Vitamin D Effect on Ultrasonography and Laboratory Indices and Biochemical Indicators in the Blood: an Interventional Study on 12 to 18-Year-Old Children with Fatty Liver

1,25-dihydroxyvitamin D3 improves non-alcoholic steatohepatitis phenotype in a diet-induced rat model

We studied the potential protective effects of 1,25-dihydroxyvitamin D3 (1,25 VD3) supplementation on liver damage induced by a choline-deficient (CD) diet in rats, where impaired liver function leads to decreased 25-hydroxyvitamin D3 levels, the precursor for the active 1,25 VD3. The CD diet reduced serum 25 VD3 levels and increased liver enzymes, indicative of liver damage. Conversely, 1,25 VD3 supplementation alleviated liver damage, reducing liver enzymes and improving histopathological features characteristic of non-alcoholic steatohepatitis (NASH). Oxidative stress and inflammation were mitigated by 1,25 VD3, as evidenced by decreased malondialdehyde and nuclear factor kappa B (NF-κB) expression, and increased total antioxidant capacity (TAOC). 1,25 VD3 also enhanced fatty acid metabolism by increasing peroxisome proliferator-activated receptor alpha (PPARα) and carnitine palmitoyltransferase-1 (CPT-1) expression, promoting lipid transport and oxidation. Additionally, 1,25 VD3 supplementation modulated inflammation by increasing PPARγ expression, reducing NF-κB expression, and decreasing pro-inflammatory cytokines (TNF-α, IL-1β). Anti-inflammatory cytokines (IL-10, IL-4) were increased, and macrophage polarization was shifted towards an anti-inflammatory M2 phenotype. Moreover, 1,25 VD3 upregulated CYP2J3, a cytochrome P450 epoxygenase that converts arachidonic acid to anti-inflammatory epoxyeicosatrienoic acids (EETs) and decreased soluble epoxide hydrolase activity, likely contributing to increased EET levels. Correlation studies revealed positive associations between 1,25 VD3 supplementation, CYP2J3 expression, EETs, as well as negative correlations with NF-κB and TNF-α. PPARα expression positively correlated with TAOC and CPT-1, while PPARγ expression negatively correlated with inflammatory markers. These findings demonstrate the therapeutic potential of 1,25 VD3 in alleviating NASH through regulation of fatty acid metabolism, inflammation, and oxidative stress.

Strategic interventions in clinical randomized trials for metabolic dysfunction-associated steatotic liver disease (MASLD) and obesity in the pediatric population: a systematic review with meta-analysis and bibliometric analysis

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease (NAFLD), is a prevalent hepatic condition linked to metabolic alterations. It gradually causes liver damage and potentially progresses to cirrhosis. Despite its significance, research, especially in the pediatric population, is limited, leading to contradictory findings in diagnosis and treatment. This meta-analysis aims to synthesize existing literature on therapeutic interventions for MASLD in children and adolescents.

METHODS

A comprehensive search of randomized controlled clinical trials yielded 634 entries from PubMed, Scopus, and Web of Science up to 2023. Interventions included medications, behavioral modifications, dietary changes, probiotics, supplements, surgical procedures, or combinations. The analysis focused on studies with treatment duration of at least 3 months, employing a random-effects REML meta-analysis model. Treatment effects on anthropometric measurements and biochemical components were examined and adjusted for heterogeneity factors analysis. A bibliometric analysis for insights into research contributors was performed.

RESULTS

The systematic review incorporated 31 clinical trials, with 24 meeting criteria for meta-analysis. These comprised 3 medication studies, 20 with supplements, 4 focusing on lifestyle, and 4 centered on diets. Significant overall treatment effects were observed for ALT, AST, BMI, and HOMA-IR mainly by supplements and lifestyle. Meta-regression identified age, BMI changes, and treatment duration as factors modifying ALT concentrations. Bibliometric analysis involving 31 linked studies highlighted contributions from 13 countries, with the USA, Spain, and Chile being the most influential.

CONCLUSIONS

We conclude that supplementation and lifestyle changes can effectively impact ALT and AST levels, which can help address liver issues in obese children. However, the evaluation of risk bias, the high heterogeneity, and the bibliometric analysis emphasize the need for more high-quality studies and broader inclusion of diverse child populations to provide better therapeutic recommendations.

TRIAL REGISTRATION

PROSPERO, CRD42023393952. Registered on January 25, 2023.

Optimal vitamin D supplement dosage for improving insulin resistance in children and adolescents with overweight/obesity: a systematic review and network meta-analysis

PURPOSE

We conducted a network meta-analysis which aims to evaluate the comparative efficacy of different supplementation dosages of vitamin D on cardiometabolic and bone-metabolic indicators as well as insulin resistance in children and adolescents with overweight/obesity.

METHODS

Eligible studies published before December 10, 2022 were retrieved from PubMed, EMBASE, Cochrane Library, and Web of Science. Mean difference and 95% confidence interval (CI) were used to express pooled estimates. Network meta-analysis of multiple doses, including low (< 1000 IU/day, LDS), medium (1000-2000 IU/day, MDS), high (2000-4000 IU/day, HDS), and extremely high (> 4000 IU/day, EHDS) dosage strategy, was conducted using STATA/MP 14.0.

