Uncoupling of Bone Turnover may Compromise Skeletal Health of Young Patients With Haemophilia A.

There is evidence that bone mass is decreased and bone metabolism is dysregulated in children with haemophilia (CWH). The objective of this study was to investigate the impact of haemophilia on skeletal health in children, with regards to bone mineral density (BMD) and metabolic bone profile. This study included 51 male CWH A. Dual-energy X-ray absorptiometry (DXA) was performed to assess BMD in lumbar spine (LS) and total body less head (TBLH) and Z-scores were calculated (low BMD Z-score<-2, low-normal BMD Z-score between -1 and -2). Serum levels of osteocalcin (OC), procollagen type I C-terminal propeptide (PICP), bone alkaline phosphatase (bALP), bone tartrate-resistant acid phosphatase 5b (TRAP5b), vitamin D, parathormone (PTH), urinary calcium/creatinine (uCa/uCr) and urine deoxypyridinoline/creatinine (uDPD/uCr) were measured. Mean BMD Z-scores were lower than predicted at both sites of measurement. More specifically, 10% of CWH A had low and 20% low-normal BMD Z-scores in LS, whereas 9.1% had low-normal TBLH BMD Z-scores and there were no patients with low BMD Z-scores at this site of measurement. 36.7% of CWH had low vitamin D levels and 19.6% had a history of fracture. Also, patients with haemophilia had lower OC and higher uDPD/uCr levels while OC positively correlated to BMD Z-scores and uDPD/uCr negatively correlated to BMD Z-scores at both sites. No statistically significant differences were observed with regards to mode of treatment, number of haemorrhages and the presence of target-joints. CWH A had decreased BMD Z-scores at both sites with an uncoupling of bone turnover LS BMD seemed to be more affected than TBLH BMD.

Chronic Hemolysis May Adversely Affect Skeletal Health. A Cross-Sectional Study of a Pediatric Population.

Hereditary hemolytic disorders cause ineffective erythropoiesis and bone marrow hyperplasia. Little is known about their effect on growth and skeletal health. The aim of this study was to evaluate growth, bone and body composition of non transfusion-dependent (NTD) pediatric patients with chronic hemolysis. A detailed history and clinical examination, dual-energy X-ray absorptiometry (DXA) of the lumbar spine (LS) and total body less head (TBLH) and bone turnover markers were performed. Thirty-nine patients (22 males and 17 females, 20 prepubertal), aged 11.4 ± 3.6 years [14 had ß-thalassemia intermedia (ß-TI), 17 α-thalassemia (α-thal) and eight hereditary spherocytosis (HS)] were evaluated. Fifty-seven previously studied controls were used for statistical analysis. The patients had lower weight and body mass index (BMI) (Z-scores -0.2 and -0.3, respectively, p < 0.05). Post-traumatic fractures were reported by 28.0% of the patients. Compared to controls, they had lower lumbar and subcranial bone mineral density (BMD), as well as reduced fat mass (FM), whereas muscle mass was not affected. One in three patients had low vitamin D and there was increased bone resorption and reduced bone formation. Correlations between different parameters revealed a potential role of osteocalcin, hemoglobin (Hb) and lactate dehydrogenase (LDH) as prognostic markers for bone health, in the setting of chronic hemolysis. Hereditary spherocytosis (HS) patients were the least affected in terms of growth and bone profile. Chronic hemolysis may lead to impaired growth and bone health, even in young, NTD patients. The degree of hemolysis determines bone health risk. Regular surveillance of bone health is justifiable.

A novel frameshift deletion in PLS3 causing severe primary osteoporosis.

