Antonio Cicchella

Longitudinal Development of Physical and Performance Parameters during Biological Maturation of Young Male Swimmers

The aim of the study was to examine the development of specific physical, physiological, and biomechanical parameters in 29 young male swimmers for whom measurements were made three times for two consecutive years. During the 400-m front-crawl swimming, the energy cost of swimming, and stroking parameters were assessed. Peak oxygen consumption (VO2 peak) was assessed by means of the backward-extrapolation technique recording VO2 during the first 20 sec. of recovery period after a maximal trial of 400-m distance. Swimming performance at different points of physical maturity was mainly related to the increases in body height and arm-span values from physical parameters, improvement in sport-specific VO2 peak value from physiological characteristics, and improvement in stroke indices on biomechanical parameters. In addition, biomechanical factors characterised best the 400-m swimming performance followed by physical and physiological factors during the 2-yr. study period for the young male swimmers.

Adipocytokines and bone mineral density in adolescent female athletes

Aim:  To evaluate the relationships of visfatin, adiponectin and leptin with bone mineral density (BMD) and bone mineral content (BMC) in adolescent female athletes with different training patterns.

Effect of pubertal development and physical activity on plasma ghrelin concentration in boys

The aim of the present study was to assess the influence of regular physical activity on plasma ghrelin concentration in pre-pubertal and pubertal boys. In addition, the impact of ghrelin concentration on bone mineral density (BMD) was examined. In total, 56 healthy schoolboys aged between 10 and 16 yr were divided into the swimming (no.=28) and the control (no.=28) groups. The subjects were matched by age and body mass index (BMI), generating 9 matched pairs in pubertal group I (Tanner stage 1), 11 pairs in group II (Tanner stages 2 and 3), and 8 pairs in group III (Tanner stages 4 and 5). Swimmers in pubertal groups II and III had significantly (both p<0.05) higher mean ghrelin levels than the controls (group II: 1126.8±406.0 vs 868.3±411.2 pg/ml; group III: 1105.5±337.5 vs 850.8±306.0 pg/ml, respectively), whereas no difference was seen in the pubertal group I (1230.8±386.0 vs 1272.7±424.4 pg/ml). Ghrelin was the most important hormonal determinant for total BMD and lumbar apparent volumetric BMD (BMAD) (R2=27.2% and R2=19.8%, respectively) in swimmers, whereas in control boys, plasma IGF-I was the most important hormonal predictor accounting for 41.8% of the variability of total BMD and 20.4% of the variability of lumbar BMAD. In conclusion, ghrelin concentration decreased during puberty in physically inactive boys, while in regularly physically active boys it remained relatively unchanged. Ghrelin appears to be an important hormonal predictor for BMD in physically active boys, while BMD is mostly determined by IGF-I in physically inactive boys.

Influence of puberty on ghrelin and BMD in athletes.

The aim of our study was to examine the influence of elevated energy expenditure on ghrelin and BMD in young male competitive swimmers advancing from prepubertal to pubertal maturation levels. The study included 19 healthy swimmers (pubertal stage 1) aged between 10 and 12 years. The participants were at the pubertal stages 2 and 3, and 3 and 4 at the second and third year, respectively. Ghrelin was decreased only after the first year. No changes were observed in leptin during the study period. Testosterone increased according to the pubertal development at each measurements. IGF-I was increased at the third measurement compared to the first two measurements. Total and lumbar spine BMDs increased according to the pubertal development in all boys at each measurements, while no changes in femoral neck BMD were observed. Ghrelin was not related to BMD after adjusting for pubertal status. We conclude that ghrelin was decreased at onset of puberty, while no further changes in ghrelin were seen with advancing pubertal stage. Total and lumbar spine BMD increased, while no changes in femoral neck BMD occurred. Ghrelin did not appear to have a direct influence on BMD in young male competitive swimmers.

Plasma visfatin and adiponectin concentrations in physically active adolescent girls: relationships with insulin sensitivity and body composition variables.

Abstract The purpose of this study was to evaluate the associations of visfatin and adiponectin concentrations with insulin resistance and body composition in regularly physically active pubertal girls. In 129 girls, aged 13–15 years (pubertal stages 3–5), visfatin, adiponectin, insulin resistance measured by homeostasis model assessment (HOMA), and body composition measured by dual-energy X-ray absorptiometry were evaluated. Visfatin concentration was related to HOMA and overall adiposity (body mass index, fat mass) markers, whereas adiponectin concentration was related to overall adiposity (fat mass), central adiposity (trunk fat) and fat free mass values. These relationships remained significant (p<0.05) after adjusting for pubertal stage. Visfatin was independently related to body mass index (β=0.936; p=0.0001) and HOMA (β=0.444; p=0.039) indices, whereas adiponectin was independently related to fat free mass (β=0.889; p=0.003) and trunk fat (β=–0.468; p=0.042) values. In conclusion, visfatin could be related to insulin resistance and overall adiposity indices, whereas adiponectin was related to different body composition values in regularly physically active pubertal girls.

ADIPOQ SNP45 associated with lean body mass in physically active normal weight adolescent girls.

