Breathing problems, being an only child and having parents with possible sleep bruxism are associated with probable sleep bruxism in preschoolers: a population-based study.

PURPOSE: To determine the prevalence of probable sleep bruxism (SB) in preschoolers and associated factors. METHODS: A cross-sectional, population-based study was carried out with 862 dyads of parents/preschoolers aged 5 from Teresina, Brazil. Data collection was performed through a questionnaire answered by parents/guardians about socioeconomic, demographic, and health condition data. Each child was examined for diagnosis of probable SB based on the presence of dental wear associated or not with the report of teeth grinding by parents/guardians. The analysis of independent variables was stratified into four levels of determinants: demographic characteristics of the child (distal), characteristics of the family, environmental factors (intermediate), and health conditions (proximal). Descriptive analysis and bivariate and multivariate Poisson's regression were performed using a hierarchical approach (p < 0.05). RESULTS: The prevalence of probable SB was 36%. In the final adjusted multivariate hierarchical model, a preschooler who was the only child (PR = 1.25; 95%CI = 1.02-1.51), with breathing problems (PR = 1.43; 95%CI = 1.19-1.73), and having parents/guardians with possible sleep bruxism (PR = 1.65; 95%CI = 1.32-2.07) had a higher prevalence of probable SB. CONCLUSION: The prevalence of probable SB in preschoolers was high and associated with the condition of being an only child, the presence of breathing problems, and having parents/guardians with possible sleep bruxism.

Are only children in China more likely to be obese/overweight than their counterparts with siblings?

Family planning policy in China has resulted in a large number of one-child families. According to Becker's "quantity-quality trade-off" theory there is an inverse relationship between the number of children in a family, and spending per child. We test whether this has led to significant differences in the height, weight and BMI of only-children compared with children with siblings in China using 4414 observations derived from four recent waves (2004, 2006, 2009, and 2011) of the China Health and Nutrition Survey. We use propensity score matching and instrumental variables to control for the possible endogeneity of the number of siblings. Results show that only-children are significantly heavier (1.88 %-3.86 %), and have higher BMI (2.59 %-3.50 %). Moreover, they are more likely to be obese than children with siblings (2.33 %-3.00 %). Further analysis shows that these differences in health outcomes might be attributable to higher consumption of animal-source food (23.90-27.13 g), a higher frequency of eating western fast food (0.48-0.70 times/3-month) and drinking sweetened soft drinks (0.29-0.36 times/month), a higher share of meals eaten away from home (4.67 %-5.31 %), and more sedentary activity (20.04-34.35 minutes/week) by only children. Our study indicates that the growing share of only children due to China's family planning policies also contributes to the increasing prevalence of overweight and obesity in China. This policy has been eased in recent years, which might slow the increase in the prevalence of overweight and obesity and thus reduce the corresponding health burden for Chinese society as a whole.

Negative life events and post-traumatic stress disorder symptoms: a moderated mediation model of only-child status and depressive symptoms.

OBJECTIVES: Post-traumatic stress disorder symptoms (PTSS) and depressive symptoms are the most common adolescent psychological effects from earthquakes, with negative life events significantly influencing PTSS prolongation. However, the underlying mediating and moderating mechanisms that connect negative life events with PTSS remain unclear. The purpose of this study was to investigate (i) the mediating role of depressive symptoms on negative life events and PTSS and (ii) the moderating role of only-child status in the direct and indirect relationship between negative life events and PTSS, 3 years after the 2013 Ya'an earthquake in China. STUDY DESIGN: Quantitative study using data from the Ya'an earthquake. METHODS: Three years after the 2013 Ya'an earthquake, 4402 adolescent survivors in Lushan county were surveyed using the Adolescent Self-Rating Life Events Check list to assess the psychological effects of negative life events in the previous 12 months. In addition, the short Mood and Feeling Questionnaire and The Children's Revised Impact of Event Scale were used to assess depressive symptoms and PTSS severity, respectively. RESULTS: After controlling for gender and age, negative life events were found to be significantly positively associated with PTSS. The mediation analyses revealed that depressive symptoms mediated the association between negative life events and PTSS; however, the moderated mediation analysis found the association was much weaker for only children. CONCLUSION: The findings supported and clarified the interrelations and associations between negative life events, depressive symptoms and PTSS. The conditional process analyses found that only-child status moderated not only the direct associations but also the relationship between negative life events and depressive symptoms. Our findings highlight the need for intervention programmes targeting adolescents, especially for children with siblings.

