AimsTo synthesize evidence from randomized and non-randomized studies of physical activity interventions in children and young people with Type 1 diabetes so as to explore clinically relevant health outcomes and inform the promotion of physical activity.MethodWe conducted a search of CINAHL Plus, the Cochrane Library, EMBASE, MEDLINE, PsycINFO, SCOPUS, SportDiscus and Web of Science between October and December 2012. Eligible articles included subjects aged ≤18 years with Type 1 diabetes and a physical activity intervention that was more than a one-off activity session. Physiological, psychological, behavioural or social outcomes were those of interest.ResultsA total of 26 articles (10 randomized and 16 non-randomized studies), published in the period 1964–2012, were reviewed. Although there was heterogeneity in study design, methods and reporting, 23 articles reported at least one significant beneficial health outcome at follow-up. Meta-analyses of these studies showed potential benefits of physical activity on HbA1c (11 studies, 345 participants, standardized mean difference -0.52, 95% CI -0.97 to -0.07; P = 0.02), BMI (four studies, 195 participants, standardized mean difference -0.41, 95% CI -0.70 to -0.12; P = 0.006) and triglycerides (five studies, 206 participants, standardized mean difference -0.70, 95% CI -1.25 to -0.14; P = 0.01).The largest effect size was for total cholesterol (five studies, 206 participants, standardized mean difference -0.91, 95% CI -1.66 to -0.17; P = 0.02).ConclusionsPhysical activity is important for diabetes management and has the potential to delay cardiovascular disease, but there is a lack of studies that are underpinned by psychological behaviour change theory, promoting sustained physical activity and exploring psychological outcomes. There remains a lack of knowledge of how to promote physical activity in people with Type 1 diabetes.

ObjectiveTo determine accuracy, safety and acceptability of the FreeStyle Libre Flash Glucose Monitoring System in the paediatric population.Design, setting and patientsEighty-nine study participants, aged 4–17 years, with type 1 diabetes were enrolled across 9 diabetes centres in the UK. A factory calibrated sensor was inserted on the back of the upper arm and used for up to 14 days. Sensor glucose measurements were compared with capillary blood glucose (BG) measurements. Sensor results were masked to participants.ResultsClinical accuracy of sensor results versus BG results was demonstrated, with 83.8% of results in zone A and 99.4% of results in zones A and B of the consensus error grid. Overall mean absolute relative difference (MARD) was 13.9%. Sensor accuracy was unaffected by patient factors such as age, body weight, sex, method of insulin administration or time of use (day vs night). Participants were in the target glucose range (3.9–10.0 mmol/L) ∼50% of the time (mean 12.1 hours/day), with an average of 2.2 hours/day and 9.5 hours/day in hypoglycaemia and hyperglycaemia, respectively. Sensor application, wear/use of the device and comparison to self-monitoring of blood glucose were rated favourably by most participants/caregivers (84.3–100%). Five device related adverse events were reported across a range of participant ages.ConclusionsAccuracy, safety and user acceptability of the FreeStyle Libre System were demonstrated for the paediatric population. Accuracy of the system was unaffected by subject characteristics, making it suitable for a broad range of children and young people with diabetes.Trial registration numberNCT02388815.

Anthropometric data from three groups of adolescent girls - preoperative adolescent idiopathic scoliosis (AIS), screened for scoliosis and normals were analysed by comparing skeletal data between higher and lower body mass index subsets. Unexpected findings for each of skeletal maturation, asymmetries and overgrowth are not explained by prevailing theories of AIS pathogenesis. A speculative pathogenetic theory for girls is formulated after surveying evidence including: (1) the thoracospinal concept for right thoracic AIS in girls; (2) the new neuroskeletal biology relating the sympathetic nervous system to bone formation/resorption and bone growth; (3) white adipose tissue storing triglycerides and the adiposity hormone leptin which functions as satiety hormone and sentinel of energy balance to the hypothalamus for long-term adiposity; and (4) central leptin resistance in obesity and possibly in healthy females. The new theory states that AIS in girls results from developmental disharmony expressed in spine and trunk between autonomic and somatic nervous systems. The autonomic component of this double neuro-osseous theory for AIS pathogenesis in girls involves selectively increased sensitivity of the hypothalamus to circulating leptin (genetically-determined up-regulation possibly involving inhibitory or sensitizing intracellular molecules, such as SOC3, PTP-1B and SH2B1 respectively), with asymmetry as an adverse response (hormesis); this asymmetry is routed bilaterally via the sympathetic nervous system to the growing axial skeleton where it may initiate the scoliosis deformity (leptin-hypothalamic-sympathetic nervous system concept = LHS concept). In some younger preoperative AIS girls, the hypothalamic up-regulation to circulating leptin also involves the somatotropic (growth hormone/IGF) axis which exaggerates the sympathetically-induced asymmetric skeletal effects and contributes to curve progression, a concept with therapeutic implications. In the somatic nervous system, dysfunction of a postural mechanism involving the CNS body schema fails to control, or may induce, the spinal deformity of AIS in girls (escalator concept). Biomechanical factors affecting ribs and/or vertebrae and spinal cord during growth may localize AIS to the thoracic spine and contribute to sagittal spinal shape alterations. The developmental disharmony in spine and trunk is compounded by any osteopenia, biomechanical spinal growth modulation, disc degeneration and platelet calmodulin dysfunction. Methods for testing the theory are outlined. Implications are discussed for neuroendocrine dysfunctions, osteopontin, sympathoactivation, medical therapy, Rett and Prader-Willi syndromes, infantile idiopathic scoliosis, and human evolution. AIS pathogenesis in girls is predicated on two putative normal mechanisms involved in trunk growth, each acquired in evolution and unique to humans.

Context:Isolated 17,20 lyase deficiency is commonly defined by apparently normal 17α-hydroxylase activity but severely reduced 17,20 lyase activity of the bifunctional enzyme cytochrome P450 (CYP) enzyme 17A1 (CYP17A1), resulting in sex steroid deficiency but normal glucocorticoid and mineralocorticoid reserve. Cytochrome b5 (CYB5A) is thought to selectively enhance 17,20 lyase activity by facilitating the allosteric interaction of CYP17A1 with its electron donor P450 oxidoreductase (POR).Objective:We investigated a large consanguineous family including three siblings with 46,XY disorder of sex development (DSD) presenting with isolated 17,20 lyase deficiency.Design:We investigated the clinical and biochemical phenotype, conducted genetic analyses, and functionally characterized the identified CYB5A mutation in cell-based CYP17A1 coexpression assays.Results:All three siblings presented with 46,XY DSD, sex steroid deficiency, normal mineralocorticoids and glucocorticoids, and a urine steroid metabolome suggestive of isolated 17,20 lyase deficiency. CYP17A1 and POR sequences were normal, but we detected a homozygous CYB5A missense mutation (g.28,400A→T; p.H44L). Functional in vitro analysis revealed normal CYP17A1 17α-hydroxylase activity but severely impaired 17,20 lyase activity. In silico analysis suggested the disruption of CYB5A heme binding by p.H44L.Conclusion:We have identified the first human CYB5A missense mutation as the cause of isolated 17,20 lyase deficiency in three individuals with 46,XY DSD. Detailed review of previously reported cases with apparently isolated 17,20 lyase deficiency due to mutant CYP17A1 and POR reveals impaired 17α-hydroxylase activity as assessed by steroid metabolome analysis and short cosyntropin testing. This suggests that truly isolated 17,20 lyase deficiency is observed only in individuals with inactivating CYB5A mutations.