Evaluation of uric acid levels, thyroid function, and anthropometric parameters in Japanese children with Down syndrome

Age and gender-specific reference intervals for uric acid level and hyperuricemia in children with Down syndrome

BACKGROUND

The association between Down syndrome (DS) and hyperuricemia has been described for a long time. The cut-off points for hyperuricemia should be determined as the upper limits of the uric acid (UA) level according to age- and gender-specific reference UA values prepared for children with DS.

METHODS

This study included 238 children (140 males and 98 females) with DS, below 21 years of age, who visited our medical center from May 1991 to June 31, 2018. Laboratory data were used to calculate the reference UA levels according to age and gender. We also inquired about the relationship between hyperuricemia and the presence of other diseases and other laboratory findings in children with DS. Fourteen patients had already been definitively diagnosed and treated. The UA data from these cases were excluded from the analysis.

RESULTS

The UA levels were significantly higher in all age groups among individuals with DS in comparison with the general population. Newly established reference values revealed 55 patients with hyperuricemia. The prevalence of hyperuricemia in males and females was 25.0% (35/140) and 20.4% (20/98), respectively. The number of hyperuricemia cases increased rapidly after 10 years of age. The UA levels were closely correlated with hemoglobin (Hb) values, creatinine, and total bilirubin, which are closely associated with dehydration in children with DS.

CONCLUSIONS

These reference levels could help to evaluate hyperuricemia candidates who should be carefully monitored and treated with uric-acid-lowering drugs in the future.

Endocrine, auxological and metabolic profile in children and adolescents with Down syndrome: from infancy to the first steps into adult life

Down syndrome (DS) is the most common chromosomal disorder worldwide. Along with intellectual disability, endocrine disorders represent a remarkable share of the morbidities experienced by children, adolescents and young adults with DS. Auxological parameters are plotted on syndrome-specific charts, as growth rates are reduced compared to healthy age- and gender-matched peers. Furthermore, children with DS are at increased risk for thyroid dysfunctions, diabetes mellitus, osteopenia and obesity compared to general population. Additionally, male individuals with DS often show infertility, while women tend to experience menopause at an overall younger age than healthy controls. Given the recent outstanding improvements in the care of severe DS-related comorbidities, infant mortality has dramatically decreased, with a current average life expectancy exceeding 60 years. Accordingly, the awareness of the specificities of DS in this field is pivotal to timely detect endocrine dysfunctions and to undertake a prompt dedicated treatment. Notably, best practices for the screening and monitoring of pediatric endocrine disorders in DS are still controversial. In addition, specific guidelines for the management of metabolic issues along the challenging period of transitioning from pediatric to adult health care are lacking. By performing a review of published literature, we highlighted the issues specifically involving children and adolescent with DS, aiming at providing clinicians with a detailed up-to-date overview of the endocrine, metabolic and auxological disorders in this selected population, with an additional focus on the management of patients in the critical phase of the transitioning from childhood to adult care.

Kidney and urological involvement in Down syndrome: frequent, underestimated, but associated with impaired quality of life and risk of kidney failure

Patients with Down syndrome (DS) are at risk of multiorgan dysfunction; kidney and urological impairment are common. This is due to a likely increased risk of congenital kidney and urological malformations (odds ratio of 4.5 compared to the general population in one study), more frequent associated comorbidities at risk of kidney dysfunction (such as prematurity in 9-24% of children, intrauterine growth retardation or low birth weight in 20%, and congenital heart disease in 44%), and more frequent lower urinary tract dysfunction (reported in 27-77% of children with DS). If present, malformations and comorbidities at risk of kidney dysfunction warrant regular kidney monitoring in addition to their treatment. Serum creatinine in children with DS has been shown to be higher than in the general population and asymptomatic hyperuricemia is reported in 12-33% of children or young adults with DS. Moreover cryptorchidism and testicular cancer are also more common and should be detected by clinical examination. Thus, persons with DS at risk of presenting kidney and urological impairment should be identified by prenatal ultrasonography, comorbidities at risk of kidney sequelae considered, and during regular medical follow-up, clinically examined and questioned to diagnose testicular anomalies and lower urinary tract dysfunction. This is of importance as such kidney and urological impairments are associated with impaired quality of life and mental health, and risk of kidney failure.

