In recent years there has been increasing interest in the non-skeletal effects of vitamin D. It has been suggested that vitamin D deficiency may influence the development of diabetes, cardiovascular dysfunction and autoimmune diseases. This review focuses on the current knowledge of the effects of vitamin D and its deficiency on cardiovascular function, glucose homeostasis and immune function, with a particular focus on children. Although, there is good evidence to show that there is an association between vitamin D deficiency and an abnormality of the above systems, there is little evidence to show that vitamin D supplementation leads to an improvement in function, especially in childhood.

Energy expenditure, rather than energy intake, has a greater role in the development of obesity after cranial tumor therapy. Reductions in BMR and physical activity, leading to a positive energy balance and weight gain despite an age-appropriate calorie intake, may contribute to hypothalamic obesity.

Summary 23Obesity is the most common cause of metabolic complications and poor quality of life in

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Background: Obesity following hypothalamic damage is often severe and resistant to lifestyle changes. Disruption of hypothalamic feedback mechanisms that maintain energy homeostasis may be responsible for this intractable obesity. Adipocytokines including insulin and leptin are also known to be important regulators of appetite and weight. Objective: To investigate the role of insulin, leptin, adiponectin and resistin in the aetiology of hypothalamic obesity (HO). Design: This was a cross-sectional study of three groups of children, those with HO, congenital hypopituitarism (CH) and simple obesity (SO). Results: A total of 69 children (HOZ28, CHZ18, SOZ23) had leptin, resistin, adiponectin and insulin measured. Although fasting hyperinsulinaemia and insulin resistance were demonstrated, no differences in insulin or insulin resistance were seen between the groups. The HO group, however, had higher levels of leptin, adiponectin and resistin, which persisted even after adjusting for fat mass, compared with the other groups (P!0.05). Conclusion: No differences in fasting hyperinsulinaemia or insulin resistance were seen between the groups; however, leptin levels are elevated, even after adjusting for fat mass, suggesting that an element of leptin resistance is associated with HO. This is consistent with the inability of leptin to act on the hypothalamus, either due to transport across the blood-brain barrier or dysfunctional receptors. The lack of response to leptin may be more important in the development of obesity in these individuals, and the fasting hyperinsulinaemia is a result of the increased adipose tissue rather than the cause of the weight gain.

Background/Aims: Although childhood obesity is a major problem, routine assessment methods do not reflect fat mass. Body mass index, which is most commonly used, gives an indication of weight for height and not a degree of adiposity. Methods: Bioelectrical impedance and dual-energy X-ray absorptiometry (DEXA) were used in a group of obese children to assess body fat. Results: Comparison between DEXA and commercial bioelectrical impedance scales in 46 children showed a highly significant correlation (R = 0.944, p < 0.001) in fat mass. Fat mass measured using bioelectrical impedance was 2.4 kg lower compared to measurement using DEXA. Conclusion: These bioelectrical scales may prove useful in the management of childhood obesity as they are able to provide important clinical information regarding fat mass and adiposity.

Objective:Early diagnosis is of proven benefit in Prader-Willi syndrome (PWS). We therefore examined key perinatal features to aid early recognition.Methods:Data were collected from case records of subjects attending a multi-disciplinary clinic and from a retrospective birth questionnaire.Results:Ninety patients (54 male-36 female) were seen between 1991-2015, most with paternal deletion (n=56) or maternal isodisomy (n=26). Features included cryptorchidism in 94% males, preterm birth (26%), birthweight <2500 g (24%), polyhydramnios (23%), breech presentation (23%) and need for nasogastric feeding (83%). Reduced fetal movements (FM) were reported in 82.5% patients compared with 4% healthy siblings. Of 35 children born since 1999, 23 were diagnosed clinically within 28 days while diagnosis in 12 was >28 days: 1-12 months in seven; and 3.75-10.5 years in five. Typical PWS features in these 12 infants included hypotonia (100%), feeding difficulties (75%), cryptorchidism (83% males) and reduced FM (66%). Causes other than PWS including neuromuscular disease were considered in nine patients. Conclusion:Neonatal hypotonia, reduced FM, feeding difficulties and cryptorchidism should immediately suggest PWS, yet late diagnosis continues in some cases. Awareness of the typical features of PWS in newborn units is required to allow prompt detection even in the presence of confounding factors such as prematurity.

Until quite recently, the management of children with growth hormone deficiency (GHD) had focussed on the use of recombinant human GH (rhGH) therapy to normalise final adult height. However, research over the past two decades that has demonstrated deficits in bone health and cardiac function, as well as impaired quality of life in adults with childhood-onset GHD (CO-GHD), has questioned this practice. Some of these studies suggested that there may be short-term benefits of rhGH in certain group of adolescents with GHD during transition, although the impact of GHD and replacement during the transition period has not been adequately investigated and its long-term benefits remain unclear. GH therapy remains expensive and well-designed long-term studies are needed to determine the cost effectiveness and clinical benefit of ongoing rhGH during transition and further into adulthood. In the absence of compelling data to justify widespread continuation of rhGH into adult life, there are several questions related to its use that remain unanswered. This paper reviews the effects of growth hormone deficiency on bone health, cardiovascular function, metabolic profile and quality of life during transition and young adulthood.