Increasing maternal age is associated with taller stature and reduced abdominal fat in their children

Advanced parental age affects cardiometabolic risk in offspring

Advanced age at conception usually refers to human mothers aged 35 years plus and fathers aged 40 years plus. Advanced parental age may be responsible for genetic and/or epigenetic alterations and may affect the health of offspring. Limited epidemiological and experimental studies have addressed the effect of advanced parental age on cardio-metabolic functions in human and rodent offspring. This mini review aimed to present the knowledge by focusing on adverse and favourable outcomes related to sex-specific risks and intergenerational inheritance. The outcomes identified by this review were mainly negative, but there were also some positive results.

Parental determinants associated with early growth after the first year of life by race and ethnicity

Objective

To investigate maternal and parental factors associated with changes in children's body mass index percentile (BMI-P) from 12 to 24 months.

Methods

Data from a prospective cohort of racially and ethnically diverse mothers, fathers, and children (n = 245) were used. Changes in BMI-P from 12 to 24 months of age were examined using height and weight measurements collected at both times. Separate longitudinal mixed-effects models with maximum likelihood were introduced to examine the determinants introduced by mothers and determinants from both parents among all children, and by race and ethnicity.

Results

Models that examine maternal and parental factors showed that children's overall BMI-P decreased from 12 to 24 months [β = -4.85, 95% confidence interval (CI), -7.47 to -2.23]. Stratified tests showed that White children whose parents graduated high school or completed a 4-year college degree or higher had greater decreases in BMI-P than White children born to parents with less than high school education (β = -60.39, 95% CI, -115.05 to -5.72; β = -61.49, 95% CI, -122.44 to -0.53). Among Hispanic/Latinx children, mean BMI-P significantly decreased from 12 to 24 months (β = -7.12, 95% CI, -11.59 to -2.64). Mother's older age (β = 1.83, 95% CI, 0.29-3.36) and child female sex (β = 11.21, 95% CI, 1.61-20.82) were associated with gains in children's BMI-P, while father's older age was associated with decreases (β = -1.19, 95% CI, -2.30 to -0.08).

Conclusions

Parental determinants associated with children's early growth varied by children's sex and racial and ethnic background. Results highlight the importance of understanding racial and ethnicity-specific obesity risks and including fathers in research.

Relationship between Birth Order and Postnatal Growth until 4 Years of Age: The Japan Environment and Children’s Study

Later-borns tend to be shorter than first-borns in childhood and adulthood. However, large-scale prospective studies examining growth during infancy according to birth order are limited. We aimed to investigate the relationship between birth order and growth during the first 4 years of life in a Japanese prospective birth cohort study. A total of 26,249 full-term singleton births were targeted. General linear and multivariable logistic regression models were performed and adjusted for birth weight, parents’ heights, maternal age at delivery, gestational weight gain, maternal smoking and alcohol drinking status during pregnancy, household income, breastfeeding status, and Study Areas. The multivariate adjusted mean length Z-scores in “first-borns having no sibling”, “first-borns having siblings”, “second-borns”, and “third-borns or more” were −0.026, −0.013, 0.136, and 0.120 at birth and −0.324, −0.330, −0.466, and −0.569 at 10 months, respectively. Results similar to those at 10 months were observed at 1.5, 3, and 4 years. The adjusted odds ratios (95% confidence intervals) of short stature at 4 years in “first-borns having siblings”, “second-borns”, and “third-borns or more” were 1.08 (0.84–1.39), 1.36 (1.13–1.62), and 1.50 (1.20–1.88), respectively, versus “first-borns having no sibling”. Birth order was significantly associated with postnatal growth and may be a factor predisposing to short stature in early childhood.

Secular trends and sociodemographic determinants of thinness, overweight and obesity among Chinese children and adolescents aged 7-18 years from 2010 to 2018

Background

Most studies have focused on overweight/obesity and its secular trend, with insufficient studies on the factors influencing thinness and trends recently. To examine the trends of prevalence and sociodemographic determinants of thinness, overweight, and obesity among Chinese children and adolescents aged 7 to 18 years from 2010 to 2018.

Methods

This study was based on cross-sectional data of 11,234 children and adolescents aged 7 to 18 years from the Chinese Family Panel Studies (CFPS) in 2010, 2014, and 2018, including anthropometric and sociodemographic characteristics variables. The nutritional status of each individual was determined according to China and WHO criteria. The demographic characteristics of different subgroups were tested by chi-square, and log-binomial regression was used to analyze the trend of prevalence and the relationship between sociodemographic characteristics and different nutritional statuses.

Results

After adjusting for age, from 2010 to 2018, the overall prevalence of thinness decreased, and the prevalence of overweight increased in Chinese children and adolescents. The overall prevalence of obesity declined in boys and increased in girls, but in adolescents aged 16-18 years, it increased significantly. Log-binomial regression analysis showed that among all subjects, time (years), 16-18 years were negatively associated with thinness, while 13-15 years, walking to school, large family size, and paternal age at childbirth older than 30 years old were positively associated with thinness; 10-12/13-15/16-18 years, boarding at school, medium and large family sizes, and mother's education at junior middle school/junior high school and above were negatively associated with overweight/obesity, while time (years), boys were positively associated with overweight/obesity in the multivariate model by adjusting for the statistically significant factors (all p < 0.05).