Mutations in the gene encoding plastin-3, PLS3, have recently been associated to severe primary osteoporosis. The molecular function of plastin-3 is not fully understood. Since PLS3 is located on the X chromosome, males are usually more severely affected than females. PLS3 mutations have thus far been reported in approximately 20 young patients with low bone mineral density (BMD). We describe an 8-year-old Greek boy with severe primary osteoporosis with multiple vertebral compression fractures and one low-energy long bone fracture. His clinical manifestations were consistent with osteogenesis imperfecta, including blue sclerae, joint hypermobility, low bone mineral density, kyphosis, bilateral conductive hearing loss, and mild dysmorphic features. The family history was negative for primary osteoporosis. COL1A1 and COL1A2 mutations were excluded by Sanger sequencing. However, Sanger sequencing of PLS3 led to the identification of a de novo frameshift deletion, NM_005032: c.1096_1100delAACTT, p.(Asn366Serfs*5), in exon 10 confirming the diagnosis of PLS3 osteoporosis. In conclusion, we describe a novel frameshift deletion in PLS3 causing severe primary osteoporosis in a boy. Our finding highlights the clinical overlap between type I collagen and PLS3-related skeletal fragility and underscores the importance of PLS3 screening in patients with multiple fractures to enable proper genetic counseling.

Autosomal Recessive Osteogenesis Imperfecta Caused by a Novel Homozygous COL1A2 Mutation.

Osteogenesis imperfecta (OI) is a skeletal dysplasia characterized by brittle bones and extraskeletal manifestations. The disease phenotype varies greatly. Most commonly, OI arises from monoallelic mutations in one of the two genes encoding type I collagen, COL1A1 and COL1A2 and is inherited as an autosomal dominant trait. Here, we describe a consanguineous family with autosomal recessive OI caused by a novel homozygous glycine substitution in COL1A2, NM_000089.3: c.604G>A, p.(Gly202Ser), detected by whole-genome sequencing. The index patient is a 31-year-old Greek woman with severe skeletal fragility. She had mild short stature, low bone mineral density of the lumbar spine and blue sclerae. She had sustained multiple long bone and vertebral fractures since childhood and had been treated with bisphosphonates for several years. She also had an affected sister with similar clinical manifestations. Interestingly, the parents and one sister, all carriers of the COL1A2 glycine mutation, did not have manifestations of OI. In summary, we report on autosomal recessive OI caused by a homozygous glycine-to-serine substitution in COL1A2, leading to severe skeletal fragility. The mutation carriers lacked OI manifestations. This family further expands the complex genetic spectrum of OI and underscores the importance of genetic evaluation for correct genetic counselling.

Body composition and lung function in children with cystic fibrosis and meconium ileus.

The aim of this study was to explore whether history of meconium ileus (MI) at birth in children and adolescents with cystic fibrosis (CF) adversely affects body composition and lung function in later life. Data of children and adolescents with CF who underwent spirometry and DXA as part of their routine care were analyzed. Associations between MI (explanatory variable) and areal bone mineral density (total body less head-TBLH aBMD), lean tissue mass (LTM), and fat mass (FM) (outcomes) were assessed using general linear models. Potential relationships of TBLH aBMD, LTM, and FM with FEV1 (additional outcome) were also explored. One hundred and one subjects with CF (mean age 14 ± 3 years) were included, 19 (18.8%) of whom had history of MI. Negative associations were demonstrated between history of MI and FEV1 (P = 0.04), TBLH aBMD (P = 0.03), and FM (P < 0.01) but not between history of MI and LTM (P = 0.07) after adjustment for other variables. Lung function was positively associated with TBLH aBMD (P < 0.01) and LTM (P = 0.02) but not with FM (P = 0.20). CONCLUSION: Among children and adolescents with CF, those with history of MI have lower bone mineral density, FM, and lung function. What is Known: • Among children and adolescents with cystic fibrosis, those with history of meconium ileus in the neonatal period are at risk of having lower body mass index percentile and FEV 1 percent predicted. What is New: • Children and adolescents with cystic fibrosis and history of meconium ileus have decreased bone mineral density and fat mass compared to patients without such history. • Lower lung function in children with MI coexists with suboptimal bone mineral density.

Sclerostin distribution in children and adolescents with type 1 diabetes mellitus and correlation with bone metabolism and bone mineral density.

