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Objective: To investigate whether stair climbing performance and body composition are similarly affected by a body mass reduction (BMR) program in obese individuals of different gender, age and body mass index (BMI) level., Design: Longitudinal, clinical intervention study entailing energy-restricted diet (5023-7535 kJ/day), nutritional education, psychological counselling and moderate physical activity (indoor cycling, outdoor walking, gymnastics routines, five sessions/week) during a 3-week period., Subjects: A total of 466 male and 807 female subjects categorized as a function of gender, age (< vs >/=50 y) and BMI (< vs >/=40 kg/m(2))., Measurements: Body mass, stair climbing time and power before and after the BMR program. Fat-free mass and fat mass were also evaluated by bioimpedance analysis, in a representative subgroup of 160 patients, to evaluate the relation between fat-free mass and power output., Results: Body mass, fat-free mass and fat mass significantly decreased following the BMR program (P<0.001), with male subjects reducing body mass and fat-free mass more than and fat mass less than the female subjects. Stair climbing time decreased (P<0.001) and therefore anaerobic power significantly increased 9.7% after the treatment. The greatest improvement in stair climbing performance was observed in obese women aged >/=50 y. Significant inverse correlations were found between initial power or fat-free mass level and respective percent increases (R=-0.35/-0.37, P<0.001) and between BMR-induced percent changes in body mass and power (R=-0.13, P<0.001)., Conclusion: Subjects with the lowest baseline level in stair climbing performance (and probably with the lowest amount of fat-free mass), that is, obese women aged more than 50 y, obtained the largest enhancement after the 3-week BMR program, likely improving overall functional capacities and resulting in greater independence during daily-living activities in such a population.

Seventy-seven Italian eliteathletes(42 M, 35 F, mean age +/- SE: 24.4-0.7 yr, age range: 17-47 yr) of different sport disciplines (sprinters, triathletes, middle-distance runners, road-walkers, cyclists, rowing athletes, skiers, roller hockey players, swimmers) were sampled on-the-field (before a training session) for the determination of basal GH, IGF-I, C-terminal cross-linked telopeptide of type I collagen (ICTP) and amino-terminal propeptide of type III procollagen (PIIINP) levels, two GH-dependent peripheral markers of bone and collagen turnover, respectively. Basal GH concentrations were significantly higher (p<0.001) in female (5.8 +/- 1.0 ng/ml) vs male athletes (1.8 +/- 0.5 ng/ml), with a large spread of values in either gender. Mean GH levels of athletes were significantly higher than those recorded in age-matched sedentary controls (females: 2.5 +/- 0.5 ng/ml, p<0.001; males: 0.5 +/- 0.2 ng/ml, p<0.05). Among female athletes, 7/35 had basal GH values higher than the upper limit of control values (>9.5 ng/ml), while among males 7/42 had values higher than the upper limit of male sedentary controls (>3.6 ng/ml). No significant differences in basal GH concentrations were found between females taking oral contraceptives (OC) and those who did not receive this treatment (5.0 +/- 2.1 vs 6.0 +/- 1.2 ng/ml). IGF-I levels (236.4 +/- 7.8 ng/ml) were in the normal range for age in all athletes (except for 1 athlete with slightly increased levels), no significant correlation being found between GH and IGF-I levels (R2=0.0393). Mean ICTP (4.6 +/- 0.2 ng/ml) and PIIINP (4.4-0.1 ng/ml) concentrations of elite athletes were not significantly different from those recorded in age and matched healthy sedentary subjects; 4 athletes showed increased PIIINP levels and 2 had increased ICTP levels. ICTP and PIIINP levels were positively correlated with chronological age (p<0.001), a positive correlation being also found between the two markers (p<0.001). On the contrary, no significant correlation was found between basal GH/IGF-I levels and ICTP/PIIINP levels. In conclusion, the present study demonstrates that: 1) elite athletes (particularly females), which have frequently increased basal GH on-the-field, have actually normal IGF-I levels; 2) ICTP and PIIINP levels of athletes are similar to those recorded in healthy sedentary, being significantly higher in younger subjects of both groups; 3) the presence of increased basal GH levels, being associated with normal IGF-I, ICTP and PIIINP levels, is probably the result of a transient GH peak in this study group. Further additional studies are requested to verify the possible use of these peripheral GH-dependent markers for detecting exogenous chronic administration of recombinant GH in athletes.

