased with an increase in the number of metabolic abnormalities (0, 1, 2 and ≥3).

Conclusion

A metabolically healthy status in NAFLD patients was closely correlated with subclinical atherosclerosis, beyond that of the BMI-based obesity phenotype. The application of metabolic phenotyping strategies could enable more precise classification in evaluating cardiovascular risk in NAFLD.

The Relationship Between Non-HDL-C /HDL-C Ratio (NHHR) and Vitamin D in Type 2 Diabetes Mellitus

Purpose

The objective of this research was to examine the relationship between non-HDL cholesterol/HDL cholesterol ratio (NHHR) and vitamin D in type 2 diabetes mellitus (T2DM).

Patients and Methods

This study enrolled 617 T2DM participants. Participants were separated into two groups: no vitamin D deficiency and vitamin D deficiency. Participants were split into two categories: individuals who had a high NHHR and those with a low NHHR, with the median NHHR serving as the cut-off. Eventually, the study participants were classified into two groups by gender, which were further classified into vitamin D deficient and non-vitamin D deficient groups.

Results

NHHR values were substantially greater in vitamin D deficient group than in the non-deficient group in both male and female T2DM patients (P<0.05). The high NHHR group displayed substantially lower vitamin D levels than the low NHHR group [16.21 (12.55,21.35) vs 19.05 (14.59,24.07), P<0.001]. NHHR was discovered to be negatively and independently associated with vitamin D levels, and there was no sex difference.

Conclusion

For the first time, our research revealed a negative relationship between NHHR and vitamin D in patients with T2DM.

Indices of hepatic steatosis and fibrosis in prediabetes and association with diabetes development in the vitamin D and type 2 diabetes study

AIMS

Non-alcoholic fatty liver disease (NAFLD) is a common comorbidity that leads to poor outcomes in people at high risk for development of type 2 diabetes (T2D). Vitamin D is a possible mediator. In the vitamin D and type 2 diabetes study (D2d), we investigated the relationship of baseline indices of NAFLD with incident T2D and whether the effect of vitamin D on diabetes was modified by NAFLD.

METHODS

Cross-sectional associations of indices of NAFLD with glycemia and vitamin D status were assessed in 3972 individuals screened for the D2d study. In those with prediabetes randomized to vitamin D or placebo (n = 2423), we examined longitudinal associations of NAFLD indices with incident T2D. We used validated non-invasive scores to assess steatosis [(hepatic steatosis index (HSI); NAFLD-liver fat score (NAFLD-LFS)] and advanced fibrosis [fibrosis-4 (FIB-4) index; AST to Platelet Ratio Index (APRI)].

RESULTS

Eighty-five percent of screened participants had likely steatosis by HSI and 71 % by NAFLD-LFS; 3 % were likely to have advanced fibrosis by FIB-4 and 1.2 % by APRI. FIB-4 indicated that 20.4 % of individuals require further follow up to assess liver health. Steatosis and fibrosis scores were higher among participants with worse glycemia. The NAFLD-LFS and APRI predicted development of diabetes (hazard ratios [95%CI] 1.35 [1.07, 1.70]; P = 0.012) and 2.36 (1.23, 4.54; P = 0.010), respectively). The effect of vitamin D on diabetes risk was not modified by baseline NAFLD indices. Individuals with likely steatosis had a smaller increase in serum 25-hydroxyvitamin D level in response to vitamin D than those without steatosis.

CONCLUSIONS

The predicted high prevalence of steatosis, the need for further fibrosis workup, and the relationship between liver health and incident T2D suggest that routine screening with clinically accessible scores may be an important strategy to reduce disease burden.

Altered local RAS in the liver increased the risk of NAFLD in male mouse offspring produced by in vitro fertilization

BACKGROUND

Assisted reproductive technology (ART) is associated with an increased risk of adverse metabolic health in offspring, and these findings have been demonstrated in animal models without parental infertility issues. However, it is unclear what changes lead to abnormal metabolism. The activation of the renin-angiotensin system (RAS) has been related to various aspects of metabolic syndrome. Thus, we focused on the local RAS of the liver, which is the central organ for glucose and lipid metabolism in offspring conceived by in vitro fertilization (IVF), and studied the role of local liver RAS in metabolic diseases.

METHODS

Male C57BL/6 mouse offspring obtained by natural pregnancy and IVF were fed a standard chow diet or a high-fat diet (HFD) from 4 weeks of age through 16 weeks of age. We assessed glucose and lipid metabolism, hepatic histopathology, and the gene and protein expression of key RAS components. In addition, the blocker losartan was used from 4 weeks of age through 16 weeks of age to investigate the regulatory mechanisms of abnormal local RAS on metabolic activity in the IVF offspring liver.

RESULTS

The growth trajectories of IVF offspring body and liver weights were different from those of naturally pregnant offspring. Impaired glucose tolerance (IGT) and insulin resistance (IR) occurred in IVF-conceived male offspring. After continuous HFD feeding, male offspring in the IVF group underwent earlier and more severe IR. Furthermore, there was a trend of lipid accumulation in the livers of chow-fed IVF offspring. Hepatic steatosis was also more serious in the IVF offspring after HFD treatment. Type 1 receptor (AT1R), which is the primary receptor mediating the action of angiotensin (Ang) II, has been confirmed to be upregulated in IVF offspring livers. Losartan reduced or even eliminated most of the significant differences between the IVF and NC groups after HFD consumption.

CONCLUSIONS

The upregulation of AT1R expression in the liver increased the activity of the local RAS, resulting in abnormal glucose and lipid metabolism and lipid accumulation in the liver, significantly increasing the risk of nonalcoholic fatty liver disease (NAFLD) in IVF offspring.