The differences of lipid profiles between only children and children with siblings: A national survey in China.

With the increasing number of the one-child family, it is important to investigate whether the only-child status is associated with dyslipidemia. Among a national sample of 65,347 Chinese children aged 6-17 years, 16,100 lipid profiles were available. Children's height, weight, total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were measured. In comparison to children with siblings, only children (OC) were more likely to be boys and live in urban areas. OC had less physical activity, less fried food intake, but more meat and dairy intakes. OC had significantly higher levels of TC (3.97 ± 0.78 vs. 3.89 ± 0.77) and LDL-C (2.12 ± 0.65 vs. 2.06 ± 0.64) in the overall group, and also in the subgroups of rural boys and girls. The prevalence of hyper-TC (5.48% vs. 4.43%) and hyper-LDL-C (3.97% vs. 2.96%) were significantly higher in OC than their counterparts. Furthermore, we found higher odds of hyper-LDL-C [1.43 (1.12, 1.83)] in OC after adjustments. In the subgroup analysis, only-child status was associated with increased risk of hyper-TC [1.86 (1.06, 3.26)] and hyper-LDL-C [2.65 (1.14, 6.16)] among rural boys, and hyper-LDL-C among rural girls [2.20 (1.14, 4.22)]. In conclusion, higher levels of TC and LDL-C were found in OC especially for rural children. Being an only-child was associated with increased risk of hyper-LDL-C.

Increased obesity risks for being an only child in China: findings from a nationally representative study of 19,487 children.

OBJECTIVES: Given the rapid demographic transition and obesity growth in China, it is important to study how the large only-child population (≈100 million) might contribute to the obesity epidemic. This study evaluated associations of only-child status with weight and energy expenditure-related behaviors in China and examined how the associations may vary by sex and urbanicity. STUDY DESIGN: Secondary analyses of nationally representative cross-sectional data from China Education Panel Survey: Junior Cohorts 2013-14, which included 19,487 students from 112 middle schools in 28 regions across China. METHODS: We used propensity-score-weighted multilevel models to test associations between only-child status and weight outcomes. RESULTS: Compared with sibling-sons, only-sons had higher body mass index (BMI) (Beta = 0.32, P < 0.05) and higher risks of overweight (OR = 1.24, 95% CI = [1.07-1.45]) and obesity (OR = 1.29, 95% CI = [1.02-1.64]); and spent less time on TV watching (Incidence rate ratio (IRR) = 0.89, 95% CI = [0.81-0.98]), internet use (IRR = 0.87, 95% CI = [0.79-0.96]), after-school sports (IRR = 0.91, 95% CI = [0.83-0.99]), and household chores (IRR = 0.85, 95% CI = [0.80-0.92]). Overweight/obesity risks for only-sons were particularly pronounced in urban China, where only-sons were 36% more likely to be overweight and 43% more likely to be obese than sibling-sons. Only-daughters had a higher risk of obesity (OR = 1.43, 95% CI = [1.01-2.04]) than sibling-daughters. However, the association was not significant for either urban girls or rural girls examined separately. Only-daughters in rural areas spent less time helping with household chores (IRR = 0.88, 95% CI = [0.80-0.97]) than sibling-daughters. CONCLUSIONS: Future childhood obesity interventions should pay special attention targeting the large young only-child population in China.

The Prevalence of Only-Child Status Among Children and Adolescents Referred to a Gender Identity Service Versus a Clinical Comparison Group.

