Genetic associations with childhood brain growth,defined in two longitudinal cohorts

Genome‐wide association studies (GWASs) are unraveling the genetics of adult brain neuroanatomy as measured by cross‐sectional anatomic magnetic resonance imaging (aMRI). However, the genetic mechanisms that shape childhood brain development are, as yet, largely unexplored. In this study we identify common genetic variants associated with childhood brain development as defined by longitudinal aMRI. Genome‐wide single nucleotide polymorphism (SNP) data were determined in two cohorts: one enriched for attention‐deficit/hyperactivity disorder (ADHD) (LONG cohort: 458 participants; 119 with ADHD) and the other from a population‐based cohort (Generation R: 257 participants). The growth of the brain's major regions (cerebral cortex, white matter, basal ganglia, and cerebellum) and one region of interest (the right lateral prefrontal cortex) were defined on all individuals from two aMRIs, and a GWAS and a pathway analysis were performed. In addition, association between polygenic risk for ADHD and brain growth was determined for the LONG cohort. For white matter growth, GWAS meta‐analysis identified a genome‐wide significant intergenic SNP (rs12386571, P = 9.09 × 10^?9), near AKR1B10. This gene is part of the aldo‐keto reductase superfamily and shows neural expression. No enrichment of neural pathways was detected and polygenic risk for ADHD was not associated with the brain growth phenotypes in the LONG cohort that was enriched for the diagnosis of ADHD. The study illustrates the use of a novel brain growth phenotype defined in vivo for further study.     

E-cigarette use among women of reproductive age: Impulsivity,cigarette smoking status,and other risk factors

IntroductionThe study aim was to examine impulsivity and other risk factors for e-cigarette use among women of reproductive age comparing current daily cigarette smokers to never cigarette smokers. Women of reproductive age are of special interest because of the additional risk that tobacco and nicotine use represents should they become pregnant.MethodSurvey data were collected anonymously online using Amazon Mechanical Turk in 2014. Participants were 800 women ages 24–44 years from the US. Half (n = 400) reported current, daily smoking and half (n = 400) reported smoking < 100 cigarettes lifetime. Participants completed questionnaires regarding sociodemographics, tobacco/nicotine use, and impulsivity (i.e., delay discounting & Barratt Impulsiveness Scale). Predictors of smoking and e-cigarette use were examined using logistic regression.ResultsDaily cigarette smoking was associated with greater impulsivity, lower education, past illegal drug use, and White race/ethnicity. E-cigarette use in the overall sample was associated with being a cigarette smoker and greater education. E-cigarette use among current smokers was associated with increased nicotine dependence and quitting smoking; among never smokers it was associated with greater impulsivity and illegal drug use. E-cigarette use was associated with hookah use, and for never smokers only with use of cigars and other nicotine products.ConclusionsE-cigarette use among women of reproductive age varies by smoking status, with use among current smokers reflecting attempts to quit smoking whereas among non-smokers use may be a marker of a more impulsive repertoire that includes greater use of alternative tobacco products and illegal drugs.     

Gender and smoking status-based analysis of views regarding waterpipe and cigarette smoking in Aleppo, Syria

BACKGROUND: Narghile (waterpipe) smoking is increasing across the Eastern Mediterranean region (EMR), though little is known about the social attitudes and perceptions related to this method of tobacco use, and how those attitudes and perceptions are influenced by gender. METHODS: Data from two cross-sectional surveys conducted in 2003 in Aleppo, Syria, were used to examine these issues. Overall, 855 participants were included (439 men, 416 women; mean age, 24.4+/-7.1 years; response rate, 97%). The current analysis focuses on responses to four similar nine-item questions tapping perceptions related to narghile smoking by women or men, and cigarette smoking by women or men. Scores on the nine items were summed to yield a total score to gauge participants' perceptions about narghile and cigarette. RESULTS: Generally, participants were less positive about women smoking relative to men smoking, and cigarette smoking relative to narghile smoking. Cigarette smoking by women was the behavior least associated with positive perceptions. Individuals who resided in the city, were economically better-off, and were Christian, had higher perception scores (i.e., more positive attitudes) toward all forms of smoking, whereas older and married participants had higher perception scores for narghile only. Smoking status of participants, especially narghile smoking, was also associated with more positive perceptions toward smoking in general. CONCLUSIONS: We conclude that preliminary analysis shows that views on different forms of smoking in Syria differ by gender and smoking status.     

