Vitamin D and calcium intakes in general pediatric populations: A French expert consensus paper.

OBJECTIVES: Nutritional vitamin D supplements are often used in general pediatrics. Here, the aim is to address vitamin D supplementation and calcium nutritional intakes in newborns, infants, children, and adolescents to prevent vitamin D deficiency and rickets in general populations. STUDY DESIGN: We formulated clinical questions relating to the following categories: the Patient (or Population) to whom the recommendation will apply; the Intervention being considered; the Comparison (which may be "no action," placebo, or an alternative intervention); and the Outcomes affected by the intervention (PICO). These PICO elements were arranged into the questions to be addressed in the literature searches. Each PICO question then formed the basis for a statement. The population covered consisted of children aged between 0 and 18 years and premature babies hospitalized in neonatology. Two groups were assembled: a core working group and a voting panel from different scientific pediatric committees from the French Society of Pediatrics and national scientific societies. RESULTS: We present here 35 clinical practice points (CPPs) for the use of native vitamin D therapy (ergocalciferol, vitamin D2 and cholecalciferol, vitamin D3) and calcium nutritional intakes in general pediatric populations. CONCLUSION: This consensus document was developed to provide guidance to health care professionals on the use of nutritional vitamin D and dietary modalities to achieve the recommended calcium intakes in general pediatric populations. These CPPs will be revised periodically. Research recommendations to study key vitamin D outcome measures in children are also suggested.

Vitamin D, homocysteine and n-3PUFA status according to physical and cognitive functions in older adults with subjective memory complaint: Results from cross-sectional study of the MAPT trial.

OBJECTIVE: The aim of this study was to investigate the nutritional markers (Vitamin D, homocysteine, n-3PUFA) status of older subjects aged 70 years and older with subjective memory complaint, according to their physical and cognitive function. MAIN OUTCOME MEASURES: This study is a secondary analysis of the MAPT study. Subjects were classified into four groups: 1) Physical limitation with cognitive impairment (PLCI), 2) cognitive impairment (CI), 3) physical limitation (PL) and 4) no physical or cognitive deficits (NPCD). Baseline nutritional characteristics of the four groups according to Vitamin D (n = 732), Omega-3 polyunsaturated fatty acid (n-3PUFA) (n = 1537) and plasma total homocysteine (tHcy) (n = 729) status were investigated. Analysis was performed taking continuous and dichotomized value for Vitamin D insufficiency ([25(OH)D] < 30 ng/ml, high homocysteine level (tHcy ≥ 15 µmol/L) and low n-3PUFA (DHA + EPA ≤ 4.82%) nutritional markers for clinical relevance. RESULTS: PLCI group showed the lowest mean level of Vitamin D and highest level tHcy compared to the other groups. In multivariate analysis, taking continuous nutritional markers, only high Vitamin D was associated with reduced likelihood of PLCI (OR 0.97, 95% CI (0.95 to 0.99) P = 0.011). While taking the dichotomized values the group with low levels of n-3PUFA showed higher likelihood of PL only (OR 1.55, 95% CI (1.12 to 2.15), P = 0.009). Furthermore, our sensitivity analysis for Vitamin D with cut-off [25(OH)D] < 20 ng/ml,(i.e., Vitamin D deficiency), showed more likelihood of PL (OR 1.62, 95% CI (1.01 to 2.60) P = 0.046), CI (OR 1.90, 95% CI (1.16 to 3.10) P = 0.010), and highest likelihood of PLCI (OR 1.99, 95% CI (1.21 to 3.28) P = 0.006). CONCLUSION: In older adults with subjective memory complaints, Vitamin D deficiency status may present higher likelihood of functional deficits, including coexisting or separate physical and cognitive decline. While older adults with low level of n-3PUFA were more likely to demonstrate physical decline only.

[Severe nutritional rickets in young children: Resurgence of an old disease]. / Rachitisme carentiel sévère du nourrisson : de nouveau d'actualité.

Nutritional rickets remains a significant public health issue for children worldwide. Although it has almost disappeared in industrialized countries following routine vitamin D supplementation, recent evidence suggests an increasing incidence, especially in young children. In addition to the classical clinical consequences on bone and the growth plate, rickets may also be associated with life-threatening neurological and cardiac complications in the most severe forms. Consequently, early screening and treatment are required. Here, we report the case of a 2-year-old child who presented with severe nutritional rickets associated with seizure and cardiomyopathy. Family screening revealed rickets in all the siblings. This case report emphasizes the importance of being aware of this disease, notably in population with sociocultural risk factors.