Conclusion

Chinese children and adolescents are facing a double burden of malnutrition. Future public health policies and interventions should prioritize high-risk groups specifically young age groups, boys, larger family sizes and so on.

Smoking in pregnancy is associated with increased adiposity and retinal arteriolar wall-to-lumen ratio in adolescence: The Copenhagen Child Cohort Study 2000

PURPOSE

To investigate the association between prenatal exposures and anthropometric data and cardiovascular risk factors including retinal arteriolar wall-to-lumen ratio in adolescence.

METHODS

This longitudinal observational study included all 1445 adolescents from the Copenhagen Child Cohort 2000 who attended the 2016-2017 examination. Outcome measures included retinal arteriolar wall-to-lumen ratio, height, body mass index, waist-to-hip ratio, body composition measured by bioimpedance, and blood pressure. Information on prenatal exposures (birth weight, gestational age, maternal smoking during pregnancy) as well as sex, parental age, household income and parental educational levels were obtained from national registries. Associations between exposures and outcome measures were analyzed using general linear models.

RESULTS

Maternal smoking during pregnancy was associated with a higher retinal arteriolar wall-to-lumen ratio (0.004 or 1.9%, P = 0.009) at age 16/17 years, an association driven exclusively by the female participants (0.008 or 3.7%, P < 0.0001). Maternal smoking during pregnancy was also associated to higher body-mass index (1.43 kg/m², P < 0.0001), waist-to-hip ratio (0.02, P < 0.0001) and fat mass index (0.93 kg/m², P < 0.0001). Birth weight, gestational age, and parental age had no detectable impact on retinal arteriolar wall-to-lumen ratios.

CONCLUSION

Prenatal exposure to tobacco smoking is associated with a higher risk of obesity and, predominantly in girls, to a greater retinal arteriolar wall thickness, which suggests that maternal smoking may induce an unfavorable cardiovascular and metabolic risk profile in the child.

Fetal programming of human energy homeostasis brain networks: Issues and considerations

In this paper, we present a transdisciplinary framework and testable hypotheses regarding the process of fetal programming of energy homeostasis brain circuitry. Our model proposes that key aspects of energy homeostasis brain circuitry already are functional by the time of birth (with substantial interindividual variation); that this phenotypic variation at birth is an important determinant of subsequent susceptibility for energy imbalance and childhood obesity risk; and that this brain circuitry exhibits developmental plasticity, in that it is influenced by conditions during intrauterine life, particularly maternal-placental-fetal endocrine, immune/inflammatory, and metabolic processes and their upstream determinants. We review evidence that supports the scientific premise for each element of this formulation, identify future research directions, particularly recent advances that may facilitate a better quantification of the ontogeny of energy homeostasis brain networks, highlight animal and in vitro-based approaches that may better address the determinants of interindividual variation in energy homeostasis brain networks, and discuss the implications of this formulation for the development of strategies targeted towards the primary prevention of childhood obesity.

Large-for-Gestational-Age, Leptin, and Adiponectin in Infancy

CONTEXT

Fetal overgrowth "programs" an elevated risk of obesity and type 2 diabetes in adulthood. Plausibly, adipokines may be involved in programming metabolic health.

OBJECTIVE

This work aimed to evaluate whether large-for-gestational-age (LGA), an indicator of fetal overgrowth, is associated with altered circulating leptin and adiponectin levels in infancy, and assess the determinants.

METHODS

In the Canadian 3D birth cohort, we studied 70 LGA (birth weight > 90th percentile) and 140 optimal-for-gestational-age (OGA, 25th-75th percentiles) infants matched by maternal ethnicity, smoking, and gestational age at delivery. The primary outcomes were fasting leptin, and total and high-molecular-weight (HMW) adiponectin concentrations at age 2 years.

RESULTS

LGA infants had higher body mass index (BMI) than OGA infants. However, there were no significant differences in leptin, and total and HMW adiponectin concentrations. Leptin concentrations were positively associated with female sex, weight (z score) gain 0 to 24 months, current BMI, and the sum of triceps and subscapular skinfold thickness, and negatively associated with maternal age and White ethnicity. Female sex was associated with lower total and HMW adiponectin concentrations. Weight (z score) gain 0 to 24 months and current BMI were positively correlated with total and HMW adiponectin concentrations in LGA infants only.

CONCLUSION

This study is the first to demonstrate that LGA does not matter for circulating leptin and adiponectin concentrations in infancy, and there may be LGA-specific positive associations between weight gain or current BMI and adiponectin concentrations in infancy, suggesting dysfunction in establishing the adiposity-adiponectin negative feedback loop in LGA individuals.

