Bone remodeling in survivors of pediatric hematopoietic stem cell transplantation: Impact of heavy resistance training.

BACKGROUND: Early-onset osteoporosis is a frequent late effect after pediatric hematopoietic stem cell transplantation (HSCT). It remains unknown if physical training can improve bone formation in these patients, as the transplantation procedure may cause sustained dysregulation of the bone-forming osteoblast progenitor cells. OBJECTIVE: We aimed to explore the effect of resistance training on bone remodeling in long-term survivors of pediatric HSCT. PROCEDURE: In this prospective, controlled intervention study, we included seven HSCT survivors and 15 age- and sex-matched healthy controls. The participants completed a 12-week heavy load, lower extremity resistance training intervention with three weekly sessions. We measured fasting serum levels of the bone formation marker "N-terminal propeptide of type I procollagen" (P1NP), and the bone resorption marker "C-terminal telopeptide of type I collagen" (CTX). The hypothesis was planned before data collection began. The trial was registered at Clinicaltrials.gov before including the first participant, with trial registration no. NCT04922970. RESULTS: Resistance training led to significantly increased levels of fasting P1NP in both patients (from 57.62 to 114.99 ng/mL, p = .03) and controls (from 66.02 to 104.62 ng/mL, p < .001). No significant changes in fasting CTX levels were observed. CONCLUSIONS: Despite previous high-dose cytotoxic therapy, long-term survivors of pediatric HSCT respond to resistance training with improvement of bone formation, comparable to that of healthy controls. This suggests that resistance training might be a promising non-pharmacological approach to prevent the early decline in bone mass, and should be considered as part of a follow-up program to counteract long-term sequela after pediatric HSCT.

Metabolic syndrome as a late effect of childhood hematopoietic stem cell transplantation - A thorough statistical evaluation of putative risk factors.

BACKGROUND: Metabolic syndrome (MetS) is frequent among survivors of childhood hematopoietic stem-cell transplantation (HSCT), but assessment of risk factors is challenged by survivor and participation bias in long-term follow-up studies. METHODS: A cohort of 395 pediatric patients transplanted between 1980 and 2018 was investigated. MetS was assessed at follow-up between December 2018 and March 2020. Two composite outcomes ((a) combining MetS and death, (b) combining MetS, death, and nonparticipation) were considered to address the risk of selection bias. RESULTS: Among 234 survivors invited to the follow-up, 96 individuals (median age 27 years) participated. MetS prevalence was 30% among participants. The only significant HSCT risk factor was a variable combining HSCT indication and conditioning with total-body irradiation (TBI) (p = .0011). Compared to acute leukemias (AL) treated with high-grade TBI (8-12 Gy), a lower MetS prevalence was seen for nonmalignant diseases treated with no/low-grade TBI (0-4.5 Gy) (OR = 0.04, 95% confidence interval (CI): 0.00-0.23). Analyses of the composite outcomes indicated overestimation of the effect of high-grade TBI due to selection bias. Scrutiny showed strong residual confounding between HSCT indication and high-grade TBI within AL-patients. The HSCT effect on MetS reflected HSCT effects on high-density-lipoprotein (HDL) and triglycerides. Compared to AL treated with high-grade TBI, nonmalignant diagnoses treated with no/low-grade TBI had higher HDL (+40%, 95% CI: +21% to +62%) and lower triglyceride (-59%, 95% CI: -71% to -42%). CONCLUSION: The TBI effect on MetS may be overestimated in follow-up studies due to selection bias and confounding. The TBI effect was confined to the potentially modifiable MetS criteria  HDL and triglyceride.

Male Gonadal Function after Allogeneic Hematopoietic Stem Cell Transplantation in Childhood: A Cross-Sectional, Population-Based Study.