Nutritional and Lifestyle Therapy for NAFLD in People with HIV

HIV infection and nonalcoholic fatty liver disease (NAFLD) are two major epidemics affecting millions of people worldwide. As people with HIV (PWH) age, there is an increased prevalence of metabolic comorbidities, along with unique HIV factors, such as HIV chronic inflammation and life-long exposure to antiretroviral therapy, which leads to a high prevalence of NAFLD. An unhealthy lifestyle, with a high dietary intake of refined carbohydrates, saturated fatty acids, fructose added beverages, and processed red meat, as well as physical inactivity, are known to trigger and promote the progression of NAFLD to nonalcoholic steatohepatitis, liver fibrosis, and hepatocellular carcinoma. Furthermore, with no currently approved pharmacotherapy and a lack of clinical trials that are inclusive of HIV, nutritional and lifestyle approaches still represent the most recommended treatments for PWH with NAFLD. While sharing common features with the general population, NAFLD in PWH displays its own peculiarities that may also reflect different impacts of nutrition and exercise on its onset and treatment. Therefore, in this narrative review, we aimed to explore the role of nutrients in the development of NAFLD in PWH. In addition, we discussed the nutritional and lifestyle approaches to managing NAFLD in the setting of HIV, with insights into the role of gut microbiota and lean NAFLD.

Lipid accumulation product (LAP) index for the diagnosis of nonalcoholic fatty liver disease (NAFLD): a systematic review and meta-analysis

BACKGROUND

Lipid accumulation product (LAP) is an index calculated by waist circumference (WC) and triglyceride (TG), which reflects lipid toxicity. This study aims to investigate the association between the LAP index and nonalcoholic fatty liver disease (NAFLD) in a systematic review and meta-analysis.

METHODS AND RESULTS

PubMed, Scopus, and Web of Science online databases were searched for eligible studies that investigated the association of the LAP index and NAFLD. Sixteen observational studies with 96,101 participants, including four cohort studies, one case‒control study and 11 cross-sectional studies with baseline data, were entered into this analysis. Fourteen studies reported a significant association between the LAP index and NAFLD, and two reported that this relation was not significant; two different meta-analyses (1- mean difference (MD) and 2- bivariate diagnostic test accuracy [DTA]) were conducted using Stata version 14. The LAP index was compared in subjects with and without NAFLD, and the difference was significant with 34.90 units (CI 95: 30.59-39.31, P < 0.001) of the LAP index. The DTA meta-analysis was conducted and showed that the LAP index pooled sensitivity and specificity for screening of NAFLD were 94% (CI95: 72%-99%, I2 = 99%, P < 0.001) and 85% (CI95: 62%-96%, I2 = 99%, P < 0.001), respectively.

CONCLUSION

The LAP Index is an inexpensive, sensitive, and specific method to evaluate NAFLD and may be valuable for NAFLD screening.

Beneficial Effect of Vitamin D on Non-Alcoholic Fatty Liver Disease (NAFLD) Progression in the Zebrafish Model

A major cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma, non-alcoholic fatty liver disease (NAFLD) results from excessive liver fat accumulation. Vitamin D (VitD) plays multiple important roles in diverse physiologic processes. Here, we describe the role of VitD in the complex pathogenesis of NAFLD and explore the possible therapeutic role of VitD supplementation in NAFLD therapy. To compare the effect of VitD to other interventions such as low-calorie diet, we induced NAFLD in young adult zebrafish (Danio rerio, AB strain) and monitored the effects of VitD supplementation on the disease course. The zebrafish administered with high-dose VitD (1.25 μg) had significantly reduced liver fat compared to those that received low-dose VitD (0.049 μg) or caloric restriction. Gene expression analysis revealed that VitD downregulated several pathways that may play a role in NAFLD etiology, which affected fatty acid metabolism, vitamins and their cofactors, ethanol oxidation, and glycolysis. The pathway analysis revealed that the cholesterol biosynthesis pathway and the isoprenoid biosynthetic process pathway were significantly upregulated whereas the small molecule catabolic process pathway significantly downregulated following the exposure of NAFLD zebrafish model to high VitD dose. Therefore, our findings suggest the association of novel biochemical pathways with NAFLD and highlight the potential of VitD supplementation to reverse the severity of NAFLD, especially in younger people.

Inverse Association Between Serum 25-Hydroxyvitamin D and Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS

Serum 25-hydroxyvitamin D [S-25(OH)D] and nonalcoholic fatty liver disease (NAFLD) are correlated in many observational studies, whereas the causality of this association is uncertain, especially in European populations. We conducted a bidirectional Mendelian randomization study to determine the association between S-25(OH)D and NAFLD.

METHODS

Seven and 6 independent genetic variants associated with S-25(OH)D and NAFLD at the genome-wide-significance level, respectively, were selected as instrumental variables. Summary-level data for S-25(OH)D were obtained from the Study of Underlying Genetic Determinants of Vitamin D and Highly Related Traits consortium including 79,366 individuals. Summary-level data for NAFLD were available from a genome-wide association meta-analysis (1483 cases and 17,781 controls), the FinnGen consortium (894 cases and 217,898 controls), and the UK Biobank study (275 cases and 360,919 controls). Summary-level data for 4 liver enzymes were obtained from the UK Biobank.

RESULTS

There were genetic correlations of S-25(OH)D with NAFLD and certain liver enzymes. Genetically predicted higher levels of S-25(OH)D were consistently associated with a decreased risk of NAFLD in the 3 sources. For a 1-SD increase in genetically predicted S-25(OH)D levels, the combined odds ratio of NAFLD was 0.78 (95% confidence interval [CI], 0.69 to 0.89). Genetically predicted higher levels of S-25(OH)D showed a borderline association with aspartate aminotransferase levels (change -1.17; 95% CI, -1.36 to 0.01). Genetic predisposition to NAFLD was not associated with S-25(OH)D (change 0.13; 95% CI, -1.26 to 0.53).

CONCLUSIONS

Our findings have clinical implications as they suggest that increased vitamin D levels may play a role in NAFLD prevention in European populations.