Birth weight, birth order, and age at first solid food introduction influence child growth and body composition in 6- to 8-year-old Maya children: The importance of the first 1000 days of life

OBJECTIVES

To analyze the relationship of birth weight, birth order, breastfeeding duration, and age of introduction of solid foods with height, fat mass, and fat-free mass in a sample of Maya children when aged 6 to 8 years old.

METHODS

We collected data on anthropometry, body composition, children's birth weight, birth order, early feeding practices, and household socioeconomic characteristics in a sample of 260 Maya children aged 6 to 8 years living in Merida and Motul, two cities in Yucatan, Mexico. Multiple regression models were performed to identify variables associated with height-for-age (HAZ), fat mass index (FMI), and fat-free mass index (FFMI). The predictors included in the models were birth weight (kg), birth order, duration of breastfeeding (months), age at introduction of solid foods (months), maternal age (years), and height (cm). Models were adjusted for the influence of children's age and sex, maternal educational level, and household overcrowding.

RESULTS

HAZ was positively associated with child birthweight and maternal height and age, but inversely associated with birth order and age of introduction of solid foods. FMI was positively associated with birth weight, maternal age, and height, and negatively associated with birth order. FFMI was positively associated with maternal age and birth weight.

CONCLUSIONS

These results are evidence of the importance of the first 1000 days of life for the growth and body composition of Maya children and contributed to understand the development of nutritional dual burden in this population.

Associations of parental ages at childbirth with healthy aging among women

OBJECTIVE

To examine associations of parental ages at childbirth with healthy survival to age 90 years among older women.

STUDY DESIGN

This study included a racially and ethnically diverse sub-cohort of 8,983 postmenopausal women from the larger Women's Health Initiative population, recruited during 1993-1998 and followed for up to 25 years through 2018.

MAIN OUTCOME MEASURES

The outcome was categorized as: 1) healthy survival, defined as survival to age 90 without major morbidities (coronary heart disease, stroke, diabetes, cancer, or hip fracture) or mobility disability; 2) usual survival, defined as survival to age 90 without healthy aging (reference category); or 3) death before age 90. Women reported their own and their parents' birth years, and parental ages at childbirth were calculated and categorized as <25, 25-29, 30-34, or ≥35 years.

RESULTS

Women were aged on average 71.3 (standard deviation 2.7; range 65-79) years at baseline. There was no significant association of maternal age at childbirth with healthy survival to age 90 or death before age 90. Women born to fathers aged ≥35 compared with 30-34 years at their births were more likely to achieve healthy than usual survival (OR, 1.15; 95% CI, 1.00-1.32). There was no association of paternal age at childbirth with death before age 90.

CONCLUSIONS

Findings suggest that being born to older fathers was associated with healthy survival to age 90 among women who had survived to ages 65-79 years at study baseline. There was no association of maternal age at childbirth with healthy survival to age 90 among these older women.

Parental weight status and early adolescence body weight in association with socioeconomic factors

BACKGROUND

Childhood obesity remains a major health issue. The understanding of the multifactorial nature of childhood obesity remains the cornerstone to eliminate the rising trends. This study aimed to examine the association between parental and childhood weight status, in relation to various socioeconomic (SE) factors.

METHODS

A cross-sectional survey was conducted including 1190 children aged 10-12 years and their parents, during school years 2014-2016. Primary schools from five Greek counties (including Athens metropolitan area) were randomly selected. Parental and child data were collected through self-administered, anonymous questionnaires. Children's weight status was based on gender- and age-specific tables derived from the International Obesity Task Force body mass index (BMI) cut offs. General Linear Model (GLM), Univariate and multivariate analyses were applied. Multiple logistic regressions was used to determine the association between children and parents' weight status.

RESULTS

Childhood prevalence of overweight and obesity was 25.9% (21.8% overweight and 4.1% obese), with prevalence being significantly higher in males (31.7% compared to 21.3%; P for gender differences < 0.001). The percent of overweight and obese male (34.4% and 43.1%) and female children (20.3% and 31.8%) significantly increased with paternal overweight and obesity status, respectively. The same relationship was observed between male children and maternal overweight and obesity status (43.4% and 65.7%). This was not evident among females (27% and 23.2%). Regression analysis showed a significant positive association with parental BMI, a negative association with both parental educational levels (low to high), living space, and parental age (P < 0.05, for all). Children's likelihood of being overweight or obese increased significantly with increasing parental weight status (P < 0.001).

CONCLUSIONS

Parental weight status remained the most significant predictive factor for early adolescence obesity among various SE factors. Health promotion strategies should consider parental education as an effective childhood obesity preventive measure.

