Puberty Status Modifies the Effects of Genetic Variants, Lifestyle Factors and Their Interactions on Adiponectin: The BCAMS Study.

Background: Hypoadiponectinemia has been associated with various cardiometabolic disease states. Previous studies in adults have shown that adiponectin levels were regulated by specific genetic and behavioral or lifestyle factors. However, little is known about the influence of these factors on adiponectin levels in children, particularly as mitigated by pubertal development. Methods: We performed a cross-sectional analysis of data from 3,402 children aged 6-18 years from the Beijing Child and Adolescent Metabolic Syndrome (BCAMS) study. Pubertal progress was classified as prepubertal, midpuberty, and postpuberty. Six relevant single nucleotide polymorphisms (SNPs) were selected from previous genome-wide association studies of adiponectin in East Asians. Individual SNPs and two weighted genetic predisposition scores, as well as their interactions with 14 lifestyle factors, were analyzed to investigate their influence on adiponectin levels across puberty. The effect of these factors on adiponectin was analyzed using general linear models adjusted for age, sex, and BMI. Results: After adjustment for age, sex, and BMI, the associations between adiponectin levels and diet items, and diet score were significant at prepuberty or postpuberty, while the effect of exercise on adiponectin levels was more prominent at mid- and postpuberty. Walking to school was found to be associated with increased adiponectin levels throughout puberty. Meanwhile, the effect of WDR11-FGFR2-rs3943077 was stronger at midpuberty (P = 0.002), and ADIPOQ-rs6773957 was more effective at postpuberty (P = 0.005), while CDH13-rs4783244 showed the strongest association with adiponectin levels at all pubertal stages (all P < 3.24 × 10-15). We further found that effects of diet score (Pinteraction = 0.022) and exercise (Pinteraction = 0.049) were stronger in children with higher genetic risk of hypoadiponectinemia, while higher diet score and exercise frequency attenuated the differences in adiponectin levels among children with different genetic risks. Conclusions: Our study confirmed puberty modulates the associations between adiponectin, and genetic variants, lifestyle factors, and gene-by-lifestyle interactions. These findings provide new insight into puberty-specific lifestyle suggestions, especially in genetically susceptible individuals.

A novel mutation in PLS3 causes extremely rare X-linked osteogenesis imperfecta.

BACKGROUND: Osteogenesis imperfecta (OI) is a phenotypically and genetically heterogeneous bone disease characterized by bone fragility and recurrent fractures. X-linked inherited OI with mutation in PLS3 is so rare that its genotype-phenotype characteristics are not available. METHODS: We designed a novel targeted next-generation sequencing (NGS) panel with the candidate genes of OI to detect pathogenic mutations and confirmed them by Sanger sequencing. The phenotypes of the patients were also investigated. RESULTS: The proband, a 12-year-old boy from a nonconsanguineous family, experienced multiple fractures of long bones and vertebrae and had low bone mineral density (BMD Z-score of -3.2 to -2.0). His younger brother also had extremity fractures. A novel frameshift mutation (c.1106_1107insGAAA; p.Phe369Leufs*5) in exon 10 of PLS3 was identified in the two patients, which was inherited from their mother who had normal BMD. Blue sclerae were the only extraskeletal symptom in all affected individuals. Zoledronic acid was beneficial for increasing BMD and reshaping the compressed vertebral bodies of the proband. CONCLUSION: We first identify a novel mutation in PLS3 that led to rare X-linked OI and provide practical information for the diagnosis and treatment of this disease.

A novel variant in AIRE causing a rare, non­classical autoimmune polyendocrine syndrome type 1.

Autoimmune polyendocrine syndrome type 1 (APS­1) is a rare inherited autoimmune disease, characterized by a classic triad, including chronic mucocutaneous candidiasis, primary adrenocortical insufficiency and hypoparathyroidism. The present study investigated phenotypes and pathogenic variants in a Chinese woman with non­classical APS­1. Disease­associated variants in a patient with APS­1 were identified via targeted next generation sequencing and the variant was confirmed via Sanger sequencing. Serum levels of calcium, phosphorus, parathyroid hormone (PTH), follicle­stimulating hormone (FSH), luteinizing hormone (LH), estradiol and urinary levels of calcium were measured. Blood count assays and bone marrow morphology were investigated. The patient was a 32­year­old woman who had suffered from typical carpopedal spasms since she was 7 years old. She developed syncope, primary amenorrhea, intermittent diarrhea and general fatigue in subsequent years. Hypocalcemia, hyperphosphatemia, low levels of PTH and estradiol, elevated levels of FSH and LH, and absence of erythroblasts were observed, which indicated hypoparathyroidism, primary ovarian insufficiency and pure red cell aplasia. A novel heterozygous missense variant (NM_000383.2: c.623G>T, NP_000374.1: p.Gly208Val) in exon 5 of autoimmune regulator and a reported variant (NM_000383.2: c.371C>T, NP_000374.1: p.Pro124Leu) in exon 3 were detected, of which the c.623G>T variant may be a pathogenic variation that induces APS­1. Under a regular follow­up and therapeutic adjustment of calcium, calcitriol, hormone replacement therapy and methylprednisolone, the endocrine function and clinical symptoms of the patient were notably improved. The results of the present study expand the known genetic and phenotypical spectra of APS­1.

