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Objective: The prevalence of overweight and obesity was estimated among the school children and adolescents of three provinces of central Italy, and the role of several possible influencing factors was analysed., Design, Subjects and Measurements: Body mass index (BMI) was measured in 44 231 subjects, age 3-17.5 y, and a household questionnaire was filled out by the parents of 12 143 subjects to collect the following data: subjects, only child or firstborn status, prematurity, birth weight, type of feeding until the fifth month, menarche status in girls; parents, age at the time of the subject's birth; BMI (mean of the two parents) at the time the subject was measured, mother's age of menarche, socioeconomic status. BMI was measured in a subgroup of 10 795 subjects 1 y later to study the yearly sex- and age-related variations from the categories of normal weight to overweight or obesity and vice versa. All females aged 11-14 y were asked if they had their menarche., Results: Striking differences in the proportions of overweight and obesity resulted from the use of two different criteria for defining cutoff points. The overall prevalence of overweight was 13.2 and 20.7% in males, and 13.7 and 18.6% in females, and the overall prevalence of obesity varied between 24.2 and 6.3% in males, and between 22.9 and 6.1% in females, respectively. Parents' BMI, birth weight, firstborn status and post-menarche status in girls showed a significant association with overweight and/or obesity in logistic regression models., Conclusions: A large prevalence of overweight and obesity was observed in school subjects from three provinces of central Italy. From the comparisons of the prevalence rate, the new internationally agreed criteria seem more appropriate for epidemiological studies in this population., Sponsor: University of Perugia, Region of Umbria, Commune of Perugia.

Background: A role for leptin to predict weight gain is still controversial., Objective and Design: To determine the relationship between baseline serum leptin values and responsiveness to an educational-based weight excess reduction program (WERP), 418 (241 males and 185 females) obese subjects, aged 9-15 y, were recruited. WERP required 2 y of follow-up. Body mass index (BMI) was evaluated at baseline and at each semester of follow-up. The obese subjects were subdivided into responsives and non-responsives, according to reduction or not of their BMI Z-scores during the WERP. Leptin concentrations were assayed at baseline and were included together with other independent variables in statistical multiple regression analysis., Results: At a preliminary multiple regression analysis, a significant positive correlation between leptin values and BMI Z-score reduction at the second, third and fourth semester of follow-up was registered. To determine the odds ratio of the subjects who were responsive or non-responsive at the various semesters of WERP follow-up, a stepwise logistic regression was used incorporating the same predictors, with the serum leptin values subdivided into quintiles and responsiveness and non-responsiveness as a binary outcome variable. The model offered a satisfying goodness of fit as shown by the sensitivity and specificity. The odds ratio of being responsive were significantly increased by greater quintiles of leptin serum concentrations. Furthermore, such odds ratios were much higher in pubertal than in prepubertal subjects., Conclusions: These findings support a significant role for serum leptin concentration in predicting BMI changes as a response to an educational excess weight reduction program.

Objective: The influence of weight excess reduction on height and height velocity of obese subjects should be evaluated on the basis of appropriate standards, since the pattern of growth of obese subjects is different from that of normal weight subjects., Design, Subjects and Measurements: Height, weight and triceps skinfold thickness were recorded from 17987 school subjects (9256 males and 8731 females), 3-18 y of age, from three provinces of central Italy, and a growth reference curve of height was constructed. Using BMI (as computed using the tables of Rolland-Cachera et al) and triceps skinfold thickness, normal-weight subjects (NWS) and obese subjects (OS) were identified and specific reference curves (mean+/-s.d. every sixth month of age) were developed for both groups. Centiles of height were also calculated for OS. Various (2-4) measurements of height in school subjects were performed and a graph of height velocity (HV) was constructed in NWS and in OS using the JPPS method. The yearly mean +/-s.d. of HV was also calculated, based on square root transformed data (in order to realise a Gaussian distribution), deriving from successive measurements in total subjects, in NWS and in OS. The z-scores of height and of the square root of HV were calculated in 217 obese subjects (125 males and 92 females) before and during a weight excess reduction programme (WERP). Obese subjects in WERP who showed a reduction of z-score of BMI were considered as 'responsive'; those who either maintained or showed an increase of z-score of BMI were considered as 'non-responsive'. Obese subjects in WERP were followed for 1-4 y, giving the following results: 0-1 y, 142 responsives and 75 non-responsives; 0-2 y, 76 responsives and 33 non-responsives; 0-3 y, 35 responsives and 30 non-responsives; 0-4 y, 24 responsives and 18 non-responsives., Results: Compared to NWS, OS showed a significantly greater HV in 4-9y males and in 4-8y females, but in older children the pubertal spurt was reduced and more precocious. As a result, the height of OS, which was greater in 3-13 year-old males and in 3-11.5 year-old females, subsequently showed a reduction, as compared to that of NWS, in 16-18 year-old males and in 13-18 year-old females. In both responsive and non-responsive groups of obese subjects in WERP, the z-scores of height showed a reduction during WERP when evaluated using the reference curve of the total school population. In contrast, when their growth was evaluated according to the obese-specific reference curve, no significant variation was observed comparing both z-scores before and during the WERP., Conclusions: More appropriate information on the growth of obese subjects may be obtained when evaluating the height and HV according to obese-specific reference standards from the same population of origin. Adopting this modality, no significant variation of height resulted during WERP in obese children.

Objective: Leptin, the product of the ob gene, is present in higher concentrations in blood of obese subjects than of lean subjects. There is scarce information on the role of leptin in the pathogenesis of human obesity and little is known about leptin serum levels in obese children., Design, Subjects and Measurements: To evaluate the influences of age, sex, pubertal development and weight excess on serum leptin levels, we have studied 390 obese subjects (OS) and 320 normal weight subjects (NWS) aged 5-16 y. Fasting insulin concentrations were assayed in NWS, and an oral glucose tolerance test was carried out in OS and total insulin area under the curve (TIA) was calculated., Results: Log-transformed values of leptin serum concentrations appeared to be distributed according to an acceptable Gaussian pattern. As observed in adults, serum leptin concentrations in children and adolescents were also increased (4-5 times) in OS as compared to NWS. In both males and females, subdivided according to pubertal stages, serum leptin varied significantly in stage IV-V as compared to the lower stages, with a reduction in males and an increase in females. On comparing the two sexes, greater serum leptin concentrations were observed in females of both NWS and OS. A significant linear correlation was found in both groups, subdivided according to sex and pubertal stage, between log values of serum leptin and standard deviation scores (SDS) of body mass index (BMI), and log-transformed relative body weight (RBW). Using partial correlation analysis in subjects subdivided according to sex and pubertal stages, log values of serum leptin and fasting insulin values, adjusted by age and SDS of BMI, correlated significantly with a weaker correlation in males than in females. In OS, the leptin concentrations correlated better with TIA than with fasting insulin. A weight reduction program (WRP) was carried out in 141 OS and significant reductions of serum leptin and fasting insulin were observed, showing a reduction of RBW. There was a correlation between the reduction of RBW and of serum leptin, but not of fasting insulin. No variation was found in non-responsive OS. RBW reduction correlated with leptin, but not with insulin (fasting and TIA), evaluated before the therapeutic program started., Conclusion: As observed in adults, obese children and adolescents have higher serum leptin concentrations. However, several conditions should be taken into account when evaluating leptin concentrations in children. There are differences, independent of BMI, relative to pubertal stage and sex, females having greater leptin concentrations than males. There is evidence of a possible role for leptin in the effectiveness of a weight reduction program in OS.