Bone and muscle differences in children and adolescents with type 1 diabetes: The mediating role of physical activity.

Children with type 1 diabetes (T1D) experience an increased risk of fracture, which may be related to altered bone development. We aimed to assess differences in bone, muscle and physical activity (PA), and explore if better muscle and PA measures would mitigate bone differences between children and adolescents with T1D and typically developing peers (TDP). We matched 56 children and adolescents with T1D (mean age 11.9 yrs) and 56 TDP (11.5 yrs) by sex and maturity from 171 participants with T1D and 66 TDP (6-17 yrs). We assessed the distal radius and tibia with high-resolution peripheral quantitative computed tomography (HR-pQCT), and the radius and tibia shaft bone and muscle with pQCT. We also measured muscle function from force-related measures in neuromuscular performance tests (push-up, grip test, countermovement and long jump). We compared PA based on questionnaire scores and accelerometers between groups. Bone, muscle, and neuromuscular performance measures were compared using MANOVA. We used mediation to explore the role of PA and muscle in bone differences. Children and adolescents with T1D had 6-10 % lower trabecular density, bone volume fraction, thickness and number at both distal radius and tibia, and 11 % higher trabecular separation at the distal radius than TDP. They also had 3-16 % higher cortical and tissue mineral density, and cortical thickness at the distal radius, 5-7 % higher cortical density and 1-3 % higher muscle density at both shaft sites compared to TDP. PA mediated the between-group difference in trabecular number (indirect effect -0.04) at the distal radius. Children and adolescents with T1D had lower trabecular bone density and deficits in trabecular micro-architecture, but higher cortical bone density and thickness at the radius and tibia compared to TDP. They engaged in less PA but had comparable muscle measures to those of TDP. PA participation may assist in mitigating deficit in trabecular number observed in children and adolescents with T1D.

Type 1 diabetes management responsibilities between adolescents with T1D and their parents: An integrative review.

PURPOSE: Diabetes self-management for adolescents with type 1 diabetes (T1D) is a complex and multifaceted process that requires careful consideration of a supportive or shared approach to care. The purpose of this review was to synthesize the qualitative and quantitative evidence regarding the nature of adolescent-parent interactions and relationships in the context of T1D management. Of particular interest was the role of interdependence in this relationship. METHODS: An integrative review of the literature was conducted between January 2021 and April 2021 using Whittemore and Knafl's (2005) methodological strategies. RESULTS: Eleven studies published between 2003 and 2018 met the review criteria. Thematic analysis identified the following three themes related to parent-adolescent relationships in care including the Effectiveness of Parental Involvement and T1D Management, Shared Responsibility and T1D Task Management, and Gaining Independence in T1D Management. This review highlights the importance of both parent and adolescent shared involvement in T1D management. In particular, parental involvement appears necessary for improved glycemic control, better adherence to the T1D management regime, and for practicing self-management in adolescents with T1D. PRACTICE IMPLICATIONS: Better understanding of the parent-child interaction in diabetes care will provide important information to aid family nurses to identify, support, and help maintain the sharing of T1D management responsibilities between parents and their adolescents.

Managing the unmanageable through interdependence in adolescents living with type 1 diabetes and their parents: A constructivist grounded theory.

BACKGROUND: Management of T1D is complex and requires continuous care and monitoring that place many demands on adolescents with T1D and their parents. The purpose of this study was to explore the nature of interdependence with T1D management with adolescents and their parents. METHODS: Using a constructivist grounded theory methodology, 32 open-ended interviews were conducted, transcribed, and analyzed from 11 adolescents aged 10-18 years with T1D and eight parents. FINDINGS: The data were coded using three coding phases: initial, focused, and theroetical and this process continued until theroetical saturation was reached. The substantive theory that emerged from the data describing parents' and adolescents' main concern of Maintaining Optimal Glycemic Control was Managing the Unmanageable through Interdependence. Four related subprocesses were found: Completing T1D Tasks, Attaining Support, Balancing Independence, and Reconciling Reality. These subprocesses occurred within the context of the ever-changing, Nature of the Illness. DISCUSSION: There is a dynamic relationship associated with interdependence between adolescents with T1D and their parents that varied situationally and by age. Participants also indicated interdependence occurs or they would like it to occur, with others beyond themselves and the health-care team to others willing to be involved. APPLICATION TO PRACTICE: Interdependence is a dynamic process and requires ongoing evaluation by health-care professionals of its function in the daily management of T1D by parents and adolescents. Additional research into of the roles of health professionals and others in promoting interdependence is needed.