Several studies indicate that homosexual males have a high proportion of older brothers compared to heterosexual males. Natal males with gender dysphoria who are likely to be homosexual also display this sibship pattern. Until recently, there was little evidence linking homosexuality and/or gender dysphoria in females to unique sibship characteristics. Two studies have indicated that natal female youth clinically referred for gender dysphoria are more likely to be only children (Schagen, Delemarre-van de Waal, Blanchard, & Cohen-Kettenis, 2012; VanderLaan, Blanchard, Wood, & Zucker, 2014). However, these studies did not include control groups of youth clinically referred for other reasons. Thus, it is unclear whether the increased likelihood of only-child status is specific to gender-referred natal females. This study compared only-child status among youth referred to a mental health service for gender dysphoria (778 males, 245 females) versus other reasons (783 males, 281 females). Prehomosexual gender-referred males were less likely to be only children than clinical controls. Contrary to previous findings, gender-referred females were not more likely to be only children, indicating that increased likelihood of only-child status is not specific to gender-referred females, but is characteristic of clinic-referred females more generally.

Gay Male Only-Children: Evidence for Low Birth Weight and High Maternal Miscarriage Rates.

Recent findings suggest that there may be a maternal immune response underpinning the etiology of sexual orientation of gay male only-children. This maternal immune response appears to be distinct from that which is purported to explain the classic fraternal birth order effect found in studies of male sexual orientation. We tested two predictions related to the hypothesized maternal immune response in mothers of gay male only-children: (1) elevated fetal loss among mothers who have had gay male only-children and (2) lower birth weight in gay male only-children. Mothers of at least one gay son (n = 54) and mothers of heterosexual son(s) (n = 72) self-reported their pregnancy histories, including the birth weights of newborns and number of fetal losses (e.g., miscarriages). Mothers of gay male only-children (n = 8) reported significantly greater fetal loss compared with mothers of males with four other sibship compositions (gay with no older brothers, gay with older brothers, heterosexual only-children, heterosexual with siblings) (n = 118). Also, firstborn gay male only-children (n = 4) had a significantly lower birth weight than firstborn children in the four other sibship compositions (n = 59). Duration of pregnancy was not significantly different among the groups of firstborn children in the birth weight analyses. Thus, this study found further support for a distinct pattern of maternal immune response implicated in the etiology of male sexual orientation. Mechanisms that may underlie this potential second type of maternal immune response are discussed.

The influence of Chinese one-child family status on developmental coordination disorder status.

We conducted a population-based study on Developmental Coordination Disorder (DCD) in mainland China to explore the influence of one-child status in Chinese families on DCD. A total of 4001 children selected from 160 classes in 15 public nursery schools. The Movement Assessment Battery for Children assessed motor function. The prevalence of DCD in Chinese one-child families (8.7%) was higher than that in multi-child families (5.9%). Chinese one-child family status (compared with younger children in multi-child families) were negatively related with total score (-1.793), Manual dexterity (-0.228), Aiming and catching (-1.145), Balance (-0.433) of MABC-2 and DCD (OR=2.294) when adjusted for the children's and family's characteristics, and perinatal factors (each p<0.05). As one of the studies in this Chinese context, it provides a platform for future intervention programs in one-child families in preventing children's developmental disorders.

The risk of mothers losing an only child in China.

China's one-child policy has been quite successful in bringing down the country's fertility level but has produced a large number of one-child families. The risk of one-child families losing their only child has not received enough attention. In this paper, using an extension of Goldman & Lord (1983)'s method to measure widowhood, period life-table data from China's 2000 population census are used to examine age-specific and cumulative probabilities of mothers losing their only child. It is found that a mother faces a 14.94% probability of losing a son, and 12.21% probability of losing a daughter. As the age of first-time mothers increases, the probability of losing a child declines. Urban and rural mothers have different indices regarding the loss of children. Based on these findings the prospects for China's one-child policy are discussed.

Prevalence of post-traumatic stress disorder among adolescents after the Wenchuan earthquake in China.