Imbalanced dietary patterns, anthropometric, and body composition profiles amongst adults with Down syndrome

Introduction: We aimed to analyze the anthropometric and body composition profiles of Down syndrome (DS) adults; to describe their dietary habits, nutrient intake, and physical activity patterns; and to identify the related risk factors which may influence their health status and quality of life.Methods: A cross-sectional study was conducted on a cohort of 23 DS adults (45% women) aged 21-44 years. Anthropometry and body composition were assessed by bioelectrical impedance. Dietary nutrient intake was assessed quantitatively using a 72-h recall. A food frequency questionnaire and the prevention with Mediterranean diet-PREDIMED questionnaire were used for qualitative rating.Results: Higher fat mass (FM) and lower lean mass (LM), bone mass (BM), and waist to hip ratio (WHR) were observed in women compared to men. LM and BM decreased, and body mass index (BMI), FM, and WHR increased with aging (all P < 0.05). Vitamin D and iodine intakes were not met by 70% and 60% of the studied participants, respectively. A total of 82% of the participants consumed less than 5 portions of fruits and vegetables per day and overconsumed food groups such as sweets and snacks and red meat (> 2 times per week). Protein intake showed a significant positive correlation with height (r = 0.489, P < 0.05), whereas fat intake was positively correlated with sweets and snacks (r = 0.521, P < 0.05).Conclusion: The present findings support the existence of poor anthropometric and body composition profiles, and diet quality, underscoring the need for an interdisciplinary team assessment to enhance health and quality of life in DS adults.

Characterization of LC-MS based urine metabolomics in healthy children and adults

Previous studies reported that sex and age could influence urine metabolomics, which should be considered in biomarker discovery. As a consequence, for the baseline of urine metabolomics characteristics, it becomes critical to avoid confounding effects in clinical cohort studies. In this study, we provided a comprehensive lifespan characterization of urine metabolomics in a cohort of 348 healthy children and 315 adults, aged 1 to 78 years, using liquid chromatography coupled with high resolution mass spectrometry. Our results suggest that sex-dependent urine metabolites are much greater in adults than in children. The pantothenate and CoA biosynthesis and alanine metabolism pathways were enriched in early life. Androgen and estrogen metabolism showed high activity during adolescence and youth stages. Pyrimidine metabolism was enriched in the geriatric stage. Based on the above analysis, metabolomic characteristics of each age stage were provided. This work could help us understand the baseline of urine metabolism characteristics and contribute to further studies of clinical disease biomarker discovery.

Urate-lowering therapy for gout and asymptomatic hyperuricemia in the pediatric population: a cross-sectional study of a Japanese health insurance database

BACKGROUND

Our previous research showed that uric acid lowering therapy (ULT) for gout and hyperuricemia is being prescribed for pediatric patients even though these drugs have not been approved for use in children. However, the actual clinical situation has not been clearly elucidated. In this paper, we provide an in-depth look at the details of actual clinical practice.

METHODS

This retrospective cross-sectional study accessed health insurance data for 696,277 children from April 2016 through March 2017 to identify pediatric patients with gout or asymptomatic hyperuricemia, calculate the proportion of patients prescribed ULTs, and analyze population characteristics. Adherence and mean dose for febuxostat and allopurinol, the most commonly prescribed drugs, were also analyzed.

RESULTS

Among children with gout or asymptomatic hyperuricemia, we found that 35.1% (97/276) were prescribed ULT. This proportion increased with age, especially among males. By comorbidity, ULT was prescribed to 47.9% (46/96) of patients with kidney disease, 41.3% (26/63) for cardiovascular disease, 40.0% (6/15) for Down syndrome, and 27.1% (32/118) for metabolic syndrome. In patients with kidney disease, febuxostat was prescribed more than twice as frequently as allopurinol (28 vs. 12). Median values for the medication possession ratio (MPR) of febuxostat and allopurinol were 70.1 and 76.7%, respectively, and prescriptions were continued for a relatively long period for both drugs. Both drugs were prescribed at about half the adult dose for patients 6-11 years old and about the same as the adult dose for patients 12-18 years old.

CONCLUSIONS

This study showed that the continuous management of serum uric acid is being explored using off-label use of ULT in pediatric patients with gout or asymptomatic hyperuricemia in Japan. Drug selection is based on patient characteristics such as sex, age, and comorbidities, and pediatric dosage is based on usage experience in adults. To develop appropriate pediatric ULT, clinical trials are needed on the efficacy and safety of ULT in the pediatric population.

TRIAL REGISTRATION

UMIN000036029 .