Novel variants in COL2A1 causing rare spondyloepiphyseal dysplasia congenita.

BACKGROUND: Spondyloepiphyseal dysplasia congenita (SEDC) is an extremely rare inherited chondrodysplasia characterized by abnormal epiphyses, short stature, and flattened vertebral bodies. We investigate the phenotypes and the disease-associated variants of SEDC in two unrelated Chinese families. METHODS: We identified disease-associated variants in two nonconsanguineous families with SEDC using targeted next-generation sequencing and confirmed the variants using Sanger sequencing. We investigated the phenotypes of the patients, including clinical manifestations, bone turnover biomarkers, bone mineral density and skeletal radiographic features. RESULTS: Two probands were diagnosed as SEDC according to the phenotypes of disproportionately short-trunk stature, kyphosis, lumbar lordosis and adduction deformity of hips. Radiographs revealed kyphosis and lumbar lordosis, flattened vertebral bodies, compressed femoral heads and shortening of the femurs. Bone mineral density of the probands was lower than that of age- and gender-matched normal children, but bone turnover biomarker levels were within normal range. Two novel heterozygous missense variants (NM_001844.5: c.1654 G>A, NP_001835.3: p.Gly552Arg; NM_001844.5: c.3518G>T, NP_001835.3: p.Gly1173Val) in collagen type II alpha 1 chain (COL2A1) were detected in the two families, which would impair the formation of stable triple-helical type II collagen. CONCLUSIONS: We identified two novel disease-associated variants in COL2A1, which led to severe SEDC. Our findings expanded the gene variant spectrum and phenotypic spectrum of extremely rare type II collagenopathies.

Childhood sleep duration modifies the polygenic risk for obesity in youth through leptin pathway: the Beijing Child and Adolescent Metabolic Syndrome cohort study.

BACKGROUND/OBJECTIVES: Short sleep is an obesity risk factor, however, little is known about its interplay with genetic predisposition and pathways involved in obesity pathogenesis, especially in the longitudinal setting. We aimed to investigate a possible sleep-gene interaction for childhood obesity risk, and whether the interaction in childhood longitudinally contributes to obesity risk at a 10-year follow-up and further to test if there is any mediation through the leptin pathway. SUBJECTS/METHODS: A total of 3211 children from China (6-18 years) at baseline and 848 participants at 10-year follow-up from the Beijing Child and Adolescent Metabolic Syndrome (BCAMS) cohort study were analyzed. Baseline leptin concentrations and 12 established adult body mass index (BMI) loci were examined for the associations with habitual sleep duration. RESULTS: After adjusting for covariates, including pubertal stages and behavioral factors, short sleep duration at baseline was significantly associated with increased overweight/obesity risk at both baseline and follow-up. Genetic predisposition scores (GPS), particularly consisting of leptin-related SNPs (GPSleptin), were robustly associated with baseline overweight/obesity in children who slept ≤8 h/day (P < 0.001), whereas the association was ablated in those who slept ≥10 h/day (P > 0.05). Comparable observations were made at follow-up. Mediation analysis revealed a modest direct effect of the GPSleptin-sleep interaction on BMI at baseline, while a significant indirect effect of this interaction was found to be mediated principally through elevated leptin (proportion: 52.6%); moreover, the mediation effect via leptin remained stable over 10 years. CONCLUSIONS: This study suggests that shorter sleep duration in children from China (< 8h/day), compared to longer sleep duration (≥10 h/day), has a long-term impact on the association of polygenic risk for obesity from childhood to young adulthood and leptin pathway explains a key mechanism via a modification effect. Therefore, adequate sleep duration during childhood is important for the early prevention of obesity, especially if there is a genetic predisposition to this trait.