BACKGROUND: The Wenchuan earthquake was a catastrophic earthquake in China. The aim of this study is to explore longitudinally the rates of post-traumatic stress disorder (PTSD) and depression in adolescents after the Wenchuan earthquake, and to identify independent predictors of PTSD. METHOD: PTSD and depression symptoms among adolescents at 6, 12 and 18 months after the Wenchuan earthquake were investigated using the PTSD Checklist Civilian Version and the Beck Depression Inventory (BDI). Subjects in this study included 548 high school student survivors in a local boarding high school. RESULTS: The rates of PTSD symptoms were 9.7%, 1.3% and 1.6% at the 6-, 12- and 18-month follow-ups, respectively. BDI scores were found to be the best predictor of severity of PTSD at 6, 12 and 18 months. Gender was another variable contributing significantly to PTSD at 6 and 12 months after the earthquake. In the 12-month follow-up, home damage was found to be a predictor of severity of PTSD symptoms. Being a child with siblings was found to be a predictor of severity of PTSD symptoms at 12 and 18 months after the earthquake. CONCLUSIONS: PTSD symptoms changed gradually at various stages after the earthquake. Depression symptoms were predictive of PTSD symptoms in the 18-month follow-up study. Other predictors of PTSD symptoms included female gender and being a child with siblings. The results of this study may be helpful for further mental health interventions for adolescents after earthquakes.

Infectious morbidity in 18-month-old children with and without older siblings.

BACKGROUND: Infections are the most commonly reported health problems in children. Younger age and day care outside the home are two factors of importance for infectious morbidity. The influence of siblings on infectious symptoms is not clear. OBJECTIVES: To compare families with one child and families with more than one child in terms of reported infectious symptoms, physician consultations and antibiotic prescriptions. METHODS: A prospective population-based survey was performed. During 1 month, all infectious symptoms, physician consultations and antibiotic prescriptions for 18-month-old children were noted by the parents. The 789 families also answered questions about socio-economic factors, numbers of siblings in the family and type of day care. RESULTS: No difference in number of symptom days was found between children with and without older siblings. Neither could we find any significance in terms of having older siblings in relation to physician consultations and antibiotic prescriptions. CONCLUSIONS: The results of our study indicate that having older siblings not was important in relation to number of symptoms days, physician consultations or antibiotic prescriptions for 18-month-old children in Sweden today. Changes in social activities and attitudes towards antibiotic prescription may explain our different findings as compared with previous Swedish studies and studies from other countries.

Differences in allergy trends between East and West Germany and possible explanations.

BACKGROUND: At the time of the German reunification in 1990, manifestations of most allergic diseases were less prevalent in East than in West Germany. It was hypothesized that these East-West differences would diminish with lifestyle and pollution changes in East Germany. OBJECTIVE: To investigate whether changes in the prevalence of asthma, hayfever, eczema or allergic sensitization in East Germany approached the levels seen in West Germany and to identify possible lifestyle or environmental factors that may influence this. METHODS: Between 1991 and 2000, 6-year-old children from four areas in East Germany participated in an annual survey. Every 3rd year, a parallel survey was performed in four areas of West Germany. In total, 31 903 children were included. Parents completed a questionnaire regarding lifestyle factors and diagnoses and symptoms of asthma, hayfever and eczema. In sub-areas, eczema was clinically assessed by a dermatologist. Specific IgE sensitization was determined for 6121 children. Logistic regression was used to analyse differences in time trends and the influence of lifestyle and pollution changes. RESULTS: Lifestyle and pollution changed significantly differently between East and West Germany. The trends in hayfever and in strong (specific IgE >3.5) sensitization against pollen, and particularly birch pollen, were steeper in East than in West Germany. The trend towards marked pollen sensitization was four times stronger (95% confidence interval 1.2-13.9) in East than in West Germany. Increasing numbers of only children, less single-room heating with fossil fuels and increasing importance of traffic-related pollution in East Germany partly explained these differences in time trends. CONCLUSIONS: Hayfever and sensitization against pollen were the most sensitive allergic manifestations to changes experienced specifically in East Germany. Influences of lifestyle (single-room heating, living as a single child) were important in explaining different trend developments.

Childhood family structure and personality disorders in adulthood.

