Familial concordance for age at menarche: analyses from the Breakthrough Generations Study

Age at menarche is correlated within families, but estimates of the heritability of menarcheal age have a wide range (0.45-0.95). We examined the familial resemblance for age at menarche and the extent to which this is due to genetic and shared environmental factors. Between 2003 and 2010 data were retrospectively collected by questionnaire from participants within the UK-based Breakthrough Generations Study. These analyses included 25,970 female participants aged 16-98 with at least one female relative who was also a study participant. A woman's menarche was significantly delayed for each yearly increase in the menarcheal age of her monozygotic twin (average increase = 7.2 months, P < 0.001), dizygotic twin (average increase = 3.0 months, P = 0.03), older sister (average increase = 3.3 months, P < 0.001), mother (average increase = 3.4 months, P < 0.001), maternal grandmother (average increase = 1.5 months, P = 0.04), maternal aunt (average increase = 1.4 months, P < 0.001) and paternal aunt (average increase = 3.0 months, P < 0.001). There was not a significant association between the menarcheal ages of half-sister pairs or of paternal grandmother-granddaughter pairs, based on small numbers. Heritability was estimated as 0.57 [95% confidence interval 0.53, 0.61]. Shared environmental factors did not have an effect in the model. In conclusion, approximately half of the variation in age at menarche was attributable to additive genetic effects with the remainder attributable to non-shared environmental effects.     

Maternal smoking,demographic and lifestyle factors in relation to daughter's age at menarche

A previous study suggested a younger age at menarche (AAM) among daughters of heavy prenatal smokers, especially among non‐Whites. The present study was designed to evaluate that association in another population and to examine other factors that may be related to AAM. We analysed data from the Collaborative Perinatal Project, a nationwide longitudinal study of pregnant women and their children conducted in 1959–66. At three sites, with a predominance of Black participants (80%), AAM was ascertained in the offspring when they were young adults. We included data on 1556 daughters who had a mean AAM of 12.7 years (standard deviation 1.8). Amount smoked by the mothers was obtained from a baseline interview and subsequent prenatal visits. Regression models were run including maternal smoking and other covariates, for only the prenatal period, as well as in models with some childhood characteristics. In the prenatal factor model, younger mean AAM in daughters was found with maternal characteristics of earlier AAM, being married, and of lower parity. Examining childhood variables, earlier AAM was found among girls with few or no siblings or with higher socio‐economic status. Unlike our previous findings, mean AAM was later in daughters of heavy smokers (20+ cigarettes/day), with a delay of 0.31 years [95% confidence interval (CI) 0.008, 0.61], or about 3.7 months in the prenatal model, and 0.34 years [95% CI ?0.02, 0.66] in the model with childhood variables included. The pattern was consistent by race. A number of prenatal and childhood factors related to AAM were identified that should be considered when examining exogenous exposures in relation to pubertal onset.     

Effect of age at menarche on the mother’s weight status two and four years after delivery: a cohort study

ABSTRACT

We aimed to estimate the effect of age at menarche on the risk of excess body weight in Brazilian women two and four years after delivery. This was a cohort study that used data from adult women of the Predictors of Maternal and Child Excess Body Weight (PREDI) Study obtained at baseline (2012) and at 1^st(2014) and 2^nd(2016) follow-up. A total of 435 women attending a public maternity hospital in Joinville-Brazil were initially included in the study (baseline) and 215 of them continued to participate in the 2^nd follow-up carried out in the homes of the participants. Regression analysis was used to estimate the association between age at menarche (<12; ≥12 years) and excess body weight (≥25 kg/m²) trajectory during the follow-ups. Unadjusted analysis showed that mothers with age at menarche <12 years were 1.29 times (p = .018) more likely to be overweight/obese than those with age at menarche ≥12 years. After adjustment, age at menarche continued to exert an independent effect on the mother’s body mass index (RR = 1.23; p = .037) four years after delivery. Strategies designed to attenuate the rising prevalence of maternal overweight and obesity, especially after pregnancy, could help improve the mother’s health status in the future.     

