Influence of blood sampling techniques on ionized magnesium level.

The aim of the study was to evaluate whether different blood sampling techniques (venous vs. capillary) influence the level of ionized magnesium. A total of 12 men and 20 women were included. A venous blood sample was collected from the antecubital vein without stasis in syringes containing 50 IU/ml electrolyte balanced heparin. Capillary tubes containing sodium heparin 50 IU/ml were used for blood sampling (150 microl) from the earlobe. A statistically significant difference between venous and capillary ionized magnesium at actual pH (0.57+/-0.04 vs. 0.55+/-0.04 mmol/L, p<0.05) was observed, whereas no difference was seen between adjusted ionized magnesium. No difference was observed between venous and capillary ionized calcium at actual pH or adjusted to pH 7.4. The pH level was significantly higher in capillary blood (7.44+/-0.02 vs. 7.48+/-0.02. p<0.00001). The higher pH in capillary blood may be due to greater exposure to air in capillary tubes, and this most likely explains the observed difference between venous and capillary ionized magnesium at actual pH.

Body proportions, body composition and pubertal development of children in competitive sports.

The aim of this study was primarily to investigate anthropometric variables, body composition and pubertal development in children aged 9-13 participating in competitive sports. Secondly, the influence of age, sport, training hours and pubertal development/maternal menarcheal age on body composition and pubertal development was explored. A total of 183 (96 girls, 87 boys) children performing swimming (Sw), tennis (Te), European team handball (TH), and gymnastics (Gy) took part in the study. Anthropometric measurements and pubertal development were determined. The participants completed a questionnaire regarding hours of training per week and maternal menarcheal age. Significant differences in stature (z-scores) were found in both boys (Sw=0.06; Te=0.04; TH=0.05; Gy=-0.66, P<0.004) and girls (Sw=0.12; Te=0.19; TH=0.25; Gy=-0.96, P<0.004). In girls, sum of skinfolds in millimetres (Sw=33.4; Te=33.3; TH=41.0; Gy= 27.2, P<0.02) and body mass index z-scores (SW=0.00; Te=-0.27; TH=0.35; Gy=-0.25, P<0.001) were different between the sports. A regression analysis revealed that in girls, age and maternal menarcheal age were significantly associated with pubertal development (P<0.005 and P<0.01), respectively, and sport was associated with the sum of skinfolds (P<0.05). In boys, only age was significantly associated with pubertal development (P<0.005). In conclusion, anthropometric and body composition differences exist in athletes of both sexes from different sports but are more evident in females. Most importantly, we did not find any effect of training on body composition or pubertal development, confirming previous data that children in competitive sports are selected due to constitutional factors.

Winchester syndrome.

Winchester syndrome was first described in 1969 and since then nine patients have been reported in the literature. The syndrome is characterized by short stature, coarse face, corneal opacities, generalized osteolysis and progressive painful arthropathy with joint stiffness and contractures of distal phalanges in combination with skin changes. The etiology is unknown. Parental consanguinity supports autosomal inheritance. The diagnosis is based on clinical and radiological manifestations. We describe a case in a 7-year-old Pakistani boy.

Whole blood ionized magnesium in neonatal acidosis and preterm infants: a prospective consecutive study.

UNLABELLED: The mineral magnesium is a crucial enzymatic cofactor in the cellular bioenergetic process and alternations in magnesium metabolism may be associated with neurological impairment in newborn infants. Therefore, ionized magnesium (IMg) was measured in 14 newborn infants with acidosis [umbilical arterial cord pH 7.00 +/- 0.06, Apgar score 8.3 +/- 1.6 after 5 min, gestational age (GA) 276 +/- 16 d] and 15 premature infants (umbilical arterial cord pH 7.31 +/- 0.07, GA 236 +/- 12 d). Nineteen healthy mature infants served as controls. Arterial umbilical cord samples were taken immediately after delivery and capillary blood samples were taken 2, 6, 12 and 24 h after delivery by heel stick. IMg was measured by NOVA 8. The results showed an increased umbilical cord blood IMg in infants with acidosis compared with both premature and normal infants (0.58 +/- 0.08 mmol l(-1) vs 0.51 +/- 0.03 mmol l(-1) and 0.49 +/- 0.03 mmol l(-1); p < 0.0001). In infants with acidosis IMg declined significantly 2 h after delivery to 0.49 +/- 0.05 mmol l(-1) (p < 0.0001) and did not show any further significant changes during the first day of life. In premature infants and controls IMg levels were constant during the observation period. CONCLUSION: These findings suggest that elevated IMg is associated with neonatal acidosis.

Is prepubertal growth adversely affected by sport?

PURPOSE: To study the effect of genetic factors, birth weight, early childhood growth, sport, hours of training, and pubertal status on the stature and body mass index (BMI) of children aged 9-13 participating in sports at a competitive level. METHODS: A total of 184 children (96 girls, 88 boys), competing in swimming, tennis, team handball, and gymnastics, were investigated, assessing their height, weight, pubertal development, and BMI. Of these, 137 (76 girls, 61 boys) returned a questionnaire, which enabled us to determine height and BMI at age 2-4, birth weight, and parental heights. RESULTS: Significant differences in standard deviation scores (SDS) for actual height and for height at age 2-4 were found in both sexes between the four sports. In girls, BMI SDS was significantly different between the four sports, whereas no difference was found in boys. Each sport investigated separately showed no change in height SDS and BMI SDS between ages 2-4 and 9-13. A regression analysis showed that target height, height at age 2-4, and pubertal status had a significant impact on actual height. Interestingly, the type of sport and hours of training per week had no effect on height SDS. In boys, BMI at age 2-4 and pubertal status had a significant effect on actual BMI, whereas in girls, only BMI at age 2-4 was significant. CONCLUSIONS: The results suggest that prepubertal growth is not adversely affected by sport at a competitive level and that constitutional factors are of importance for choice of sport in children.