BACKGROUND AND OBJECTIVE: Sclerostin is an inhibitor of the Wnt/beta-catenin bone metabolic pathway. Increased sclerostin levels and reduced bone mineral density (BMD) have been documented in adult patients with diabetes mellitus (DM), predominantly in those with type 2 diabetes mellitus (T2DM). No relative data exist on childhood type 1 diabetes mellitus (T1DM). Our objective was to study plasma sclerostin in T1DM children and adolescents and controls and its correlations with metabolic bone markers and BMD. SUBJECTS AND METHODS: This was a cross-sectional study that was conducted at an outpatient clinical center. Forty T1DM children and adolescents were evaluated (mean ± SD age: 13.04 ± 3.53 yr, T1DM duration: 5.15 ± 3.33 yr), along with 40 healthy matched controls (age 12.99 ± 3.3 yr). Sclerostin, soluble receptor activator of nuclear factor-kappaB ligand (s-RANKL), osteoprotegerin, osteocalcin, C-telopeptide crosslinks, electrolytes, parathyroid hormone (PTH), and total 25(OH)D were measured. Lumbar and subcranial total body BMD were evaluated with dual energy X-ray absorptiometry (DXA). RESULTS: Sclerostin levels demonstrated a Gaussian distribution, with no significant difference between patients and controls (51.56 ± 12.05 vs. 50.98 ± 13.55 pmol/L, p = 0.84). Significantly lower values were found in girls and prepubertal children. Sclerostin values were significantly and gradually increased in children through pubertal Tanner stages 1-3, were reduced at stage 4 and increased again at pubertal stage 5. Sclerostin levels were positively correlated with logCTX (logarithm of C-terminal telopeptide crosslinks of type I collagen), logOsteocalcin (logarithm of Osteocalcin), magnesium, total body, and L1-L4 BMD z-score. CONCLUSIONS: T1DM patients had similar levels of sclerostin with controls. Sclerostin correlated with bone resorption and formation markers and also with bone mass indices, gender, and pubertal stage. The decrease in sclerostin values observed in pubertal stage 4 adolescents coincides with the concurrent growth spurt, and is consistent with sclerostin physiology as an inhibiting signal.

A toddler with severe vitamin D-dependent rickets type 1 A (VDDR1A), hungry bone syndrome, and severe RSV infection: presentation and therapeutic challenges.

BACKGROUND: Vitamin D-dependent rickets type 1 A (VDDR1A) is an autosomal recessive disorder due to mutations in the CYP27B1 gene which result in inability to generate 1,25(OH)2D. CASE PRESENTATION: An 18-month-old boy with VDDR1A presented with hypotonia and respiratory distress. He had been diagnosed 2 months earlier, having been evaluated for stunted growth, hypotonia, and delayed developmental milestones. He was stabilized with oxygen and bronchodilators for his bronchiolitis and high doses of alfacalcidol, calcium, and phosphate supplements for his hungry bone syndrome. Of note, the patient sustained upper limb fractures after a fall from his bed during admission. Overall, he had a protracted disease course; however, his bone profile gradually improved and he steadily recovered. CONCLUSION: VDDR1A causes failure to thrive, hypotonia, and increased fracture risk and may complicate the clinical course of lower respiratory tract infections. Furthermore, management of hungry bone syndrome requires supraphysiologic doses of vitamin D metabolites and calcium.

Severe hypophosphataemia can be an early sign of osteopetrorickets: a case report.

Osteopetrorickets is a rare complication of autosomal recessive ("malignant") osteopetrosis. Its prompt diagnosis is essential, because early suspicion of infantile osteopetrosis enables treatment with human stem cell transplantation, depending on the gene involved. It is important to identify not only the characteristic radiological changes of rickets, but also the coexistence of increased bone density, so as not to miss this very rare entity. Herein, a brief case report is presented.

Bone health evaluation of children and adolescents with homozygous ß-thalassemia: implications for practice.

