Tracking of physical activity during adolescence: the 1993 Pelotas Birth Cohort, Brazil

OBJECTIVE To analyze physical activity during adolescence in participants of the 1993 Pelotas Birth Cohort Study, Brazil. METHODS Data on leisure time physical activity at 11, 15, and 18 years of age were analyzed. At each visit, a cut-off point of 300 min/week was used to classify adolescents as active or inactive. A total of 3,736 participants provided data on physical activity at each of the three age points. RESULTS A significant decline in the proportion of active adolescents was observed from 11 to 18 years of age, particularly among girls (from 32.9% to 21.7%). The proportions of girls and boys who were active at all three age points were 28.0% and 55.1%, respectively. After adjustment for sex, economic status, and skin color, participants who were active at 11 and 15 years of age were 58.0% more likely to be active at 18 years of age compared with those who were inactive at 11 and 15 years of age. CONCLUSIONS Physical activity declined during adolescence and inactivity tended to track over time. Our findings reinforce the need to promote physical activity at early stages of life, because active behavior established early tends to be maintained over time.

Effect of the exposure to maternal smoking during pregnancy and childhood on the body mass index until adolescence

OBJECTIVE Investigate the effect of exposure to smoking during pregnancy and early childhood on changes in the body mass index (BMI) from birth to adolescence.METHODS A population-based cohort of children (0-5 years old) from Cuiabá, Midwest Brazil, was assessed in 1999-2000 (n = 2,405). Between 2009 and 2011, the cohort was re-evaluated. Information about birth weight was obtained from medical records, and exposure to smoking during pregnancy and childhood was assessed at the first interview. Linear mixed effects models were used to estimate the association between exposure to maternal smoking during pregnancy and preschool age, and the body mass index of children at birth, childhood and adolescence.RESULTS Only 11.3% of the mothers reported smoking during pregnancy, but most of them (78.2%) also smoked during early childhood. Among mothers who smoked only during pregnancy (n = 59), 97.7% had smoked only in the first trimester. The changes in body mass index at birth and in childhood were similar for children exposed and those not exposed to maternal smoking. However, from childhood to adolescence the rate of change in the body mass index was higher among those exposed only during pregnancy than among those who were not exposed.CONCLUSIONS Exposure to smoking only during pregnancy, especially in the first trimester, seems to affect changes in the body mass index until adolescence, supporting guidelines that recommend women of childbearing age to stop smoking.

Congenital toxoplasmosis in dizygotic twins, Paraná, Brazil

This is the first report of congenital toxoplasmosis in dizygotic twins in Brazil. We emphasize the need for early diagnosis of the mother and follow-up of children with suspected or confirmed infection from birth to adolescence, in order to avoid the hazard and damage from congenital toxoplasmosis.

Antibody levels in children after 10 years of vaccination against hepatitis B: a brazilian community-based study

INTRODUCTION: It is known that the hepatitis B (HB) vaccine is effective, but it is alarming that sudden drops of antibody levels may coincide with the onset of adolescence. METHODS: Antibody levels against HB vaccine surface antigen (anti-HBs) and HB vaccine core antigen (anti-HBc) were measured on the blood samples of children with a mean age of 11.4 years. RESULTS: About 54.8% had protective levels of anti-HBs. Of those who were anti-HBc-positive (4.4%), an average of 218.4 anti-HBs mIU/mL was found. CONCLUSIONS: Immunological protection was found in the majority of children. However, more studies are needed to elucidate the heritability of nonresponders and establish strategies against such events.

Left atrial myxoma as the cause of syncope in an adolescent

A case of left atrial myxoma is reported in a 14-year-old female patient with recurrent episodes of syncope. The patient was immediately referred to the cardiologist after an inconclusive neurological investigation. Syncope is a symptom thoroughly described as being associated with heart myxomas, but its specific association with adolescence is extremely rare. The authors discuss the clinical manifestations of the disease, emphasizing the diagnostic difficulties on the basis of the unspecific symptoms. As part of the analysis a Brazilian literature review was carried out. Also, the authors experience in the surgical treatment of the heart tumors is briefly presented.