Male gonadal dysfunction is a frequent late effect after pediatric hematopoietic stem cell transplantation (HSCT), but detailed insight into patterns of male gonadal function at long-term is limited by retrospective studies without semen sample data. In this study, we investigated the risk of azoospermia and testosterone deficiency, the diagnostic value of markers of spermatogenesis, and paternity at long-term follow-up after pediatric allogeneic HSCT. All male HSCT survivors age ≥18 years, transplanted in Denmark or Finland between 1980 and 2010, were invited to participate in this cross-sectional study. Examinations included a semen sample, measurements of reproductive hormones and testicular volume, and screening for chronic graft-versus-host disease (GVHD). Cumulative (pre-HSCT plus HSCT) treatment doses were calculated. Of 181 eligible patients, 98 participated, at a median 18 years (range, 8 to 35 years) after undergoing HSCT. Sperm was found in 30 patients, azoospermia in 42, and azoospermia during testosterone substitution in 24. A higher cumulative testicular irradiation dose was associated with increased risk of azoospermia and testosterone substitution (odds ratio [OR] per +1 Gy, 1.27; 95% confidence interval [CI], 1.14 to 1.46 [P < .001] and 1.21; 95% CI, 1.11 to 1.38 [P < .001], respectively). All patients treated with >12 Gy had azoospermia, and all but 1 patient treated with >16 Gy needed testosterone substitution. In patients treated with chemotherapy only (n = 23), a higher cumulative cyclophosphamide equivalent dose was associated with an increased risk of azoospermia (OR per +1 g/m2, 1.34; 95% CI, 1.01 to 2.15; P = .037). Prepubertal stage at HSCT was a risk factor for testosterone substitution (OR, 15.31; 95% CI, 2.39 to 315; P = .017), whereas chronic GVHD was unrelated to gonadal dysfunction. Inhibin B was the best surrogate marker of azoospermia (area under the curve, .91; 95% CI, .85 to .98; 90% sensitivity and 83% specificity) compared with follicle-stimulating hormone and testicular volume. Of 24 males who had attempted to conceive, 6 had fathered children. In conclusion, the risk of male gonadal dysfunction after pediatric HSCT is high and depends primarily on the cumulative testicular irradiation dose and pubertal stage at transplantation. Our findings support the need for fertility preservation before HSCT, as well as for prolonged follow-up of pediatric HSCT recipients into adulthood.

Dietary habits, metabolic health and vitamin D status in Greenlandic children.

OBJECTIVE: To compare the dietary habits of children living in northern villages and in the capital of Greenland, given the reported transition from traditional to westernised diet in adults over recent decades, and to explore the association between consumption of marine mammals and fish (MMF) and the children's metabolic profile and vitamin D status. DESIGN: Children answered an FFQ encompassing sixty-four individual food types pooled into six food categories. Their pubertal stage, body fat, fitness level, metabolic profile (non-HDL-cholesterol, glycated Hb, insulin, glucose, high-sensitivity C-reactive protein) as well as serum 25-hydroxyvitamin D (25(OH)D) concentration were evaluated. SETTING: Siorapaluk and Qaanaaq (north of Greenland) and Nuuk (west). PARTICIPANTS: Children aged 6-18 years (n 177). RESULTS: MMF were most frequently eaten by children from Siorapaluk (mean (sd): 73·4 (14·1) times/month), followed by children from Qaanaaq (37·0 (25·0) times/month), and least often eaten by children from Nuuk (23·7 (24·6) times/month; P < 0·001). Children from Qaanaaq consumed 'junk food' more frequently (P < 0·001) and fruits and vegetables less frequently (P < 0·01) than children from Nuuk. MMF consumption was positively associated with serum 25(OH)D concentration (P < 0·05), but the overall prevalence of vitamin D deficiency was high (18 %). No association was found between MMF consumption and metabolic parameters. CONCLUSIONS: The dietary transition and influence of western diets have spread to the north of Greenland and only the most remote place consumed a traditional diet highly based on MMF. We found no strong associations of MMF consumption with metabolic health, but a positive association with vitamin D status.

Feasibility of extracorporeal photopheresis in pediatric patients with graft-versus-host disease after hematopoietic stem cell transplantation.

Graft-versus-host disease (GVHD) is a main cause of morbidity and mortality following hematopoietic stem cell transplantation. The cumulative incidence of acute and chronic GVHD (aGVHD, cGVHD) reaches 30%-50% and 20% in pediatric populations, respectively. Prednisolone and/or calcineurin inhibitors (CNI) are first-line treatments, but no superior second-line treatment has yet been established. Several treatments have been suggested, among others extracorporeal photopheresis (ECP). Technical advances have made treatment of pediatric patients possible; however, only few reports on the feasibility of ECP in children have been published. We retrospectively studied the feasibility, safety, and efficacy of ECP in 15 children with steroid-dependent/refractory acute or chronic GVHD, who initiated ECP treatment between April 2014 and January 2018. Only few and mild side effects directly related to the ECP procedure were registered, even in patients with low body weight. The most frequent cause of shortened or canceled ECP treatment was difficulties with vascular accesses, which were more rarely seen using central venous catheters with larger lumens and made of stiffer material. Nine patients had grade II-III aGVHD. Six of these experienced a response to ECP at day 28, while eight of nine had responded at the last ECP treatment. Six patients had cGVHD when ECP was initiated, and of these, four had a partial response at last ECP treatment. We found ECP to be a feasible and safe treatment, and particularly, children with aGVHD appeared to respond well to ECP.