OBJECTIVE: Bone tissue is adversely affected in patients with homozygous ß-thalassemia. The aim of this study was to find warning signs of bone loss in young patients with ß-thalassemia and allow prompt therapeutic interventions. METHODS: Thirty-eight patients were studied, 20 boys and 18 girls, aged 5 to 18 years (median = 14.13 y), on regular transfusions and chelation treatments. Their bone mineral density (BMD) was measured with dual x-ray absorptiometry. The recorded parameters were weight, height, bone age (BA), transfusion adequacy (mean fetal hemoglobin value), and chelation efficacy (mean ferritin value, compliance). Tanner stage was also evaluated: 8 prepubertal subjects (stage 1), 18 peripubertal subjects (stages 2 and 3), and 12 postpubertal patients (stages 4 and 5). Blood and urine samples were collected for biochemical analysis. RESULTS: Mean BMD z score was -1.56 ± 1.25. Thirteen patients had normal BMD (z score >-1), 17 patients had low BMD (z score: -1 up to -2.4), and 8 patients had very low BMD (z score <-2.5). Low BMD was observed in patients older than 12 years and was associated with short stature (r = 0.33, P = 0.04), delayed BA (r = 0.61, P = 0.01), and increased bone formation markers. There was no correlation of BMD z score with sex, fetal hemoglobin value, ferritin, and compliance. Regarding Tanner stage, it was associated strongly with short stature (r = 0.57, P = 0.01), ferritin (r = -0.38, P = 0.02), and compliance (r = 0.58, P = 0.01). CONCLUSIONS: [corrected] The decline in BMD may start early, even in the well-transfused patients. This study targets the young patients who are mostly at the risk for bone loss, that is short adolescents with delayed BA. Their prompt recognition in everyday practice is important, as they will need close monitoring of their BMD and metabolic bone profile. In addition, therapeutic interventions, such as adequate calcium intake and sunlight exposure, weight-bearing exercise and, in cases of vitamin D insufficiency, proper supplementation could be suggested.

Hypophosphatasia.

Hypophosphatasia (HPP) is an inherited metabolic disease caused by loss-of-function mutations in the tissue non-specific alkaline phosphatase (TNAP) gene. Reduced activity of TNAP leads to the accumulation of its substrates, mainly inorganic pyrophosphate and pyridoxal-5'-phosphate, metabolic aberrations that largely explain the musculoskeletal and systemic features of the disease. More than 400 ALPL mutations, mostly missense, are reported to date, transmitted by either autosomal dominant or recessive mode. Severe disease is rare, with incidence ranging from 1:100,000 to 1:300,000 live births, while the estimated prevalence of the less severe adult form is estimated to be between 1:3100 to 1:508, in different countries in Europe. Presentation largely varies, ranging from death in utero to asymptomatic adults. In infants and children, clinical features include skeletal, respiratory and neurologic complications, while recurrent, poorly healing fractures, muscle weakness and arthropathy are common in adults. Persistently low serum alkaline phosphatase is the cardinal biochemical feature of the disease. Management requires a dedicated multidisciplinary team. In mild cases, treatment is usually symptomatic. Severe cases, with life-threating or debilitating complications, can be successfully treated with enzyme replacement therapy with asfotase alfa.

Circulating Irisin Levels in Preadolescents and Adolescents Born Preterm.

INTRODUCTION: Prematurity is associated with increased cardiometabolic risk later in life. The adipomyokine irisin has been acknowledged as a modulator of energy metabolism and insulin sensitivity. The aim of this study was to investigate circulating levels of irisin and their relation to anthropometric measurements and cardiometabolic phenotype in a population of preterm-born children versus full-term-born peers. METHODS: A total of 160 children (87 born preterm aged 8.1-14.8 years and 73 born full-term of similar age and gender distribution) were studied. Arterial blood pressure, anthropometry, body composition assessments with dual energy X-ray absorptiometry, and skinfold measurements were performed. Blood biochemistry and circulating levels of irisin, insulin, cortisol, leptin, and adiponectin were also determined. RESULTS: The preterm group had higher diastolic blood pressure, triceps skinfold, subscapular skinfold (SSSF), and abdominal skinfold measurements and more central adiposity than the full-term group. Irisin was significantly lower (p = 0.002), whereas leptin was higher (p = 0.03) in the preterm than the full-term group. Irisin correlated positively with gestational age (r = 0.19, p = 0.01), birth weight (r = 0.23, p = 0.003), and high-density lipoprotein cholesterol (r = 0.20, p = 0.01) and negatively with SSSF (r = -0.25, p = 0.003) and chronological age (r = -0.21, p = 0.008). CONCLUSION: Lower levels of irisin and a slightly unhealthy adiposity and cardiometabolic pattern were detected in preterm-born children in comparison to their full-term-born peers. Whether low irisin levels in preadolescents and adolescents born prematurely could be of prognostic value for the development of cardiometabolic sequelae later in life remains to be further studied.