Effects of zoledronic acid on vertebral shape of children and adolescents with osteogenesis imperfecta.

Vertebral compression fracture (VCF) is a common and severe complication of osteogenesis imperfecta (OI). We prospectively observe the changes of vertebral shape during zoledronic acid (ZOL) treatment and assess influence factors of VCF in OI children. 32 children with VCF and 10 children without VCF (NVCF) were included and given ZOL treatment for 2 years, who were matched in age and gender. Control group included 17 treatment naïve OI patients with VCF who were matched in age, gender and clinical severity to 17 patients in VCF group received ZOL treatment for 1 year (as ZOL treated group). We performed quantitative vertebral morphometry and calculated concavity index (mh/ph), height-length ratio (ah/LL, mh/LL, ph/LL) and projection area (PA) of vertebrae from T4 to L4 before and after treatment. At baseline, patients in VCF group had significantly lower PA, mh/ph, ah/LL, mh/LL and ph/LL than patients in NVCF group (P < 0.01). PA, mh/ph, ah/LL, mh/ LL and ph/LL of patients with VCF were raised by (35.2 ±â€¯19.5)%, (22.9 ±â€¯15.1)%, (19.6 ±â€¯13.9)%, (33.6 ±â€¯25.5)%, and (8.1 ±â€¯8.8)% (P < 0.01) after 1-year treatment of ZOL, and were increased by (71.8 ±â€¯28.2)%, (42.8 ±â€¯21.8)%, (35.1 ±â€¯20.6)%, (65.4 ±â€¯43.2)%, and (12.5 ±â€¯11.4)% after 2-year treatment of ZOL (P < 0.01). Compared to control group, mh/ph, ah/LL and mh/LL were significantly higher (P < 0.01) in ZOL treated group. LS-BMD and its increase were positively correlated to vertebral height and PA at baseline and the improvement of vertebral height and PA after ZOL treatment, respectively. In conclusion, the compressive vertebrae of OI children could be effectively reshaped during ZOL treatment. Low LS-BMD was an independent risk factor for VCF and its increase was positively correlated to the improvement in vertebral shape after ZOL treatment.

A novel missense mutation in P4HB causes mild osteogenesis imperfecta.

Osteogenesis imperfecta (OI) is a rare heritable bone disorder characterized by low bone mineral density (BMD), recurrent bone fractures, and progressive bone deformities. P4HB encodes protein disulfide isomerase (PDI) and is identified as a novel candidate gene of OI. The purposes of the present study are to detect pathogenic mutation, to evaluate the phenotypes of a Chinese family with mild OI, and to investigate the effects of bisphosphonates on bone of the proband. We detected the pathogenic mutation by next generation sequencing and Sanger sequencing. Laboratory and radiological investigations were conducted to evaluate the phenotypes. The proband was a 12-year-old girl with low BMD, history of recurrent non-traumatic fractures, slight scoliosis, with bluish grey sclera and ligamentous laxity. Her father suffered from one fragility fracture and slight wedge changes of vertebras, with bluish grey sclera. We identified a novel heterozygous missense mutation (c.692A>C, p.His231Pro) in P4HB in the proband and her father. This mutation was predicted to affect the combination of PDI with type I procollagen and lead to the disorder of its triple helix formation. Bisphosphonates were effective in reducing bone resorption and increasing BMD of the proband with well tolerance. In conclusion, we identified a novel mutation in P4HB in a Chinese family with mild OI, which expanded the genotypic and phenotypic spectrum of OI. Bisphosphonates were effective to this extremely rare OI induced by P4HB mutation.

Genotype-phenotype relationship in a large cohort of osteogenesis imperfecta patients with COL1A1 mutations revealed by a new scoring system.