BACKGROUND: The association between childhood family structure and sociodemographic characteristics and personality disorders (PDs) in a general population sample was studied. METHODS: This study is a substudy of the prospective Northern Finland 1966 Birth Cohort Project with 1588 young adult subjects. The case-finding methods according to the DSM-III-R criteria for PDs were: (1) Structured Clinical Interview for DSM-III-R (SCID) for 321 cases who participated in a 2-phase field study, (2) Finnish Hospital Discharge Register data, and (3) analysis of the patient records in public outpatient care in 1982-1997. Statistical analyses were performed on the association between PDs and family background factors. RESULTS: Altogether 110 (7.0%) of the subjects had at least one probable or definite PD. After adjusting for confounders (gender, parental social class and parental psychiatric disorder) the results indicated that single-parent family type in childhood was associated with cluster B PDs in adulthood. Being an only child in childhood was associated with cluster A PDs. No special childhood risk factors were found for cluster C PDs. CONCLUSIONS: Results suggest that single-parent family type at birth and being an only child in the 1960s are associated with PD in adulthood. Further studies are needed to explore the psychosocial aspects of family environment which may nowadays promote vulnerability to PDs in adulthood.

[Individual social characteristics, municipal environment and the prevalence of weight problems in early childhood: a multilevel analysis]. / Caractéristiques sociales individuelles, contexte résidentiel et prévalence des problèmes de poids dans la petite enfance: une analyse multiniveau.

BACKGROUND: Few studies have examined the prevalence of weight problems before the age of 5 years although this period is critical in the development of obesity. An inverse association between socio-economic status and weight problems is well documented in adult women but not for young children. Similarly several studies of adults and adolescents or older children show that the prevalence of weight problems is associated with the level of deprivation of the neighbourhood environment and the degree of urbanization, independent of social individual factors, even though this has not been examined for young children. METHODS: We evaluated prevalence rates of weight problems in children aged 3.5-4.5 years in southeastern France and their association with both individual social factors and municipal environment characteristics. Random stratified cluster sampling allowed us to select 112 nursery schools. Physicians from the early childhood protective services conducted a mandatory medical examination and collected data with a new questionnaire (EVALMATER), developed to standardise these examinations. Overweight and obesity were defined by international references after calculation of each child's BMI (kg/m(2)). We constructed a social disadvantage index to assess characteristics of the municipalities where the nursery schools were located and used multilevel analysis to study the associations of municipal characteristics (the disadvantage index and a urban/rural classification of the municipalities) with weight problems independently of individual socio-economic variables. RESULTS: The study included 2495/2959 (84.3%) children, with a mean age of 3.9+/-0.3 years. The prevalence of overweight was 8.2% (CI95%=7.1-9.3) and that of obesity 2.1% (CI95%=1.5-2.7). Prevalence of obesity was significantly higher in girls, only children, those who had not attended day-care before nursery school, whose mother was not employed, or whose father was not a white-collar-worker. Independently of these variables, it was also significantly higher among children who lived in urban areas or deprived municipalities. None of these factors were found associated with overweight alone. CONCLUSION: Actions of prevention in France should target parents of young children.

[Behavioral characteristics of the only child vs first-born and children with siblings]. / Características de comportamento do filho único vs filho primogênito e não primogênito.

OBJECTIVE: To assess the impact of being an only child on characteristics of parental and peer relationships, school achievement, social and sexual behavior. METHODS: In the total, 360 adolescents identified at third year of high school were sampled from a private school from Porto Alegre in 2000 and 2001. Fifteen to nineteen years old male and female were selected in a cross-sectional study. Assessment of demographic data, education of the parents, birth order (only child, first born and non-first born children), cigarette smoking, alcoholic beverages consumption, illicit drug use, school achievement, social and sexual behavior were gathered with a pre-tested self-administered questionnaire, anonymously fulfilled at the classroom. RESULTS: This study encompassed 8% of only children, 35% first-born, and 57% non-first born adolescents of a socioeconomic homogeneous sample. Social behavior, parents and peer relationships, sports participation, smoking and illicit drug were not associated with birth order. Only children were less likely to report an episode of alcohol intoxication (39%) than first-born (68.9%; p=0.03) and adolescents with siblings (72.3%; p<0.001). Only children had high school achievement than adolescents with siblings (p=0.03). Sexual behavior distinguished only children due to younger age at first sexual intercourse and lower rate of heterosexual self-identification, which persisted even after adjustment for confounding variables in comparison with non first-born adolescents (p=0.038). CONCLUSIONS: Our findings suggest that the status of being only child is not associated with a poor outcome in several areas of the development. The impact of the presence of siblings in the development of sexual identification should be further explored.