Parietal aplasia and hypophosphatasia in a child harboring a novel mutation in RUNX2 and a likely pathogenic variant in TNSALP.

Cleidocranial dysplasia is a dominantly inherited skeletal dysplasia resulting from inherited or spontaneous mutations of Runt-related transcription factor 2 gene (RUNX2). It represents a clinical continuum typically characterized by wide calvarial sutures, clavicular hypoplasia and dental abnormalities. CDD has been rarely associated with skeletal and biochemical features that mimic hypophosphatasia. We report clinical, biochemical and molecular profile of a 3-year-old female with CCD, presented in utero with large cranial defects. She displayed severe parietal dysplasia, wide cranial sutures, clavicular abnormalities and biochemical features of hypophospatasia (HHP). She was preliminary diagnosed with benign perinatal HHP, harboring a likely pathogenic heterozygous TNSALP variant (p.Ser181Leu) inherited by the mother, who also displayed low levels of ALP. Asfotase alfa was introduced for a six-month-period with rather positive impact on cranial ossification. Nevertheless, focal skeletal disease (cranium and clavicles) and absence of clinical symptoms in the mother, carrier of the same genetic variant, posed diagnosis into question and further genetic analysis detected the novel spontaneous frameshift mutation c.1191delC (p.Phe398Leufs*86) in RUNX2 gene, establishing the CCD diagnosis. Although genotype-phenotype correlations are difficult, p.Phe398Leufs*86 appears to be associated with a severe cranial phenotype and absence of parietal bones, similarly to other adjacent frameshift/splicing mutations. The TNSALP variant (p.Ser181Leu) may contributed to patient's final phenotype, as well as to maternal low ALP levels. However, since low ALP levels have been also reported in few CCD patients with no alterations in TNSALP gene, studies to elucidate RUNX2 and TNSALP interactions could shed more light on differential diagnosis between CCD and HHP, CCD appropriate therapy and genetic counselling. ACCESSION NUMBER: (SUB8185506).

Novel Hemizygous Missense Variant of Spermine Synthase (SMS) Gene Causes Snyder-Robinson Syndrome in a Four-Year-Old Boy.

Snyder-Robinson syndrome (SRS) is an extremely rare X-linked intellectual disability syndrome (MRXSSR; MIM #309583). The main clinical features of SRS include psychomotor delay, hypotonia, and asthenic-type body habitus - reduced body weight and bone abnormalities (osteoporosis, fractures, kyphoscoliosis). We report a case of SRS with a hemizygous missense variant in the SMS gene,c.334C>G (p.Pro112Ala), in a 4-year-old boy, who initially developed hypotonia, delayed motor skills, and subsequently epilepsy. This variant in SMS was found to be de novo. To the best of our knowledge, this novel SMS gene variant has never been previously reported in disease-related variation databases, such as ClinVar or HGMD.

Serum Spexin is Correlated with Lipoprotein(a) and Androgens in Female Adolescents.

The Spexin gene is considered the most dysregulated in obese human fat. Limited data suggest that the novel peptide spexin may potentially impact food intake, weight regulation and body adiposity. The aim of this case-control study was to compare fasting serum spexin concentrations between normal weight (NW) and overweight/obese (OB/OW) adolescent females and explore the relationship between circulating spexin and anthropometric, bone and fat mass, metabolic and hormonal parameters. Eighty post-menarcheal females (mean age ± SD 16.23 ± 2.26 years); 55 NW (mean BMI ± SD 19.72 ± 2.52 kg/m2) and 25 OB/OW (mean BMI ± SD 29.35 ± 3.89 kg/m2) participated in the study. Circulating spexin levels did not differ significantly (p = 0.378) between NW (median (interquartile range), 0.26 (0.17) ng/mL) and OB/OW (median (interquartile range), 0.28 (0.06) ng/mL) adolescents and did not correlate with BMI (rs = -0.090, p = 0.438), % body fat (rs = -0.173, p = 0.409), glucose or insulin resistance indices derived from fasting and oral glucose tolerance states. In the total study sample, spexin concentrations correlated positively with lipoprotein(a) (rs = 0.402, p = 0.046). In the OB/OW adolescents spexin levels correlated positively with testosterone (rs = 0.727, p = 0.011) and free androgen index (rs = 0.755, p = 0.007). In the NW adolescents, spexin concentrations correlated negatively with dehydroepiandrosterone sulphate (rs = -0.445, p = 0.038). Results may suggest potential involvement of spexin in the regulation of lipoprotein(a) and of the reproductive/adrenal axis in post-menarcheal adolescent females.

