Magnetic Resonance Imaging to Assess Body Composition Change in Adolescents With Obesity After Sleeve Gastrectomy.

OBJECTIVES: Metabolic and bariatric surgery is the most effective weight loss treatment for severe obesity. The number of adolescents undergoing sleeve gastrectomy is increasing. We investigated changes in body composition in adolescents undergoing sleeve gastrectomy 12-26 weeks post-operatively using whole-body magnetic resonance imaging (WB-MRI). METHODS: This prospective cohort study assessed changes in adipose tissue compartments (ie, visceral, subcutaneous, and intermuscular) and muscle in 18 obese adolescents, ages 14-19, 89% female, with body mass index z -score of 2.6 ± 0.25 (range 2.16-3.2). All underwent WB-MRI 1.5-17 weeks pre-operatively and 12-26 weeks post-operatively. RESULTS: Pre- and post-operative WB-MRI showed decreases in all adipose tissue compartments, as well as decreased skeletal muscle and liver fat fraction ( P < 0.0001). The post-operative percentage loss of adipose tissue in subcutaneous, visceral, and intermuscular compartments (89.0%, 5.8%, 5.2%, respectively) was similar to the pre-operative percentages of corresponding adipose tissue compartments (90.5%, 5.0%, 4.5%, respectively). Of note, participants with obstructive sleep apnea had significantly higher pre-operative volume of subcutaneous and intermuscular adipose tissue than participants without obstructive sleep apnea ( P = 0.003). CONCLUSIONS: We found, contrary to what is reported to occur in adults, that pre-operative percentage loss of adipose tissue in subcutaneous, visceral, and intermuscular compartments was similar to the post-operative percentage loss of corresponding adipose tissue compartments in adolescents 12-26 weeks after sleeve gastrectomy.

Response to Long-term Vitamin D Therapy for Bone Disease in Children With Sickle Cell Disease.

Patients with sickle cell disease (SCD) are at risk for bone fragility from multiple factors including vitamin D deficiency. To date, no studies have evaluated the efficacy and safety of long-term vitamin D therapy for bone disease in children with SCD. We report a cohort of 4 children with SCD found to have severe vitamin D deficiency, secondary hyperparathyroidism, and abnormal bone mineral density treated with monthly high-dose oral cholecalciferol over 2 years. All patients exhibited a positive response to therapy without hypervitaminosis D or hypercalcemia. Further studies are needed to standardize guidelines for optimal vitamin D dosing and prevention of toxicity.

Complexities of Care in Klinefelter Syndrome: An APRN Perspective.

47,XXY (Klinefelter Syndrome) is associated with a spectrum of complex clinical needs that are associated with variable physical, neurocognitive and psychosocial aspects. For patients and families affected by this sex chromosome trisomy, navigation of health care services is difficult due to lack of 47,XXY awareness among many health care providers and little evidence to support endocrine and additional treatment plans. While endocrine management of androgen deficiency has been the mainstay of treatment for patients from puberty through adulthood, testosterone replacement, alone, fails to mitigate many symptoms and issues. Prior to the onset of puberty, boys with 47,XXY often do not receive interdisciplinary evaluations and treatment. Since multiple health and ancillary therapeutic services are required for the management of 47,XXY, patients and families often experience disjointed and uncoordinated care. We discuss complexities of caring for patients with 47,XXY and the benefit of integrating advanced practice nursing and medical perspectives to improve care delivery.

Phenotype and Adverse Quality of Life in Boys with Klinefelter Syndrome.

OBJECTIVES: To characterize associations among psychosocial well-being, physical phenotype, and sex hormones in a sample of youth with Klinefelter syndrome (KS). We hypothesized that KS physical traits (phenotype) are associated with adverse psychosocial health measures and that testosterone levels are associated with adverse psychosocial health. STUDY DESIGN: Forty-three boys with KS (ages 8-18 years) participated in a cross-sectional study. Participants underwent physical examination, hormone analyses, and psychosocial health questionnaires. RESULTS: Using an investigator-developed Klinefelter Phenotype Index Scale, the number of KS physical traits ranged from 1-13 (mean 5.1 ± 1.9). Pubertal boys presented with more KS traits compared with prepubertal boys (5.6 vs 4.2, P = .01). Boys diagnosed prenatally had a milder phenotype compared with those diagnosed postnatally. Gonadotropins were elevated without androgen deficiency in 45%. Psychosocial health scores indicated adverse quality of life (QOL) (67%), low self-esteem (38%), poor self-concept (26%), and risk for depression (16%) without a difference between pubertal groups. Linear regression showed that 22% of the variance in QOL (P = .0001) was explained by phenotype. Testosterone level was not associated with psychosocial health measures. CONCLUSIONS: Depending on the degree of phenotypic abnormality, boys with KS may be at risk for impaired QOL. Testosterone levels were not shown to influence psychosocial health. The Klinefelter Phenotype Index Scale may be a useful tool to characterize KS features in boys.