Laboratory diagnosis of hypophosphatasia.

The laboratory diagnosis of hypophosphatasia (HPP) is primarily based on the precise analysis of circulating serum alkaline phosphatase (ALP) activity, determined by biochemical assays. This analysis requires specific conditions of implementation and interpretation and should always be viewed in the light of the clinical and radiological data. Concerns regarding the normal ranges of ALP with respect to age, regarding ALP values that may overlap those of normal subjects in HPP patients, regarding apparently normal ALP values in cases of proven HPP, regarding differential diagnoses that may be responsible for low ALP values outside of HPP will be discussed. High levels of pyridoxal phosphate, a substrate of APL, are of supportive value in the diagnosis of HPP.

[Acromegaly and pregnancy: report of six new cases]. / Acromégalie et grossesse: six nouvelles observations.

INTRODUCTION: Pregnancies in acromegalic women are rare. Data from the literature indicate absence of congenital malformation in newborns, an increase of pituitary adenoma volume rarely clinically symptomatic, an increased risk of gestational diabetes and gravid hypertension in women with non-controlled GH/IGF-1 hypersecretion before gestation. The changes of somatotroph function are rarely described. AIM OF THE STUDY: Report of six new pregnancies in five women with acromegaly. PATIENTS AND METHODS: Before pregnancy three women had incomplete surgical resection of GH-secreting pituitary adenoma, all were treated with somatostatin analogues, and the medical treatment was withdrawal at the diagnosis of gestation. We studied clinical (blood pressure, headaches, visual field), biological (blood glucose concentration) signs, GH and IGF-1 levels were measured during each trimester of pregnancy as well as in post-partum and were compared with pregestational values, MRI of the pituitary performed during the second trimester and in the post-partum were compared with MRI examen before pregnancy. RESULTS: All those pregnancies were normal without gestational diabetes, gravid hypertension and pituitary tumor syndrome. Clinical signs of acromegaly improved in 50 % of the patients, and IGF-1 decreased (22 %) in comparison of pregestational value without significant change in GH levels. No newborn had congenital malformation. CONCLUSION: Pregnancies in those women with acromegaly are uneventful without obstetrical or foetal complication, but a maternal follow-up is necessary in order to diagnose gravid hypertension and gestational diabetes. On the other hand, a clinical monitoring of pituitary tumor syndrome is necessary in women with non-operated GH-secreting macroadenoma before pregnancy. During the first trimester of gestation, an improvement of acromegalic signs can be due to a decrease of IGF-1 levels related to hepatic GH-resistance state secondary to physiological secretion of estrogens during gestation.

Prevalence of IGF1 deficiency in prepubertal children with isolated short stature.

BACKGROUND/AIMS: 'Primary IGF1 deficiency (IGFD)' is defined by low levels of IGF1 without a concomitant impairment in GH secretion in the absence of secondary cause. The aims of this study were to evaluate the prevalence of non-GH deficient IGFD in prepubertal children with isolated short stature (SS) and to describe this population. METHODS: This retrospective study included all children with isolated SS seen in our Pediatric Endocrinology Unit from January 2005 to December 2007. Children were included based on the following criteria: i) SS with current height SDS < or = -2.5, ii) age > or = 2 years, and iii) prepubertal status. Exclusion criteria were: i) identified cause of SS and ii) current or past therapy with rhGH. IGF1-deficient children were defined as children without GH deficiency and with IGF1 levels below or equal to -2 SDS. RESULTS: Among 65 children with isolated SS, 13 (20%) had low IGF1 levels, consistent with a diagnosis of primary IGFD, four of which were born small for gestational age and nine were born appropriate for gestational age. When compared with non-IGFD children, IGFD children had higher birth weight (-0.7 vs -1 SDS, P=0.02) and birth height (-1.7 vs -2 SDS, P=0.04) and more delayed bone age (2.6 vs 1.7 years, P=0.03). CONCLUSION: The prevalence of primary IGFD was 20% in children with isolated SS. Concerning the pathophysiology, our study emphasizes that IGFD in some children may be secondary to nutritional deficiency or to maturational delay.

Hypercalciuria induced by a high dose of cinacalcet in a renal-transplant recipient.