CYP24A1 and SLC34A1 Pathogenic Variants Are Uncommon in a Canadian Cohort of Children with Hypercalcemia or Hypercalciuria.

OBJECTIVES: Biallelic pathogenic variants in CYPA24A1 and SLC34A1 are causes of idiopathic infantile hypercalcemia. Pathogenic variants in both may also give rise to hypercalciuria with nephrocalcinosis or nephrolithiasis without previous hypercalcemia (renal group). Our objective was to examine the frequency of CYP24A1 or SLC34A1 variants in children with early hypercalcemia or late-onset hypercalciuria. METHOD: Forty-one children from 7 centers across Canada were recruited. Local investigations were undertaken. The serum was evaluated by liquid chromatography tandem-mass spectrometry for the ratio of 25-hydroxyvitamin D3 to 24,25-dihydroxyvitamin D3, (25-OH-D3:24,25-(OH)2D3), an elevation pathognomonic for the loss of function of the CYP24A1 enzyme. Mutational analyses were undertaken. Family cascade screening was performed if pathogenic variants were detected in probands. RESULTS: Twenty-nine children had early-onset hypercalcemia; none had elevated 25-OH-D3:24,25-(OH)2D3 or variants. Interestingly, 2 of 12 in the renal group had elevated 25-OH-D3:24,25-(OH)2D3 and presented as preadolescents. In case 1, cascade testing revealed a sibling and parent with asymptomatic pathogenic variants in CYP24A1. Four CYP24A1 pathogenic variants were identified in these 2 probands: 3 have been described in European populations, and 1 is a rare variant in exon 7 (c931delC) that is likely pathogenic. No SLC34A1 pathogenic variants were detected. CONCLUSION: In Canada, pathogenic variants in CYP24A1 appear to manifest with late-onset hypercalciuria and its sequelae. The 25-OH-D3:24,25-(OH)2D3 ratio is an excellent tool for screening for biallelic pathogenic variants in CYP24A1. We confirm that cascade testing is important for these variants.

Perioperative care of congenital adrenal hyperplasia - a disparity of physician practices in Canada.

BACKGROUND: Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is the most common cause of primary adrenal insufficiency in children. Current guidelines recommend the use of perioperative stress dose (supraphysiologic) glucocorticoids for children with CAH undergoing anesthesia, although a perceived difference in practice patterns among Canadian pediatric subspecialists prompted an assessment of perioperative glucocorticoid administration. METHODS: We performed a cross-sectional survey of Canadian Pediatric Anesthesia Society (CPAS) and Canadian Pediatric Endocrine Group (CPEG) members via membership email lists to assess reported practice patterns to select clinical scenarios. RESULTS: Responses were collected from 49 anesthesiologists and 37 pediatric endocrinologists. Less than half of anesthesiologists reported they would provide stress dose corticosteroids for patients undergoing cystoscopy while a significant majority of pediatric endocrinologists reported they would recommend stress dose corticosteroid administration (45% vs 92% respectively, p < 0.0001). Twenty-one percent of anesthesiologists reported they would not provide stress dose corticosteroids for patients undergoing laparotomy. Pediatric endocrinologists reported they were more likely to refer to guidelines for management of stress dose steroids (84% vs 51%, p < 0.001), with many Canadian pediatric endocrinologists reporting to use institution specific guidelines. CONCLUSIONS: Our results demonstrate a clear difference in the reported approach to perioperative stress dose steroids between pediatric anesthesiologists and pediatric endocrinologists which may impact patient care. Further dialogue is required to address this apparent discrepancy in practice patterns and future research is needed to provide evidence-based practice recommendations.