Ninety-nine Italian elite athletes (61 M, 38 F, mean age +/- SE: 24.1 +/- 0.6 yr, age range: 17-47 yr) of different disciplines volunteered to participate in this investigation. Basal GH concentrations were significantly higher (p<0.0001) in females (6.2 +/- 1.1 ng/ml) vs males (1.9 +/- 0.5 ng/ml). Basal GH values were negatively correlated with age and body mass index (BMI); no significant correlation was found between GH and IGF-I levels. Among female athletes, 8/38 had basal GH values higher than 10 ng/ml [2/8 athletes were taking oral contraceptives (OC)], while among males 6/61 had values higher than 5 ng/ml. In females, training sessions significantly increased (p<0.0001) basal GH concentrations (peak GH: 18.5 +/- 1.9 ng/ml), while in males GH responses were lower than in females (11.8 +/- 1.4 ng/ml, vs F: p<0.005). Six out of 38 female and 6/61 male athletes were considered GH hypo-responders (i.e. negative difference between peak GH and basal GH values), the large majority of them being subjects with elevated basal GH concentrations. In responsive athletes, peak GH values occurred immediately at the end of the training session both in males and in females; GH concentrations rapidly declined during recovery. No significant correlations were found between peak GH and age, body weight and BMI in either gender. GH responses were directly related (p<0.001) to the intensity of the workload during the sessions. In conclusion, the present study demonstrates that: 1) some elite athletes had increased GH concentrations before training, which were however associated with normal IGF-I levels; 2) GH peaks after a discipline-specific training session were significantly higher in females than in males performing the same discipline, gender-related differences disappearing when post-exercise total GH outputs (area under the curve) were compared; 3) peak GH values were directly correlated with training workload; 4) GH concentrations rapidly declined during recovery, values at the end of the post-training GH sampling being generally lower than those found in basal condition.

Objective: To depict the general trends of muscle anaerobic performance in obese subjects within a wide range of age and body weight., Design: Cross-sectional study for the measurement of lower limb maximal anaerobic power output with a modification of the Margaria stair climbing test in a large population of obese subjects of both genders within a wide span of age (18-80 y) and body mass index (BMI, 30-68 kg m(-2)). Furthermore, body composition was also determined by bioimpedance analysis in a representative subgroup, in order to evaluate the relationships between fat-free mass (FFM) and power output., Subjects: A total of 1298 obese subjects (486 males, 812 females) from an Italian population seeking medical support for body weight reduction. Within this sample, a consistent subgroup of 193 subjects (59 males, 134 females) was also selected for accessory study of body composition., Results: In general, male subjects developed significantly higher lower limb power output (W) than female subjects (P<0.001-0.01), both in absolute terms and per unit body mass. In both genders, W was influenced negatively by age (P<0.001) and positively by BMI (P<0.001). While the effect of age was similar in both genders, BMI had a different positive effect in male and in female subjects, being more definite in male subjects. In the subgroup, FFM was found to depend both on age and BMI, in a fashion comparable with that displayed by W. The gender-related differences in W disappeared when expressed per unit FFM and a significant linear correlation was found between FFM and W, both in male and female subjects (R2=0.32-0.51, P<0.001)., Conclusions: The lower limb maximal power output is significantly higher in obese male subjects than in female subjects, being negatively influenced by age but positively related to BMI. Female subjects appear to be at a greater disadvantage for effect of obesity, the major motor limitations being suffered by older women with higher BMI. These gender differences in age- and BMI-dependent W changes seem to be related to changes in FFM in the subgroup in whom body composition was studied.

Ghrelin, the endogenous ligand of GH-secretagogue receptors, has been implicated in the regulation of feeding behavior and energy balance. Aim of the study was to investigate ghrelin levels in fasting conditions and after a standard meal test in obese subjects before and after a 3-week integrated body weight reduction (BWR) program (consisting of energy-restricted diet, exercise training, psychological counselling and nutritional education). Weight, height, fat mass, fat free mass (by impedentiometry), circulating ghrelin, insulin and leptin levels were evaluated in 10 obese subjects (3 male, 7 female; mean age: 35 +/- 9.3 yr; body mass index BMI: 45.2 +/- 10.6 kg/m2) before and after weight reduction. At baseline, obese subjects showed significantly lower ghrelin levels than controls, which were negatively correlated with BMI, weight, insulin and leptin levels. Fasting ghrelin levels were not modified by standard meal test in obese subjects (from 110.8 +/- 69.7 to 91.8 +/- 70.2 pmol/l p=ns), while a significant reduction was observed in controls (from 352.4 +/- 176.7 to 199.0 +/- 105.2 pmol/l; p<0.01). After a 3-week integrated BWR program obese subjects significantly reduced weight, BMI and leptin levels, while no significant changes were found both in fasting ghrelin and in ghrelin response after the meal. In conclusion, 5% weight loss obtained after a short-term period of integrated BWR program is not sufficient to normalize fasting ghrelin levels nor to restore the normal ghrelin suppression after a meal in severely obese subjects.