Secular trends in growth: the narrowing of ethnic differences in stature

Summary Ethnic differences in growth patterns between countries have been observed even after controlling for nutrition, environment, and a range of other factors. The literature on markers of human growth patterns in different affluent populations was compared, with the aim of identifying similarities or differences that might be ascribed to nonenvironmental factors. To this end, the stature characteristics of different affluent child populations at various ages and stages (stature attained at 7 and 8 years of age; age at peak height velocity; peak height velocity) have been compared. The obvious flaw to this approach is that not all of them show maximal growth trajectories, because mean body size is still increasing for many, as the secular trend toward increasing body size has not ceased for many populations. Therefore, a review of the extent to which the same stature characteristics of populations of differing ethnicities have changed across time has been carried out, to determine the extent to which they might be approaching or attaining similar secular trend end‐points associated with the achievement of genetic potential for growth. The comparison of mean heights of 7‐year‐old boys from populations of industrialised countries and from the highest socio‐economic groups in developing countries, shows that the range of means for European and European‐origin populations is similar to those of African and African‐origin, and Latin‐American and Indo‐Mediterranean populations, but slightly higher than those of Asiatic populations. This supports the view that genetic potential for prepubertal growth may be similar for all groups examined in this way, apart from Asiatic populations. However, the secular trend toward increased body size has continued to take place among many populations, including affluent ones. The Asiatic populations observed since 1990 are much more similar in stature to their counterparts elsewhere in the world than they were prior to this date. A similar comparison among affluent adolescents shows Asiatic populations to have earlier onset of the pubertal growth spurt in stature than other major population typologies, but to have similar peak height velocities. The similarities in attained stature by mid‐childhood of children of most major population typologies, apart from the Asiatic one, suggests that an international growth reference could be used currently for all major population typologies apart from the Asiatic one. It is possible that they may also be applicable to preadolescent Asiatic populations, given the dramatic secular increase in childhood stature in recent decades, if they were to achieve the same statures for age as affluent populations elsewhere in the world. With respect to pubertal growth, international references may be applied to all major population typologies apart from the Asiatic one, as the earlier age of peak height velocity in these populations is unlikely to be due to differences in environmental quality.     

中国10个地区成年女性初潮年龄与身高和腿长的关联研究

目的 描述中国慢性病前瞻性研究（CKB）项目覆盖的10个地区30～79岁成年女性初潮年龄与身高和腿长的地区及出生年代分布,并分析初潮年龄与身高和腿长的关联性。方法 剔除初潮年龄缺失或初潮年龄在生理范围外（<9岁或>18岁）个体后,285 187名女性纳入分析。使用多元线性回归模型分析初潮年龄与身高和腿长的关系,并根据出生年代和城乡进行亚组分析。结果 10个项目地区女性的平均初潮年龄为（15.2±1.7）岁,平均身高和腿长分别为（154.2±6.0）cm和（71.0±3.7）cm。女性身高和腿长呈现出随出生年代逐渐增加的趋势（线性趋势检验均P<0.001）。而初潮年龄在1940-1949年代出生的个体略有推迟,之后出生的女性则表现为逐渐提前的趋势（线性趋势检验P<0.001）。在调整了年龄、地区、教育程度和臀围（仅在分析腿长时调整）后,初潮年龄每晚一岁,身高和腿长分别平均增加0.17 cm和0.20 cm（P值均<0.001）。相比出生年代较早的女性,出生年代越晚的女性中,初潮年龄与身高和腿长的回归系数越大（交互检验P值均<0.001）。结论 CKB的10个项目地区女性的初潮年龄与身高和腿长均存在正相关关联。     

Lower age at menarche affects survival in older Australian women: results from the Australian Longitudinal Study of Ageing

Background  

While menarche indicates the beginning of a woman's reproductive life, relatively little is known about the association between age at menarche and subsequent morbidity and mortality. We aimed to examine the effect of lower age at menarche on all-cause mortality in older Australian women over 15 years of follow-up.     