Insulin-mediated pseudoacromegaly: a report of two pediatric patients.

BACKGROUND: Insulin-mediated pseudoacromegaly is a rarely described pediatric phenotype. We present two patients displaying excessive growth associated with marked acanthosis nigricans, hyperinsulinemia and metabolic dysregulation. CASE PRESENTATION: Both patients, of First Nations descent, presented with excessive growth - patient one at 3.92 years (height z-score +3.75) and patient two at 9.0 years (height z-score 5.15). Insulin-like growth factor-1 (IGF-1) levels were normal with appropriate growth hormone suppression, yet marked hyperinsulinemia. Prepubescent growth velocities exceeded 9 cm/year, resulting in final adult height predictions exceeding 3 standard deviations (SDs) of predicted. Clinical courses were complicated by type 2 diabetes, marked acanthosis nigricans and long-standing psychosocial distress. CONCLUSIONS: Pediatric patients with insulin-mediated pseudoacromegaly are at risk of significant physical, metabolic and psychosocial comorbidities. Unlike adults, the implications in childhood prompt consideration for therapies to decelerate linear growth and avert progression to metabolic dysregulation. Increased recognition of this condition may improve pathophysiological understanding, diagnostic criteria and therapeutic options.

Clinical, genetic, and structural basis of congenital adrenal hyperplasia due to 11ß-hydroxylase deficiency.

Congenital adrenal hyperplasia (CAH), resulting from mutations in CYP11B1, a gene encoding 11ß-hydroxylase, represents a rare autosomal recessive Mendelian disorder of aberrant sex steroid production. Unlike CAH caused by 21-hydroxylase deficiency, the disease is far more common in the Middle East and North Africa, where consanguinity is common often resulting in identical mutations. Clinically, affected female newborns are profoundly virilized (Prader score of 4/5), and both genders display significantly advanced bone ages and are oftentimes hypertensive. We find that 11-deoxycortisol, not frequently measured, is the most robust biochemical marker for diagnosing 11ß-hydroxylase deficiency. Finally, computational modeling of 25 missense mutations of CYP11B1 revealed that specific modifications in the heme-binding (R374W and R448C) or substrate-binding (W116C) site of 11ß-hydroxylase, or alterations in its stability (L299P and G267S), may predict severe disease. Thus, we report clinical, genetic, hormonal, and structural effects of CYP11B1 gene mutations in the largest international cohort of 108 patients with steroid 11ß-hydroxylase deficiency CAH.

Anterior Hypopituitarism and Treatment Response in Hunter Syndrome: A Comparison of Two Patients.

Hypopituitarism is a clinically important diagnosis and has not previously been reported in Hunter syndrome. We contrast two cases with anatomic pituitary anomalies: one with anterior panhypopituitarism and the other with intact pituitary function. Patient 1, a 10-year-old boy with Hunter syndrome, was evaluated for poor growth and an ectopic posterior pituitary gland. Endocrine testing revealed growth hormone (GH) deficiency, secondary adrenal insufficiency, and tertiary hypothyroidism. An improvement in growth velocity with hormone replacement (GH, thyroxine, and corticosteroid) was seen; however, final adult height remained compromised. Patient 2, a 13-year-old male with Hunter syndrome, was evaluated for growth failure. He had a large empty sella turcica with posteriorly displaced pituitary. Functional endocrine testing was normal and a trial of GH-treatment yielded no significant effect. Panhypopituitarism associated with pituitary anomalies has not been previously reported in Hunter syndrome and was an incidental finding of significant clinical importance. In the setting of documented anterior hypopituitarism, while hormone replacement improved growth velocity, final height remained impaired. In patient 2 with equivocal GH-testing results, treatment had no effect on linear growth. These cases highlight the importance of careful clinical assessment in Hunter syndrome and that judicious hormone replacement may be indicated in individual cases.