Persistent epigenetic changes in adult daughters of older mothers

Women of advanced maternal age account for an increasing proportion of live births in many developed countries across the globe. Offspring of older mothers are at an increased risk for a variety of subsequent health outcomes, including outcomes that do not manifest until childhood or adulthood. The molecular underpinnings of the association between maternal aging and offspring morbidity remain elusive. However, one possible mechanism is that maternal aging produces specific alterations in the offspring's epigenome in utero, and these epigenetic alterations persist into adulthood. We conducted an epigenome-wide association study (EWAS) of the effect of a mother's age on blood DNA methylation in 2,740 adult daughters using the Illumina Infinium HumanMethylation450 array. A false discovery rate (FDR) q-value threshold of 0.05 was used to identify differentially methylated CpG sites (dmCpGs). We identified 87 dmCpGs associated with increased maternal age. The majority (84%) of the dmCpGs had lower methylation in daughters of older mothers, with an average methylation difference of 0.6% per 5-year increase in mother's age. Thirteen genomic regions contained multiple dmCpGs. Most notably, nine dmCpGs were found in the promoter region of the gene LIM homeobox 8 (LHX8), which plays a pivotal role in female fertility. Other dmCpGs were found in genes associated with metabolically active brown fat, carcinogenesis, and neurodevelopmental disorders. We conclude that maternal age is associated with persistent epigenetic changes in daughters at genes that have intriguing links to health.

Mother's age at delivery and daughters' risk of preeclampsia

BACKGROUND

Some cardiovascular disease risk factors are associated with both risk of preeclampsia and having been born to a younger or older mother. We examined whether mother's age at delivery predicts a primiparous daughter's risk of preeclampsia.

METHODS

The analysis included 39 803 Sister Study participants (designated as "daughters") born between 1930 and 1974. Using log-binomial regression, we estimated relative risks (RR) of preeclampsia in the first pregnancy ending in birth ("primiparous preeclampsia") associated with mother's age at the daughter's birth. Models included: number of older full and maternal half-siblings, income level growing up, daughter's age at delivery, race/ethnicity, and 5-year birth cohort. We examined self-reported relative weight at age 10 (heavier than peers versus not) as a potential effect measure modifier.

RESULTS

Overall, 6.2% of daughters reported preeclampsia. Compared with those who had been born to 20-24-year old mothers, daughters of teenage mothers had a relative risk of 1.20 (95% confidence interval (CI) 1.01, 1.43) and daughters of mothers ≥25 had a ~10% lower risk. Relative weight at age 10 modified the association, with an inverse association between mother's age at delivery and preeclampsia seen only among daughters with low/normal childhood relative weight. In this subset, results were consistent across strata of daughter's age at menarche and age at first birth.

CONCLUSIONS

These findings, based on self-reported data, require replication. Nevertheless, as women increasingly delay childbearing, they provide some reassurance that having been born to an older mother is not, per se, a risk factor for primiparous preeclampsia.

Associations of maternal, perinatal and postnatal factors with the eruption timing of the first primary tooth

We recruited 1296 mothers in their first trimester from the Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University between May 2014 and September 2015 to investigate the associations of maternal, perinatal and postnatal factors with the eruption timing of the first primary tooth (ETFPT) in a Chinese population. We collected maternal demographic information and clinical data during the perinatal and postnatal period, and oral examinations of the infants were performed by a doctor at 6, 9 and 12 months of age. Multiple regression analysis was used to identify significant explanatory variables for ETFPT. The mean age at eruption of the first primary tooth for all the infants was 6.82 ± 1.90 months. After adjustment for confounders, higher maternal childbearing age (β = 0.57; 95%CI = 0.13–1.02), female sex (β = 0.26; 95%CI = 0.07–0.52), and low birth weight (β = 0.98; 95%CI = 0.20–1.76) were significantly associated with delayed eruption of the first primary tooth, while macrosomia (β = −0.79; 95%CI = −1.30–−0.28) was significantly associated with earlier eruption of the first primary tooth. Maternal childbearing age, infant sex and infant birth weight were significant determinants of ETFPT.

Mode of infant feeding, eating behaviour and anthropometry in infants at 6-months of age born to obese women - a secondary analysis of the UPBEAT trial

BACKGROUND

Maternal obesity and rapid infant weight gain have been associated with increased risk of obesity in childhood. Breastfeeding is suggested to be protective against childhood obesity, but no previous study has addressed the potential benefit of breastfeeding as a preventive method of childhood obesity amongst obese women. The primary aim of this study was to assess the relationship between mode of feeding and body composition, growth and eating behaviours in 6-month-old infants of obese women who participated in UPBEAT; a multi-centre randomised controlled trial comparing a lifestyle intervention of diet and physical activity to standard care during pregnancy.

METHODS

Three hundred and fifty-three mother and infant pairs attended a 6-months postpartum follow-up visit, during which they completed the Baby-Eating Behaviour Questionnaire, a parent-reported psychometric measure of appetite traits. Measures of infant body composition were also undertaken. As there was no effect of the antenatal intervention on infant feeding and appetite the study was treated as a cohort. Using regression analyses, we examined relationships between: 1) mode of feeding and body composition and growth; 2) mode of feeding and eating behaviour and 3) eating behaviour and body composition.