Elevated serum IGF-I, but unaltered sex steroid levels, in healthy boys with pubertal gynaecomastia.

OBJECTIVE: Pubertal gynaecomastia is a very common condition. Although the underlying aetiology is poorly understood, it is generally accepted that excess of oestrogens and deficit of androgens are involved in the pathogenesis. Furthermore, adiposity as well as the GH/IGF-I axis may play a role. In this study, we elucidate the association of adiposity and levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), sex hormone-binding globulin (SHBG), testosterone, oestrogen, IGF-I and IGFBP-3 with the presence of pubertal gynaecomastia in a large cohort of healthy boys. PATIENTS: A total of 501 healthy Danish school boys (aged 6·1-19·8 year) from the COPENHAGEN Puberty Study. MEASUREMENTS: Anthropometry and pubertal stages (PH1-6 and G1-5) were evaluated, and the presence of gynaecomastia was assessed. Body fat percentage was calculated by means of four skin folds and impedance. Nonfasting blood samples were analysed for FSH, LH, testosterone, SHBG, oestradiol, IGF-I, IGFBP-3 and prolactin. RESULTS: We found that 23% (31/133) of all pubertal boys had gynaecomastia. More specifically, 63% (10/16) of boys in genital stage 4 had gynaecomastia. Boys with gynaecomastia had significantly higher IGF-I levels compared with controls (IGF-I SD-score 0·72 vs -0·037, P < 0·001). This difference was maintained after adjusting for confounders (age and pubertal stage). Sex steroid levels, oestradiol/testosterone ratio or free testosterone were not associated with the presence of gynaecomastia with or without adjustment for confounders. CONCLUSIONS: IGF-I levels were elevated in healthy boys with pubertal gynaecomastia compared with boys without gynaecomastia, whereas sex steroid levels did not differ. We speculate that the GH-IGF-I axis may be involved in the pathogenesis of pubertal gynaecomastia.

The 2014 Danish references from birth to 20 years for height, weight and body mass index.

AIM: To construct new Danish growth charts for 0- to 20-year-olds and to compare them with Danish references from 1982 and with World Health Organization (WHO) standards for children aged 0-5 years from 2006, by applying similar inclusion and exclusion criteria. METHODS: Anthropometric data from three contemporary Danish population-based studies were combined. References for height were based on healthy Caucasian children born at term. A total of 12,671 height measurements (8055 in boys and 4616 in girls) were included. Reference charts were developed using the generalised additive models for location, scale and shape. RESULTS: From prepubertal ages, a secular increase in height was observed for both genders. The differences were most pronounced in puberty, and final heights were increased by 1.4 cm in boys and 2.9 cm in girls compared to 1982 references. In boys, but not girls an upward shift in body mass index (BMI) above median levels was found. Reference curves for height were superimposable with standard curves based on the selective WHO criteria. Danish children were longer/taller and heavier and they had larger head circumferences than those reported in the recent multiethnic WHO standards. CONCLUSION: We recommend national implementation of these contemporary 2014 Danish references for anthropometric measurements.

Birth size and age at menarche: a twin perspective.

STUDY QUESTION: Do birthweight (BW) and co-twin sex influence the age at menarche in twins? SUMMARY ANSWER: BW, but not co-twin sex, was associated with age at menarche in twins. However, BW was not associated with age at menarche after controlling for genetics and shared rearing environment. WHAT IS KNOWN ALREADY: Nutritional deprivation during critical developmental periods can trigger long-term effects on health. A small size at birth has been associated with early age at menarche in singletons. However, the relative influence of genetics and environmental factors on this association remains unresolved. STUDY DESIGN, SIZE, DURATION: In total, 2505 twin pairs were included in this cohort study. PARTICIPANTS/MATERIALS, SETTING, METHODS: All participants were recruited from the Danish Twin Register. Data on the age at menarche were collected by questionnaire and combined with data on BW, birth length (BL) and gestational age (GA) from the Danish Medical Birth register. The BW for GA standard deviation score (BW-SDS) was calculated. MAIN RESULTS AND THE ROLE OF CHANCE: BW-SDS [hazard ratio (HR) 0.96; 95% confidence interval (CI): 0.93-0.00], P = 0.04], but not BW, BL or GA (P ≥ 0.15), was positively associated with age at menarche in all twins after adjustment for zygosity and year of birth. However, BW-SDS was not associated with menarcheal age within twin pairs (HR 1.01; 95% CI: 0.91-1.12, P = 0.88). No differences were found in the age at menarche or birth size between twin girls from same sex and twin girls from opposite-sex pregnancies. Heritability of menarcheal age and BW were estimated to be 0.61 (95% CI: 0.38-0.84) and 0.27 (95% CI: 0.18-0.38), respectively. Both BW and menarcheal age were influenced by genetic and environmental factors. LIMITATIONS, REASONS FOR CAUTION: A limitation of this study is recall bias on the age at menarche. It is also not clear how these results should be extrapolated to the non-twin population. WIDER IMPLICATIONS OF THE FINDINGS: lower BW for GA is associated with earlier age at menarche in twin girls. However, the lack of within-pair differences in menarcheal age between even markedly BW-discordant twins indicates that this association is governed by environmental or genetic factors shared by both twins. Thus, within-pair differences in intrauterine nutritional factors leading to discordant growth do not seem to influence timing of menarche. STUDY FUNDING/COMPETING INTEREST(S): The authors have nothing to declare. Departmental funds were used to support all authors during the study period and preparation.