Características de comportamento do filho único vs filho primogênito e não primogênito / Behavioral characteristics of the only child vs first-born and children with siblings

OBJETIVO: Avaliar o impacto de ser filho único sobre as caraterísticas de relacionamento com amigos e pais, desempenho escolar, comportamento social e sexual. MÉTODOS: Realizou-se um estudo, incluindo um total de 360 adolescentes identificados no terceiro ano do ensino médio de uma escola privada de Porto Alegre, em 2000 e 2001. Adolescentes do sexo masculino e feminino, com idade entre 15 e 19 anos foram selecionados para participar de um estudo transversal. Um questionário anônimo, pré-testado e auto-administrado foi preenchido em sala de aula com dados demográficos, educação dos pais, ordem de nascimento (filho único, primogênito e não primogênito), tabagismo, consumo de bebidas alcoólicas, uso de drogas ilícitas, desempenho escolar, comportamento social e sexual e outras características. RESULTADOS: Identificaram-se 8 por cento de adolescentes filhos únicos, 35 por cento primogênitos e 57 por cento não primogênitos em uma amostra socioeconomicamente homogênea. Comportamento social, relacionamento com os pais e amigos, prática de esportes, tabagismo e uso de drogas não se associaram com ordem de nascimento. Os filhos únicos menos freqüentemente relataram intoxicação alcoólica (39 por cento) comparativamente aos primogênitos (68,9 por cento; p=0,03) e adolescentes com irmãos (72,3 por cento; p<0,001). Filhos únicos obtiveram melhor desempenho escolar do que os filhos com irmãos (p=0,03). Comportamento sexual diferenciou os filhos únicos devido à idade mais precoce com que iniciaram a atividade sexual e pela menor taxa de auto-identificação como heterossexual, a qual persistiu mesmo após controle para fatores de confusão comparativamente a filhos não primogênitos (p=0,038). CONCLUSÕES: Nossos achados sugerem que ser filho único não está associado com pior desempenho em diversas áreas do desenvolvimento. O impacto da presença de irmãos no desenvolvimento da identificação sexual deve ser explorado em trabalhos futuros.

Is obesity associated with asthma in young children?

OBJECTIVE: The aim of this study was to evaluate the association between obesity and asthma in a population-based sample of Canadian children. STUDY DESIGN: Baseline data from the National Longitudinal Survey of Children and Youth were used in this cross-sectional study. We included 11199 children age 4 to 11 years whose biological mother reported data on asthma, height, and weight. Body mass index was categorized, and obesity was defined as body mass index >or=85th percentile. Children with asthma had parents who reported the diagnosis, and they took prescribed inhalants, had wheezing or an attack in the previous year, or had their activities limited by asthma. Multiple logistic regression was used. RESULTS: The prevalence of asthma was 9.9%. Maternal history of asthma was a risk factor for asthma among all children. Single child status and maternal depression were risk factors for girls. The odds ratio for asthma, comparing highest and lowest body mass index categories, was 1.02 (99% confidence interval, 0.70-1.46) for boys and 1.06 (99% confidence interval, 0.67-1.69) for girls. CONCLUSION: This study suggests that there is no statistical association between obesity and asthma among Canadian children age 4 to 11 years.

The one-child family and violent criminality: a 31-year follow-up study of the Northern Finland 1966 Birth Cohort.

OBJECTIVE: Serious defects in social skills acquired during childhood may be associated with aggressive behavior in later life. The authors studied whether being an only child was associated with criminality in adulthood and, secondly, if parental factors increased the putative risk. METHOD: The authors used an unselected, prospectively collected large birth cohort. Data on crimes were linked with being an only child as well as with perinatal risk and maternal and paternal psychological risk factors among male subjects. RESULTS: The risk for violent crimes later in life was elevated among the only children. If perinatal or parental risks were combined with being an only child, the odds ratios for violent offending increased four-fold to eight-fold. A corresponding risk increase between being an only child and nonviolent offending was not detected. CONCLUSIONS: These results support the hypothesis that growing up as an only child is associated with violent criminality among male subjects.