Parental smoking and neonatal serum levels of polychlorinated biphenyls and hexachlorobenzene

Polychlorinated biphenyls (PCB) and hexachlorobenzene (HCB) are ubiquitous compounds that have tumor-promoting properties if applied together with tobacco-specific carcinogens. It was the purpose of the present study to investigate whether parental smoking by itself will increase the prenatal uptake of such organochloric compounds. With the informed consent of the parents, blood samples were taken from 80 full-term neonates before the first oral feeding. Six PCB congeners (PCB 28, 52, 101, 138, 153, and 180) and HCB were analyzed with capillary gas chromatography. Information about parental smoking behavior, the geographic origin of the parents, and their actual and previous working places was recorded. We composed three study groups for statistical analyses: active smoking mothers (n = 12), passive smoking mothers (n = 33), and nonsmoking families (n = 35). Neonates born to active smoking mothers had the highest PCB and HCB concentrations compared with children of passive or nonsmoking mothers. These differences were statistically significant (p < 0.01) in the cases of PCB 138, total PCB, and HCB. Newborns of passive smoking mothers had higher PCB and HCB concentrations than children of nonsmoking families but lower values than those of active smoking mothers. These differences were statistically significant for all compounds with the exception of PCB 180. It is concluded that active and passive maternal smoking increases the neonatal burden with PCB and HCB.     

Bone growth from 11 to 17 years: relationship to growth, gender and changes with pubertal status including timing of menarche

The tempo and change in bone growth during puberty in relation to physical growth is described in a cohort of 56 boys and 52 girls. Distal forearm bone width, mineral content and volumetric density, anthropometry and pubertal status were measured at ages 11, 13, 15 and 17 y, and bone age at 17 y. Bone width and mineral content increased independently with age for each pubertal stage. Volumetric density fell during early puberty and then increased rapidly. Maximal increase of all bone variables occurred earlier in girls than in boys and earliest for bone width, then mineral content, then density. In girls most change occurred in the 12 mo before and after menarche. The degree of tracking was similar to that for height. Bone growth followed physical growth but at a slower tempo. By age 17 y boys had attained 86% of the reference adult bone mineral content and volumetric density; girls had attained 93% of the reference adult bone mineral content and 94% of volumetric density. Those skeletally mature at 17 y had greater mineral content and volumetric density. To maximize peak bone mass, modifiable environmental factors should be optimized before the onset of puberty and be maintained throughout this period of rapid growth and beyond attainment of sexual maturity.     

Effects of in utero exposure to polychlorinated biphenyls and related contaminants on cognitive functioning in young children

Because prenatal exposure to polychlorinated biphenyls (PCBs) and related contaminants has been associated with reduced birth weight, neonatal behavioral anomalies, and poorer recognition memory in infants born to women who have consumed Lake Michigan sports fish, 236 children, previously evaluated for PCB-related deficits in infancy, were assessed at 4 years of age. Prenatal exposure (indicated by umbilical cord serum PCB level) predicted poorer short-term memory function on both verbal and quantitative tests in a dose-dependent fashion. These effects cannot be attributed to a broad range of potential confounding variables, the impact of which was evaluated statistically. Although much larger quantities of PCBs are transferred postnatally via lactation than prenatally across the placenta, exposure from nursing was unrelated to cognitive performance. The data demonstrate the continuation of a toxic impact received in utero and observed initially during infancy on a dimension of cognitive functioning fundamental to learning.     

Relations among arm, arm muscle, arm fat areas and menarche in adolescents in the municipality of Botucatu

The authors show the relations among arm circumference, arm muscle and arm fat areas with or without menarche, by carrying out an anthropometric study in 717 adolescents in the municipality of Botucatu. It must be emphasized that those adolescents who had already menstruated presented significantly higher nutritional indicators than those who had not menstruated yet. There was an increase in fat tissue and lean body mass in those adolescents who had already menstruated. Body changes might be expressed by calculating muscle and arm fat areas using triceps skinfold and arm circumference.     

Relation of peer and media influences to the development of purging behaviors among preadolescent and adolescent girls.

OBJECTIVE: To assess prospectively the relation of peer and media influences on the risk of development of purging behaviors. DESIGN: Prospective cohort study. SETTING: One year follow-up of 6982 girls aged 9 to 14 years in 1996 who completed questionnaires in 1996 and 1997 and reported in 1996 that they did not use vomiting or laxatives to control weight. MAIN OUTCOME MEASURE: Self-report of using vomiting or laxatives at least monthly to control weight. RESULTS: During 1 year of follow-up, 74 girls began using vomiting or laxatives at least monthly to control weight. Tanner stage of pubic hair development was predictive of beginning to purge (odds ratio [OR] = 1.8; 95% confidence interval [CI], 1.3-2.4). Independent of age and Tanner stage of pubic hair development, importance of thinness to peers (OR = 2.3; 95% CI, 1.8-3.0) and trying to look like females on television, in movies, or in magazines (OR= 1.9; 95% CI, 1.6-2.3) were predictive of beginning to purge at least monthly. Regardless of the covariates included in the logistic regression model, the risk of beginning to purge increased approximately 30% to 40% per 1-category increase in frequency of trying to look like females on television, in movies, or in magazines. CONCLUSIONS: Both peers and popular culture, independent of each other, exert influence on girls' weight control beliefs and behaviors. Therefore, to make eating disorder prevention programs more effective, efforts should be made to persuade the television, movie, and magazine industries to employ more models and actresses whose weight could be described as healthy, not underweight.     