Recommended Nordic paediatric reference intervals for 21 common biochemical properties.

Paediatric reference intervals based on samples from healthy children are difficult to establish and consequently data are often from hospitalized children. Furthermore, biases may present in published data due to differences in the analytical methods employed. Blood samples from 1429 healthy Danish children were collected for establishing reference intervals for 21 common biochemical properties (Alanine transaminase, Albumin, Alkaline phosphatase, Aspartate transaminase, Bilirubin, Calcium, Cholesterol, Creatinine, Creatine kinase, HDL-Cholesterol, Iron, Lactate dehydrogenase, LDL- Cholesterol, Magnesium, Phosphate, Potassium, Protein, Sodium, Transferrin, Triglycerides and Urate). Samples were analyzed on a Roche-Modular-P/ISE-system. The NORIP reference material (NFKK Reference Serum X) was included in all the analytical runs. Reference values were recalculated according to the target values of X for the properties and statistical calculations carried out as performed in the NORIP study. Thus commutable (regarding analytical method) reference intervals for 20 properties were established and for LDL-Cholesterol reference intervals were reported for the specific analytical method employed. The data were compared to previous studies and to those obtained from the youngest age group in the NORIP study. Marked age differences were observed for most of the properties. Several properties also showed gender-related differences, mainly at the onset of puberty. Data are presented as suggested intervals for combined age groups, but can be accessed via the NORIP home page if more detailed division according to age or gender is desired.

Metabolic Dysregulation in Adult Survivors of Pediatric Hematopoietic Stem Cell Transplantation: The Role of Incretins.

CONTEXT: Survivors of pediatric hematopoietic stem cell transplantation (HSCT) have increased risk of developing metabolic syndrome (MetS), but the mechanisms are poorly understood. OBJECTIVE: We aimed to test the hypothesis that insufficient secretion of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) plays a pathogenetic role in HSCT survivors with MetS. METHODS: This cross-sectional cohort study, conducted at the Danish national referral center for HSCT, studied 42 male HSCT survivors (median age 28.9 years) for a median 21.2 years from HSCT, along with 15 age- and sex-matched healthy controls. Main outcome measures were glucose metabolism and incretin hormones (by oral glucose tolerance test [OGTT]) and MetS criteria. The hypothesis was formulated before data collection. RESULTS: GLP-1, GIP, and glucagon during an OGTT were similar in patients and controls, with no overall difference between survivors with (24%) and without MetS. However, fasting glucagon was significantly higher in patients with hypertriglyceridemia (mean difference [MD]: 6.1 pmol/L; 95% CI, 1.5-10.8; P = 0.01), and correlated with HDL (MD: 4.7 mmol/L; 95% CI, -0.6 to 9.9; P = 0.08), android-gynoid ratio (correlation coefficient [r] = 0.6, P = 0.0001) and waist-hip ratio (r = 0.5, P = 0.002). A similar pattern was seen for GIP, correlating positively with triglyceride (MD: 60%; 95% CI, 44-82; P = 0.002). GIP levels were significantly increased in patients treated with total body irradiation (TBI) (MD: 165%; 95% CI, 118-230; P = 0.004), which was found to be a significant risk factor for MetS. CONCLUSION: This study demonstrates an altered production of incretin hormones in HSCT survivors previously treated with TBI, developing dyslipidemia and abdominal adiposity.