The successful use of cinacalcet in dialysis patients and in patients with primary hyperparathyroidism has prompted transplant physicians to use it to treat renal-transplant patients with persisting hyperparathyroidism. However, in the setting of kidney transplantation, many questions remain unanswered, i.e. the time of initiation of cinacalcet after transplantation, its dosage and the side effects on kidney function all remain unknown. Herein, we report on a kidney-transplant recipient with persisting hyperparathyroidism who developed hypercalciuria afterreceiving high doses of cinacalcet. Cinacalcet was started 3 months after transplantation at a once-daily dose of 60 mg. Thereafter, the dosage was increased progressively because of persistant hyperparathyroidism and hypercalcemia. At a dose of 90 mg b.i.d, hypercalciuria occurred. The latter disappeared after reduction of cinacalcet dosage. Cinacalcet might be responsible for urinary calcium excretion, either by reduction of tubular calcium reabsorption via the reduction of PTH level, or by its direct effect on the calcium sensor receptor located in the upper thick ascending limb of the loop of Henle. We conclude that cinacalcet should be used with caution in renal-transplant patients. Further investigations are required to determine the best way to use this drug in this setting.

[Bone mineral metabolism: recent data and perspectives related to osteogenesis]. / Métabolisme minéral osseux: données récentes et perspectives relatives à l'ostéogenèse.

Important data have recently been added to our knowledge of bone mineral metabolism in children. Molecular pathophysiology of several pediatric syndromes has been clarified. Specially, the components of endocrine and metabolic regulations are tightly related with regard to the trophicity of bone. On another hand, the impact of several therapeutics of bone diseases like biphosphonates, parathormone (PTH) or growth hormone on bone anabolism is now strongly emphasized. All these points are important for the becoming of bone pediatric diseases in the adult life. Here we analyze the essential components of mineral metabolism and of its regulation in view of the recent biological data, like PTH/PTHrP (PTH-related peptide)-evoked cell signaling, the role of FGF 23 (Fibroblast growth factor 23) in hypophosphatemia and the regulation of vitamin D metabolism by 1alpha-hydroxylase. Inter-relation of these regulating elements is present in several genetic diseases and in the Mc Cune Albright syndrome. Relationships between metabolic and endocrine factors are analyzed considering their impact on PTH secretion and osteogenesis.

Polymorphism of the 5' untranslated region of NHE1 gene associated with type-I diabetes.

The ubiquitous form of the sodium-hydrogen exchanger, NHE1, is devoted to the regulation of intracellular pH and cell volume. In addition, NHE1 activity is stimulated by growth factors and increased NHE rates are found in both circulating and immortalized cells during diabetes or diabetic nephropathy. In this context, we searched for polymorphisms of the 5'-flanking regulatory region of NHE1 gene in subjects with type-I diabetes. We identified a C/T transition 696 bases upstream the translation initiation start site which disrupts a repeated palindromic GC sequence. The TT genotype was significantly more frequent in type-1 diabetics and may have functional importance. Genetic linkage between NHE1 and diabetes has been previously described in NOD mice strains with consequences on NHE rates. Hence, the polymorphism described hereby may act as a predisposition factor to type-I diabetes or to diabetic complications, and may be useful to investigate the genetic involvement of NHE1 in human pathophysiology.

Effects of lysophosphatidic acid on proliferation and cytosolic Ca++ of human adult vascular smooth muscle cells in culture.

Lysophosphatidic acid (LPA) is a lipid mediator generated by activated platelets and having various effects on numerous cell types. We investigated some effects of 1-oleyl LPA on vascular smooth muscle cells cultured from adult human normal arteries. At micromolar concentrations, LPA induced a mitogenic effect ([3H]-thymidine incorporation and cell proliferation) on quiescent cells, without an additional growth factor being required. This effect was equipotent to that of 10% fetal calf serum, and it was accompanied by early (5 minutes) and late (1-3 hours) phosphorylation of mitogenactivated protein kinase. LPA inhibited cell migration through collagen coated membranes, with or without platelet-derived growth factor BB as chemoattractant. LPA induced a typical biphasic Ca2+ signal response made up of a rapid first phase due to Ca2+ release from intracellular stores followed by a second wave due to external Ca2+ influx. These findings support the proposal that LPA released from activated platelets is a mediator for smooth muscle cell response at the site of vessel injury in humans.