Serum 25-hydroxyvitamin D levels and the risk of non-alcoholic fatty liver: A two-sample Mendelian randomization study

BACKGROUND

Accumulated studies have shown that low expression of 25-hydroxyvitamin D [25(OH)D] was significantly associated with the risk of non-alcoholic fatty liver disease (NAFLD). However, the exact causality is still unknown. The aim of this study was to investigate whether levels of 25(OH)D are associated with risk of NAFLD, using a two-sample Mendelian randomization (MR).

METHODS

Data from a recent large vitamin D genome-wide association study (GWAS) on 417,580 Europeans were utilized, and the largest published histology-based NAFLD GWAS study (1,483 cases and 17,781 healthy controls) for genetic variants predicted to cause NAFLD were searched. All genetic datasets for the MR analyses were obtained using publicly available summary statistics based on individuals of European ancestry from the MR-Base and NHGRI-EBI GWAS Catalog database. Inverse-variance weighted (IVW) MR approach was used to estimate causal effects in the main analysis, complemented by 4 additional methods to control for pleiotropy. Sensitivity analyses were conducted to verify whether heterogeneity and pleiotropy can bias the MR results.

RESULTS

The MR analysis did not provide strong evidence for the causal association of circulating 25(OH)D with NAFLD by IVW method (OR = 0.746, 95%CI 0.517-1.078; P = 0.119). The results were consistent using four other MR methods. Sensitivity analysis using all different analytical approaches yielded similar results. There was no evidence for pleiotropy (MR-Egger intercept: -0.0003758, P = 0.970). The replication process also showed consistent results using IVW method (P = 0.710).

CONCLUSION

This study indicates that serum 25(OH)D levels did not possess an obvious effect on the risk of NAFLD. The associations in previous studies may be due to residual confounding or reverse causation.

Role of Vitamin D in Liver Disease and Complications of Advanced Chronic Liver Disease

Vitamin D is a crucial nutrient with many pleiotropic effects on health and various chronic diseases. The purpose of this review is to provide a detailed report on the pathophysiological mechanisms underlying vitamin D deficiency in patients with chronic liver disease, addressing the different liver etiologies and the condition of advanced chronic liver disease (cirrhosis) with related complications. To date, patients with liver disease, regardless of underlying etiology, have been shown to have reduced levels of vitamin D. There is also evidence of the predictive role of vitamin D values in complications and progression of advanced disease. However, specific indications of vitamin D supplementation are not conclusive concerning what is already recommended in the general population. Future studies should make an effort to unify and validate the role of vitamin D supplementation in chronic liver disease.

The impact of health status, diet and lifestyle on non-alcoholic fatty liver disease: Narrative review

Non-alcoholic fatty liver disease (NAFLD) is defined as the abnormal accumulation of triglycerides in the liver. NAFLD has a global prevalence of almost 30%, while incidence is rising with increasing levels of obesity, type 2 diabetes mellitus (T2DM) and metabolic syndrome. Nutrition plays a significant role in both the prevention and treatment of NAFLD. Therefore, the aim of this literature review is to explore the associations between dietary, lifestyle and other risk factors and the risk for developing NAFLD. Dietary patterns, lifestyle behaviours, comorbidities, or a combination of any may contribute to either the progression or prevention of NAFLD. Having diabetes, hypertension, or having obesity might increase the progression of NAFLD if not well treated and controlled. Diet influences the progression of NAFLD; following a western diet or simply a high-fat diet may contribute to the worsening of NAFLD and further progression to non-alcoholic steatohepatitis (NASH) and cirrhosis in later stages. On the other hand, the Mediterranean diet is the gold standard for both the treatment and prevention of NAFLD. Social behaviours, such as smoking, caffeine consumption and physical activity also play a role in the pathophysiology of NAFLD. Nutrition contributes significantly to the prevention or treatment of NAFLD, since this disease can be managed by diet and physical activity. However, further studies are still needed for a better understanding of the mechanisms of action. Randomized control trials are also needed to confirm findings in observational studies.

Resolution of, and Risk of Incident Non-alcoholic Fatty Liver Disease With Changes in Serum 25-hydroxy Vitamin D Status

CONTEXT

A protective or causative role of vitamin D status on the risk of nonalcoholic fatty liver disease (NAFLD) remains inconclusive.

OBJECTIVE

To evaluate the association between changes in serum 25-hydroxyvitamin D [25(OH)D] status during follow-up and the risk of incident NAFLD and resolution of preexisting NAFLD.

DESIGN

A retrospective cohort study.

SETTING

Kangbuk Samsung Health Study based on routine health screening examinations.

PARTICIPANTS

Korean adults (mean age, 36.8 years; range, 18-96 years) who underwent comprehensive health examinations including assessment of serum 25(OH)D levels.

MAIN OUTCOME MEASURES

The main outcomes were (1) incidence and (2) resolution of NAFLD assessed by liver ultrasound. Cox proportional hazard models were used to estimate hazard ratios (HRs) with 95% CIs for outcomes according to serum 25(OH)D levels.

RESULTS

Among 139 599 participants without NAFLD at baseline, 27 531 developed NAFLD during follow-up. Serum 25(OH)D levels were significantly and inversely associated with NAFLD development. Among 48 702 participants with NAFLD at baseline, 13 449 showed NAFLD resolution. Multivariable-adjusted HR (95% CI) for NAFLD resolution comparing 25(OH)D 10 to <20, 20 to <30, and ≥30 ng/mL to <10 ng/mL were 1.09 (1.03-1.15), 1.13 (1.06-1.21), and 1.21 (1.09-1.35), respectively. Additionally, an increase in 25(OH)D levels between baseline and the subsequent visit (median, 1.8 years) was associated with decreased NAFLD incidence, while persistently adequate 25(OH)D levels over time was associated with decreased incidence and increased resolution of NAFLD.