Autoimmune thyroid disease following alemtuzumab therapy and hematopoietic cell transplantation in pediatric patients with sickle cell disease.

Allogenic hematopoietic cell transplantation (alloHCT) is currently the only curative treatment option for patients with sickle cell disease. Alemtuzumab is a monoclonal antibody directed against CD52 positive cells used in myeloablative conditioning regimens for alloHCT. Its use has been associated with development of autoimmune disease in adult patients with rheumatologic conditions. We report on three cases of new onset autoimmune thyroid disease after alloHCT treatment with alemtuzumab in pediatric patients with sickle cell disease.

Using information technology and social networking for recruitment of research participants: experience from an exploratory study of pediatric Klinefelter syndrome.

BACKGROUND: Recruiting pediatric samples for research may be challenging due to parental mistrust of the research process, privacy concerns, and family time constraints. Recruitment of children with chronic and genetic conditions may further complicate the enrollment process. OBJECTIVE: In this paper, we describe the methodological challenges of recruiting children for research and provide an exemplar of how the use of information technology (IT) strategies with social networking may improve access to difficult-to-reach pediatric research participants. METHODS: We conducted a cross-sectional descriptive study of boys between the ages of 8 and 18 years with Klinefelter syndrome. This study presented unique challenges for recruitment of pediatric participants. These challenges are illustrated by the report of recruitment activities developed for the study. We reviewed the literature to explore the issues of recruiting children for research using conventional and IT approaches. Success rates of conventional recruitment approaches, such as brochures, flyers in medical offices, and physician referrals, are compared with IT-based outreach. The IT approaches included teleconferencing via a Klinefelter syndrome support group, services of a Web-based commercial recruitment-matching company, and the development of a university-affiliated research recruitment website with the use of paid advertising on a social networking website (Facebook). RESULTS: Over a 3-month period, dissemination of over 150 recruitment brochures and flyers placed in a large urban hospital and hospital-affiliated clinical offices, with 850 letters to physicians and patients were not successful. Within the same period, face-to-face recruitment in the clinical setting yielded 4 (9%) participants. Using Web-based and social networking approaches, 39 (91%) agreed to participate in the study. With these approaches, 5 (12%) were recruited from the national Klinefelter syndrome advocacy group, 8 (19%) from local and teleconference support groups, 10 (23%) from a Web-based research recruitment program, and 16 (37%) from the university-affiliated recruitment website. For the initial 6 months, the university website was viewed approximately 2 to 3 times per day on average. An advertisement placed on a social networking site for 1 week increased website viewing to approximately 63 visits per day. Out of 112 families approached using all of these methods, 43 (38%) agreed to participate. Families who declined cited either travel distance to the study site (15, 22%) or unwillingness to disclose the Klinefelter syndrome diagnosis to their sons (54, 78%) as the reasons for nonparticipation. CONCLUSIONS: Use of Web-based technologies enhances the recruitment of difficult-to-reach populations. Of the many approaches employed in this study, the university-affiliated recruitment website supported by a Facebook advertisement appeared to be the most successful. Research grant budgets should include expenses for website registration and maintenance fees as well as online advertisements on social networking websites. Tracking of recruitment referral sources may be helpful in planning future recruitment campaigns.

Childhood Obesity, Diabetes. and Cardiovascular Disease Risk.

This mini-review aims to briefly summarize the pathophysiology of childhood obesity, type 2 diabetes mellitus (T2DM), and cardiovascular disease (CVD) risk in children and adolescents. Recent data on efficacy of lifestyle interventions, medications, and metabolic surgery for obesity, T2DM, and CVD risk factors are also reviewed. We conducted a PubMed search of English-language original and review articles relevant to childhood obesity, T2DM, and CVD risk factors, and biomarkers in children with an emphasis on recent publications. Childhood obesity arises from an intricate interaction between genetic, physiologic, environmental, and socioeconomic factors. The rise in the prevalence of childhood obesity is associated with the development of comorbidities including T2DM and CVD at an early age. A multipronged approach is central to the detection, monitoring, and management of childhood obesity and associated adverse metabolic consequences.

