Critical need for pharmacologic treatment options in NAFLD: A pediatric perspective

Nonalcoholic fatty liver disease (NAFLD) affects up to 70% of children with obesity and has become the number one etiology for liver transplant in the United States. Early, effective intervention is critical to prevent disease progression into adulthood. Yet, it is seldom achieved through lifestyle modification alone. Thus, children must be included in NAFLD pharmacology trials, which, to date, continue to focus primarily on adult populations. This commentary serves as a call to action.

Three hundred forty million children worldwide are affected by overweight/obesity (https://www.who.int/end‐childhood‐obesity/publications/taking‐action‐childhood‐obesity‐report/en/). Without intervention, > 75% of these children will continue to gain excessive weight and become adults with obesity. ¹ Alarmingly, almost all adults with obesity (90%) develop comorbid nonalcoholic fatty liver disease (NAFLD), the leading etiology for liver transplant in the United States. ² Thus, effective, early life intervention is critical for children with obesity, up to 70% of whom already have comorbid NALFD by adolescence. ² Lifestyle modifications (e.g., diet and exercise) resulting in weight loss of as little as one kilogram can improve NAFLD in children. ³ However, overall adherence to lifestyle modification is low, with the exception of a few pediatric research studies that offer intense follow‐up ³ , ⁴ or comprehensive in‐home services. ⁴ As such, bariatric surgery is increasingly recognized as an option for weight reduction in children, but it is invasive and there is an unpredictable subset of patients who experience worsening liver fibrosis and NAFLD progression postsurgery. ⁵ This leaves a critical, unmet need for effective pharmacologic interventions in pediatric NAFLD.Currently, there are no approved medications for NAFLD; however, the landscape of potential therapeutic agents is evolving rapidly and showing promise, as highlighted in a comprehensive review by Attia et al. published in Clinical and Translational Science. ⁶ In addition to the many novel therapeutic agents discussed (e.g., obeticholic acid, fibroblast growth factor 19 and 21 analogues, thyroid hormone receptor‐β agonists, etc.), the authors briefly mention past therapeutic experiences with medications already on the market for other clinical indications. Although the adult experience with some of these medications was equivocal, it is important to note that some agents show promise for repurposing in pediatric NAFLD.One example is metformin, a drug already approved for the treatment of type 2 diabetes in children > 10 years of age. In a study of lifestyle modifications combined with either metformin or placebo in children with obesity and insulin resistance ± NAFLD, the metformin group demonstrated a significant decrease in NAFLD scores and NAFLD prevalence, whereas the placebo group experienced an increase from baseline for both. ⁷ Interestingly, when metformin was administered at lower doses in other pediatric trials, it demonstrated isolated improvement in histopathology features (e.g., hepatic ballooning), ⁸ but not in the overall histopathology NAFLD score, suggesting that metformin’s effect on NAFLD may be dose dependent. Therefore, further studies of metformin in the setting of pediatric NAFLD are indicated.Other drugs already approved for obesity‐related comorbidities may also be of interest for repurposing in pediatric NAFLD. Statins, cholesterol‐lowering agents prescribed to patients with obesity and hypercholesterolemia, have been shown to significantly improve hepatic function in patients with obesity and NAFLD ⁹ —presumably through anti‐inflammatory mechanisms in the liver. Although no data are available in pediatrics, in adults with NAFLD, statin therapy is well‐tolerated, with low frequency of hepatotoxicity similar to placebo, ⁹ making statins intriguing drug candidates to consider for the treatment of pediatric NAFLD. Secondary analyses of off‐target treatment effects of medications already prescribed to children with obesity (e.g., statins and metformin) may be helpful in uncovering important insights into therapeutic options for pediatric NAFLD treatment. Especially while best practices for expanding novel NAFLD therapeutics trials to pediatrics remain under development, as referenced in a recent draft guidance from the US Food and Drug Administration (https://www.fda.gov/media/119044/download).In our opinion, and the opinion of other experts, ¹⁰ inclusion of pediatric populations in adult NAFLD pharmacology trials is important and represents a strategy that has been successfully implemented in oncology trials. Yet, the majority of new NAFLD agents continue to be pursued more aggressively for adults than children. As illustrated in the review by Attia et al., ⁶ only 2 of the 17 therapeutic trials discussed included children. By excluding children, we are missing a critical opportunity for early intervention to prevent NAFLD progression from simple hepatic steatosis to more advanced disease (i.e., steatohepatitis, fibrosis, cirrhosis, hepatocellular carcinoma, and end‐stage liver failure). Our hope is that increased awareness of pediatric NAFLD prevalence, coupled with the National Institutes of Health policy for inclusion of research subjects across the lifespan (https://grants.nih.gov/policy/inclusion/lifespan.html), will encourage investigators to include pediatric patients in clinical trials of NAFLD therapeutics.Inclusion of children in pharmacology trials comes with its own set of unique challenges and nuances (e.g., ontogeny, age‐appropriate outcome measures, parental informed consent and informed assent of minors, etc.), beyond the scope of this commentary and as comprehensively reviewed in a pediatric tutorial guide by Shakhnovich et al. ¹¹ In addition, to facilitate inclusion of children specifically in pharmacology trials for NAFLD, NAFLD‐specific noninvasive biomarkers are urgently needed. The majority of studies reviewed by Attia et al. ⁶ relied on histopathology‐based assessment of NAFLD as a therapeutic outcome measure. However, liver biopsy is invasive and histopathology assessment is not always feasible or ethical in children, especially in the context of research. Alanine aminotransferase, the most commonly utilized clinical serum biomarker of liver injury is nonspecific for NAFLD. Therefore, several more‐specific biomarkers are currently under investigation; among them, serum bile acids. Total fasting and postprandial bile acids, and the ratios of conjugated and secondary bile acids, are consistently higher in the sera of adults with nonalcoholic hepatic steatosis, compared with healthy controls. ¹² Pediatric studies of bile acids lag behind, are sparse and inconsistent, and are needed to establish minimally invasive biomarkers of NAFLD for children.Recently, noninvasive liver imaging biomarkers have become more widely available, and it is encouraging to see these modalities incorporated into NAFLD therapeutics research, including four trials discussed by Attia et al. ⁶ Both ultrasound elastography and magnetic resonance elastography can quantify liver stiffness as a noninvasive surrogate for liver fibrosis. However, NAFLD presents a challenge to both techniques because elastography values are affected by both fat and fibrosis. Magnetic resonance proton density fat fraction (MR‐PDFF) can directly estimate hepatic fat content and allows clinicians and researchers to separate the individual contributions from fat vs. fibrosis to liver stiffness. However, MR‐PDFF is only available in specialized tertiary care centers and is expensive. Ultrasound techniques for fat quantification could offer a cheaper, more readily available alternative to MR‐PDFF and these techniques are likely to become widely available in the near future.Thus, the landscape of therapeutic pharmacology trials for NAFLD is rapidly evolving. The advent of noninvasive biomarkers for monitoring NAFLD treatment response offers promise and opportunity, especially for inclusion of pediatric patients in research. A concerted effort must be made to include children in NAFLD pharmacology trials, as NAFLD affects up to 70% of children with obesity, ² and early childhood intervention is key to minimize/reverse disease progression to end‐stage liver disease in adulthood.     