Consistency between cross-sectional and longitudinal SNP: blood lipid associations

Various studies have linked different genetic single nucleotide polymorphisms (SNPs) to different blood lipids (BL), but whether these “connections” were identified using cross-sectional or longitudinal (i.e., changes over time) designs has received little attention. Cross-sectional and longitudinal assessments of BL [total, high-, low-density lipoprotein cholesterol (TC, HDL, LDL), triglycerides (TG)] and non-genetic factors (body mass index, smoking, alcohol intake) were measured for 2,002 Geneva, Switzerland, adults during 1999–2008 (two measurements, median 6 years apart), and 20 SNPs in 13 BL metabolism-related genes. Fixed and mixed effects repeated measures linear regression models, respectively, were employed to identify cross-sectional and longitudinal SNP:BL associations among the 1,516 (76%) study participants who reported not being treated for hypercholesterolemia at either measurement time. One-third more (12 vs. 9) longitudinal than cross-sectional associations were found [Bonferroni-adjusted two-tailed p < 0.00125 (=0.05/2)/20) for each of the four ensembles of 20 SNP:individual BL associations tested under the two study designs]. There was moderate consistency between the cross-sectional and longitudinal findings, with eight SNP:BL associations consistently identified across both study designs: [APOE.2 and APOE.4 (rs7412 and rs429358)]:TC; HL/LIPC (rs2070895):HDL; [APOB (rs1367117), APOE.2 and APOE.4 (rs7412 and rs429358)]:LDL; [APOA5 (rs2072560) and APOC III (rs5128)]:TG. The results suggest that cross-sectional studies, which include most genome-wide association studies (GWAS), can assess the large majority of SNP:BL associations. In the present analysis, which was much less powered than a GWAS, the cross-sectional study was around 2/3 (67%) as efficient as the longitudinal study.     

Lower prevalence of cigarette and waterpipe smoking, but a higher risk of waterpipe dependence in Lebanese adult women than in men

The objective of this study was to evaluate whether nicotine dependence was higher in Lebanese women smokers compared with men smokers. Data were taken from a national cross-sectional study. Lebanese residents aged ≥ 40 years were enrolled between October 2009 and September 2010. After informed consent, participants answered a standardized questionnaire about smoking behaviors and dependence (measured by the Fagerstr?m-Test-Nicotine-Dependence for cigarettes and the Lebanon-Waterpipe-Dependence-Scale 11 for waterpipes): 1,066 males and 1,134 females were interviewed. 58.7% versus 42.9% of them, respectively, ever smoked cigarettes, while 6.9% versus 6.7% ever smoked a waterpipe (p < 0.001). Moreover, 57.5% in male versus 49.1% in female cigarette smokers (p = 0.041), 35.9% versus 51.6% in waterpipe smokers (p = 0.076), and 67.9% versus 43.6% in mixed smokers were tobacco dependent. A dose-effect relationship was observed with increased rates of women versus men with waterpipe dependence) and an increased odds of dependence among women in multivariable analysis (ORa = 2.28). Positive (smoking waterpipe for pleasure and conviviality) and negative (smoking waterpipe to relax nerves and improve morale) reinforcements were significantly more frequent in women, while no significant sex difference was observed for nicotine dependence or psychological craving. In exclusive waterpipe smokers, significantly higher respiratory diseases and symptoms prevalences were found in females compared with males. Women who smoke waterpipes should receive attention during tobacco health education and smoking cessation.     

Television viewing and smoking volume in adolescent smokers: a cross-sectional study

BACKGROUND: Previous research has shown a relationship between television viewing and smoking initiation. The relationship between television viewing and the amount of cigarettes consumed by adolescent smokers per time unit (day, week, month...) has not yet been studied. METHODS: A cross-sectional sample of children by means of self-reports administered by research assistants in schools was obtained. Participants were 421 smokers in a random sample of 4th year students in 15 secondary schools in Flanders, Belgium. Main outcome measures were quantifiable, closed survey questions about smoking volume, whether or not parents and friends smoked, frequency of going out and average weekly TV viewing volume. RESULTS: Television viewing was a significant predictor of smoking volume. Smokers who watch more TV smoke more. The relationship was curvilinear (quadratic). The relationship becomes stronger (curves upward) for higher levels of viewing. Those who watch 5 or more hours a day smoke between 60 and 147 cigarettes more per week than those who watch 1 h or less. CONCLUSIONS: Television viewing is significantly related to smoking volume. The content of television may glamorize smoking. Children may learn to associate smoking with viewing regardless of content. It is also possible that heavier smoking leads to more viewing or that a third variable influences both smoking volume and viewing. Regardless of the causal direction of the relationship television viewing appears to be an indicator or predictor of smoking volume. The curvilinear nature of the relationship deserves further attention.     