The Relationship Between Metabolic Comorbidities and Post-surgical Weight Loss Outcomes in Adolescents Undergoing Laparoscopic Sleeve Gastrectomy.

BACKGROUND: Little is known about the relationship between metabolic factors and weight loss success in adolescents undergoing bariatric surgery. METHODS: The objective of this study was to assess if baseline metabolic characteristics associate with weight loss in adolescents undergoing laparoscopic sleeve gastrectomy. A retrospective study was conducted in a comprehensive adolescent bariatric surgery center of 151 subjects (34 male, 117 female). Anthropometric measurements and metabolic factors including blood pressure, fasting glucose, HbA1c, Metabolic Syndrome (MeS), liver function, triglycerides, and waist circumference were collected at one pre-surgical visit, and at 6 and/or 12 months post-laparoscopic sleeve gastrectomy. Weight loss was compared between subjects with normal or abnormal baseline metabolic factors. Absolute BMI change was used to measure successful weight loss. RESULTS: Higher baseline systolic blood pressure (SBP) was associated with greater weight loss as measured by body mass index (BMI) change and BMI standard deviation score (BMI-SDS) change at 6 and 12 months. Those patients in the 6-month follow up group with an abnormal hemoglobin A1C (HbA1c) at baseline had significantly more weight loss as measured by BMI-SDS. None of the other parameters, including fasting glucose, Metabolic Syndrome (MeS), liver function, triglycerides and waist circumference showed a predictive relationship. DISCUSSION/CONCLUSION: Elevated SBP and HbA1c in adolescents with morbid obesity may reflect a population more likely to achieve successful weight loss, and thus, may be a good target for bariatric surgery, specifically laparoscopic sleeve gastrectomy, as an intervention for severe obesity. An assessment of behavioral differences in patients with and without elevated BP and HbA1c might explain the mechanism for the improved weight loss.

Predicted loss of function alleles in Bassoon (BSN) are associated with obesity.

Bassoon ( BSN ) is a component of a hetero-dimeric presynaptic cytomatrix protein that orchestrates neurotransmitter release with Piccolo ( PCLO ) from glutamatergic neurons throughout the brain. Heterozygous missense variants in BSN have previously been associated with neurodegenerative disorders in humans. We performed an exome-wide association analysis of ultra-rare variants in about 140,000 unrelated individuals from the UK Biobank to search for new genes associated with obesity. We found that rare heterozygous predicted loss of function (pLoF) variants in BSN are associated with higher BMI with log10-p value of 11.78 in the UK biobank cohort. The association was replicated in the All of Us whole genome sequencing data. Additionally, we have identified two individuals (one of whom has a de novo variant) with a heterozygous pLoF variant in a cohort of early onset or extreme obesity at Columbia University. Like the individuals identified in the UKBB and All of us Cohorts, these individuals have no history of neurobehavioral or cognitive disability. Heterozygosity for pLoF BSN variants constitutes a new etiology for obesity.

Weight Loss After Laparoscopic Sleeve Gastrectomy in Children and Adolescents.

PURPOSE: For children and adolescents with severe obesity, metabolic and bariatric surgery including laparoscopic sleeve gastrectomy (LSG) is increasingly used to facilitate weight loss and reduce associated medical problems. Outcomes of LSG are understudied among patients under age 15 years. We sought to examine surgical complications and weight loss outcomes among children and adolescents who underwent LSG. MATERIALS AND METHODS: This is a single-center retrospective cohort analysis at a high-volume metropolitan children's hospital in the northeast USA between 2011 and 2021. Weight loss was assessed at routine follow-up appointments for up to 36 months postoperatively. RESULTS: There were 12 patients under 13 years of age (< 13), 45 from 13 up to 15 years of age (13-14), and 57 patients aged 15 years or over (≥ 15). Among all patients, 70% were female, 41% were Hispanic, and 18% were non-Hispanic Black. There were no operative mortalities. Two patients had surgical complications requiring reoperation. Follow-up beyond 6 months occurred for 62% of patients. Weight loss was evident for each group at all time points, and there was no statistically significant difference among groups at any time point. BMI Z-score reduction at 6 months was 1.53 for the < 13 group, 0.89 for the 13-14 group, and 0.86 for the ≥ 15 group and at 36 months was 1.79, 1.50, and 1.16, respectively. CONCLUSION: These results support that LSG is a safe and effective method of achieving weight loss for young adolescents with severe obesity. Strategies to promote postoperative follow-up are needed.