Transrectal ultrasonography: relationship with anorectal manometry, electromyography and sensitivity tests in irritable bowel syndrome

Irritable bowel syndrome is the most frequently diagnosed disorder in gastroenterology. It has been demonstrated with specialized motility studies that these patients compared to healthy subjects show changes in rectoanal electrical and mechanical activity and in rectoanal sensitivity. However, until now no report has been published on morphological alterations in the rectum or the internal anal sphincter. Twenty-five consecutive patients with irritable bowel syndrome (mean age 32, range 17–47 years; 24 females) were evaluated prospectively by transrectal ultrasonography, rectal sensitivity studies, and recordings of both electrical and mechanical activity of the distal rectum and internal anal sphincter during a 2-h interdigestive period. Ten healthy volunteers (mean age 34.5, range 19–50 years) served as a control group. Paired and non-paired Student's two-tailed t test and linear regression analysis were used. It was shown that muscle thickness of the rectum during rest (4.7±0.1 mm) was correlated neither with its rectal spike amplitude (0.73±0.1 mV) nor with rectal spike frequency (17.06±3.6 spike/2 h). In addition, the diameter of the internal anal sphincter (1.2±0.1 mm) was correlated neither with its resting pressure, nor with frequency (17.1±3.2/2 h), duration (14.9±1.5 s), or amplitude (14.1 ±1.9 mmHg), of inhibition of the spontaneous rectoanal inhibitory reflex. No correlation was found between ultrasonographic parameters and rectal distension variables (r=0.03). This study demonstrates for the first time morphological anorectal changes in patients with irritable bowel syndrome compared to healthy subjects, in addition to showing that morphological changes are independent of physiological ones. Therefore both transrectal ultrasonography to determine anorectal morphology and electromanometry to assess anorectal function are important measures in the evaluation of patients with irritable bowel syndrome. Accepted: 21 November 1997     

Iron overload in Africans and African-Americans and a common mutation in the SCL40A1 (ferroportin 1) gene