The aim of this study was to assess the effects on performance and work capacity of a short-term (3-week) integrated body weight reduction programme consisting of an energy-restricted diet, nutritional education, psychological counselling and aerobic exercise training at a constant metabolic load (5 days/week) in 71 severely obese patients (18 males and 53 females aged 29.3 +/- 0.8 years, with a mean weight of 113.8 +/- 2.2 kg and a mean BMI of 41.3 +/- 0.5 kg/m(-2)). Body mass and composition, and maximum oxygen consumption (VO2max) were determined before and after the programme. The caloric equivalent of work output and a performance index (PI) during 10 min of bicycle ergometer pedalling (50-60 rpm) and 20 min of treadmill walking (incline 0-3%) at a constant metabolic load (50% of individual VO2max during the preliminary conditioning period--1st week--and 60% during the exercise conditioning period--2nd and 3rd week) were evaluated daily throughout the study. After the programme, body mass reduced significantly (-4.5%, p<0.001), the weight loss being sustained entirely by a significant reduction in fat mass (-7.6%, p<0.001) without any significant changes in fat-free mass. Absolute and body mass-related VO2max significantly increased by respectively 14.5% and 20.2% (p<0.001). Both daily work output during constant metabolic load (ANOVA, p<0.05-0.001) and PI (ANOVA, p<0.05-0.001) increased significantly during each week of the programme, leading to a total increase in work output in response to exercise conditioning of 44.6 +/- 5.8 kcal. It is concluded that the changes in exercise capacity induced by the present programme offer significant advantages for obese patients that can be quantified in terms of an improvement in their ability to perform everyday activities, thus contributing towards improving their quality of life.

The effects of short-term (3 weeks) integrated body weight reduction (BWR) program (including energy-restricted diet, aerobic and strength exercise (5 days/week), nutritional education and psychological counseling) on plasma leptin levels and body composition were investigated in 54 morbidly obese patients (38 females/16 males; mean BMI +/- SE: 41.8 +/- 0.1 kg/m2, range 35-58 kg/m2; mean age: 29.8 +/- 1.0 yr, age range: 18-46 yr). The BWR program induced a significant (p < 0.001) weight loss (BMI reduction: -4.8%) and a significant modification in body composition, consisting in a fat mass (FM) decrease (-7.0 +/- 0.4%, p < 0.001) with a concomitant fat-free (FFM) mass increase (1.8 +/- 0.3%, p < 0.001). On average, plasma leptin levels decreased significantly both in males (from 19.4 +/- 2.6 ng/ml to 11.6 +/- 1.3 ng/ml, p < 0.001) and in females (from 41.1 +/- 3.6 ng/ml to 29.9 +/- 3.0 ng/ml, p < 0.001). Both before and after weight loss, leptin levels were positively correlated (p < 0.001) with BMI and percent fat mass (FM) values. Weight changes after the BWR program were negatively correlated with baseline leptin concentrations both in absolute terms and expressed per unit FM. In conclusion, a short-term diet plus aerobic/strength training effectively induces body composition changes and reduces plasma leptin levels. Body FM reduction appears to be not the unique determinant of leptin levels regulation and the degree of leptin over-expression may negatively affect weight loss in morbidly obese patients.

The leaf is a coordinated mosaic of developmental domains, which are evident from leaf inception on the flanks of the apical meristem. The subdivision of the meristem into molecularly defined domains is regulated by the interactions of a number of gene products and by receptor kinase-mediated signals. The acquisition of symmetry axes in the emerging leaf is a process coordinated by hormones (such as auxin and cytokinins) and the expression of classes of genes (such as the knox and the ARP, as1/rs2/phan, genes). As with simple leaves, the architecture of compound leaves is defined by spatial/temporal gradients of regulatory gene functions: complexity results from the interplay between leaf differentiation processes and genes maintaining a partial level of indeterminacy in the developing primordium. Boundaries between regions with different molecular 'addresses' are considered, in plants as in Drosophila, as organizing centres for lateral organ development., (Copyright 2001 Academic Press.)