Bone health assessment of food allergic children on restrictive diets: a practical guide.

BACKGROUND: Food allergy in childhood is on the rise globally and is managed with avoidance diets; recent case reports of food allergic children with nutritional rickets in the literature highlight the importance of close monitoring of bone health in this population. METHODS: There is no consensus as yet with regard to bone health evaluation in food allergic children; therefore, extensive literature search was performed and the existing evidence is presented, along with a relevant algorithm. RESULTS: Children allergic to cow's milk protein or presenting with allergy in more than three food items, as well as patients with severe allergic phenotypes or comorbidities known to affect the skeleton, seem to be at risk of metabolic bone disorders. As a practical guide, suspicious cases can be investigated with basic bone profile, whereas more severe cases (persistent bone pain and fractures) may undergo advanced bone health assessment, with bone mineral density (BMD) and metabolic bone markers' evaluation. Of note, these diagnostic steps call for further studies in the field of food allergy, as they are not performed as a routine. Evidence is accumulating with regard to vitamin D deficiency, osteopenia and imbalanced bone metabolism in those food allergic children who show poor dietary compliance or have inadequate medical supervision. CONCLUSIONS: Ensuring optimal bone accrual in a food allergic child is an important task for the clinician and requires close monitoring of the restrictive diet and prompt therapeutic intervention, in an effort to avoid rickets or osteopenia.

Long-term follow-up of a child with Klinefelter syndrome and achondroplasia from infancy to 16 years.

BACKGROUND: Achondroplasia (ACH), an autosomal dominant skeletal dysplasia, occurs in approximately 1:20,000 births. On the other hand, 47,XXY aneuploidy (Klinefelter syndrome [KS]) is the most common sex chromosome disorder, with a prevalence of approximately 1:600 males. To the best of our knowledge, only five cases of patients presenting both ACH and KS have been reported to date in the international literature. However, none of these cases has been longitudinally followed during the entire childhood. CASE PRESENTATION: We report a male patient with ACH and KS, diagnosed in early infancy because of his typical phenotype of ACH. The diagnosis was confirmed by molecular analysis revealing a de novo heterozygous 1138 G-to-A mutation of the FGFR3 gene. During his first assessment, a karyotype was performed, which also revealed coexistence of KS. He was followed by our pediatric endocrinology team until the age of 16 years, then he was gradually transferred to adult endocrine care. CONCLUSIONS: This is the first reported case with both conditions that was diagnosed in infancy and was longitudinally followed by a pediatric endocrinology team regularly, from infancy to late adolescence. With a typical phenotype of ACH, it is striking and noteworthy that he did not develop the classical endocrine complications of a child with KS, neither did he necessitate testosterone supplementation during his pubertal development, due to his normal virilization and testosterone levels.

Bone Health in Classic Galactosemia: Systematic Review and Meta-Analysis.