Relationship between early‐life nutrition and ages at menarche and first pregnancy,and childbirth rates of young adults: Evidence from APCAPS in India

India's Integrated Child Development Services (ICDS) provides daily supplementary nutrition and other public health services to women and children. We estimated associations between exposure to early‐childhood ICDS nutrition and adult reproductive outcomes. During 1987–1990, a balanced protein–calorie supplement called “upma”—made from locally available corn–soya ingredients—was rolled out by subdistricts near Hyderabad and offered to pregnant women and children under age 6 years. In a controlled trial, 15 villages received the supplement and 14 did not. We used data from a 2010–2012 resurvey of adults born during the trial (n = 715 in intervention and n = 645 in control arms). We used propensity score matching methods to estimate the associations between birth in an intervention village and menarcheal age, age at first pregnancy, and fertility of adults. We found that women born in the intervention group during the trial, as compared with the control group, had menarche 0.45 (95% confidence interval [CI: 0.22, 0.68]; p < .001) years later and first pregnancy 0.53 (95% CI [0.04, 1.02]; p < .05) years later. Married women from the intervention group had menarche 0.36 (95% CI [0.09, 0.64]; p < .01) years later, first cohabitation with partner 0.8 (95% CI [0.27, 1.33]; p < .01) years later, and first pregnancy 0.53 (95% CI [0.04, 1.02]; p < .05) years later than married women in the control group. There was no significant difference between intervention and control group women regarding whether they had at least one childbirth or the total number of children born. The findings were similar when we employed inverse propensity score weighted regression models.     

Perceived pubertal timing, pubertal status and the prevalence of alcohol drinking and cigarette smoking in early and late adolescence: a population based study of 8950 Norwegian boys and girls

Aim: To study whether perceived pubertal timing is related to the prevalence of alcohol drinking and cigarette smoking among adolescent boys and girls. Methods: The Young‐HUNT study (95–97), conducted in Nord‐Trøndelag County in Norway, comprises information from 8950 students, aged 13–19 years. Odds ratios (OR) with 95% confidence intervals (CI) related to alcohol drinking and cigarette smoking were estimated by logistic regression analyses. Results: Boys and girls who perceived themselves as early matured were more likely to report more risky drinking than those who perceived themselves as being on time, both in middle school and high school. A nearly identical pattern was found for smoking. However, boys in middle school, who perceived themselves as late, were more likely to smoke than those who were on time. Conclusion: In both genders, perceived early maturation was associated with increased risk behaviour involvement. Perceptions of being early in combination with high pubertal status yielded the highest prevalence of alcohol and tobacco use.     

Prediction of adult height from height, bone age, and occurrence of menarche, at ages 4 to 16 with allowance for midparent height.

Multiple regression equations for predicting the adult height of boys and girls from height and bone age at ages 4 and upwards are presented. There is a separate equation for each half year of chronological age; and for pre- and postmenarcheal girls at ages 11 to 14. These are based on longitudinal data from 116 boys and 95 girls of the Harpenden Growth Study and the London group of the International Children's Centre longitudinal study. The bone age used is the revised version of the Tanner-Whitehouse standards, omitting the score for carpal bones (RUS age, TW 2 system). Boys aged 4 to 12 are predicted in 95% of instances to within plus or minus 7 cm of true height, and at ages 13 and 14 to within plus or minus 6 cm. Girls ages 4 to 11 are predicted to within plus or minus 6 cm; premenarcheal girls aged 12 and 13 to within plus or minus 5 and plus or minus 4 cm, respectively; and postmenarcheal girls aged 12 and 13 to within plus or minus 4 and plus or minus 3 cm, respectively. Prediction can be somewhat imporved by allowing for midparent height. One-third of the amount that midparent height differs from mean midparent height is added or subtracted. An alternative system of equations which are based on initial classification by bone age rather than chronological age is given. These have about the same accuracy as the equations based on initial classification by chronological age, but allowance for bone age retardation is less. It is not clear which system is preferable. The equations probably apply to girls complaining of tall stature and boys or girls complaining of shortness and needing reassurance as to normality. In clearly pathological children, such as those with endocrinopathies, they do not apply.