Metabolic Syndrome and Importance of Associated Variables in Children and Adolescents in Guabiruba - SC, Brazil

Background:The risk factors that characterize metabolic syndrome (MetS) may be present in childhood and adolescence, increasing the risk of cardiovascular disease in adulthood.Objective:Evaluate the prevalence of MetS and the importance of its associated variables, including insulin resistance (IR), in children and adolescents in the city of Guabiruba-SC, Brazil.Methods:Cross-sectional study with 1011 students (6–14 years, 52.4% girls, 58.5% children). Blood samples were collected for measurement of biochemical parameters by routine laboratory methods. IR was estimated by the HOMA-IR index, and weight, height, waist circumference and blood pressure were determined. Multivariate logistic regression models were used to examine the associations between risk variables and MetS.Results:The prevalence of MetS, IR, overweight and obesity in the cohort were 14%, 8.5%, 21% and 13%, respectively. Among students with MetS, 27% had IR, 33% were overweight, 45.5% were obese and 22% were eutrophic. IR was more common in overweight (48%) and obese (41%) students when compared with eutrophic individuals (11%; p = 0.034). The variables with greatest influence on the development of MetS were obesity (OR = 32.7), overweight (OR = 6.1), IR (OR = 4.4; p ≤ 0.0001 for all) and age (OR = 1.15; p = 0.014).Conclusion:There was a high prevalence of MetS in children and adolescents evaluated in this study. Students who were obese, overweight or insulin resistant had higher chances of developing the syndrome.

Correlation of Insulin Resistance with Anthropometric Measures and Blood Pressure in Adolescents

Abstract Background: Blood pressure is directly related to body mass index, and individuals with increased waist circumference have higher risk of developing hypertension, insulin resistance, and other metabolic changes, since adolescence. Objective: to evaluate the correlation of blood pressure with insulin resistance, waist circumference and body mass index in adolescents. Methods: Cross-section study on a representative sample of adolescent students. One group of adolescents with altered blood pressure detected by casual blood pressure and/or home blood pressure monitoring (blood pressure > 90th percentile) and one group of normotensive adolescents were studied. Body mass index, waist circumference were measured, and fasting glucose and plasma insulin levels were determined, using the HOMA-IR index to identify insulin resistance. Results: A total of 162 adolescents (35 with normal blood pressure and 127 with altered blood pressure) were studied; 61% (n = 99) of them were boys and the mean age was 14.9 ± 1.62 years. Thirty-eight (23.5%) adolescents had altered HOMA-IR. The group with altered blood pressure had higher values of waist circumference, body mass index and HOMA-IR (p<0.05). Waist circumference was higher among boys in both groups (p<0.05) and girls with altered blood pressure had higher HOMA-IR than boys (p<0.05). There was a significant moderate correlation between body mass index and HOMA-IR in the group with altered blood pressure (ρ = 0.394; p < 0.001), and such correlation was stronger than in the normotensive group. There was also a significant moderate correlation between waist circumference and HOMA-IR in both groups (ρ = 0.345; p < 0.05). Logistic regression showed that HOMA-IR was as predictor of altered blood pressure (odds ratio - OR = 2.0; p = 0.001). Conclusion: There was a significant association of insulin resistance with blood pressure and the impact of insulin resistance on blood pressure since childhood. The correlation and association between markers of cardiovascular diseases was more pronounced in adolescents with altered blood pressure, suggesting that primary prevention strategies for cardiovascular risk factors should be early implemented in childhood and adolescence.

Seroepidemiology of hepatitis B virus infection and high rate of response to hepatitis B virus Butang®vaccine in adolescents from low income families in Central Brazil

In order to evaluate the seroepidemiology and response to Butang® vaccine in adolescents from low income families in Central Brazil, blood samples of 664 adolescents were tested for hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), and hepatitis B surface antibody (anti-HBs) markers, and multiple logistical regression analysis was carried out to determine variables associated with hepatitis B virus (HBV) infection markers. further, three 20 µg butang® vaccine doses were offered to all susceptible individuals (n = 304). Among those who accepted them (n = 182), the seroresponse was evaluated in 170 individuals by quantitative anti-HBs. an overall hbv prevalence of 5.9% was found: four adolescents were HBsAg positive, 24 were anti-HBc, anti-HBs-reactive, and 11 were anti-HBc only. The analyse of risk factors showed that age 16-19 years, place of birth outside Goiás, school B and body piercing were statistically associated with HBV infection markers (p < 0.05). All 170 adolescents responded to butang®, and a geometric mean titer (gmt) of 4344 mui/ml was obtained. these results reinforce the importance of hepatitis b vaccine in adolescents despite of the hbv regional endemicity, and suggest that three doses of 20 µg of the butang® should guarantee protective anti-hbs levels to individuals at a critical time for hepatitis b acquiring such as latter adolescence and adulthood.

Kant, Nietzsche and the idealization of friendship into nihilism

Is friendship still possible under nihilistic conditions? Kant and Nietzsche are important stages in the history of the idealization of friendship, which leads inevitably to the problem of nihilism. Nietzsche himself claims on the one hand that only something like friendship can save us in our nihilistic condition, but on the other hand that precisely friendship has been unmasked and become impossible by these very conditions. It seems we are struck in the nihilistic paradox of not being allowed to believe in the possibility of what we cannot do without. Literary imagination since the 19th century seems to make us even more skeptical. Maybe Beckett provides an illustration of a way out that fits well to Nietzsche's claim that only "the most moderate, those who do not require any extreme articles of faith" will be able to cope with nihilism.