INTRODUCTION: Previous studies have reported an association between classic galactosemia (CG) and decreased bone mass. The primary objective of this systematic review with meta-analysis was to determine the extent of bone mineral density (BMD) Z-score reduction. Low BMD was defined as a Z-score ≤-2 standard deviations (SD). The secondary objective was to evaluate other indicators of bone status through a descriptive analysis. METHODS: Systematic search strategies were developed by an experienced clinical librarian. Selection of relevant manuscripts, risk of bias assessment, and data extraction were performed independently by two investigators. RESULTS: Four studies were included in the meta-analysis. BMD Z-scores in children and adults with CG measured at the lumbar spine (LBMD; 4 studies; n  = 112), total hip (HBMD; 2 studies; n = 58), and femoral neck (FBMD; 2 studies; n = 73) were assessed. Mean BMD Z-scores in the CG population were LBMD -0.70 (95% CI: -0.88, -0.52); HBMD -0.89 (95% CI: -1.14, -0.64); and FBMD -0.63 (95% CI -1.29, 0.02). Results from studies included in the descriptive analysis (n = 7) show that vitamin D levels were frequently in the low reference range, whereas serum calcium levels were within reference range. CONCLUSION: The mean BMD Z-score in the CG population is -0.7, which is lower than in the general population, though still within two SD of the reference mean of zero. This indicates that bone health is mildly affected in CG and that more patients, compared to the general population, are at risk for a BMD Z-score ≤-2 SD. In conclusion, clinicians should ensure appropriate preventive and therapeutic measures for CG patients.

Body composition of patients with Duchenne muscular dystrophy: the Greek experience.

Greece ranks among the first countries suffering from the obesity epidemic globally. The aim of the study was to evaluate body composition in Greek patients with Duchenne muscular dystrophy (DMD). We hypothesized that able-bodied patients would not differ from controls, in terms of adiposity, based on clinical observations during everyday practice. STUDY DESIGN: Cross-sectional study of steroid-dependent DMD subjects, who underwent dual-energy X-ray absorptiometry and laboratory metabolic bone profile evaluation. Forty-two patients and thirty-one controls were studied. Overall, DMD subjects were shorter (height Z-score = -1.4, p = 0.01). Their bone mineral density (BMD) was low (lumbar spine BMD Z-score = -1.2, p < 0.01, subcranial total body BMD Z-score = -1.8, p < 0.01). Lean tissue mass (LTM) was also decreased (LTM Z-score = -2.2, p < 0.01). The above findings were more pronounced in adolescence. Regarding adiposity, increased fat mass (FM) was found only in pubertal DMD patients (FM Z-score = 1.4, p < 0.01), whereas prepubertal, able-bodied patients did not differ from controls, thus confirming the initial hypothesis. Finally, 65 % of DMD subjects had increased bone resorption markers and 57 % had suboptimal vitamin D levels. The importance of using native population as controls for body composition analysis is highlighted. In Greece, abnormal body composition in DMD patients is more striking when loss of ambulation occurs and not during the prepubertal period, due to the concurrent presence of obesity in the pediatric population. Thus, adolescents with this neuromuscular disorder should be targeted toward prompt lifestyle interventions.

Effects of L-phenylalanine on acetylcholinesterase and Na+,K+-ATPase activities in suckling rat frontal cortex, hippocampus and hypothalamus.

The effect of different L-phenylalanine (Phe) concentrations (0.12-12.1 mM) on acetylcholinesterase (AChE), (Na+,K+)-ATPase and Mg2+-ATPase activities was evaluated in homogenates of suckling rat frontal cortex, hippocampus and hypothalamus. Phe, at high concentrations, reduced AChE activity in frontal cortex and hippocampus by 18%-20%. On the contrary, the enzyme activity was unaltered in the hypothalamus. Na+,K+-ATPase was stimulated by high levels of the amino acid, both in the frontal cortex and the hypothalamus by 60%, whereas it was inhibited in the hippocampus by 40%. Mg2+-ATPase was not influenced by Phe. It is suggested that: a) In the frontal cortex, the improper acetylcholine (ACh) release, due to AChE inhibition by Phe, combined with the stimulation of Na+,K+-ATPase, possibly explain tremor and the hyperkinetic behaviour in patients with classical phenylketonuria (PKU). b) In the hippocampus, inhibition of AChE by Phe could lead to problems in memory, while Na+,K+-ATPase inhibition by Phe may induce metabolic disorders and electrical instability of the synaptosomal membrane. c) In the hypothalamus, the behavioral problems in PKU "off diet" may be related to noradrenaline (NA) levels, which are probably correlated with the modulated Na+,K+-ATPase by Phe.