Individual serum levels of anti-Müllerian hormone in healthy girls persist through childhood and adolescence: a longitudinal cohort study.

BACKGROUND: In adult women, the circulating level of anti-Müllerian hormone (AMH) is a novel marker of ovarian function, as it reflects the number of remaining ovarian follicles. Therefore, AMH has gained widespread attention in fertility clinics, and a low AMH is believed to predict impaired fertility and imminent menopause. However, the natural course of circulating AMH levels during female childhood and adolescence is not known. METHODS: Serum levels of AMH and FSH were measured in girls participating in The COPENHAGEN Puberty Study. Longitudinal part: 85 healthy girls and adolescents were examined, and blood samples were drawn every 6 months for an average of 3 years: median (range) number of samples per girl was 6 (2-10), age at baseline was 9.2 (5.9-12.9) years. Cross-sectional part: 224 prepubertal girls (age 8.3, 5.6-11.7 years) were examined and each girl had one blood sample drawn. RESULTS: The individual mean AMH levels in girls followed longitudinally ranged from 5 to 54 pmol/l (median 18 pmol/l). The mean intra-individual coefficient of variation of AMH was 22% (range 0-54%). Overall, each girl maintained her AMH level throughout childhood and adolescence although minor, but significant, changes occurred during pubertal transition. In prepubertal girls, AMH was negatively correlated with FSH (r = -0.31, P < 0.001). Twelve per cent (10/85) had mean AMH below a cut-off value of 8 pmol/l, indicating that the interpretation of low AMH as a marker of approaching menopause may not apply to pre- and peri-pubertal girls. CONCLUSIONS: Circulating AMH exhibits only minor fluctuations during childhood and adolescence, and a random AMH measurement seems representative for a given girl. The negative AMH-FSH correlation in prepubertal girls supports the notion that AMH is a quantitative marker of ovarian follicles even in young girls.

Urinary phthalate excretion in 555 healthy Danish boys with and without pubertal gynaecomastia.

Pubertal gynaecomastia is a clinical sign of an oestrogen-androgen imbalance, which occurs in 40-60% of adolescent Caucasian boys. In most cases no underlying endocrinopathy can be identified. A recent study reports higher plasma phthalate levels in Turkish boys with pubertal gynaecomastia. Therefore, we asked whether there was an association between concurrent measures of urinary phthalate metabolites and pubertal timing as well as the presence of gynaecomastia in otherwise healthy boys. We studied a total of 555 healthy boys (age 6.07-19.83 years) as part of the COPENHAGEN Puberty Study. Anthropometry and pubertal stages (PH1-6 and G1-5) were evaluated, and the presence of gynaecomastia was assessed. Non-fasting blood samples were analysed for serum testosterone and morning urine samples were analysed for the total content of 12 phthalate metabolites (MEP, MnBP, MiBP, MBzP, MEHP, MEHHP, MEOHP, MECPP, MiNP, MHiNP, MiONP and MCiOP) by LC-MS/MS. A statistically significant negative correlation was observed between chronological age and the urinary concentration of the sum of measured metabolites DEHP (∑DEHPm) (r = -0.164) and DiNP (∑DiNPm) (r = -0.224), respectively, and the sum of monobutyl phthalate (MBP) isomers (∑MBP((i+n))) (r = -0.139) (all with p < 0.01). In contrast urinary monoethyl phthalate concentration was positively correlated to age (r = 0.187, p < 0.01). The urinary levels of phthalate metabolites were not associated with age at pubertal onset, serum testosterone levels or presence of gynaecomastia. In conclusion, we did not find evidence of anti-androgenic effects of phthalates in our healthy boys. Thus, current phthalate exposure was not associated with pubertal timing, testosterone levels or with the presence of pubertal gynaecomastia in this cross-sectional study. However, longitudinal studies are needed to evaluate possible perinatal or long-term postnatal effects of phthalates on healthy boys.

Male Gonadal Function After Pediatric Hematopoietic Stem Cell Transplantation: A Systematic Review.