The product of the SLC40A1 gene, ferroportin 1, is a main iron export protein. Pathogenic mutations in ferroportin 1 lead to an autosomal dominant hereditary iron overload syndrome characterized by high serum ferritin concentration, normal transferrin saturation, iron accumulation predominantly in macrophages, and marginal anemia. Iron overload occurs in both the African and the African-American populations, but a possible genetic basis has not been established. We analyzed the ferroportin 1 gene in 19 unrelated patients from southern Africa (N = 15) and the United States (N = 4) presenting with primary iron overload. We found a new c. 744 C-->T (Q248H) mutation in the SLC40A1 gene in 4 of these patients (3 Africans and 1 African-American). Among 22 first degree family members, 10 of whom were Q248H heterozygotes, the mutation was associated with a trend to higher serum ferritin to amino aspartate transferase ratios (means of 14.8 versus 4.3 microg/U; P = 0.1) and lower hemoglobin concentrations (means of 11.8 versus 13.2 g/dL; P = 0.1). The ratio corrects serum ferritin concentration for alcohol-induced hepatocellular damage. We also found heterozygosity for the Q248H mutation in 7 of 51 (14%) southern African community control participants selected because they had a serum ferritin concentration below 400 microg/L and in 5 of 100 (5%) anonymous African-Americans, but we did not find the change in 300 Caucasians with normal iron status and 25 Caucasians with non-HFE iron overload. The hemoglobin concentration was significantly lower in the African community controls with the Q248H mutation than in those without it. We conclude that the Q248H mutation is a common polymorphism in the ferroportin 1 gene in African populations that may be associated with mild anemia and a tendency to iron loading.     

Evolution of quality of life and health‐related behaviors among Spanish university students

At the beginning of their academic studies (testing phase), the quality of life and certain health‐related behaviors were evaluated. Four years later (retest phase), they were reevaluated. Between the two evaluation periods, a health promotion (HP) program was applied. The battery of instruments included measures: health‐related quality of life (HRQOL), alcoholic and nicotine dependence, eating habits, physical activity, and sexual behaviors. It also included a number of sociodemographic data. The results show that, in general, the students reported adequate levels of HRQOL, and there were no important differences between the two evaluation moments. Regarding dietary behavior, no significant changes were detected in the pattern of adherence to the Mediterranean diet, which remained at an average level of adequacy. On the contrary, significant decreases were detected in relation to alcohol and tobacco dependence as well as significant increases in physical activity levels. Lastly, with regard to sexual behavior, although certain aspects of improvement were perceived, there is a need to increase awareness of the systematic use of condoms. In conclusion, this study provides relevant information that will serve as a starting point for monitoring changes in health behaviors and for the design and implementation of HP actions directed at university students.     

Increased levels of high-density lipoprotein cholesterol are ineffective in inhibiting the development of immune responses to oxidized low-density lipoprotein and atherosclerosis in transgenic rabbits expressing human apolipoprotein (apo) A-I with severe hypercholesterolaemia

High levels of high-density lipoprotein (HDL) cholesterol have been reported to protect against the development of atherosclerosis in humans by increasing reverse cholesterol transport and inhibiting the oxidation of low-density lipoprotein (LDL) due to the paraoxonase content of HDL. The purpose of the present study was to assess if there are any relationships between in vivo increases in serum levels of immunological LDL oxidation markers [autoantibodies against oxidized LDL, autoantibodies against malondialdehyde-modified LDL, LDL immune complexes and anti-cardiolipin autoantibodies], paraoxonase activity and the development of atherosclerosis in control rabbits and in transgenic rabbits expressing human apolipoprotein (apo) A-I. A total of 13 apo A-I transgenic rabbits and 18 non-transgenic littermates were fed on a cholesterol-rich diet (0.4%, w/w) for 14 weeks, and were monitored at weeks 0, 2, 6, 10 and 14. Aortic atherosclerotic lesions were measured at the end of this period. Human apo A-I transgenic rabbits with high HDL cholesterol levels were not protected against the development of atherosclerosis when they were fed on a cholesterol-rich diet which induced dramatic hypercholesterolaemia. Immunological markers of LDL oxidation increased and serum paraoxonase activity decreased similarly in control and transgenic rabbits. In conclusion, the present study demonstrates that high HDL cholesterol levels are ineffective in inhibiting increases in immunological markers of LDL oxidation and the development of atherosclerosis in a mammal with severe hypercholesterolaemia.     

Evaluation of EMIT methods for the determination of the five major antiepileptic drugs on an automated kinetic analyser.

We have evaluated the performance of enzyme-multipled immunoassay methods for the five major antiepileptic drugs on an automated system, the Perkin-Elmer Model KA-150 Kinetic Analyzer. The precision in the normal duplicate mode was found to be in the range of 6% to 10% for all five tests over a typical working day. All EMIT methods were compared to gas-liquid chromatographic procedures and, in addition, the phenytoin and phenobarbital assays were compared to a liquid-chromatographic method. The phenytoin assay was also compared to RIA and to a manual spectroscopic method. In general, most of the comparison studies resulted in acceptable correlation, although one gas chromatographic method did not correlate very well with the phenytoin and phenobarbital immunoassays.