Projected socioeconomic disparities in the prevalence of obesity among Australian adults

Objective: To project prevalence of normal weight, overweight and obesity by educational attainment, assuming a continuation of the observed individual weight change in the 5‐year follow‐up of the national population survey, the Australian Diabetes, Obesity and Lifestyle study (AusDiab; 2000–2005). Methods: Age‐specific transition probabilities between BMI categories, estimated using logistic regression, were entered into education‐level‐specific, incidence‐based, multi‐state life tables. Assuming a continuation of the weight change observed in AusDiab, these life tables estimate the prevalence of normal weight, overweight and obesity for Australian adults with low (secondary), medium (diploma) and high (degree) levels of education between 2005 and 2025. Results: The prevalence of obesity among individuals with secondary level educational attainment is estimated to increase from 23% in 2000 to 44% in 2025. Among individuals with a degree qualification or higher, it will increase from 14% to 30%. If all current educational inequalities in weight change could be eliminated, the projected difference in the prevalence of obesity by 2025 between the highest and lowest educated categories would only be reduced by half (to a 6 percentage point difference from 14 percentage points). Conclusion: We predict that almost half of Australian adults with low educational status will be obese by 2025. Current trends in obesity have the potential to drive an increase in the absolute difference in obesity prevalence between educational categories in future years. Implications: Unless obesity prevention and management strategies focus specifically on narrowing social inequalities in obesity, inequalities in health are likely to widen.     

Socioeconomic status and quality of life in population‐based Australian men: data from the Geelong Osteoporosis Study

Objective : To investigate the relationship between socioeconomic status (SES) and reported perceptions of quality of life (QOL) in a cross‐sectional population‐based analysis of a representative sample of Australian men. Methods : In 917 randomly recruited men aged 24–92 years, we measured QoL in the domains of physical health, psychological health, environment and social relationships, using the Australian World Health Organization Quality of Life Instrument (WHOQOL‐BREF). Residential addresses were cross‐referenced with Australian Bureau of Statistics 2006 census data to ascertain SES. Participants were categorised into lower, mid, or upper SES based on the Index of Relative Socioeconomic Disadvantage and Advantage (IRSAD), the Index of Economic Resources (IER), and the Index of Education and Occupation (IEO). Lifestyle and health information was self‐reported. Results : Males of lower SES reported poorer satisfaction with physical health (OR=0.6, 95%CI 0.4–0.9, p=0.02), psychological health (OR=0.4, 95%CI 0.3–0.7, p<0.001) and environment (OR=0.5, 95%CI 0.3–0.7, p<0.001), although not social relationships (p=0.59). The poorest QOL for each domain was observed in the lower and upper SES groups, representing an inverse U‐shaped pattern of association; however, statistical significance was only observed for psychological health (OR=0.5, 95%CI 0.4–0.7, p<0.001). These relationships were similar for IEO and IER. Conclusions : Men from lower and upper SES groups have lower QOL compared to their counterparts in the mid SES group.     

Secular trends in the epidemiology of pre-eclampsia throughout 40 years in Norway: prevalence, risk factors and perinatal survival

Pre-eclampsia is a leading complication of pregnancy, associated with maternal and neonatal morbidity. The present study describes the epidemiology of pre-eclampsia in Norway, with data from the Medical Birth Registry of Norway, covering 40 years. We aimed at describing time trends in prevalence, selected risk factors and perinatal mortality. We also analysed time trends in recurrence risk of total pre-eclampsia and pre-eclampsia with preterm delivery. A total of 2,416,501 women giving birth during 1967-2008 were included. Prevalence of pre-eclampsia increased from 1967 to 1999 and decreased thereafter, with an overall prevalence of 3%. Rates increased more over time among younger than older women, resulting in a significantly lower excess risk of pre-eclampsia associated with high maternal age in later years. For example, relative risk (RR) of pre-eclampsia among primiparae aged ≥35 relative to <25 years changed from 2.4 [95% confidence interval (CI) 2.1, 2.7] in 1967-1976 to 1.2 [95% CI 1.1, 1.3] in 1999-2008. For recurrence risk, subsequent pregnancies to a mother were linked, with the mother being the unit of analysis. Recurrence risk of pre-eclampsia was high, particularly recurrence of preterm pre-eclampsia, with overall RR close to 50 of a second pregnancy with pre-eclampsia and preterm birth compared with women without pre-eclampsia in first pregnancies. Finally, stillbirth associated with pre-eclampsia decreased more than neonatal mortality over time, and in the last 5 years only a moderate excess risk of stillbirth and neonatal death was observed.     