Quantification of serum thyroid hormones using tandem mass spectrometry in patients with Down syndrome

Thyroid dysfunction is common in patients with Down syndrome (DS), the most common chromosomal disorder. Thyroid hormones (THs) are important for normal growth, neurodevelopment, and metabolism, highlighting the importance of quantifying the levels in patients with DS. However, current methods possess cross-reactivity that results in inaccuracies in quantification. We aimed at developing a new analytical method for quantifying the total 3,3',5-triiodo-l-thyronine (TT3), total 3,3',5,5'-tetraiodo-l-thyronine (TT4), 3,3',5'-triiodo-l-thyronine, and reverse T3 (rT3) levels using LC-MS/MS. Repeatability and reproducibility with coefficient of variation values of 2-9 and 3-13%, respectively, were acceptable, suggesting that the assay was suitable for measuring serum THs. We measured the serum TH levels of patients with DS but without thyroid dysfunction (age, 3-20 years) and compared the levels to those of controls (patients with idiopathic short stature; age, 3-17 years). When TH levels were summarized by age group, the serum TT4 concentrations were not significantly different between the controls and patients with DS across all age groups. Meanwhile, the serum TT3 concentrations differed according to age. In addition, the serum rT3 concentrations were significantly higher in patients with DS than in controls, except for those in the 12-14 age group. We also calculated the T3/T4 and rT3/T4 ratios to elucidate the reason for the higher rT3 in patients with DS; however, no useful findings were obtained. Thus, further investigation is needed to clarify our findings.

The Role of Inflammatory Diet and Vitamin D on the Link between Periodontitis and Cognitive Function: A Mediation Analysis in Older Adults

Patients suffering from periodontitis are at a higher risk of developing cognitive dysfunction. However, the mediation effect of an inflammatory diet and serum vitamin D levels in this link is unclear. In total, 2062 participants aged 60 years or older with complete periodontal diagnosis and cognitive tests from the National Health and Nutrition Examination Survey (NHANES) 2011-2012 and 2013-2014 were enrolled. The Consortium to Establish a Registry for Alzheimer's disease (CERAD) word learning subtest (WLT) and CERAD delayed recall test (DRT), the animal fluency test (AFT) and the digit symbol substitution test (DSST) was used. Dietary inflammatory index (DII) was computed via nutrition datasets. Mediation analysis tested the effects of DII and vitamin D levels in the association of mean probing depth (PD) and attachment loss (AL) in all four cognitive tests. Periodontitis patients obtained worse cognitive test scores than periodontally healthy individuals. DII was negatively associated with CERAD-WLT, CERAD-DRT, AFT and DSST, and was estimated to mediate between 9.2% and 36.4% of the total association between periodontitis with cognitive dysfunction (p < 0.05). Vitamin D showed a weak association between CERAD-DRT, AFT and DSST and was estimated to between 8.1% and 73.2% of the association between periodontitis and cognitive dysfunction (p < 0.05). The association between periodontitis and impaired cognitive function seems to be mediated both by a proinflammatory dietary load and vitamin D deficiency. Future studies should further explore these mediators in the periodontitis-cognitive decline link.

Subclinical Hypothyroidism as the Most Common Thyroid Dysfunction Status in Children With Down's Syndrome

INTRODUCTION

Thyroid dysfunctions are one of the most common abnormalities coexisting in children with Down's syndrome (DS) and have been reported in up to 54% of cases.

AIM OF THE STUDY

The purposes of this retrospective study were to investigate the course of subclinical hypothyroidism in children with DS, to evaluate the thyroid function of these subjects in relation to the risk of developing overt thyroid disease and autoimmunity, and to identify clinical and biochemical characteristics of patients prescribed L-T4 therapy in children and adolescents with DS and SH.

MATERIAL AND METHODS

The records of DS patients referred to the Endocrinology Outpatient Clinic between 2010 and 2015 for screening of thyroid function were observed till the end of 2019 June and analyzed retrospectively. The children diagnosed with congenital hypothyroidism, acute lymphoblastic leukemia, and seizures and treated with drugs that may have interfered with thyroid function like lithium, antiepileptic, or iodinated drugs and glucocorticoids were excluded from the study.