RESULTS

Our network meta-analysis of 15 RCTs suggested that, compared with placebo and LDS, EHDS was increased 25-(OH)-D, with a pooled MD of 8.65 (95% CI 4.72-12.58) and 7.66 (95% CI 0.91-14.41), respectively. Meanwhile, EHDS also decreased ho meostasis model assessment-insulin resistance (HOMA-IR) (MD: - 0.74; 95% CI: - 1.45 to - 0.04) and C-reactive protein (CRP) (MD: - 18.99; 95% CI - 21.60 to - 16.38), and EHDS was also better than LDS (MD: - 18.47; 95% CI - 20.66 to - 16.28) and MDS (MD: - 19.69; 95% CI - 22.17 to - 17.21) in decreasing CRP. Ranking probability suggested that EHDS ranked best for increasing 25-(OH)-D, and decreasing HOMA-IR and CRP, with a probability of 86.1%, 83.1%, and 76.6%, respectively.

CONCLUSIONS

The results of our network meta-analysis suggest that EHDS may be the best strategy for vitamin D supplementation to reduce inflammatory responses as well as improve insulin resistance in children and adolescents with overweight/obesity.

PROSPERO REGISTRATION NUMBER

CRD42023387775.

Dietary and Nutritional Interventions in Nonalcoholic Fatty Liver Disease in Pediatrics

Nonalcoholic fatty liver disease (NAFLD) is pediatrics' most common chronic liver disease. The incidence is high in children and adolescents with obesity, which is associated with an increased risk of disease progression. Currently, there is no effective drug therapy in pediatrics; therefore, lifestyle interventions remain the first line of treatment. This review aims to present an updated compilation of the scientific evidence for treating this pathology, including lifestyle modifications, such as exercise and dietary changes, highlighting specific nutritional strategies. The bibliographic review was carried out in different databases, including studies within the pediatric population where dietary and/or nutritional interventions were used to treat NAFLD. Main interventions include diets low in carbohydrates, free sugars, fructose, and lipids, in addition to healthy eating patterns and possible nutritional interventions with n-3 polyunsaturated fatty acids (EPA and DHA), amino acids (cysteine, L-carnitine), cysteamine, vitamins, and probiotics (one strain or multi-strain). Lifestyle changes remain the main recommendation for children with NAFLD. Nevertheless, more studies are required to elucidate the effectiveness of specific nutrients and bioactive compounds in this population.

Efficacy of vitamin D supplementation on child and adolescent overweight/obesity: a systematic review and meta-analysis of randomized controlled trials

The global prevalence of overweight and obesity in children and adolescents has been increasing. Child and adolescent overweight/obesity has been demonstrated to be partially associated with vitamin D deficiency. This systematic review and meta-analysis aims to assess the efficacy of vitamin D supplementation on child and adolescent overweight/obesity. PubMed, Embase, Cochrane Library, and Web of science were searched from inception to June 20th, 2022. Randomized controlled trials (RCTs) assessing the efficacy of vitamin D on child and adolescent overweight/obesity were included. The Cochrane bias risk assessment tool was used to assess the bias risk of included studies, and subgroup analysis was conducted based on different administration dosages. All data-analyses were performed using R 4.2.1. There were 1502 articles retrieved, and 10 eligible studies were finally included, with a total of 595 participants. Meta-analysis showed no differences in LDL, TC, TG, BMI, ALP, Ca, and PTH between vitamin-D (Vit-D) group and placebo, while Vit-D group resulted in improved HOMA-IR[WMD =  - 0.348, 95%CI (- 0.477, - 0.219), p = 0.26]. Subgroup-analysis showed no significant difference in the increase of 25-(OH)-D between subgroups (p = 0.39), whereas the serum 25-(OH)-D level was increased under different Vit-D doses [WMD = 6.973, 95%CI (3.072, 10.873)]. High daily dose (≥ 4000 IU/d) of Vit-D might decrease CRP and increase HDL levels.   Conclusion: High dose of Vit-D supplementation (over 4000 IU/d) would reduce several cardiometabolic risk indicators and improve insulin resistance. More high-quality and large-scale RCTs are needed to provide more robust evidence. What is Known: • Vit-D deficiency is common in overweight/obesity (OW/OB) children and adolescents. • Previous randomized studies on the benefit of Vit-D supplementation to OW/OB children and adolescents are inconsistent. What is New: • This is the first meta-analysis conducted to assess the efficacy of Vit-D supplementation on child and adolescent OW/OB. • High dose of Vit-D supplementation is beneficial to cardiovascular metabolism, and improve insulin resistance on child and adolescent OW/OB.

Metabolic dysfunction-associated fatty liver disease in obese youth with insulin resistance and type 2 diabetes

PURPOSE OF REVIEW

The aim of this review is to present the new definition of the disease, defining the epidemiology, risk factors with a particular attention to the role of insulin resistance (IR) and to define the main treatments explored.

RECENT FINDINGS

Nonalcoholic fatty liver disease (NAFLD) was previously considered a primary liver disease, but it would be more correct to consider it a component of the metabolic syndrome (MetS) in which IR might play a key role. Based on these findings, it has been recently proposed to modify the classic term of NAFLD to metabolic dysfunction-associated fatty liver disease (MAFLD) that better reflects the pathophysiology of this complex disease.

SUMMARY

Currently, no treatments approved in childhood are available, thus the only recommended approach is the prevention and correction of the known risk factors, and particularly of IR. However, further studies are needed to better clarify the pathogenetic mechanisms of NAFLD in order to establish more tailored therapies.