BACKGROUND: Osteogenesis imperfecta (OI), a heritable bone fragility disorder, is mainly caused by mutations in COL1A1 gene encoding α1 chain of type I collagen. This study aimed to investigate the COL1A1 mutation spectrum and quantitatively assess the genotype-phenotype relationship in a large cohort of Chinese patients with OI. METHODS: A total of 161 patients who were diagnosed as OI in Department of Endocrinology of Peking Union Medical College Hospital from January 2010 to December 2017 were included in the study. The COL1A1 mutation spectrum was identified by next generation sequencing and confirmed by Sanger sequencing. A new clinical scoring system was developed to quantitatively assess the clinical severity of OI and the genotype-phenotype relationship was analyzed. The independent sample t-test, analysis of variance, Mann-Whitney U-test, Chi-squared test, Pearson correlation, and multiple linear regression were applied for statistical analyses. RESULTS: Among 161 patients with OI, 32.9% missense mutations, 16.8% non-sense mutations, 24.2% splice-site mutations, 24.8% frameshift mutations, and 1.2% whole-gene deletions were identified, of which 38 variations were novel. These mutations led to 53 patients carrying qualitative defects and 67 patients carrying quantitative defects in type I collagen. Compared to patients with quantitative mutations, patients with qualitative mutations had lower alkaline phosphatase level (296 [132, 346] U/L vs. 218 [136, 284] U/L, P = 0.009) and higher clinical score (12.2 ±â€Š5.3 vs. 7.4 ±â€Š2.4, P < 0.001), denoting more severe phenotypes including shorter stature, lower bone mineral density, higher fracture frequency, more bone deformity, vertebral compressive fractures, limited movement, and dentinogenesis imperfecta (DI). Patients would not present with DI if the glycine substitutions happened before the 79th amino acid in triple helix of α1 chains. CONCLUSIONS: This presented distinctive COL1A1 mutation spectrum in a large cohort of Chinese patients with OI. This new quantitative analysis of genotype-phenotype correlation would be helpful to predict the prognosis of OI and genetic counseling.

Novel mutations in BMP1 induce a rare type of osteogenesis imperfecta.

BACKGROUND: Osteogenesis imperfecta (OI) is a group of hereditary disorders characterized by low bone mass and recurrent fractures. OI patients of autosomal recessive inheritance are extremely rare, of which OI type XIII is attributable to mutation in BMP1 gene. CASE REPORT: Here, we detect the pathogenic mutations and analyze their relation to the phenotypes in a Chinese family with OI using next-generation sequencing (NGS) and Sanger sequencing. We also evaluate the efficacy of alendronate treatment in the patient with OI type XIII. The clinical phenotypes of the patient included recurrent fractures, muscle weakness, bone deformity, macrocephaly and elbow contractures, but no blue sclera or dentinogenesis imperfecta. High-resolution peripheral quantitative computed tomography revealed high bone mineral density and bone volume, but reduced trabecular numbers, increased porosity and comprised strength in this patient. Novel heterozygous mutations of c.1324G > T (p.Asp442Tyr) and c.148 + 1G > A in BMP1 gene were found in the proband, which would affect the CUB2 domain and the prodomain of mutant proteins. The parents were heterozygous carriers for the two mutations respectively, but with normal phenotype. CONCLUSIONS: We report for the first time that the novel pathogenic mutations in BMP1 can lead to the extremely rare OI type XIII, which exhibit unique characters of high bone mass, but with impaired bone microstructure and comprised bone strength. Alendronate is beneficial in increasing bone mineral density and decreasing bone resorption biomarkers, but concerns still remain whether it can reduce fracture incidence in this rare type of OI.

Circulating Osteonectin and Adipokine Profiles in Relation to Metabolically Healthy Obesity in Chinese Children: Findings From BCAMS.

Background The role of adipokine dysregulation in determining the metabolic fate of obesity is not well studied. We aimed to examine whether the matricellular protein osteonectin and the profiles of certain adipokines could differentiate metabolically healthy obese ( MHO ) versus metabolically unhealthy obese phenotypes in childhood. Methods and Results This study included 1137 obese children and 982 normal-weight healthy ( NWH ) controls recruited from the BCAMS (Beijing Child and Adolescent Metabolic Syndrome) study. MHO was defined by the absence of insulin resistance and/or any metabolic syndrome components. Six adipokines-osteonectin, leptin, adiponectin, resistin, FGF21 (fibroblast growth factor 21), and RBP-4 (retinol binding protein 4)-were assessed. Approximately 20% of obese children displayed the MHO phenotype. MHO children had a more favorable adipokine profile than metabolically unhealthy obese children, with lower osteonectin, leptin, and RBP -4 and higher adiponectin (all P<0.05). Compared with normal-weight healthy controls, MHO children displayed increased leptin, resistin, and RBP -4 levels and reduced adiponectin concentrations (all P<0.05) but similar osteonectin and FGF 21 levels. Among obese subjects, decreased osteonectin (odds ratio [OR]: 0.82; 95% confidence interval [CI] per standard deviation, 0.70-0.97), RBP -4 (OR: 0.77; 95% CI per standard deviation, 0.64-0.93), and leptin/adiponectin ratio (OR: 0.58; 95% CI per standard deviation, 0.43-0.77) were independent predictors of MHO . In addition, compared with children without abnormalities, those with any 3 adipokine abnormalities were 80% less likely to exhibit the MHO phenotype ( OR : 0.20; 95% CI , 0.10-0.43) and 3 times more likely to have metabolic syndrome ( OR : 2.77; 95% CI , 1.52-5.03). Conclusions These findings suggest that dysregulation of adipokines might govern the metabolic consequences of obesity in children. Low osteonectin levels, along with a healthy adipokine profile, might be used as an early marker of the MHO phenotype.