Male gonadal dysfunction is a frequent late effect after pediatric hematopoietic stem cell transplantation (HSCT) that can lead to disturbances in pubertal development, sexual dysfunction, and infertility. However, no systematic review exists regarding prevalence and risk factors in relation to different treatment regimens. We aimed to systematically evaluate the current evidence regarding the prevalence of male gonadal dysfunction after pediatric HSCT, related risk factors, and the diagnostic value of surrogate markers of spermatogenesis in this patient group. We searched PubMed and Embase using a combination of text words and subject terms. The eligibility screening was conducted using predefined criteria. Data were extracted corresponding to the Leydig cell compartment involved in testosterone production and the germ cell compartment involved in spermatogenesis, respectively. Subsequently, data synthesis was performed. Of 2369 identified records, 25 studies were eligible. The studies were heterogeneous in terms of included diagnoses, gonadotoxic therapy, follow-up time, and definitions of gonadal dysfunction. The data synthesis revealed a preserved Leydig cell function in patients treated with non-total body irradiation (TBI) regimens, whereas the evidence regarding the impact of TBI conditioning on Leydig cell function was conflicting. Based on surrogate markers of spermatogenesis and only limited data on semen quality, the germ cell compartment was affected in half of the patients treated with non-TBI regimens and in nearly all patients treated with TBI conditioning. Testicular irradiation as part of front-line therapy before referral to HSCT led to complete Leydig cell failure and germ cell failure. Evidence regarding the impact of diagnosis, pubertal stage at HSCT, and chronic graft-versus-host disease is limited, as is the evidence of the diagnostic value of surrogate markers of spermatogenesis. Testicular irradiation as part of front-line therapy and TBI conditioning are the main risk factors associated with male gonadal dysfunction after pediatric HSCT; however, impaired spermatogenesis is also observed in half of the patients treated with non-TBI regimens. Methodological shortcomings limit existing evidence, and future studies should include semen quality analyses, follow-up into late adulthood, and evaluation of the cumulative exposure to gonadotoxic therapy.

Physical Fitness and Frailty in Males after Allogeneic Hematopoietic Stem Cell Transplantation in Childhood: A Long-Term Follow-Up Study.

PURPOSE AND METHODS: To analyze physical fitness, physical activity and the prevalence of frailty in male long-term survivors of pediatric allogeneic hematopoietic stem cell transplantation (HSCT). We performed a Nordic two-center study of 98 male survivors (mean age 28.7 years, range 18.5-47.0) treated with pediatric allogeneic hematopoietic stem cell transplantation (HSCT) 1980-2010 in denmark or finland. physical fitness was evaluated by the dominant hand grip-strength, timed up-and-go, sit-to-stand, gait speed and two-minute walk tests. RESULTS: Survivors presented significantly lower muscle strength and muscle endurance in the dominant hand-grip strength (median Z-score -0.7, range -4.3-3.9) and sit-to-stand tests (median Z-score -1.5, range -3.5-2.5) compared to age and sex matched normative values of the tests. However, mobility and gait speed were not affected on a group level. The prevalence of frailty (pre-frail 20% or frail 10%) was high among the survivors. In multiple regression analysis, chronic graft-versus-host disease, shorter stature, higher body fat mass and hazardous drinking predicted prefrail/frail status. Common cardiovascular risk factors, such as increased levels of serum triglycerides, higher resting heart rate and diastolic blood pressure, were associated with lower physical fitness. CONCLUSION: Low muscle strength and a high incidence of frailty were observed in survivors of pediatric HSCT. There is a predominant risk of cardiovascular and metabolic diseases in the long-term.

Urinary excretion of phthalate metabolites in 129 healthy Danish children and adolescents: estimation of daily phthalate intake.

BACKGROUND: Phthalates are a group of chemicals with widespread use in the industrial production of numerous consumer products. They are suspected to be involved in male reproductive health problems and have also been associated with several other health problems in children including obesity and asthma. OBJECTIVES: To study the urinary excretion of phthalate metabolites in Danish children recruited from the general population, and to estimate the daily intake of phthalates in this segment of the population. METHOD: One 24 h urine sample and to consecutive first morning urine samples were collected from 129 healthy Danish children and adolescents (range 6-21 yrs). The concentrations of 11 phthalate metabolites of 5 different phthalate diesters were analyzed by liquid chromatography-tandem mass spectrometry. RESULTS: The analyzed metabolites were detectable in almost all 24h urine samples. The median concentrations of monoethyl phthalate (MEP), monobenzyl phthalate (MBzP) and the sums of the two monobutyl phthalate isoforms (∑MBP(i+n)), metabolites of di-(2-ethylhexyl) phthalate (∑DEHPm) and of di-iso-nonyl phthalate (∑DiNPm) were 29, 17, 111, 107 and 31 ng/mL, respectively. The youngest children were generally more exposed to phthalates than older children and adolescents (except diethyl phthalate (DEP)). Boys were more exposed than girls. The median estimated daily intake of phthalate diesters was: 4.29 (dibutyl phthalate isoforms (DBP(i+n))), 4.04 (DEHP), 1.70 (DiNP), 1.09 (DEP) and 0.62 (butylbenzyl phthalate (BBzP)), all calculated as µg/kg body weight/24h. Between 40% and 48% of the absolute amount of phthalate metabolites excreted over 24h were excreted in first morning urine voids. CONCLUSION: Danish children are exposed simultaneously to multiple phthalates. The highest exposure levels were found for DBP(i+n) and DEHP, which in animal models are the known most potent anti-androgenic phthalates. The combined exposure to the two isoforms of DBP, which have similar endocrine-disrupting potencies in animal models, exceeded the TDI for di-n-butyl phthalate (DnBP) in several of the younger children.