Peers, schools, and adolescent cigarette smoking.

PURPOSE: To investigate the effects of popularity, best friend smoking, and cigarette smoking within the peer networks on current smoking of seventh- through 12th-grade students. These factors were examined for adolescents attending schools with varying rates of student cigarette smoking. METHODS: This study used data from the saturated school sample of National Longitudinal Study of Adolescent Health (Add Health), a nationally representative school-based sample. The sample for the present study was 2525 adolescents in Grades 7-12 who completed an in-school questionnaire and an in-home interview. Information from the in-school questionnaire was used to construct measures of school smoking prevalence and popularity. Using peer nominations from the in-home interview, best friend smoking, and peer network smoking exposure were constructed using the peers' own reports of their cigarette smoking. Multiple regression techniques were used to estimate the risk of current cigarette smoking as a function of popularity, best friend smoking, peer network smoking, and school smoking prevalence, and all first-order interactions between measures of peer and school smoking prevalence. RESULTS: Adjusting for age, gender, race/ethnicity, parent education, school, and availability of cigarettes in the home, the risk of current smoking was significantly associated with peer networks in which at least half of the members smoked [odds ratio (OR) = 1.91], one or two best friends smoked (OR = 2.00), and with increasing rates of school smoking prevalence (OR = 1.73). In addition, there was a significant interaction of popularity and school smoking prevalence such that risk of current smoking was somewhat greater among popular students in schools with high smoking prevalence than among popular students in schools with low smoking prevalence. CONCLUSION: Findings suggest that school environments are important contexts for understanding peer group influences on adolescent cigarette smoking.     

Prevalence of cigarette smoking among subsequent cohorts of Italian males and females

Prevalence of cigarette smoking among successive cohorts of Italian males and females born between 1890 and 1969 was estimated from data of the 1983 National Health Survey (based on 89,765 persons randomly selected within strata of geographical area, size of place of residence, and size of household), opportunely corrected for excess mortality of smokers. The overall participation rate for the original sample was 93.6%; impossibility of tracing or refusal of the interview led to substitution of 2,058 households. Among males, smoking prevalence in the young and middle-aged increased steadily up to the generation born in 1920-1929, which, in its 30s, showed the highest absolute smoking prevalence (68.3% in 1960). Moderate declines followed, chiefly on a calendar-period basis (i.e., between 1970 and 1980 in each birth cohort). These declines occurred later and at a lower rate than in several other Western countries. Among females, cigarette smoking was extremely rare for those generations born at the turn of the century (only about 3% of Italian females born in 1890-1899 ever smoked), but increased steadily in each birth cohort and calendar period to reach a rate only about one-third lower than that of males in the 1960-1969 cohort.     

Child and adolescent labor and smoking: a cross-sectional study in southern Brazil

This cross-sectional study assessed the association between smoking and child and adolescent labor among 3,269 individuals 10 to 17 years of age in Pelotas, Rio Grande do Sul State, in southern Brazil (excluding higher income census tracts) in 1998. Adjusted hierarchical analysis was performed using Poisson regression. Prevalence of child labor was 13.8%. Current smoking prevalence was 6.3% in the sample as a whole (15.7% among working versus 3.4% among non-working children). In the multivariate analysis, smoking was significantly associated with child labor, with a prevalence ratio of 1.75 (95%CI: 1.30-2.36). Smoking was also associated with family characteristics (lower maternal schooling, mother currently without husband/partner, household members with alcohol or drug problems, single mother, and history of serious injuries), and the children's characteristics (age greater than 16 years, inadequate school performance, and externalizing behavior). The findings point to smoking as one of the harmful consequences of child labor and suggest the workplace as an appropriate target for smoking prevention.     

Romantic relationship characteristics and alcohol use: longitudinal associations with dual method contraception use

PurposeDual method contraception use, or the use of one type of contraceptive intended to prevent pregnancy combined with another type intended to reduce the risk of sexually transmitted infection, may be the most effective method to prevent both unintended pregnancy and sexually transmitted infection. This study tested the association between relationship length, relationship type (married, cohabiting, dating but not cohabiting), global alcohol use, and situational alcohol use and the probability of dual method contraception use from 20 to 23 years of age.MethodsHierarchical linear modeling analyses were conducted using longitudinal data from 754 sexually active male and female young adults aged 20–23 years. Dependent variables included both any dual method contraception use and consistent dual method contraception use.ResultsBetween 15% and 20% of respondents reported consistent dual method contraception use at each time point. Longer relationship length and more committed relationship type were associated with a lower probability of both any and consistent dual method contraception use. Situational alcohol use (drinking before sex), but not global alcohol use, also was related to a lower probability of both any and consistent dual method contraception use. Increasing age was associated with a lower probability of any dual method contraception use, but was not related to consistent dual method use.ConclusionsEfforts to promote dual method contraception among young adults should include messages discouraging drinking before sex and supporting dual method use even in the context of committed relationships.     