Clinical characteristics and bisphosphonates treatment of rare pregnancy- and lactation-associated osteoporosis.

Pregnancy- and lactation-associated osteoporosis (PLO) is a rare disorder with poorly known etiology, pathophysiology, and therapy. We aimed to investigate the clinical characteristics of PLO and evaluate the effectiveness and safety of bisphosphonates on it. A total of 12 patients were diagnosed with PLO on the basis of medical history, bone mineral density (BMD), and/or fragility fractures during pregnancy and lactation. We investigated the clinical, biochemical, and radiological characteristics of patients. We assessed the effects of alendronate or zoledronic acid through observing the changes of bone turnover biomarkers and BMD during the treatment. Secondary osteoporosis was excluded by comprehensive differential diagnosis. The mean age of these patients was 31 ± 5 years old. All of these patients presented severe back pain. Multiple vertebral compression fractures (VCFs) were found in 10 patients, and the median (P25th, P75th) number of compressed vertebra was 3 (3, 5). Ten patients had vitamin D insufficiency or deficiency. Serum level of bone resorption marker (ß-CTX with mean of 0.68 ± 0.41 ng/ml) was moderately higher than the normal range. BMD at lumbar spine, femoral neck, and total hip were low as 0.894 ± 0.153 g/cm2, 0.728 ± 0.090 g/cm2, and 0.728 ± 0.080 g/cm2, respectively. Either alendronate or zoledronic acid could effectively relieve bone pain, reduce ß-CTX level, and increase BMD. PLO is a rare type of osteoporosis, which was characterized by increased bone resorption and decreased BMD, even VCFs. Bisphosphonate therapy was well tolerated and effective in management of PLO, but needed to be further verified in randomized controlled trial.

Loss of Cardio-Protective Effects at the CDH13 Locus Due to Gene-Sleep Interaction: The BCAMS Study.

Left ventricular mass index (LVMI) provides a metric for cardiovascular disease risk. We aimed to assess the association of adiponectin-related genetic variants resulting from GWAS in East Asians (loci in/near CDH13, ADIPOQ, WDR11FGF, CMIP and PEPD) with LVMI, and to examine whether sleep duration modified these genetic associations in youth. The 559 subjects aged 15-28 years were recruited from the Beijing Child and Adolescent Metabolic Syndrome study. Among the six loci, CDH13 rs4783244 was significantly correlated with adiponectin levels (p = 8.07 × 10-7). The adiponectin-rising allele in rs4783244 locus was significantly associated with decreased LVMI (p = 6.99 × 10-4) after adjusting for classical cardiovascular risk factors, and further for adiponectin levels, while no significant association was found between the other loci and LVMI. Moreover, we observed a significant interaction effect between rs4783244 and sleep duration (p = .005) for LVMI; the genetic association was more evident in long sleep duration while lost in short sleep duration. Similar interaction was found in the subgroup analysis using longitudinal data (p = .025 for interaction). In this young Chinese population, CDH13 rs4783244 represents a key locus for cardiac structure, and confers stronger cardio-protection in longer sleep duration when contrasted with short sleep duration.

Role of adipokines FGF21, leptin and adiponectin in self-concept of youths with obesity.

The mechanisms by which obesity increases the risk of psychosocial disorders remain unclear. We aimed at exploring the association between obesity and self-concept in Chinese youths and the role of adipokines. Data for 559 participants (aged 14-28 years) were analyzed. Self-concept was assessed by utilizing the Self-Description Questionnaire II (SDQ-II). Subjects with obesity had higher leptin, FGF21 and lower adiponectin levels (all p < 0.001). They also had lower SDQ-II scores especially in the domains of general school, physical abilities, physical appearance and opposite-sex relations (all p < 0.001). Both elevated FGF21 and leptin were correlated with lower scores in math (p < 0.01), physical abilities (p < 0.01), and opposite-sex relations (p < 0.05), meanwhile FGF21 negatively correlated with the scores in general school and honesty/trustworthiness, and leptin negatively correlated with physical appearance (p < 0.01) but positively with verbal (p < 0.01). In contrast, decreased adiponectin was correlated with poorer physical abilities (p < 0.05), physical appearance (p < 0.05), and parent relations (p < 0.01). Moreover, these associations of leptin, FGF21 and adiponectin with certain domains remained significant after adjustment for BMI and other metabolic confounders. In conclusion, youths with obesity experienced poorly on self-concept, and these associations may be explained in part by adipokines leptin, FGF21 and adiponectin.