Effects of socio-economic status on mortality: separating the nearby from the farther away

Socio-economic status effects on total and cause-specific mortality are studied using data on all 15.8 million inhabitants of the Netherlands in 1999. Two problems are addressed that often hamper this kind of research: the lack of reliable social status information at the individual level and the intermingling of individual and neighbourhood status effects. The first problem is dealt with by using socio-economic status information of the very close environment of the detailed postcode areas (average 41 inhabitants) in which one is living and the second one by combining this information with such area information at the much larger level of neighbourhoods (1500 inhabitants) or boroughs (6600 inhabitants). Clear and independent effects of socio-economic status at all three levels of aggregation are found on total mortality and for a majority of causes of death. In almost all cases, the effects are to the disadvantage of people living in the lowest status areas. The effects are generally strongest at the detailed postcode level and weakest at the borough level, suggesting greater importance of factors at the nearby or individual level than at the farther away level(s).     

Attitudes to weight and weight management in the early teenage years: a qualitative study of parental perceptions and views

Background

As most young teenagers grow up in families, parents might be well situated to facilitate and support their weight management and thereby prevent or manage obesity prior to adulthood.

Aim

This paper explores parents'' perceptions of, and views about, their teenage children''s weight and the factors that influence parents'' weight management strategies.

Design, setting and participants

We conducted two qualitative studies in Scotland, UK, involving in‐depth interviews with the parents of overweight/obese and ‘normal’ weight 13–15 year olds (n = 69).

Findings

Parents'' concerns about their own weight provided useful context for understanding their attitudes or actions with regards to their teenage child. Some parents described their teenager''s weight as being of concern to them, although puberty often introduced confusion about a child''s weight status. Genetic explanations were very often put forward as a way of making sense of teenage weight or body size. Frustration about advising teenagers about weight management was expressed, and some parents worried about giving their growing child a ‘problem’ if they directly raised concerns about weight with them.

Discussion

Parents'' views about their own weight as well as social and moral norms about labelling a teenager as overweight or as needing help with their weight could usefully inform patient‐centred service development. Parent/teenage partnerships and supporting parents to create a healthy home in which teenagers can make healthier choices are suggestions for intervention development.

Conclusion

The study highlights the importance of taking parents'' perceptions into account when developing family‐based interventions to address teenage overweight and obesity.     

Suicide by occupational skill level in the Australian construction industry: data from 2001 to 2010

Objective: This study examines variation in suicide deaths by occupational skill level within the construction industry and changes in the rate of suicide over time. Methods: Suicide deaths were extracted from a national coronial database and occupations were coded. Adjusted suicide rates over the period 2001 to 2010 were calculated and incidence‐rate ratios (IRRs) used to compare the overall burden of suicide in the lowest skilled group (machine operators and labourers) against skilled tradespersons in the construction industry. Results: Those employed as labourers or machine operators had an adjusted rate of 18 per 100,000 persons (95%CI 14–22) and those employed in skilled trades had an adjusted rate of 13 per 100,000 (95%CI 11–15) over the period 2001 to 2010. Compared to skilled trades, the lower skilled group had significantly elevated suicide at several time points over the period 2001 to 2010. The most observable difference in IRRs were in the years 2002 and 2007. Conclusions: Low‐skilled workers in the construction industry had elevated rates of suicide compared to skilled trades workers. Implications: These workers should be targeted by prevention efforts.