Serum concentrations of Anti-Müllerian Hormone (AMH) in 95 patients with Klinefelter syndrome with or without cryptorchidism.

AIM: Anti-Müllerian hormone (AMH) is produced by foetal Sertoli cells at the time of sexual differentiation and is responsible for the regression of the Müllerian ducts in the male foetus. AMH is a testis-specific marker of diagnostic value in infants with ambiguous genitalia or with bilateral cryptorchidism. However, little is known about AMH in boys and adult men with normal or abnormal gonadal function. We therefore aimed at determining circulating AMH concentrations in patients with 47,XXY Klinefelter syndrome (KS) with or without cryptorchidism. METHODS: AMH was determined in 95 47,XXY patients aged 0.2-64.5 years, of which 12 patients had a history of cryptorchidism. RESULTS: AMH was within the normal range in boys with Klinefelter syndrome until puberty. The pubertal decline was delayed, especially in patients with a history of cryptorchidism. AMH was below -2 SD in 85% of adult KS. CONCLUSION: AMH secretion in patients with 47,XXY KS was within normal limits during mini-puberty and until puberty. Thereafter, AMH declined to subnormal levels in all patients. We hypothesize that this decline was a result of the hyalinization of seminiferous tubules in relation to puberty, rather than caused by disrupted regulatory mechanisms at the level of the pituitary-gonadal axis.

Clinical use of anti-Müllerian hormone (AMH) determinations in patients with disorders of sex development: importance of sex- and age-specific reference ranges.

Determination of postnatal AMH levels in circulation has been used for decades when evaluating a child with ambiguous genitalia. We describe the age- and gender-specific changes of postnatal AMH serum levels to enable an appropriate clinical use of AMH assessment in pediatric endocrinology. In males, cord blood AMH is measurable at high levels (mean 148 (53-340) pmol/L), whereas AMH is undetectable (54%) or very low (95% CI: < 2-16 pmol/L) in female infants. AMH is constant through childhood in both sexes, boys having approximately 35 times higher levels than girls with no overlapping between the sexes until puberty. Ambiguous genitalia due to impaired androgen secretion or action may be a result of various conditions with low, normal or high AMH. Furthermore, low AMH is a marker of premature ovarian failure in Turner Syndrome girls. Measurement of AMH is an important tool in assessing gonadal function in children. In this context, detailed normative data are essential.

Altered body composition in male long-term survivors of paediatric allogeneic haematopoietic stem cell transplantation: impact of conditioning regimen, chronic graft-versus-host disease and hypogonadism.

Changes in body composition related to metabolic syndrome are frequent among survivors of haematopoietic stem cell transplantation (HSCT), but insights into predisposing factors are incomplete, and it is unknown to what degree these changes persist at long term. We cross-sectionally investigated body composition by dual-energy X-ray absorptiometry in 98 male survivors of paediatric allogeneic HSCT. Median (range) age at follow-up was 28.1 (18.5-47.0) years and median (range) time from transplant was 18.3 (7.7-34.6) years. Lean Body Mass Index and Skeletal Muscle Mass Index were lower in patients compared to the reference population (mean (SD) standard deviation score (SDS) -1.29 (0.99), p < 0.001 and -1.20 (1.03), p < 0.001). Fat Mass Index was comparable to the reference population, but android/gynoid (AG) fat ratio SDS was higher (mean (SD) 0.46 (1.28), p < 0.001). These changes were found in patients treated with total body irradiation (TBI) as well as non-TBI regimens, although most pronounced in the former. Further, low lean mass was associated with chronic graft-versus-host disease, while high AG ratio was associated with lower testosterone levels. Since the combination of low lean mass and high AG ratio increases the risk of cardio-metabolic disease, these health issues should be monitored at long-term clinical follow-up after paediatric HSCT.