Impact of Growth Hormone on Adult Bone Quality in Turner Syndrome: A HR-pQCT Study.

Women with Turner syndrome (TS) are known to be at risk of osteoporosis. While childhood growth hormone (GH) treatment is common in TS, the impact of this therapy on bone health has been poorly understood. The objective of this study was to determine the influence of childhood GH treatment on adult bone quality in women with TS. 28 women aged 17-45 with confirmed TS (12 GH-treated) agreed to participate in this cross-sectional study. Dual X-ray absorptiometry (DXA) of lumbar spine, hip, and radius and high-resolution peripheral quantitative computed tomography (HR-pQCT) scans of the radius and tibia were used to determine standard morphological and micro-architectural parameters of bone health. Finite element (FE) analysis and polar moment of inertia (pMOI) were used to estimate bone strength. GH-treated subjects were +7.4 cm taller (95% CI 2.5-12.3 cm, p = 0.005). DXA-determined areal BMD of hip, spine, and radius was similar between treatment groups. Both tibial and radial total bone areas were greater among GH-treated subjects (+20.4 and +21.2% respectively, p < 0.05), while other micro-architectural results were not different between groups. pMOI was significantly greater among GH-treated subjects (radius +35.0%, tibia +34.0%, p < 0.05). Childhood GH treatment compared to no treatment in TS was associated with an increased height, larger bones, and greater pMOI, while no significant difference in DXA-derived BMD, HR-pQCT micro-architectural parameters, or FE-estimated bone strength was detected. The higher pMOI and greater bone size may confer benefit for fracture reduction in these GH-treated patients.

Height augmentation in 11ß-hydroxylase deficiency congenital adrenal hyperplasia.

CONTEXT: 11ß-hydroxylase deficiency is the second most common form of congenital adrenal hyperplasia. Untreated, this enzyme deficiency leads to virilization, hypertension, and significant height impairment. PATIENT: We describe a patient from abroad who first presented to us at age 7 years for follow-up of ambiguous genitalia. He had been investigated and treated in Pakistan at 3-years-of-age following presentation for bilateral cryptorchidism. He was found to have 46, XX karyotype, elevated 17-OH progesterone and was diagnosed with congenital adrenal hyperplasia. In Pakistan, the patient had abdominal hysterectomy, bilateral salpingoophrectomy, and was started on corticosteroid replacement. At 7 years, shortly after immigrating to Canada, height was 138 cm and BMI 19.3 kg/m(2) (+2.9 SDS and +1.7 SDS, respectively, male growth chart) and blood pressure was greater than the 99th percentile for age and height. The patient had Prader stage III - IV genital anatomy. Bone age was significantly advanced, yielding a severely compromised predicted final adult height. Biochemical evaluation was consistent with 11ß-hydroxylase deficiency congenital adrenal hyperplasia. INTERVENTION AND OUTCOME: In an attempt to improve final height, in addition to glucocorticoid replacement, this patient was treated with recombinant growth hormone and a third generation aromatase inhibitor (Letrozole) with an improvement in final height attained as compared with predicted height. CONCLUSIONS: This case of a 46,XX patient raised as male with congenital adrenal hyperplasia due to 11ß-hydroxylase deficiency highlights a number of unique and difficult treatment challenges; specifically, the role of new therapeutic options for optimization of growth in the context of prior suboptimal disease management.

Current concepts surrounding bone health and osteoporosis in Turner syndrome.

Although Turner syndrome is the most common chromosomal disorder in women, a great deal remains to be understood in terms of optimal patient care, particularly as it relates to bone health. These women are known to be at risk for osteoporosis and fracture later in life as a result of a multitude of risk factors. While estrogen replacement and childhood growth hormone treatment are now considered standard of care, little is known of the role of further interventions to prevent and treat osteoporosis in these women. This review aims to highlight the specifics of bone health in Turner syndrome. We explore the bone diagnostic modalities and therapeutic interventions available and their role in the coming years of bone health management in this unique population.