CONCLUSIONS

Maintaining adequate serum 25(OH)D concentrations may be beneficial for both prevention as well as resolution of NAFLD.

Role of Vitamin B12 and Vitamin D levels in intrahepatic cholestasis of pregnancy and correlation with total bile acid

This study aimed to evaluate the relationship between intrahepatic cholestasis of pregnancy (ICP) and Vitamin D and B12 levels. The study was a retrospective, cross-sectional, case-control study that evaluated 92 ICP cases and 102 pregnant women without any additional disease. ICP cases were grouped as mild and severe according to their total bile acid (TBA) levels, and their relationship with Vitamin D and B12 levels and perinatal outcomes was evaluated. Vitamin D and B12 levels of the ICP group were significantly lower than those of the control group. There was a moderate negative correlation between TBA and Vitamin D levels and a low negative correlation between TBA and Vitamin B12 levels. Adverse neonatal outcomes were significantly higher in the severe ICP group than in the mild ICP group. IMPACT STATEMENTWhat is already known on this subject? The pathophysiology of ICP, which can lead to adverse perinatal outcomes, is not yet fully understood, and there is no preventive treatment.What do the results of this study add? This study showed that Vitamins B12 and D levels were low in women with ICP and that TBA levels were negatively correlated with Vitamin D and B12 levels.What are the implications of these findings for clinical practice and/or further research? This study may guide future studies in terms of explaining the etiopathogenesis of ICP and developing treatment options.

Emerging Roles of Vitamin D-Induced Antimicrobial Peptides in Antiviral Innate Immunity

Vitamin D deficiency, characterized by low circulating levels of calcifediol (25-hydroxyvitamin D, 25D) has been linked to increased risk of infections of bacterial and viral origin. Innate immune cells produce hormonal calcitriol (1,25-dihydroxyvitamin D, 1,25D) locally from circulating calcifediol in response to pathogen threat and an immune-specific cytokine network. Calcitriol regulates gene expression through its binding to the vitamin D receptor (VDR), a ligand-regulated transcription factor. The hormone-bound VDR induces the transcription of genes integral to innate immunity including pattern recognition receptors, cytokines, and most importantly antimicrobial peptides (AMPs). Transcription of the human AMP genes β-defensin 2/defensin-β4 (HBD2/DEFB4) and cathelicidin antimicrobial peptide (CAMP) is stimulated by the VDR bound to promoter-proximal vitamin D response elements. HDB2/DEFB4 and the active form of CAMP, the peptide LL-37, which form amphipathic secondary structures, were initially characterized for their antibacterial actively. Notably, calcitriol signaling induces secretion of antibacterial activity in vitro and in vivo, and low circulating levels of calcifediol are associated with diverse indications characterized by impaired antibacterial immunity such as dental caries and urinary tract infections. However, recent work has also provided evidence that the same AMPs are components of 1,25D-induced antiviral responses, including those against the etiological agent of the COVID-19 pandemic, the SARS-CoV2 coronavirus. This review surveys the evidence for 1,25D-induced antimicrobial activity in vitro and in vivo in humans and presents our current understanding of the potential mechanisms by which CAMP and HBD2/DEFB4 contribute to antiviral immunity.

A clinical model to predict fibrosis on liver biopsy in paediatric subjects with nonalcoholic fatty liver disease

The incidence of nonalcoholic fatty liver disease (NAFLD) in children is rapidly increasing. Liver fibrosis is a poor prognostic feature that independently predicts cirrhosis. The time that intercedes the first medical encounter and biopsy is rate-limiting to multi-modal treatment. This study aimed to identify non-invasive parameters to predict advanced NAFLD and fibrosis. We conducted a single-center, retrospective 10-year analysis of 640 paediatric patients who underwent liver biopsy. 55 patients, age 3-21 years, had biopsy-confirmed NAFLD. We assessed primary outcomes, NAFLD activity score (NAS) and fibrosis scores, against non-invasive parameters by linear regression, by using binary cutoff values, and by a multivariate logistic regression fibrosis prediction model. NAS correlated with platelets and female sex. Fibrosis scores correlated with platelet counts, gamma glutamyl transferase (GGT), and ultrasound shear wave velocity. 25-hydroxy-vitamin D and GGT differentiated mild versus moderate-to-advanced fibrosis. Our multivariate logistical regression model-based scoring system predicted F2 or higher (parameters: BMI%, vitamin D, platelets, GGT), with sensitivity and specificity of 0.83 and 0.95 (area under the ROC curve, 0.944). We identify a clinical model to identify high-risk patients for expedited biopsy. Stratifying patients to abbreviate time-to-biopsy can attenuate delays in aggressive therapy for high-risk patients.

Vitamin D supplementation for chronic liver diseases in adults

BACKGROUND

Vitamin D deficiency is often reported in people with chronic liver diseases. Improving vitamin D status could therefore be beneficial for people with chronic liver diseases.

OBJECTIVES

To assess the beneficial and harmful effects of vitamin D supplementation in adults with chronic liver diseases.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, LILACS, Science Citation Index Expanded, and Conference Proceedings Citation Index-Science. We also searched ClinicalTrials.gov  and the World Health Organization International Clinical Trials Registry Platform. We scanned bibliographies of relevant publications and enquired experts and pharmaceutical companies as to additional trials. All searches were up to November 2020.