Childhood reproductive hormone levels after pediatric hematopoietic stem cell transplantation in relation to adult testicular function.

OBJECTIVES: Longitudinal assessment of testicular function after pediatric hematopoietic stem cell transplantation (HSCT) is needed to guide clinical follow-up. We investigated dynamics in male reproductive hormones after pediatric HSCT, focusing on pubertal timing and associations with testosterone deficiency and azoospermia in adulthood. METHODS: This retrospective, longitudinal study included 39 survivors median 19 years after pediatric HSCT. Serum concentrations of LH, testosterone, FSH, and inhibin B from the time of HSCT, during puberty, and into adulthood were analyzed. Pubertal timing (rise in LH and testosterone) was compared to a reference cohort of 112 healthy boys. Associations between reproductive hormone levels during puberty and adult testicular function (including semen quality) were investigated. RESULTS: Pubertal induction with testosterone was needed in 6/26 patients who were prepubertal at HSCT. In the remaining patients, pubertal timing was comparable to the reference cohort. However, 9/33 patients (without pubertal induction) developed testosterone deficiency in early adulthood, which was associated with higher LH levels from age 14 to 16 years. Azoospermia in adulthood was found in 18/26 patients without testosterone substitution. Higher FSH and lower inhibin B levels from mid-pubertal age were associated with azoospermia in adulthood, in patients being prepubertal at HSCT. CONCLUSION: Our results indicate a substantial risk of deterioration in testicular function after pediatric HSCT, despite normal pubertal timing. Although reproductive hormone levels from mid-puberty indicated adult testicular function, prolonged follow-up into adulthood is needed in these patients, including clinical examination, reproductive hormone analysis, and semen sample for patients interested in their fertility potential.

Metabolic Syndrome in Male Survivors of Pediatric Allogeneic Hematopoietic Stem Cell Transplantation: Impact of Total Body Irradiation, Low-Grade Inflammation, and Hypogonadism.

Metabolic syndrome (MetS) is a growing concern in survivors of pediatric hematopoietic stem cell transplantation (HSCT), but little is known about the underlying mechanisms. This study aimed to determine the prevalence and clinical presentation of MetS in male long-term survivors of pediatric HSCT and to investigate predisposing factors, including low-grade inflammation, altered fat distribution, and low testosterone levels. We included 98 survivors age 19 to 47 years at a median follow-up of 18 years (range, 8 to 35 years) after pediatric HSCT. MetS was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria. The prevalence and clinical manifestations of MetS were compared between our cohort and a control group of males from the background population (n = 4767). Fat distribution was assessed by android/gynoid ratio from a whole-body dual-energy X-ray absorptiometry scan. Systemic inflammation was evaluated by IL-6 and high-sensitivity C-reactive protein (hsCRP). Serum testosterone levels were measured in morning samples. The prevalence of MetS was 30%, corresponding to the prevalence in the 50- to 80-year-old males from the background population. In individuals with MetS, hyperglycemia was more frequent in the HSCT survivors compared with age-matched controls with MetS (76% versus 20%; P < .001), whereas hypertension was more dominant in the control group with MetS (69% versus 93%; P = .01). In addition, normal or low body mass index was more commonly observed among HSCT survivors with MetS compared with age-matched controls with MetS (41% versus 11%; P = .002). MetS was more often associated with total body irradiation (TBI) compared with chemotherapy regimens (odds ratio [OR], 4.3; 95% confidence interval [CI], 1.2 to 24.4; P = .02), lower testosterone levels (OR, 5.4; 95% CI, 1.3 to 23.6; P = .02), higher IL-6 levels (OR, 1.8; 95% CI, 1.2 to 2.8; P = .004), and higher hsCRP levels (OR, 1.8; 95% CI, 1.3 to 2.6; P < .001) (estimates per 2-fold increase). In addition, an increased android/gynoid (AG) fat ratio was strongly associated with MetS (OR, 2.1; 95% CI, 1.5 to 2.9; P < .001), even though only 7% of patients met the criteria for increased abdominal circumference. Our results indicate an increased risk of MetS in early adulthood after pediatric HSCT. The clinical manifestations differed from those seen in age-matched controls with MetS, indicating different pathophysiology driven by hyperglycemia, altered fat distribution (despite no clinical abdominal obesity), and low-grade inflammation. Risk factors included TBI-based conditioning and low testosterone levels. These results underline the importance of continuous clinical assessment of the cardiometabolic risk profile and stress the presence of important dissimilarities in the pathophysiology of MetS in HSCT survivors compared with the background population.