Determinants of glycated haemoglobin in the general population: associations with diet, alcohol and cigarette smoking

OBJECTIVE: We evaluated cigarette smoking, alcohol intake and consumption of different foods as determinants of glycated haemoglobin in a general population sample. DESIGN: Cross-sectional survey. SETTING: England. SUBJECTS: Representative sample of 15 809 adults aged 16 y and older. Data analysed for 9772 non-diabetic, white European subjects. MAIN OUTCOME MEASURES: Glycated haemoglobin (GHb). Analyses were adjusted for age, sex, body mass index (BMI), waist-hip circumference ratio, activity level, and educational attainment. RESULTS: After adjusting for confounding, GHb was 0.277% (95% confidence interval 0.218 to 0.336) higher in current smokers of 20 or more per day, compared with non-smokers. GHb was 0.189% (0.101 to 0.277) lower in those drinking 42 or more units of alcohol per week than in non-drinkers. GHb was not associated with frequency of consumption of pulses, fruit, vegetables and salads, cakes, bread or confectionery. GHb was higher in subjects who took sugar in tea (0.051%, 0.015 to 0.087%) or in coffee (0.069%, 0.034 to 0.105%). GHb was higher in subjects who used solid fat for cooking (0.082%, 0.022 to 0.142%), or who drank whole rather than reduced-fat milk (0.088%, 0.036 to 0.140%), or used butter or hard margarine rather than low-fat spreads (0.075%, 0.029 to 0.121%). CONCLUSIONS: In the general population, higher GHb may be associated with cigarette smoking, or frequent consumption of fat-containing foods. Consumption of alcohol may be associated with lower GHb. SPONSORSHIP: None.     

Cigarette smoking during pregnancy in two regions: cross-sectional study

ObjectiveSmoking in pregnancy is associated with the risk of congenital malformations and functional disorders. The aim of the study was to assess the prevalence of cigarette smoking in pregnancy, and the rate of congenital malformations in children at in utero exposure.MethodsThe trial was designed as a cross-sectional study to measure exposure of pregnant women to adverse influence of smoking and their health status. The study consists of two arms: one was conducted at four Zagreb maternity hospitals (Croatia) and the other at the same hospitals in Novi Sad (Serbia).ResultsData analysis revealed the habit of cigarette smoking during pregnancy in 829 (11.9%) of 6 992 (6 099+893) women. Malformations were found in 105 (1.5%) fetuses and newborns. Major congenital malformations were present in four (0.6%), minor malformations in 73 (10.5%) and LBW in 12 (1.7%) newborns. In all these cases pregnant women smoked until becoming aware of pregnancy or during pregnancy. Tobacco smoking and congenital abnormalities that define the contingency table are not significantly related in Zagreb (P=0.385), as well as in Novi Sad (P=0.345).ConclusionsThe rate of congenital malformations is higher in fetuses and newborns at in utero exposure to maternal cigarette smoking as well as to alcohol consumption and drug abuse than in the general population. The results of the present study did not identify the exact cause of these malformations because of fetal concurrent exposure to multiple teratogenic factors.     

Cigarette smoking during pregnancy in two regions: cross-sectional study

ObjectiveTo assess the prevalence of cigarette smoking in pregnancy, and the rate of congenital malformations in children at in utero exposure.MethodsThe trial was designed as a cross-sectional study to measure exposure of pregnant women to adverse influence of smoking and their health status. The study consists of two arms: one was conducted at four Zagreb maternity hospitals (Croatia) and the other at the same hospitals in Novi Sad (Serbia).ResultsData analysis revealed the habit of cigarette smoking during pregnancy in 829 (11.9%) of 6 992 (6 099+893) women. Malformations were found in 105 (1.5%) fetuses and newborns. Major congenital malformations were present in 4 (0.6%), minor malformations in 73 (10.5%) and low birth weight in 12 (1.7%) newborns. In all these pregnant women smoked until becoming aware of pregnancy or during pregnancy. Tobacco smoking and congenital abnormalities that define the contingency table were not significantly related in Zagreb (P=0.385), as well as in Novi Sad (P=0.345).ConclusionsThe proportion of pregnant women reporting cigarette smoking was quite similar in Zagreb and Novi Sad. There is no statistically significant association between cigarette smoking and congenital malformations.     