RESULTS

Formula fed infants of obese women in comparison to those exclusively breastfed, demonstrated higher weight z-scores (mean difference 0.26; 95% confidence interval 0.01 to 0.52), higher rate of weight gain (0.04; 0.00 to 0.07) and greater catch-up growth (2.48; 1.31 to 4.71). There was also a lower enjoyment of food (p = 0.002) amongst formula fed infants, following adjustment for confounders. Independent of the mode of feeding, a measure of infant appetite was associated with sum of skinfold thicknesses (β 0.66; 95% CI 0.12 to 1.21), calculated body fat percentage (0.83; 0.15 to 1.52), weight z-scores (0.21; 0.06 to 0.36) and catch-up growth (odds ratio 1.98; 1.21 to 3.21).

CONCLUSIONS

In obese women, exclusive breastfeeding was protective against increasing weight z-scores and trajectories of weight gain in their 6-month old infants. Measures of general appetite in early infancy were associated with measures of adiposity, weight and catch up growth independent of cord blood leptin concentrations and mode of early feeding.

Exercise in pregnancy: 1-year and 7-year follow-ups of mothers and offspring after a randomized controlled trial

There are limited data on long-term outcomes of mothers or their offspring following exercise interventions during pregnancy. We assessed long-term effects of an exercise intervention (home-based stationary cycling) between 20–36 weeks of gestation on anthropometry and body composition in mothers and offspring after 1 and 7 years. 84 women were randomised to intervention or usual activity, with follow-up data available for 61 mother-child pairs (38 exercisers) at 1 year and 57 (33 exercisers) at 7 years. At 1 year, there were no observed differences in measured outcomes between mothers and offspring in the two groups. At the 7-year follow-up, mothers were mostly similar, except that exercisers had lower systolic blood pressure (−6.2 mmHg; p = 0.049). However, offspring of mothers who exercised during pregnancy had increased total body fat (+3.2%; p = 0.034) and greater abdominal (+4.1% android fat; p = 0.040) and gynoid (+3.5% gynoid fat; p = 0.042) adiposity compared with controls. Exercise interventions beginning during pregnancy may be beneficial to long-term maternal health. However, the initiation of exercise during pregnancy amongst sedentary mothers may be associated with adverse effects in the offspring during childhood. Larger follow-up studies are required to investigate long-term effects of exercise in pregnancy.

Microbes in Infant Gut Development: Placing Abundance Within Environmental, Clinical and Growth Parameters

Sound and timely microbial gut colonization completes newborn’s healthy metabolic programming and manifests in infant appropriate growth and weight development. Feces, collected at 3, 30, and 90 days after birth from 60 breastfed Slovenian newborns, was submitted to microbial DNA extraction and qPCR quantification of selected gut associated taxa. Multivariate regression analysis was applied to evaluate microbial dynamics with respect to infant demographic, environmental, clinical characteristics and first year growth data. Early microbial variability was marked by the proportion of Bacilli, but diminished and converged in later samples, as bifidobacteria started to prevail. The first month proportions of enterococci were associated with maternity hospital locality and supplementation of breastfeeding with formulae, while Enterococcus faecalis proportion reflected the mode of delivery. Group Bacteroides-Prevotella proportion was associated with infant weight and ponderal index at first month. Infant mixed feeding pattern and health issues within the first month revealed the most profound and extended microbial perturbations. Our findings raise concerns over the ability of the early feeding supplementation to emulate and support the gut microbiota in a way similar to the exclusively breastfed infants. Additionally, practicing supplementation beyond the first month also manifested in higher first year weight and weight gain Z-score.

Maternal age and child morbidity: A Danish national cohort study

INTRODUCTION

The mean age at delivery has increased over the latest half of a century. Women of advanced maternal age have increased obstetrical risks and increased risk of chromosomal abnormalities and some other specified diagnoses in the offspring. The aim of this study was to assess the association between maternal age and overall child morbidity according to main diagnosis groups.

MATERIAL AND METHODS

We conducted a national cohort study including 352 027 live firstborn singleton children. The children were born between Jan 1994 and Dec 2009 and followed to Dec 2012. Children were divided into groups according to maternal age: 15-24, 25-29, 30-34, and 35+ years. Poisson regression analyses calculated adjusted incidence rate ratios (IRR) of child morbidities according to main diagnoses groups A-Q of the International Classification of Disease 10 with adjustment for year of birth, body mass index, smoking, and mother's level of education.

RESULTS

Average follow-up time was 11 years. Compared to children born to women 25-29 years, firstborn children to mothers aged 35+ had higher child morbidity in 8 of 19 main diagnosis groups and firstborn children to mothers 15-24 years had higher child morbidity in 12 of 19 main diagnosis groups. Thus, for a majority of diseases a U-shaped correlation was found, with lowest rates in women 25-29 years.

CONCLUSION

Firstborn children to both older and younger mothers have higher overall morbidity as compared to children born by mothers 25-29 years.