Serum leptin concentration during puberty in healthy nonobese adolescents

Data obtained during the past five years have indicated that there are important age- and gender-based differences in the regulation and action of leptin in humans. To study the physiological changes of leptin during puberty in both sexes, and its relationship with body composition and sexual maturation, we measured leptin concentrations in 175 healthy adolescents (80 girls, 95 boys, 10-18 years of age), representing all pubertal stages. We excluded individuals with a body mass index (BMI) below the 5thor above the 95th percentile relative to age. Serum concentrations of leptin were determined by a monoclonal antibody-based immunofluorimetric assay, developed in our laboratory. Body composition was determined by dual-energy X-ray absorptiometry. Pubertal stage was assigned by physical examination, according to Tanner criteria for breast development in females and genital development in males. Leptin concentration in girls (N = 80) presented a positive linear correlation with age (r = 0.35, P = 0.0012), BMI (r = 0.65, P < 0.0001) and %fat mass (r = 0.76, P < 0.0001). In boys (N = 95) there was a positive correlation with BMI (r = 0.49, P < 0.0001) and %fat mass (r = 0.85, P < 0.0001), but a significant negative linear correlation with Tanner stage (r = -0.45, P < 0.0001) and age (r = -0.40, P < 0.0001). The regression equation revealed that %fat mass and BMI are the best parameters to be used to estimate leptin levels in both sexes. Thus, the normal reference ranges for circulating leptin during adolescence should be constructed according to BMI or %fat mass to assure a correct evaluation.

Gender-related pathways for behavior problems in the offspring of alcoholic fathers

The objective of the present study was to examine gender differences in the influence of paternal alcoholism on children's social-emotional development and to determine whether paternal alcoholism is associated with a greater number of externalizing symptoms in the male offspring. From the Mannheim Study of Risk Children, an ongoing longitudinal study of a high-risk population, the developmental data of 219 children [193 (95 boys and 98 girls) of non-alcoholic fathers, non-COAs, and 26 (14 boys, 12 girls) of alcoholic fathers, COAs] were analyzed from birth to the age of 11 years. Paternal alcoholism was defined according to the ICD-10 categories of alcohol dependence and harmful use. Socio-demographic data, cognitive development, number and severity of behavior problems, and gender-related differences in the rates of externalizing and internalizing symptoms were assessed using standardized instruments (IQ tests, Child Behavior Checklist questionnaire and diagnostic interviews). The general linear model analysis revealed a significant overall effect of paternal alcoholism on the number of child psychiatric problems (F = 21.872, d.f. = 1.217, P < 0.001). Beginning at age 2, significantly higher numbers of externalizing symptoms were observed among COAs. In female COAs, a pattern similar to that of the male COAs emerged, with the predominance of delinquent and aggressive behavior. Unlike male COAs, females showed an increase of internalizing symptoms up to age 11 years. Of these, somatic complaints revealed the strongest discriminating effect in 11-year-old females. Children of alcoholic fathers are at high risk for psychopathology. Gender-related differences seem to exist and may contribute to different phenotypes during development from early childhood to adolescence.

Do early life factors influence body mass index in adolescents?

The association between early life factors and body mass index (BMI) in adulthood has been demonstrated in developed countries. The aim of the present study was to assess the influence of early life factors (birth weight, gestational age, maternal smoking, and social class) on BMI in young adulthood with adjustment for adult socioeconomic position. A cohort study was carried out in 1978/79 with 6827 mother-child pairs from Ribeirão Preto city, located in the most developed economic area of the country. Biological, economic and social variables and newborn anthropometric measurements were obtained shortly after delivery. In 1996, 1189 males from this cohort, 34.3% of the original male population, were submitted to anthropometric measurements and were asked about their current schooling on the occasion of army recruitment. A multiple linear regression model was applied to determine variables associated with BMI. Mean BMI was 22.7 (95%CI = 22.5-23.0). After adjustment, BMI was 1.22 kg/m² higher among infants born with high birth weight (³4000 g), 1.21 kg/m² higher among individuals of low social class at birth and 0.69 kg/m² higher among individuals whose mothers smoked during pregnancy (P < 0.05). The association between social class at birth and BMI remained statistically significant (P < 0.05) even after adjustment for adult schooling. These findings suggest that early life social influences on BMI were more important and were not reversed by late socioeconomic position. Therefore, prevention of overweight and obesity should focus not only on changes in adult life styles but also on factors such as high birth weight.

Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although cross-sensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P) 28-37) and adult (P60-67) rats received nicotine (0.4 mg/kg, sc) or saline (0.9% NaCl, sc) and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc) or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.