Rare predicted loss of function alleles in Bassoon (BSN) are associated with obesity.

Bassoon (BSN) is a component of a hetero-dimeric presynaptic cytomatrix protein that orchestrates neurotransmitter release with Piccolo (PCLO) from glutamatergic neurons throughout the brain. Heterozygous missense variants in BSN have previously been associated with neurodegenerative disorders in humans. We performed an exome-wide association analysis of ultra-rare variants in about 140,000 unrelated individuals from the UK Biobank to search for new genes associated with obesity. We found that rare heterozygous predicted loss of function (pLoF) variants in BSN are associated with higher BMI with p-value of 3.6e-12 in the UK biobank cohort. Additionally, we identified two individuals (one of whom has a de novo variant) with a heterozygous pLoF variant in a cohort of early onset or extreme obesity and report the clinical histories of these individuals with non-syndromic obesity with no history of neurobehavioral or cognitive disability. The BMI association was replicated in the All of Us whole genome sequencing data. Heterozygous pLoF BSN variants constitute a new etiology for obesity.

The History of Obesity Research.

Perhaps the most unexpected development in pediatric endocrinology in the past 50 years has been the recognition of obesity as an endocrine/metabolic disorder rather than a life choice or moral failing. The history of obesity research is disjointed, having followed two separate paths in the 20th century, based on two independent yet overlapping paradigms. Proponents of the "Energy Storage" hypothesis point to data implicating monogenetic disorders, the ventromedial hypothalamus, insulin, cortisol, and the adipocyte itself in the pathogenesis of obesity. Alternatively, proponents of the "Energy Balance" hypothesis point to data implicating increased caloric intake, decreased caloric expenditure, gastrointestinal hormones, and microbiome changes as being critical for obesity. These two separate lines of research merged somewhat with the discovery of leptin in 1994, as leptin established a major hormonal role in weight control. Leptin has explained some of the dichotomy and has proved essential in understanding the importance of developmental programming and epigenetics. However, the mystery of leptin resistance remains unsolved. Despite all our collective knowledge, we appear no closer in solving the obesity puzzle today than we were 50 years ago.

Data assimilation on mechanistic models of glucose metabolism predicts glycemic states in adolescents following bariatric surgery.

Type 2 diabetes mellitus is a complex and under-treated disorder closely intertwined with obesity. Adolescents with severe obesity and type 2 diabetes have a more aggressive disease compared to adults, with a rapid decline in pancreatic ß cell function and increased incidence of comorbidities. Given the relative paucity of pharmacotherapies, bariatric surgery has become increasingly used as a therapeutic option. However, subsets of this population have sub-optimal outcomes with either inadequate weight loss or little improvement in disease. Predicting which patients will benefit from surgery is a difficult task and detailed physiological characteristics of patients who do not respond to treatment are generally unknown. Identifying physiological predictors of surgical response therefore has the potential to reveal both novel phenotypes of disease as well as therapeutic targets. We leverage data assimilation paired with mechanistic models of glucose metabolism to estimate pre-operative physiological states of bariatric surgery patients, thereby identifying latent phenotypes of impaired glucose metabolism. Specifically, maximal insulin secretion capacity, σ, and insulin sensitivity, SI, differentiate aberrations in glucose metabolism underlying an individual's disease. Using multivariable logistic regression, we combine clinical data with data assimilation to predict post-operative glycemic outcomes at 12 months. Models using data assimilation sans insulin had comparable performance to models using oral glucose tolerance test glucose and insulin. Our best performing models used data assimilation and had an area under the receiver operating characteristic curve of 0.77 (95% confidence interval 0.7665, 0.7734) and mean average precision of 0.6258 (0.6206, 0.6311). We show that data assimilation extracts knowledge from mechanistic models of glucose metabolism to infer future glycemic states from limited clinical data. This method can provide a pathway to predict long-term, post-surgical glycemic states by estimating the contributions of insulin resistance and limitations of insulin secretion to pre-operative glucose metabolism.