RESULTS

The data of 77 DS patients were collected, evaluated, and analyzed. The study group consisted of 73 patients (32 girls and 41 boys with the mean age at baseline of 3.0 ± 4.5 years). A total of 63/73 (87%) children were diagnosed with SH. The 16/63 (25.4%) patients were followed-up without the treatment (group SH-T0), and therapy with levothyroxine (L-T4) was introduced in 47/63 (74.6%) SH children with a mean dosage of 1.8 ± 1.0 μg/kg/day (group SH-T1). Thyroxine supplementation did not improve growth expressed as ΔhSDS (0.1 ± 1.3, ranged -2.1 to 3.8 in SH-T0 vs. 0.0 ± 0.7, ranged -1.7 to 1.4 in SH-T1, p = 0.96) and ΔBMI Z-score (0.3 ± 0.9, ranged -0.9 to 2.6 in SH-T0 vs. 0.3 ± 1.1, ranged -2.1 to 2.9 in SH-T1, p = 0.65). Positive anti-TPO and anti-TG antibodies were detected in 7/63 (11.1%) DS cases.

CONCLUSIONS

SH is the most frequent presentation of thyroid gland dysfunction in DS children. A small percentage of patients develop an overt hypothyroidism, particularly in females with mostly positive titer of antithyroid autoantibodies.

Prevalence of gout and asymptomatic hyperuricemia in the pediatric population: a cross-sectional study of a Japanese health insurance database

Background

Although gout is rare in children, chronic sustained hyperuricemia can lead to monosodium urate deposits progressing to gout, just as in adults. This study assessed prevalence and characteristics of gout and asymptomatic hyperuricemia, and incidence of gouty arthritis in the pediatric population, using data from Japanese health insurance claims. The diagnosis and treatment of pediatric gout and hyperuricemia were analyzed, and specific characteristics of those patients were assessed. Since Japanese guidelines recommend treatment with uric acid lowering drugs for asymptomatic hyperuricemia as well as for gout, these data were also used to investigate the real-world use of uric acid lowering drugs in a pediatric population.

Methods

This cross-sectional study was based on a 2016–2017 Japanese health insurance claims database, one of the largest epidemiology claims databases available in Japan, which included 356,790 males and 339,487 females 0–18 years of age. Outcomes were measured for prevalence, patient characteristics, treatment with uric acid lowering drugs for gout and asymptomatic hyperuricemia, and prevalence and incidence of gouty arthritis. Because uric acid can be elevated by some forms of chemotherapy, data from patients under treatment for malignancies were excluded from consideration.

Results

Total prevalence of gout and asymptomatic hyperuricemia in 0–18 year-olds was 0.040% (276/696,277 patients), with gout prevalence at 0.007% (48/696,277) and asymptomatic hyperuricemia at 0.033% (228/696,277). Prevalence of gout and asymptomatic hyperuricemia was highest in adolescent males, at 0.135% (176/130,823). The most common comorbidities for gout and asymptomatic hyperuricemia were metabolic syndrome at 42.8% (118/276) and kidney disease at 34.8% (96/276). Of the patients diagnosed with gout or asymptomatic hyperuricemia, 35.1% (97/276) were treated with uric acid lowering drugs. Gouty arthritis developed in 43.8% (21/48) of gout patients during the study, at an incidence of 0.65 flares/person-year.

Conclusions

Even the pediatric population could be affected by asymptomatic hyperuricemia, gout, and gouty arthritis, and uric acid lowering drugs are being used in this population even though those drugs have not been approved for pediatric indications. Such off-label use may indicate a potential need for therapeutic agents in this population.

Trial registration

UMIN000036029.

Evaluation of biochemical and hematological parameters in adults with Down syndrome

Down syndrome (DS) is the most common worldwide cause of intellectual disability of genetic origin and the most common chromosomal disorder affecting live-born infants. In addition to intellectual disability, individuals with DS have other comorbidities and complex medical conditions. The increase in the life expectancy of patients with DS requires expanding the knowledge about their clinical characteristics and related laboratory parameters. Several studies exploring laboratory tests in DS patients exist, but their focus is limited to specific areas of metabolism. Therefore, our main goal was to describe the biochemical and hematological findings in a DS cohort and to compare the values to those of a control population. A total of 248 DS individuals and 84 control subjects were enrolled. DS individuals had a higher frequency of several clinical conditions compared to control individuals and presented with significant differences with respect to the controls in both biochemical and hematological parameters. We found age- and sex-related differences in several of the parameters. A good understanding of the differences in our cohort might be of aid in the clinical follow-up of adults with DS, especially considering that the lifespan of DS individuals may reach 60 years of age in developed countries.