Recently, two single nucleotide polymorphisms at position 45 and 276 on the adiponectin gene (ADIPOQ) have been recognized as determinants of total adiponectin levels, insulin resistance, and risk for diabetes in various obese populations.

Sleep-dependent consolidation of motor skills in patients with narcolepsy-cataplexy

BACKGROUND AND OBJECTIVES This study investigated whether the altered organization of post-training sleep in patients with narcolepsy-cataplexy (NC) is associated with a lower off-line improvement in the consolidation of motor skills compared with normal subjects. STUDY DESIGN Fourteen drug-naive NC patients, fulfilling the international clinical and polysomnographic diagnostic criteria, and 14 individually-matched controls underwent training at a sequential finger tapping task (FTT) and were re-tested on the next morning (after a night with polysomnographic recording) and after another six nights (spent at home). SETTING Training and retrieval sessions were performed in a controlled laboratory setting. RESULTS FTT performance was worse in NC patients than controls at training and at both retrieval sessions and showed a fairly different time course (slower than in controls) of consolidation. Several sleep indices (lower values of stage-2 NREM sleep and SWS) were compatible with a lower effectiveness of sleep for consolidation of motor skills in NC patients, although no statistically significant relationship was found between such indices and improvement rate. CONCLUSION The consolidation process of motor skills results less effective in NC patients since training and slower than in normal subjects over the week following training. The wider variations in performance scores and sleep parameters of post.-training night in NC patients relative to controls suggest that a) the lower initial consolidation may be due to a less effective encoding consequent to altered prior sleep, and b) the consolidation process over the 24 h following training is negatively influenced not only by the altered characteristics of post-training sleep, but also by the daytime sleepiness following training.

Moderate Physical Activity Correlates with Elevated Leptin in Physically Active 10–12-Year-Old Boys with Normal BMI

The aim of this study is to examine the relations between physical activity of differing intensity and duration with body energy-balance hormone leptin in 10–12-year-old boys (N = 94) who participated in moderate-to-vigorous physical activity at least four to five times per week. The boys reported their physical activity using a questionnaire. They had normal body mass index (BMI, kg/m2), and were at Tanner Stage 2 of development. Boys were divided into three subgroups by leptin levels: normal serum leptin (M ± .5 SD, n = 44, 1.2–3.9 ng/ml), low leptin (≤ M – .5 SD; n = 31, < 1.2 ng/ml), and high leptin (≥ M +.5 SD; n = 19, > 3.9 ng/ml). There were significant differences between subgroups in anthropometric parameters and serum leptin levels, but not in physical activity. A significant correlation was found between leptin and moderate physical activity of at least five times per week for at least 30 minutes each time in the high leptin group (r = .61). In conclusion, the correlations between physical activity and leptin are weak; only moderate physical activity was correlated with leptin levels in the high leptin group.

The associations between peak O2 consumption and leptin in 10- to 12-year-old boys.

The aim of this study was to assess the associations of circulating levels of leptin with the peak O2 consumption (VO2peak) in 10‐ to 12‐year‐old boys of different BMI selected by Cole et al. (BMJ, 320,2000,1–6): total group (n = 248), normal (n = 190), overweight (n = 34) and obese (n = 24). We hypothesized that there is a close relationship in overweight and obese subgroups of boys with relative VO2peak kg−1(ml min−1 kg−1) and leptin. Most of the subjects were Tanner stage 2. Peak O2 consumption was measured directly using an increasing incremental protocol until volitional exhaustion on an electronically braked cycle ergometer. The expired gas was sampled continuously breadth‐by‐breadth mode for the measurement of oxygen consumption (MetaMax, Germany). Blood samples were obtained after an overnight fast from an antecubital vein for leptin measurements. Peak O2 consumption (l min−1) was higher or lower (ml min−1 kg−1) in overweight and obese groups, compared with normal BMI group. Leptin was higher in overweight and obese groups, compared with normal BMI group. Peak O2 consumption (l min−1) correlated significantly with leptin only in total group (n = 248, r = 0·196). Contrary, relative VO2peak kg−1 correlated significantly and negatively with leptin. The relationship was highest on the total group (r = −0·674). We can conclude that leptin first of all correlated negatively with relative peak O2 consumption. Absolute VO2peak correlated with leptin only in total group.

Response to the Commentary “Methodological Considerations for Analysing the Relation of Physical Activity with Leptin Levels in Children: Comment on the Study by Cicchella et al. (2013)” by David Jiménez-Pavon

This is a response to commentary by Jiménez-Pavon (2015) on the relationships of leptin levels with children’s physical activity. The present response suggests actigraphs are superior to questionnaires for measuring children’s physical activity. Cicchella, Stefanelli, Jurimae, Saar and Purge (2013) pointed out some interesting methodological issues related to the relationships of leptin and physical activity in normal weight children. The questions dealt with the reliability of the questionnaires in assessing physical activity in children, choices of the cut-off points for considering levels of physical activity as moderate or intense, and the association of leptin with PA levels. Some considerations in Jiménez-Pavon (2015) remain unclear.