Age-Related Association of Calcitonin with Parameters of Anthropometry, Bone and Calcium Metabolism during Childhood.

INTRODUCTION: The thyroid parafollicular hormone calcitonin (CT) shows particularly high blood levels in early childhood, a period of high bone turnover, which decrease with increasing age. Data about the physiological role of CT during infancy, childhood, and adolescence are contradictory or lacking. OBJECTIVE: We hypothesize that CT demonstrates age-related correlations with parameters of bone growth and turnover as well as with parameters of calcium homeostasis. METHODS: 5,410 measurements of anthropometric data and venous blood samples were collected from 2,636 participants of the LIFE Child study, aged 2 months-18 years. Univariate correlations and multiple regression analysis were performed between serum CT and anthropometric indicators (height standard deviation scores [SDS] and BMI-SDS), markers of calcium (Ca) homeostasis (Ca, parathyroid hormone, 25-OH vitamin D, and phosphate [P]), bone formation (procollagen type 1 N-terminal propeptide [P1NP], osteocalcin), and bone resorption (ß-CrossLaps). RESULTS: CT was significantly associated with Ca (ß = 0.26, p < 0.05) and P1NP/100 (ß = 0.005, p < 0.05) in children aged 2 months-1.1 years. These relations were independent of age and sex and could not be confirmed in children aged 1.1-8 years. Independent of age, sex, puberty, P, and height SDS CT showed a significant positive relation to Ca (ß = 0.26; p < 0.001) in children aged 8-18 years. CONCLUSIONS: Our findings suggest a unique association between CT and Ca in periods of rapid bone growth and point to a possible involvement of CT in promoting bone formation during the first year of life.

Effects of an Alkalizing or Acidizing Diet on High-Intensity Exercise Performance under Normoxic and Hypoxic Conditions in Physically Active Adults: A Randomized, Crossover Trial.

Pre-alkalization caused by dietary supplements such as sodium bicarbonate improves anaerobic exercise performance. However, the influence of a base-forming nutrition on anaerobic performance in hypoxia remains unknown. Herein, we investigated the effects of an alkalizing or acidizing diet on high-intensity performance and associated metabolic parameters in normoxia and hypoxia. In a randomized crossover design, 15 participants (24.5 ± 3.9 years old) performed two trials following four days of either an alkalizing (BASE) or an acidizing (ACID) diet in normoxia. Subsequently, participants performed two trials (BASE; ACID) after 12 h of normobaric hypoxic exposure. Anaerobic exercise performance was assessed using the portable tethered sprint running (PTSR) test. PTSR assessed overall peak force, mean force, and fatigue index. Blood lactate levels, blood gas parameters, heart rate, and rate of perceived exertion were assessed post-PTSR. Urinary pH was analyzed daily. There were no differences between BASE and ACID conditions for any of the PTSR-related parameters. However, urinary pH, blood pH, blood bicarbonate concentration, and base excess were significantly higher in BASE compared with ACID (p < 0.001). These findings show a diet-induced increase in blood buffer capacity, represented by blood bicarbonate concentration and base excess. However, diet-induced metabolic changes did not improve PTSR-related anaerobic performance.

The effect of practice on low-level auditory discrimination, phonological skills, and spelling in dyslexia.

Phonological awareness is believed to play a major role in the auditory contribution to spelling skills. The previous paper reports low-level auditory deficits in five different subdomains in 33-70% of the dyslexics. The first study of this paper reports the results of an attempt to improve low-level auditory skills by systematic daily practice of those tasks that had not been passed in previous diagnostic sessions. The data of 140 dyslexics indicate that the average number of unsolved tasks can be reduced from 3 of 5 to 1 of 5. The success rates have values of 70-80% for intensity and frequency discrimination and for gap detection, but reach only 36% for time-order judgement and 6% for side-order judgement. The second study reports that successful low-level auditory training transfers completely to language-related phonological skills and also to spelling with the largest profit in spelling errors due to poor auditory analysis. Control groups (waiting and placebo) did not exhibit significant improvements. It is concluded that low-level auditory deficits should be considered and improved by practice in order to give the dyslexics more phonological help when trying to transfer what they hear to spelling.