Childhood retinol-binding protein 4 (RBP4) levels predicting the 10-year risk of insulin resistance and metabolic syndrome: the BCAMS study.

BACKGROUND: Elevated retinol-binding protein 4 (RBP4) levels may contribute to the development of metabolic abnormalities, but prospective studies evaluating the association between childhood RBP4 levels and metabolic syndrome (MS) in adulthood are lacking. We investigated whether RBP4 levels during childhood predict cardiometabolic risk at 10-year follow-up. METHODS: The relationships between RBP4 levels, the established adipokines (leptin and adiponectin) and the components of MS were examined in 3445 school-aged children recruited in 2004 for the Beijing Child and Adolescent Metabolic Syndrome study. In 2015, 352 of these individuals completed an in-depth follow-up examination. RESULTS: Participants with higher childhood RBP4 levels had adverse cardiometabolic profiles at follow-up. Those with incident or persistent MS had higher baseline RBP4 levels than those who never exhibited the elements of MS. Moreover, baseline RBP4 predicted hyperglycemia (OR per SD increase = 1.48, P = 0.009), elevated triglyceride (OR = 1.54, P < 0.001), elevated blood pressures (OR = 1.46, P = 0.015), MS (OR = 1.68, P = 0.002) and insulin resistance (OR = 1.44, P = 0.015) in the 10-year follow-up phase, independent of baseline BMI. Significant improvements were seen for the net reclassification improvement and integrated discrimination index after adding childhood RBP4 levels into the risk models using conventional cardiometabolic risk factors in predicting MS at follow-up (P < 0.05). Leptin and adiponectin demonstrated the expected associations with metabolic disorders. CONCLUSIONS: Childhood RBP4 serves as a risk factor for subsequent development of MS and its components, independent of pediatric obesity. Incorporating childhood RBP4 into conventional cardiometabolic risk assessment models significantly improves the prediction of MS.

ZOLEDRONIC ACID VERSUS ALENDRONATE IN THE TREATMENT OF CHILDREN WITH OSTEOGENESIS IMPERFECTA: A 2-YEAR CLINICAL STUDY.

OBJECTIVE: Bisphosphonates have been demonstrated to increase the bone mineral density (BMD) of osteogenesis imperfecta (OI) patients. We aimed to compare the efficacy and safety of intravenous zoledronic acid and oral alendronate in patients with OI. METHODS: A total of 161 patients with OI ranging from 2 to 16 years old were included and randomized at a 2:1 ratio to receive either weekly oral alendronate (ALN) 70 mg or a once-yearly infusion of zoledronic acid (ZOL) for 2 years. The primary endpoints were percentage change from baseline in lumbar spine (LS) BMD and change in Z-scores of LS BMD. RESULTS: A total of 136 patients with OI completed the 2-year clinical study, 90 of whom were assigned to receive ALN, while 46 received ZOL treatment. The percentage change in LS BMD was 60.01 ± 7.08% in the ALN group and 62.04 ± 5.9% in the ZOL group ( P = .721). The corresponding BMD Z-score increased by 0.50 ± 0.05 in the ALN group and 0.71 ± 0.06 in the ZOL group ( P = .013). ZOL was superior to ALN in reducing the clinical fracture rate (hazard ratio, 0.23; 95% confidence interval, 0.118 to 0.431). There was no difference in the incidence of severe side effects between the two groups. CONCLUSION: A once-yearly 5 mg infusion of ZOL and weekly oral ALN had similar effects in increasing BMD and reducing bone resorption in children and adolescents with OI. ZOL was superior to ALN in reducing the clinical fracture rate. ABBREVIATIONS: 25OHD = 25-hydroxyvitamin D ALN = alendronate ALP = alkaline phosphatase ß-CTX = cross-linked C-telopeptide of type I collagen BMD = bone mineral density BP = bisphosphonate FN = femoral neck LS = lumbar spine OI = osteogenesis imperfecta SAE = severe adverse event ZOL = zoledronic acid.

Effects of alendronate and alfacalcidol on bone in patients with myasthenia gravis initiating glucocorticoids treatment.