SELECTION CRITERIA

Randomised clinical trials that compared vitamin D at any dose, duration, and route of administration versus placebo or no intervention in adults with chronic liver diseases. Vitamin D could have been administered as supplemental vitamin D (vitamin D₃ (cholecalciferol) or vitamin D₂ (ergocalciferol)), or an active form of vitamin D (1α-hydroxyvitamin D (alfacalcidol), 25-hydroxyvitamin D (calcidiol), or 1,25-dihydroxyvitamin D (calcitriol)).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included 27 randomised clinical trials with 1979 adult participants. This review update added 12 trials with 945 participants. We assessed all trials as at high risk of bias. All trials had a parallel-group design. Eleven trials were conducted in high-income countries and 16 trials in middle-income countries. Ten trials included participants with chronic hepatitis C, five trials participants with liver cirrhosis, 11 trials participants with non-alcoholic fatty liver disease, and one trial liver transplant recipients. All of the included trials reported the baseline vitamin D status of participants. Participants in nine trials had baseline serum 25-hydroxyvitamin D levels at or above vitamin D adequacy (20 ng/mL), whilst participants in the remaining 18 trials were vitamin D insufficient (less than 20 ng/mL). Twenty-four trials administered vitamin D orally, two trials intramuscularly, and one trial intramuscularly and orally. In all 27 trials, the mean duration of vitamin D supplementation was 6 months, and the mean follow-up of participants from randomisation was 7 months. Twenty trials (1592 participants; 44% women; mean age 48 years) tested vitamin D₃ (cholecalciferol); three trials (156 participants; 28% women; mean age 54 years) tested vitamin D₂; four trials (291 participants; 60% women; mean age 52 years) tested 1,25-dihydroxyvitamin D; and one trial (18 participants; 0% women; mean age 52 years) tested 25-hydroxyvitamin D. One trial did not report the form of vitamin D. Twelve trials used a placebo, whilst the other 15 trials used no intervention in the control group. Fourteen trials appeared to be free of vested interest. Eleven trials did not provide any information on clinical trial support or sponsorship. Two trials were funded by industry. We are very uncertain regarding the effect of vitamin D versus placebo or no intervention on all-cause mortality (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.51 to 1.45; 27 trials; 1979 participants). The mean follow-up was 7 months (range 1 to 18 months). We are very uncertain regarding the effect of vitamin D versus placebo or no intervention on liver-related mortality (RR 1.62, 95% CI 0.08 to 34.66; 1 trial; 18 participants) (follow-up: 12 months); serious adverse events such as hypercalcaemia (RR 5.00, 95% CI 0.25 to 100.8; 1 trial; 76 participants); myocardial infarction (RR 0.75, 95% CI 0.08 to 6.81; 2 trials; 86 participants); thyroiditis (RR 0.33, 95% CI 0.01 to 7.91; 1 trial; 68 participants); circular haemorrhoidal prolapse (RR 3.00, 95% CI 0.14 to 65.9; 1 trial; 20 participants); bronchopneumonia (RR 0.33, 95% CI 0.02 to 7.32; 1 trial 20 participants); and non-serious adverse events. The certainty of evidence for all outcomes is very low. We found no data on liver-related morbidity such as gastrointestinal bleeding, hepatic encephalopathy, hepatorenal syndrome, ascites, or liver cancer. There were also no data on health-related quality of life. The evidence is also very uncertain regarding the effect of vitamin D versus placebo or no intervention on rapid, early, and sustained virological response in people with chronic hepatitis C.

AUTHORS' CONCLUSIONS

Given the high risk of bias and insufficient power of the included trials and the very low certainty of the available evidence, vitamin D supplementation versus placebo or no intervention may increase or reduce all-cause mortality, liver-related mortality, serious adverse events, or non-serious adverse events in adults with chronic liver diseases. There is a lack of data on liver-related morbidity and health-related quality of life. Further evidence on clinically important outcomes analysed in this review is needed.

Inverse Association between Serum 25-hydroxyvitamin D Levels and Risk of Suspected Non-Alcoholic Fatty Liver Disease in Obese Population

BACKGROUND

Worldwide, vitamin D deficiency is a public health issue and the prevalence of obesity and non-alcoholic fatty liver disease (NAFLD) are rapidly increasing. There are a limited number of studies assessing the association between serum levels of 25-hydroxyvitamin D (25(OH)D) and NAFLD risk in obese population.

OBJECTIVE

We evaluated the associations between serum 25(OH)D levels and risk of suspected NAFLD after stratification by obesity using data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2014.

METHODS

This study included 25,755 subjects without significant alcohol consumption for the serum alanine aminotransferase (ALT) and hepatic steatosis index (HSI) analyses (8922 subjects for the serum gamma-glutamyl transferase (GGT) and fatty liver index (FLI) analyses), based on a cross-sectional study design. Serum 25(OH)D levels were measured using a Gamma counter with radioimmunoassay. A survey logistic regression model was applied to estimate ORs and 95% CIs. Restricted cubic smoothing splines were applied to evaluate nonlinear associations.

RESULTS

The risk of suspected NAFLD was reduced per unit of natural log-transformed serum 25(OH)D concentration in obese individuals (OR [95% (CI)]; for ALT, 0.80 [0.67, 0.96]; for GGT, 0.70 [0.49, 0.99; for FLI, 0.68 [0.47, 1.01]; for HSI, 0.70 [0.56, 0.87]). The ORs [95% CI] of suspected NAFLD changed across the quartiles: for serum ALT, from 1.02 [0.85, 1.23] to 0.72 [0.59, 0.87]; for serum GGT, from 0.79 [0.56, 1.13] to 0.64 [0.44, 0.92]; for FLI, from 0.98 [0.67, 1.44] to 0.70 [0.48, 1.02]; and for HSI, from 0.91 [0.73, 1.14] to 0.65 [0.52, 0.81] with dose-response relationships (all p for trend < 0.01).

CONCLUSIONS

This study suggests that vitamin D sufficiency for public health should be emphasized in order to prevent adverse health effects in obese populations.