Fasting Serum IGFBP-1 as a Marker of Insulin Resistance in Diverse School Age Groups.

Introduction: The known markers of insulin resistance in obese children are well studied. However, they require serial measurements and complicated calculations. The objective is to study IGFBP-1 and its relation with other known risk measures. Materials and Methods: The study included 98 New York City school students of diverse ethnic/racial backgrounds (57 males and 41 females), 11-15 years of age. Subjects were enrolled in a cross-sectional study, and anthropometric measures were collected. They underwent fasting intravenous glucose tolerance tests (IVGTT), and glucose, insulin, lipids, IGFBP-1, adiponectin and inflammatory markers were collected. Results: The subjects were stratified into 3 groups based upon the BMI Z-score. Out of all the subjects, 65.3% were in the group with a BMI Z-score <1 SDS, 16.3% subjects were in the group with a BMI Z-score of 1 to 2 SDS, and 18.4% of the subjects were in the group with a BMI Z-score of more than 2 SDS. The group with a BMI Z-score of more than 2 SDS had increased waist circumference (WC), body fat, increased fasting insulin, and triglycerides (TG). This group had decreased levels of adiponectin and HDL and low IGFBP-1 as compared to the group with BMI <1 SDS. The group with a BMI Z-score of 1 to 2 SDS had a decreased level of IGFBP-1 as compared to the group with a BMI Z-score less than 1 SDS. IGFBP-1 inversely correlated with age, WC, BMI, body fat, TG, and insulin levels. IGFBP-1 positively correlated with adiponectin and HDL levels. Conclusion: IGFBP-1 in children can identify the presence of insulin resistance in the group with BMI 1 to 2 SDS, even before the known markers of insulin resistance such as elevated triglycerides and even before decreased HDL and adiponectin levels are identified.

Testosterone and the child (0-12 years) with Klinefelter syndrome (47XXY): a review.

AIM: To review the evidence base for providing testosterone therapy in the infant and prepubertal child with Klinefelter syndrome (KS). METHODS: Major databases were searched to identify articles that addressed the role of testosterone in the development of the male foetus with and without KS and that characterized testicular function in infants with KS. RESULTS: Infants with KS have been shown to have an increased frequency of clinical features consistent with deficient testosterone production. However, there are conflicting results regarding whether testosterone levels are low or normal. No direct data address the outcome of therapy in the prepubertal child. CONCLUSION: There is an absence of data that directly address the risks and benefits of testosterone therapy in prepubertal children with KS outside of the entity of microphallus. At this time, there is no other documented benefit for testosterone therapy in these children.

Clinical and hormonal status of infants with nonmosaic XXY karyotype.

AIM: To compare our recent findings in a cohort of 77 nonmosaic XXY infants <2 years of age with clinical and biological features already reported. RESULTS: The majority of reported XXY neonates had normal external genitalia. Only undescended testes and/or micropenis were identified reasons for referral. Delayed ambulation and speech skills were also indications for postnatally karyotyping. All subjects from our cohort (73 prenatally detected subjects, five postnatal diagnoses) had height and weight within the normal range, and were not dysmorphic. Insulin-like-peptide-3 and testosterone secretion by Leydig cells appeared normally sensitive to luteinizing hormone. In reported studies, inhibin B levels were within normal range, anti-Mullerian hormone levels were normal or high and follicle-stimulating hormone (FSH) levels were significantly higher than control values, data consistent with a relative resistance to FSH. CONCLUSION: Early detection of Klinefelter syndrome is desirable for prospectively monitoring the apparition of developmental problems and the progressive decline in the tubular function of the testis, with the hope of designing future conservative interventions before germ cell degeneration is completed.

Retinol binding protein 4 is associated with adiposity-related co-morbidity risk factors in children.