Associations of parental age with health and social factors in adult offspring. Methodological pitfalls and possibilities

Parental age is increasing rapidly in many countries. Analysis of this potentially important influence on offspring well-being is hampered by strong secular trends and socioeconomic patterning and by a shortage of follow-up data for adult offspring. We used Swedish national data on up to 3,653,938 offspring to consider the associations of parental age with a suite of outcomes in adult offspring, comparing the results from an array of statistical methods for optimal causal inference. The offspring of older mothers had higher BMI, blood pressure, height, intelligence, non-cognitive ability and socioeconomic position. They were less likely to smoke or to be left-handed. Associations with paternal age were strongly, but not completely, attenuated by adjustment for maternal age. Estimates from the commonly-used sibling comparison method were driven primarily by a pathway mediated by offspring date of birth when outcomes showed strong secular trends. These results suggest that the intra-uterine and early life environments provided by older mothers may be detrimental to offspring cardiovascular health, but that their greater life experience and social position may bring intellectual and social advantages to their offspring. The analysis of parental age presents particular challenges, and further methodological developments are needed.

Maternal age at childbirth is associated with offspring insulin sensitivity: a cross-sectional study in adult male siblings

OBJECTIVE

Maternal age at childbirth is increasing worldwide, but studies investigating the consequences of this trend on offspring metabolic health are scarce. We investigated the associations of maternal age at childbirth with metabolic outcomes in adult male siblings.

METHODS

We used data from 586 men aged 25-45 participating in a cross-sectional, population-based sibling-pair study, including maternal age at childbirth and offspring birthweight, adult weight, height, dual-energy X-ray absorptiometry (DXA)-derived body composition, blood pressure, and total cholesterol, glucose and insulin levels from fasting serum samples. Insulin sensitivity was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR).

RESULTS

Maternal age at childbirth was 27·1 ± 4·7 years and was inversely associated with glucose levels (β = -0·10, P = 0·022) and HOMA-IR (β = -0·06, P = 0·065) in age- and body composition-adjusted analyses. Moreover, sons of younger (aged <25 and 25-29) and older (aged ≥35) mothers had higher HOMA-IR values than sons of mothers aged 30-34 (1·39, 1·35 and 1·42 vs 1·19, P = 0·028). Additional adjustment for birthweight did not substantially alter these results. Maternal age was inversely associated with cholesterol levels in unadjusted (β = -0·09, P = 0·032), but not in age- and body composition-adjusted analyses. No associations of maternal age were observed with blood pressure, leptin, or adiponectin levels or with any of the body composition measurements.

CONCLUSIONS

Increasing maternal age at childbirth is associated with lower fasting glucose levels and higher insulin sensitivity in adult male offspring. However, this association might not hold true in offspring of women aged ≥35 years at childbirth.

Advanced maternal age causes adverse programming of mouse blastocysts leading to altered growth and impaired cardiometabolic health in post-natal life

STUDY QUESTION

Does advanced maternal age (AMA) in mice affect cardiometabolic health during post-natal life in offspring derived from an assisted reproduction technology (ART) procedure?

SUMMARY ANSWER

Offspring derived from blastocysts collected from aged female mice displayed impaired body weight gain, blood pressure, glucose metabolism and organ allometry during post-natal life compared with offspring derived from blastocysts from young females; since all blastocysts were transferred to normalized young mothers, this effect is independent of maternal pregnancy conditions.

WHAT IS KNOWN ALREADY

Although studies in mice have shown that AMA can affect body weight and behaviour of offspring derived from natural reproduction, data on the effects of AMA on offspring cardiometabolic health during post-natal development are not available. Given the increasing use of ART to alleviate infertility in women of AMA, it is pivotal to develop ART-AMA models addressing the effects of maternal aging on offspring health.

STUDY DESIGN, SIZE, DURATION

Blastocysts from old (34-39 weeks) or young (8-9 weeks) C57BL/6 females mated with young CBA males (13-15 weeks) were either subjected to differential cell staining (inner cell mass and trophectoderm) or underwent embryo transfer (ET) into young MF1 surrogates (8-9 weeks) to produce young (Young-ET, 9 litters) and old (Old-ET, 10 litters) embryo-derived offspring. Offspring health monitoring was carried out for 30 weeks.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All animals were fed with standard chow. Blood pressure was measured at post-natal Weeks 9, 15 and 21, and at post-natal Week 30 a glucose tolerance test (GTT) was performed. Two days after the GTT mice were killed for organ allometry. Blastocyst cell allocation variables were evaluated by T-test and developmental data were analysed with a multilevel random effects regression model.