The effect of 1,25-dihydroxyvitamin D3 on liver damage, oxidative stress, and advanced glycation end products in experimental nonalcoholic- and alcoholic- fatty liver disease

Background/aim

Oxidative stress and advanced glycation end products (AGEs) formation are proposed as effective mechanisms in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD). 1,25(OH)2D3 was proposed to have antioxidant, antiinflammatory and antiglycation properties. In this study, the effect of 1,25(OH)2D3 treatment on oxidative stress parameters and AGEs levels together with hepatic histopathology was investigated in high fructose (HFr) or ethanol (EtOH)-treated rats.

Materials and methods

Rats were treated with fructose (30%) or ethanol (5-20%) in drinking water with and without 1,25(OH)2D3 treatment (5 µg/kg two times a week) for 8 weeks. Insulin resistance (IR), oxidative stress parameters, AGEs, triglyceride (TG), and hydroxyproline (Hyp) levels together with histopathology were investigated in the liver.

Results

1,25(OH)2D3 decreased hepatic reactive oxygen species, lipid and protein oxidation products together with histopathological improvements in HFr- and EtOH-treated rats. 1,25(OH)2D3 treatment was observed to decrease significantly serum and hepatic AGEs in HFr group, and hepatic AGEs in EtOH group.

Conclusion

Our results clearly show that 1,25(OH)2 D3 treatment may be useful in the alleviation of hepatic lesions by decreasing glycooxidant stress in both NAFLD and ALD models created by HFr- and EtOH-treated rats, respectively.

Non-alcoholic Fatty Liver and Vitamin D Levels in Extremely Obese Individuals: A Case–Control Study

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is currently one of the most prevalent liver diseases. NAFLD is exemplified by the deposition of fat in the liver, in the absence of other etiologies. The spectrum of histological features in NAFLD ranges from macro-vesicular steatosis and nonalcoholic steatohepatitis, and it can eventually end in fibrosis, cirrhosis, or hepatocellular carcinoma. Vitamin D deficiency (VDD) is the most common micronutrient deficiency worldwide. Obese subjects are more prone to VDD, particularly those with liver disease. Non-classic functions of Vitamin D may be involved in the metabolic pathways beyond NAFLD development and progression. AIM: The aim of the study was to evaluate the relationship between NAFLD and Vitamin D levels in extreme obese subjects, and the correlation between Vitamin D levels and NAFLD severity. MATERIALS AND METHODS: The study included 80 Egyptian subjects of both sexes, divided into two groups: 50 patients with Stage III obesity (defined as body mass index [BMI] ≥40 kg/m2) and NAFLD, their age ranging from 20 to <60 years, and 30 age- and sex-matched healthy volunteers as control subjects. All patients were recruited from nutrition outpatient clinic at endocrinology unit, Cairo University Hospitals during the period from January 2019 to June 2019. Diagnosis of NAFLD was done by ultrasonography and laboratory evaluation included Vitamin D level. Nutritional evaluation included BMI, waist circumference, and weight. RESULTS: Vitamin D was significantly lower in the NAFLD group versus healthy controls: About 34%, deficient, 32% insufficient, and 34% sufficient in NAFLD group versus 23.3% insufficient, and 76.7% sufficient only in control, p ˂ 0.001. The severity of NAFLD, as graded by ultrasonography, was positively correlated with BMI and inversely correlated with Vit D levels, p = 0.001 and 0.024, respectively. Multivariate linear regression proved that both BMI and Vit D were independent predictors for NAFLD progression, BMI in a positive manner and Vit D in a negative manner. A cutoff Vit D level of 27.75 had 64% sensitivity and 90% specificity in NAFLD detection, area under the curve was 0.821. CONCLUSION: Vitamin D is significantly lower in the NAFLD group versus healthy controls in this cohort. VDD and BMI were associated with increased NAFLD severity. VDD was found to be an independent predictor of NAFLD progression. Vitamin D supplementation may be added to lifestyle modifications to prevent NAFLD occurrence in obese subjects.

The efficacy of calcitriol treatment in non-alcoholic fatty liver patients with different genotypes of vitamin D receptor FokI polymorphism

Background

Vitamin D deficiency is prevalent in patients with non-alcoholic fatty liver disease (NAFLD), but there are debates on the usefulness of vitamin D treatment. The interindividual variations in response may be due to different genetic backgrounds.

The present study evaluated the efficacy of calcitriol treatment in NAFLD patients with regard to the vitamin D receptor (VDR) genotypes of FokI polymorphism.

Methods

The study was conducted on 128 NAFLD patients randomly divided into two groups and were subjected to intervention with 0.25 mcg calcitriol/day or placebo for 4 months, while anthropometric parameters, glycemic status, lipid profiles, inflammatory markers, liver enzymes, and fatty liver indices were measured. The ARMS-PCR method was used to genotype the VDR FokI polymorphism.

Results

Calcitriol treatments along with weight loss and diet recommendations decreased the liver enzymes (AST, ALT, and ALP, p < 0.001 for all) and fatty liver indices (HSI, p < 0.01 and APRI, p < 0.001), compared to the baseline. But when the calcitriol effects were compared to the placebo group, only ALP decrease remained significant (17.5 IU. P = 0.02). The prevalent FokI variants in our population were FF (53.1%) and Ff genotype (45.3%). No significant interaction of FokI variants to the calcitriol effects was found except for ALP. The decrease in the ALP activity was higher in calcitriol-received patients with the Ff genotype (p = 0.05).

Conclusions

The FF and Ff variants of VDR FokI polymorphism did not interact with the effects of calcitriol on fatty liver, but the ALP was more responsive in subjects with the Ff variant.

IRCT registration number

IRCT2017053034222N1 Registration date: 2017-06-28 - Retrospectively registered, https://en.irct.ir/trial/26203

Low serum vitamin D concentrations are associated with obese but not lean NAFLD: a cross-sectional study

BACKGROUND

A low serum vitamin D concentration has been reported to be associated with an increased risk of non-alcoholic fatty liver disease (NAFLD); however, whether lean or obese individuals show a similar association between vitamin D and NAFLD remains speculative. This study aimed to explore the relationship between serum vitamin D concentration and NAFLD in lean and obese Chinese adults.