OBJECTIVE: In adults, elevated levels of retinol binding protein 4 (RBP4) have been associated with biochemical markers of adiposity-related co-morbidities including insulin resistance, dyslipidemia, hypertension, and abdominal obesity. This study examined the relationship between RBP4 and risk factors for co-morbidities of adiposity in a population of ethnically diverse children in early- to mid-adolescence in the public school system of New York City. MATERIALS/METHODS: We analyzed anthropometric (body mass index, % body fat, waist circumference), metabolic (lipids, glucose), and inflammatory (TNF-alpha, interleukin-6, C-reactive protein, adiponectin) markers for adiposity-related co-morbidities and serum alanine aminotransferase (ALT) in 106 school children (65 males, 41 females) 11-15 years of age (mean +/- SD = 13.0 +/- 0.1 years) who were enrolled in the Reduce Obesity and Diabetes (ROAD) project. Insulin sensitivity was assessed by quantitative insulin sensitivity check index. Insulin secretory capacity was measured as acute insulin response and glucose disposal index. RESULTS: Serum RBP4 was significantly correlated directly with ALT, triglycerides, and triglyceride z-score, and inversely correlated with adiponectin. Correlations with ALT and adiponectin remained significant when corrected for % body fat, age, and gender. There were significant ethnic differences in the relationship of RBP4 to ALT, glucose disposal index and adiponectin. CONCLUSIONS: In early- to mid-adolescents, circulating concentrations of RBP4 are correlated with multiple risk factors for adiposity-related co-morbidities. The observation that many associations persisted when corrected for % body fat, suggests that RBP4 can be viewed as an independent marker of adiposity-related co-morbidity risk in children.

The Prevalence of Co-morbidities in Adult and Adolescent Bariatric Surgery Candidates.

Severe obesity is often associated with co-morbid conditions such as diabetes mellitus, hypertension, and obstructive sleep apnea. Successful weight loss can result in remission of these conditions. The authors retrospectively examined the co-morbidity profiles of pre-operative gastric sleeve adult patients from the MBSAQIP database with subjects from our adolescent bariatric program. Five conditions were compared: hypertension (HTN), type 2 diabetes mellitus (T2DM), dyslipidemia (DL), obstructive sleep apnea (OSA), and gastroesophageal reflux disease (GERD). Patients were matched by gender and body mass index (BMI). The prevalence of each condition was statistically more significant in the adult cohort. Successful weight loss at an earlier age may reduce the prevalence of these co-morbid conditions.

Clinical variability and novel neurodevelopmental findings in 49, XXXXY syndrome.

49, XXXXY is a rare chromosomal syndrome due to double nondisjunction of the replicating X chromosome. Considered a severe variant of XXY or Klinefelter syndrome, boys with this chromosome constitution are assumed to have severe mental retardation (MR) in addition to craniofacial, genital, endocrine, and heart abnormalities. Here, we present a multidisciplinary analysis including the clinical and neurobehavioral aspects of this condition in 20 boys with 49, XXXXY who share a common phenotype and neurobehavioral profile. The phenotypic presentation of the boys with 49, XXXXY shares some characteristics with 47, XXY, but there are also other unique and distinctive features. Previously unappreciated intact nonverbal skills are evident in conjunction with moderate to severe developmental dyspraxia. Variability in clinical and cognitive functioning may reflect skewed X inactivation, mosaicism, or other factors that warrant further investigation.

The effects of adolescent laparoscopic adjustable gastric band and sleeve gastrectomy on markers of bone health and bone turnover.

25-hydroxy vitamin D (25 OHD) deficiency and secondary hyperparathyroidism have been seen after metabolic and bariatric surgery, but data are lacking on the bone health outcomes of adolescent sleeve gastrectomy (SG). The purpose of this study was to examine bone-related nutrition after SG, compared to laparoscopic adjustable gastric band (LAGB), and trend bone turnover markers following SG. This is an observational study of 197 adolescents who underwent LAGB (n = 98) or SG (n = 99). Bone health labs were collected at baseline and 6 and/or 12 months after LAGB or SG, with additional analysis of bone turnover markers in the SG group. Calcium and 25 OHD levels increased at 6 and 12 months after LAGB and SG, with no difference between the surgeries. Parathyroid hormone levels decreased only in the SG group. SG patients had increased osteocalcin and carboxy-terminal cross-linking telopeptide of type 1 collagen (CTX) at 6 and 12 months post-SG, although CTX decreased between 6 and 12 months. Excess weight loss at 6 months predicted the rise in CTX, but the changes in osteocalcin and CTX could not be attributed to 25 OHD deficiency, hypocalcemia or hyperparathyroidism. Patients had improved 25 OHD levels post-surgery, which may be secondary to stringent vitamin supplementation guidelines. However, there were marked increases in bone turnover markers following SG. More studies are needed to evaluate the effects of SG on adolescent bone health and to correlate the early changes in bone turnover with bone mineral density and fracture risk.