MAIN RESULTS AND THE ROLE OF CHANCE

The total number of cells in blastocysts from aged mice was decreased (P < 0.05) relative to young mice due to a lower number of cells in the trophectoderm (mean ± SEM: 34.5 ± 2.1 versus 29.6 ± 1.0). Weekly body weight did not differ in male offspring, but an increase in body weight from Week 13 onwards was observed in Old-ET females (final body weight at post-natal Week 30: 38.5 ± 0.8 versus 33.4 ± 0.8 g, P < 0.05). Blood pressure was increased in Old-ET offspring at Weeks 9-15 in males (Week 9: 108.5 ± 3.13 versus 100.8 ± 1.5 mmHg, Week 15: 112.9 ± 3.2 versus 103.4 ± 2.1 mmHg) and Week 15 in females (115.9 ± 3.7 versus 102.8 ± 0.7 mmHg; all P < 0.05 versus Young-ET). The GTT results and organ allometry were not affected in male offspring. In contrast, Old-ET females displayed a greater (P < 0.05) peak glucose concentration at 30 min during the GTT (21.1 ± 0.4 versus 17.8 ± 1.16 mmol/l) and their spleen weight (88.2 ± 2.6 ± 105.1 ± 4.6 mg) and several organ:body weight ratios (g/g × 10(3)) were decreased (P < 0.05 versus Young-ET), including the heart (3.7 ± 0.06 versus 4.4 ± 0.08), lungs (4.4 ± 0.1 versus 5.0 ± 0.1), spleen (2.4 ± 0.06 versus 3.2 ± 0.1) and liver (36.4 ± 0.6 versus 39.1 ± 0.9).

LIMITATIONS, REASONS FOR CAUTION

Results from experimental animal models cannot be extrapolated to humans. Nevertheless, they are valuable to develop conceptual models that can produce hypotheses for eventual testing in the target species (i.e. humans).

WIDER IMPLICATIONS OF THE FINDINGS

Our data show that offspring from mouse embryos from aged mothers can develop altered phenotypes during post-natal development compared with embryos from young mothers. Because all embryos were transferred into young mothers for the duration of pregnancy to normalize the maternal in vivo environment, our findings indicate that adverse programming via AMA is already established at the blastocyst stage. Whilst human embryos display increased aneuploidy compared with mouse, we believe our data have implications for women of AMA undergoing assisted reproduction, including surrogacy programmes.

STUDY FUNDING/COMPETING INTERESTS

This work was supported through the European Union FP7-CP-FP Epihealth programme (278418) to T.P.F. and the BBSRC (BB/F007450/1) to T.P.F. The authors have no conflicts of interest to declare.

Influence of metabolic-linked early life factors on the eruption timing of the first primary tooth

AIM

Early eruption of permanent teeth has been associated with childhood obesity and diabetes mellitus, suggesting links between tooth eruption and metabolic conditions. This longitudinal study aimed to identify pre-, peri- and postnatal factors with metabolic consequences during infancy that may affect the eruption timing of the first primary tooth (ETFT) in children from an ethnically heterogeneous population residing within the same community.

MATERIAL AND METHODS

Participants were recruited (n = 1033) through the GUSTO (Growing Up in Singapore Towards healthy Outcomes) birth cohort (n = 1237). Oral examinations were performed at 3-month intervals from 6 to 18 months of age. Crude and adjusted analyses, with generalized linear modelling, were conducted to link ETFT to potential determinants occurring during pregnancy, delivery/birth and early infancy.

RESULTS

Overall mean eruption age of the first primary tooth was 8.5 (SD 2.6) months. Earlier tooth eruption was significantly associated with infant's rate of weight gain during the first 3 months of life and increased maternal childbearing age. Compared to their Chinese counterparts, Malay and Indian children experienced significantly delayed tooth eruption by 1.2 and 1.7 months, respectively.

CONCLUSIONS

Infant weight gain from birth to 3 months, ethnicity and maternal childbearing age were significant determinants of first tooth eruption timing. Early life influences can affect primary tooth development, possibly via metabolic pathways.

CLINICAL RELEVANCE

Timing of tooth eruption is linked to general growth and metabolic function. Therefore, it has potential in forecasting oral and systemic conditions such as caries and obesity.

Bisphenol a exposure disrupts metabolic health across multiple generations in the mouse

Accumulating evidence has suggested that a suboptimal early life environment produces multigenerational developmental defects. A proposed mechanism is stable inheritance of DNA methylation. Here we show that maternal bisphenol A (BPA) exposure in C57BL/6 mice produces multigenerational metabolic phenotypes in their offspring. Using various methods including dual-energy X-ray absorptiometry analyses, glucose tolerance tests, and perifusion islet studies, we showed that exposure to 10 μg/kg/d and 10 mg/kg/d BPA in pregnant F0 mice was associated with higher body fat and perturbed glucose homeostasis in F1 and F2 male offspring but not female offspring. To provide insight into the mechanism of the multigenerational metabolic abnormalities, we investigated the maternal metabolic milieu and inheritance of DNA methylation across generations. We showed that maternal glucose homeostasis during pregnancy was altered in the F0 but not F1 female mice. The results suggested that a compromised maternal metabolic milieu may play a role in the health of the F1 offspring but cannot account for all of the observed multigenerational phenotypes. We further demonstrated that the metabolic phenotypes in the F1 and F2 BPA male offspring were linked to fetal overexpression of the imprinted Igf2 gene and increased DNA methylation at the Igf2 differentially methylated region 1. Studies in H19(Δ3.8/+) mouse mutants supported the role of fetal Igf2 overexpression in altered adult glucose homeostasis. We conclude that early life BPA exposure at representative human exposure levels can perturb metabolic health across multiple generations in the mouse through stable inheritance of DNA methylation changes at the Igf2 locus.