Changes in nicotine intake and cigarette use over time in two nationally representative cross-sectional samples of smokers

Population surveys have observed decreases in cigarette use over time among smokers. These decreases have probably been influenced by tobacco control measures implemented over the past several decades, but few data exist on whether smokers have also reduced their nicotine intake. The authors examined data from two cross-sectional National Health and Nutrition Examination Surveys (NHANES), conducted in 1988-1994 and 1999-2002. Laboratory, examination, and interview data from current smokers not reporting nicotine intake from other sources were examined. From NHANES III (1988-1994) to NHANES 1999-2002, the average number of cigarettes smoked per day (CPD) fell by nearly 15% (three cigarettes), while the mean serum cotinine level fell by 13% (30 ng/ml). Finer breakdowns of CPD data in each time period suggested that most of the change occurred in the lower (<10 CPD) and higher (>or=20 CPD) smoking categories. These data suggest that CPD may represent a proxy for exposure to nicotine and perhaps other tobacco smoke constituents on the population level, since the decline in serum cotinine levels observed among smokers closely paralleled the decline in self-reported CPD between 1988-1994 and 1999-2002. In addition, these data are inconsistent with the hypothesis that the remaining population of smokers is becoming more dependent on nicotine over time.     

Mediators and moderators of magazine advertisement effects on adolescent cigarette smoking

The purpose of the present study is to examine the relation between magazine advertising for cigarettes and adolescent cigarette smoking. Participants (242 adolescents) reported their frequency of reading 46 magazines and their attention to cigarette ads. Recognition of cigarette ads, passive peer pressure (i.e., normative beliefs), and the smoker image also were assessed. Results indicate that exposure to cigarette advertising and recognition of ads augment the effect of passive peer pressure on smoking. In addition, a positive smoker image was associated with attention to advertising and mediated the relation between attention and smoking. It is suggested that the effect of magazine ads on adolescents should be considered in policymaking on cigarette advertising.     

Social correlates of cigarette smoking among Icelandic adolescents: A population-based cross-sectional study

Background  

Previous research has shown that between 80 and 90 percent of adult smokers report having started smoking before 18 years of age. Several studies have revealed that multiple social factors influence the likelihood of smoking during adolescence, the period during which the onset of smoking usually occurs. To better understand the social mechanisms that influence adolescent smoking, we analyzed the relationship and relative importance of a broad spectrum of social variables in adolescent smoking in Iceland, a Nordic country with high per-capita income.     

DSS and DHS: longitudinal and cross-sectional viewpoints on child and adolescent mortality in Ethiopia

Background  

In countries where routine vital registration data are scarce, Demographic Surveillance Sites (DSS: locally defined populations under longitudinal surveillance for vital events and other characteristics) and Demographic and Health Surveys (DHS: periodic national cluster samples responding to cross-sectional surveys) have become standard approaches for gathering at least some data. This paper aims to compare DSS and DHS approaches, seeing how they complement each other in the specific instance of child and adolescent mortality in Ethiopia.     

Systematic review of social network analysis in adolescent cigarette smoking behavior

BACKGROUND: Social networks are important in adolescent smoking behavior. Previous research indicates that peer context is a major causal factor of adolescent smoking behavior. To date, however, little is known about the influence of peer group structure on adolescent smoking behavior. METHODS: Studies that examined adolescent social networks with regard to their cigarette smoking behavior were identified through online and manual literature searches. Ten social network analysis studies involving a total of 28,263 adolescents were included in the final review. RESULTS: Of the 10 reviewed studies, 6 identify clique members, liaisons, and isolates as contributing factors to adolescent cigarette smoking. Significantly higher rates of smoking are noted among isolates than clique members or liaisons in terms of peer network structure. Eight of the reviewed studies indicate that peer selection or influence precedes adolescents' smoking behavior and intent to smoke. Such peer selection or influence accounts for a large portion of similarities among smoking adolescents. CONCLUSION: Adolescents who are identified as isolates are more likely to smoke and engage in risk‐taking behaviors than others in the peer network structure. Given that the vast majority of current adult smokers started their smoking habits during adolescence, adolescent smoking prevention efforts will likely benefit from incorporating social network analytic approaches and focusing the efforts on isolates and other vulnerable adolescents from a peer selection and influence perspective.