METHODS

This cross-sectional study included 2538 participants (1360 men and 1178 women) who underwent health checkups at the First Affiliated Hospital, Zhejiang University School of Medicine in 2019. NAFLD was diagnosed by liver ultrasound excluding other causes. The association of serum vitamin D concentration with NAFLD was analyzed in lean and obese participants.

RESULTS

The overall prevalence of NAFLD was 33.61% (13.10% in lean and 53.32% in obese) in this study population. The serum vitamin D levels of obese NAFLD patients were lower than those of obese NAFLD-free controls. However, the serum vitamin D levels of lean NAFLD patients were comparable to those of lean NAFLD-free controls. Serum vitamin D level was negatively correlated with the prevalence of NAFLD in obese but not lean participants. Serum vitamin D level was independently associated with the risk of NAFLD in obese participants, with an adjusted odds ratio (95% CI) of 0.987 (0.981-0.993). However, serum vitamin D level was not related to the risk of NAFLD in lean participants.

CONCLUSIONS

A low serum vitamin D level is associated with NAFLD in obese but not lean participants.

Probiotic Yogurt Fortified with Vitamin D Can Improve Glycemic Status in Non-Alcoholic Fatty Liver Disease Patients: a Randomized Clinical Trial

Non-alcoholic fatty liver disease (NAFLD) is a significant public health problem globally and the most notable chronic liver disease in Asian countries. Various dietary supplements have been assessed as potential methods to alleviate the metabolic damages related to NAFLD, but the results of these works have been equivocal. This study aimed to evaluate the effects of probiotic yogurt fortified with vitamin D (Pro-YFD) on glycemic and anthropometric indices in patients with NAFLD. One hundred and four NAFLD patients of both sexes were randomly allocated to 2 groups: group A (Pro-YFD) and group B (unfortified yogurt). The intervention period was 3 months. Fasting blood samples were obtained for measuring fasting blood sugar (FBS) and insulin level. Food intake was measured using a validated food frequency questionnaire. Body composition was estimated by bio-impedance. Eighty-eight patients completed the study. The mean serum level of 25(OH)D₃ was elevated significantly (p < 0.001), while insulin level decreased significantly (p < 0.003) in group A at the end of the study. FBS levels showed no significant differences between the groups at the end of the trial. Also, there were no significant changes in diet caloric intake, physical activity, or anthropometric indices in the 2 groups during the interventions. Pro-YFD in the diets of patients with NAFLD may attenuate insulin resistance and improve serum level of 25(OH)D₃.

Association of vitamin D supplementation with serum leptin and metabolic parameters in Egyptian patients with non-alcoholic steatohepatitis: a prospective study

Background

Nonalcoholic steatohepatitis (NASH) is the progressive form of NAFLD, a common cause of liver disease, with increased chance of progression to liver fibrosis, cirrhosis, and hepatocellular carcinoma. Circulating leptin is increased in patients with NASH. It is an independent positive predictor of the severity of hepatic steatosis. Vitamin D is a lipophilic molecule essential to maintain calcium and phosphate balance. Moreover, it has antifibrotic, antiproliferative, and anti-inflammatory effects on the liver. Vitamin D deficiency is a worldwide condition and very common in patients with NASH. Low serum vitamin D has been shown to predispose to intrahepatic lipid accumulation leading to NAFLD. The aim of this study was to investigate the association of vitamin D supplementation with serum leptin and metabolic parameters in Egyptian patients with non-alcoholic steatohepatitis

Results

Patients with NASH group had statistically significant higher values of diastolic blood pressure (94.3 ± 11.9 mmHg, p < 0.0001), glycated hemoglobin (8.0 ± 2.4%, p < 0.0001), fasting blood sugar (165.6 ± 62.0 mg/dL, p < 0.0001), fasting insulin level (24.2 ± 3.0 μU/ml, p < 0.0001), homeostatic model assessment of insulin resistance (HOMA-IR) (1.8 ± 0.7, p < 0.0001), alanine transferase (ALT) (78.2 ± 36.7 U/L, p < 0.0001), aspartate transferase (AST) (108.6 ± 85.6 U/L, p < 0.0001), NAFLD fibrosis score (− 0.78 ± 0.9, p < 0.0001), total cholesterol (233.0 ± 40.9 mg/dL, p = 0.0011), low-density lipoprotein (117.5 ± 41.6 mg/dL, p = 0.0084), and triglycerides (229.7 ± 62.1 mg/dL, p < 0.0001) than the control group. Moreover, they had lower serum vitamin D level (15.6 ± 6.6 ng/ml, p = 0.0004) and higher serum leptin level (35.9 ± 28.4 ng/ml, p < 0.0001) than the control group. Following vitamin D supplementation, there was a statistically significant reduction in HbA1c (6.8 ± 1.3%, p = 0.0055), fasting blood sugar (136.1 ± 32.7 mg/dL, p = 0.0094), fasting insulin level (22.9 ± 1.8 μU/ml, p = 0.0236), HOMA-IR (1.4 ± 0.4, p = 0.0026), ALT (55.3 ± 21.3 U/L, p = 0.0010), AST (73.1 ± 54.2 U/L, p = 0.0297), and triglycerides (203.6 ± 49.8 mg/dL, p = 0.0415) in patients with NASH. There was a statistically significant increase in serum vitamin D level (33.0 ± 7.6 ng/ml, p < 0.0001) and decrease in serum leptin level (23.5 ± 12.9 ng/ml, p = 0.0140) after treatment.

Conclusions

Vitamin D supplementation in patients with NASH in a dose of 4000 IU/day for 12 weeks improves severity of hepatic inflammation, decreases insulin resistance, improves glycemic control, corrects dyslipidemia, and protects against lipotoxicity by inhibition of serum leptin.