OBJECTIVE: Glucocorticoids (GCs) are the first-line treatment for myasthenia gravis (MG) and act as long-term immunosuppressants. However, GCs can induce osteoporosis and bone fractures. In this study, we evaluate the effects of oral alendronate and alfacalcidol, or alfacalcidol alone on the bone of Chinese patients with MG who will initiate treatment with GCs. DESIGN AND METHODS: A total of 75 patients were included in this 12-month prospective, open-label, single-centre study. Patients with bone mineral density (BMD) T-score less than -1.0 at baseline were treated with 70 mg of alendronate per week. Patients with BMD T-score greater than -1.0 at baseline were included in the alfacalcidol-alone group. Patients in two groups were treated with 0.25 µg of alfacalcidol every other day and 600 mg of calcium daily. RESULTS: After 12 months of treatment, the mean BMD of lumbar spine, femoral neck and total hip increased by 3.4% (P = .002), 1.8% (P = .21) and 2.6% (P = .02), respectively, in alendronate group. In alfacalcidol-alone group, the mean BMD of lumbar spine, femoral neck and total hip decreased by 6.1%, 3.2% and 3.3%, respectively (all P < .001 vs baseline). CONCLUSIONS: We demonstrated for the first time that treatment with alendronate combined with alfacalcidol significantly increased BMD, decreased bone turnover biomarker levels and reduced the occurrence of hypercalciuria in a large cohort of Chinese patients with MG who initiated treatment with glucocorticoids. However, treatment with alfacalcidol alone failed to prevent bone loss in patients with MG receiving glucocorticoid therapy.

Novel Mutations in PLOD2 Cause Rare Bruck Syndrome.

Bruck syndrome is a rare autosomal recessive form of osteogenesis imperfecta (OI), which is mainly characterized by joint contractures and recurrent fragility fractures. Mutations in FKBP10 and PLOD2 were identified as the underlying genetic defects of Bruck syndrome. Here we investigated the phenotypes and the pathogenic mutations of three unrelated Chinese patients with Bruck syndrome. Clinical fractures, bone mineral density (BMD), bone turnover biomarkers, and skeletal images were evaluated in detail. The pathogenic mutations were identified by targeted next-generation sequencing and subsequently confirmed by Sanger sequencing and cosegregation analysis. We also evaluated the effects of zoledronic acid on bone fracture incidence and BMD of the patients. Three patients had congenital joint contractures, recurrent fragility fractures, camptodactyly, clubfoot, scoliosis, but without dentinogenesis imperfecta and hearing loss. Five novel heterozygous mutations were detected in PLOD2, including three heterozygous missense mutations (c.1138C>T, p.Arg380Cys; c.1153T>C, p.Cys385Arg; and c.1982G>A, p.Gly661Asp), one heterozygous nonsense mutation (c.2038C>T, p.Arg680X), and one heterozygous splice-site mutation (c.503-2A>G). Their parents were all heterozygous carriers of these mutations in PLOD2. No clear genotype-phenotype correlations were found in these patients with PLOD2 mutations. Z-score of BMD was significantly increased, but scoliosis progressed and new bone fractures occurred during the treatment of zoledronic acid. Our findings expanded the spectrum of gene mutations of Bruck syndrome.

Extremely low level of serum pigment epithelium-derived factor is a special biomarker of Chinese osteogenesis imperfecta patients with SERPINF1 mutations.

BACKGROUNDS: SERPINF1 mutations caused deficiency of pigment epithelium-derived factor (PEDF) and would lead to osteogenesis imperfecta (OI) type VI. However, serum PEDF levels were unclear in Chinese OI patients who had clear molecular diagnosis. OBJECTIVE: To assess PEDF levels in different genotypes of OI, to evaluate the influencing factors of PEDF in Chinese OI patients with clear molecular diagnosis. METHODS: Known candidate genes of OI were examined by a targeted next generation sequence. Serum PEDF levels were measured by ELISA in 6 OI patients with SERPINF1 mutations, 6 carriers of one copy of the SERPINF1 mutation, 88 OI patients with COL1A1, CLO1A2, IFITM5 and other pathogenic mutations of OI and 24 healthy controls. We compared the differences in serum PEDF levels among different OI patients and normal controls. RESULTS: Serum PEDF levels were extremely low in OI patients with SERPINF1 mutations (0.66±1.60µg/ml) than in OI patients with other pathogenic mutations (4.88±1.43-7.07±2.43µg/ml), carriers of one copy of SERPINF1 mutation (4.94±2.35µg/ml), and normal controls (7.29±2.31µg/m) (P<0.001). No significant differences in serum PEDF concentrations were found among patients with OI type I, III or IV, and between patients with or without bisphosphonate treatment. Serum PEDF level was positively correlated with Z-score of weight (r=0.310, P=0.004), BMI (r=0.253, P=0.020) and alanine aminotransferase (r=0.291, P=0.007). CONCLUSIONS: Extremely low level of PEDF was demonstrated as a specific, convenient, and inexpensive diagnostic biomarker for OI patients with SERPINF1 mutations, but it could not provide information regarding the clinical severity of OI and the efficacy of bisphosphonates treatment.