The association between vitamin D status and non-alcoholic fatty liver disease in adults: a hospital-based study

Background

The association between vitamin D levels and non-alcoholic fatty liver disease (NAFLD) has been increasingly determined in recent researches. The aim of this study was to determine the association between vitamin D levels, measured as serum 25-hydroxy vitamin D (25(OH)D) and NAFLD. Serum 25(OH)D was prospectively determined in 80 patients. Of them, 40 subjects had NAFLD, whereas 40 subjects served as healthy control. Vitamin D deficiency was defined as serum 25(OH)D level < 20 ng/ml. Receiver operating characteristic (ROC) and regression analysis methods were used in our analysis.

Results

About 70% of patients with NAFLD had vitamin D deficiency, but only 35% in the control group had. The mean serum 25 (OH)D was significantly lower in patients with NAFLD than the healthy control group (16.13 ± 10.23 versus 27.35 ± 10.58 ng/mL; P < 0.001). ROC curve analysis revealed that serum 25(OH)D level of less than 11.2 ng/ml increases the risk of NAFLD with 45% sensitivity and 97.5% specificity (Serum 25(OH)D level ≤ 18.1 ng/ml in males and ≤ 9.4 ng/ml in females increase the risk of NAFLD). Multivariate regression analysis showed that vitamin D deficiency, high age, and high BMI were associated with a significant high risk of NAFLD.

Conclusion

NAFLD patients have low serum vitamin D concentrations, suggesting that vitamin D may have a role in the development of NAFLD. Future studies are recommended to determine the important therapeutic implications of vitamin D for the prophylaxis or the treatment of NAFLD.

Established and emerging factors affecting the progression of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease affecting approximately 25% of the global population. Although a majority of NAFLD patients will never experience liver-related symptoms it is estimated that 5-10% will develop cirrhosis-related complications with risk of death or need for liver transplantation. NAFLD is closely associated with cardiovascular disease and components of the metabolic syndrome. However, NAFLD is not uncommon in lean individuals and may in these subjects represent a different entity with separate pathophysiological mechanisms involved implying a higher risk for development of end-stage liver disease. There is considerable fluctuation in the histopathological course of NAFLD that may partly be attributed to lifestyle factors and dietary composition. Nutrients such as fructose, monounsaturated fatty acids, and trans-fatty acids may aggravate NAFLD. Presence of type 2 diabetes mellitus seems to be the most important clinical predictor of liver-related morbidity and mortality in NAFLD. Apart from severity of the metabolic syndrome, genetic polymorphisms and environmental factors, such as moderate alcohol consumption, may explain the variation in histopathological and clinical outcome among NAFLD patients.

Low-vitamin-D diet lowers cerebral serotonin concentration in mature female mice

Low circulating 25-hydroxyvitamin D (25OHD) is commonly found in obese individuals and is often attributed to a volume dilution effect of adipose tissue. However, low vitamin D (LD) intake may contribute to the obesity itself. In this study, we examine whether low vitamin D status contributes to increased food intake and weight gain and can be explained by altered brain serotonin metabolism in 8-month-old female C57BL/6J mice. In a first experiment, mice were fed a 45% high-fat diet (HFD) containing different amounts of vitamin D at low (100 IU/kg), normal (1,000 IU/kg) or high (10,000 IU/kg) intake. After 10 weeks, mice fed LD had greater energy intake, weight gain, total and hepatic fat than the higher vitamin D groups (P < .05). In a second experiment, mice were examined for the central serotonin regulation of food intake after a 10% normal-fat diet (NFD) or 45% HFD containing low (100 IU/kg) or normal (1000 IU/kg) vitamin D. After 10 weeks, both HFD and LD diets attenuated circulating 25OHD concentration. Additionally, LD intake lowered cortical serotonin level, regardless of dietary fat intake (P < .05). In the arcuate and raphe nuclei, gene expression of vitamin D 1α-hydroxylase was lower due to LD during HFD feeding (P < .05). Tryptophan hydroxylase-2 and serotonin reuptake transporter gene expression was not altered due to LD. Overall, these findings suggest that a LD diet alters peripheral 25OHD, reduces central serotonin, and may contribute to weight gain in an obesogenic environment.

Low serum vitamin D is independently associated with unexplained elevated ALT only among non-obese men in the general population

INTRODUCTION AND OBJECTIVES

There are inconsistent findings on the association between human non-alcoholic fatty liver disease (NAFLD) and vitamin D, perhaps due to insufficient specificity for gender and obesity status. We aimed to assess whether serum levels of 25-hydroxyvitamin D are associated with unexplained elevated alanine aminotransferase (ALT) in general population across gender and body mass index (BMI) levels.

MATERIALS AND METHODS

A cross-sectional analysis of a population-based cohort with a nationwide-distribution using electronic medical database. The population consisted of individuals aged 20-60 years who underwent blood tests for ALT and vitamin D.

RESULTS

A total of 82,553 subjects were included (32.5% men, mean age 43.91±10.15 years). The prevalence of elevated ALT was higher among men and women with vitamin D insufficiency or deficiency, but in multivariate analysis, adjusting for: age, BMI, serum levels of glucose, total cholesterol, triglycerides, statin use and season, only the association among men remained significant for the vitamin D deficiency category (OR=1.16, 95%CI 1.04-1.29, P=0.010). Stratification by BMI revealed that only among normal weight and overweight men vitamin D deficiency was associated with elevated ALT (OR=1.27, 95%CI 1.01-1.59, P=0.041 and OR=1.27, 95%CI 1.08-1.50, P=0.003, respectively). No independent association was shown among women at all BMI categories.

CONCLUSIONS

In a "real-life" general population, the association between vitamin D deficiency and unexplained elevated ALT is specific for non-obese men. The clinical significance of vitamin D for human NAFLD should be further elucidated with attention for a modifying effect of gender and adiposity.