The role of established East Asian obesity-related loci on pediatric leptin levels highlights a neuronal influence on body weight regulation in Chinese children and adolescents: the BCAMS study.

Genome-wide association studies have identified multiple variants associated with adult obesity, mostly in European-ancestry populations. We aimed to systematically assess the contribution of key loci, which had been previously shown to be associated in East Asian adults, to childhood obesity, related adipokine profiles and metabolic traits in a Chinese pediatric population. Twelve single-nucleotide polymorphisms (SNPs) plus metabolic profiles and levels of five adipokines (leptin, adiponectin, resistin, fibroblast growth factor 21 and retinol binding protein 4) were evaluated in 3,506 Chinese children and adolescents aged 6-18. After correction for multiple comparisons, six of these SNPs were robustly associated with childhood obesity: FTO-rs1558902 (P=5.6×10-5), MC4R-rs2331841 (P=4.4×10-4), GNPDA2-rs16858082 (P = 3.4×10-4), PCSK1-rs261967 (P = 0.001), SEC16B-rs516636 (P = 0.004) and MAP2K5-rs4776970 (P = 0.004), with odds ratios ranging from 1.211 to 1.421; while ITIH4-rs2535633 and BDNF-rs2030323 yielded nominal association with the same trait (P < 0.05). Moreover, the risk alleles of six SNPs displayed significant (P < 0.004) or nominal (P < 0.05) association with leptin levels, namely at in/near PCSK1, MC4R, FTO, MAP2K5, GNPDA2 and BDNF plus their cumulative genetic score yielded stronger association with increased leptin levels (P = 6.2×10-11). Our results reveal that key obesity-associated loci previously reported in Europeans, but also associated with East Asian adults, are also associated with obesity and/or metabolic quantitative traits in Chinese children. These associations coincide with six brain-expressed loci that correlate with leptin levels, thus may point to an important neuronal influence on body weight regulation in the pediatric setting.

Leptin-adiponectin imbalance as a marker of metabolic syndrome among Chinese children and adolescents: The BCAMS study.

PURPOSE: Leptin and adiponectin have opposite effects on subclinical inflammation and insulin resistance, both involved in the development of metabolic syndrome (MS). We aimed to investigate whether leptin/adiponectin ratio (L/A), as a marker of these two adipokines imbalance, may improve diagnosis of MS in children and adolescents, and determined its cut-off value in the diagnosis of MS. METHODS: A total of 3,428 subjects aged 6-18 years were selected from Beijing Child and Adolescent Metabolic Syndrome study. Adipokine leptin and adiponectin were measured using enzyme-linked immunosorbent assay. Odds ratio of MS per 1 z-score of adipokine was examined using logistic regression. Diagnosis accuracy was assessed using c-statistics (AUC) and net reclassification index. RESULTS: The levels of leptin and L/A increased with number of positive MS components, while the levels of adiponectin declined in both boys and girls (all P <0.001). AUCs for diagnosis of MS in girls were 0.793, 0.773, and 0.689 using L/A, leptin and adiponectin, respectively; and AUCs in boys were 0.822, 0.798, and 0.697 for L/A, leptin and adiponectin, respectively. Notably, L/A outperformed individual leptin or adiponectin in discriminating a diagnosis of MS (all P < 0.02 in AUC comparisons). In addition, the optimal cut-offs of L/A by ROC curve differed by genders and pubertal stages, which were 1.63, 1.28, 1.95 and 1.53 ng/ug for total, pre-, mid- and postpubertal boys, respectively and 2.19, 0.87,1.48 and 2.27 ng/ug for total, pre-, mid- and postpubertal girls, respectively, yielding high sensitivity and moderate specificity for a screening test. CONCLUSIONS: In this pediatric population, leptin-adiponectin imbalance, as reflected by an increase in L/A level, was found to be a better diagnostic biomarker for MS than leptin or adiponectin alone. Future longitudinal studies are needed to further validate the gender-specific cutoff values.