How Are Children of Older Mothers Doing? Evidence from the United Kingdom

Childbearing has been increasingly delayed in Western countries. As older mothers are likely to be advantaged over their younger counterparts, the demographic literature has tended to view this demographic trend as potentially beneficial for child well-being. Conversely, less attention has been given to medical studies showing that giving birth at advanced ages is associated with health risks for children. This article uses data from the Millennium Cohort Study (UK) and ordinary least squares and logistic regression models to compare cognitive and behavioral outcomes, and obesity at age 5 for first-born children by maternal age at first birth. On one hand, the findings suggest that giving birth to the first child at ages 30-39 compared to ages 23-29 is positively associated with children's cognitive and behavioral outcomes and not associated with obesity. On the other hand, delaying the first birth to ages 40 and above is not associated with children's cognitive and behavioral outcomes and is associated with increased risk of obesity. Although the results are unable to support the argument that this occurs because of the health risks associated with giving birth at advanced maternal ages, they suggest that there is a need to more closely investigate the potential trade-offs involved when births are delayed toward older maternal ages.

Increasing parental age at childbirth is associated with greater insulin sensitivity and more favorable metabolic profile in overweight adult male offspring

OBJECTIVE

To assess the effect of parental age at childbirth on insulin sensitivity and other metabolic outcomes in overweight middle-aged males.

METHODS

We studied 73 men aged 46.0±5.4 years, who were overweight (body mass index, BMI 25-30 kg/m(2) ) but otherwise healthy. Insulin sensitivity was assessed by the Matsuda method from an oral glucose tolerance test. Other assessments included dual-energy X-ray absorptiometry-derived body composition, lipid profile, 24-hour ambulatory blood pressure, and carotid intima-media thickness. Maternal and paternal ages were highly correlated (r = 0.71; P < 0.0001), and the main parameter of interest in this study was the mean parental age at childbirth (MPAC), calculated as the average of maternal and paternal ages.

RESULTS

Increasing MPAC was associated with a continuous increase in insulin sensitivity (β = 0.193; P = 0.008), as well as reductions in insulin resistance (HOMA-IR; β = -0.064; P = 0.011), fasting insulin (β = -0.221; P = 0.018) and fasting glucose (β = -0.030; P = 0.033) concentrations. Increasing MPAC was also associated with reductions in night time systolic (β = -0.500; P = 0.020) and diastolic (β = -0.325; P = 0.047) blood pressure, as well as with improved (greater) nocturnal diastolic blood pressure dipping (β = 0.413; P = 0.046). Subgroup analyses on participants of European descent (n = 64) showed that increasing MPAC was associated with reduced carotid intima-media thickness (β = -0.008; P = 0.018) and lower low-density lipoprotein cholesterol concentrations (β = -0.042; P = 0.028).

CONCLUSIONS

Increasing parental age at childbirth was associated with a more favorable metabolic phenotype in overweight middle-aged males. However, it is unknown whether the effect was maternal, paternal, or both. Future studies on the effects of parental age at childbirth on the metabolism of males and females across the BMI range are required.

The phenotype of an IVF child is associated with peri-conception measures of follicular characteristics and embryo quality

STUDY QUESTION

Are childhood measures of phenotype associated with peri-conception parental, IVF treatment and/or embryonic characteristics of IVF children?

SUMMARY ANSWER

Birthweight, childhood body mass index (BMI) and height of pre-pubertal IVF children were strongly associated with peri-conception factors, including follicular and embryonic characteristics.

WHAT IS KNOWN ALREADY

A growing number of studies have identified a range of phenotypic differences between IVF and naturally conceived pre-pubertal children; for example, birthweights are lower following a fresh compared with a thawed embryo transfer.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study included IVF children (n = 96) born at term (>37 weeks) after a singleton pregnancy from the transfer of either fresh or thawed embryos in New Zealand. Between March 2004 and November 2008, these children were subjected to clinical assessment before puberty.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Clinical assessment provided anthropometric measures of children aged 3.5-11 years old. Peri-conception factors (n = 36) derived retrospectively from parental, treatment, laboratory and embryonic variables (n = 69) were analysed using multiple stepwise regression with respect to standard deviation scores (SDSs) of the birthweight, mid-parental corrected BMI and height of the IVF children. Data from children conceived from fresh (n = 60) or thawed (n = 36) embryos, that met inclusion criteria and had high-quality data with >90% completeness, were analysed.

MAIN RESULTS AND THE ROLE OF CHANCE

Embryo treatment at transfer was identified as a predictor of birthweight with thawed embryos resulting in heavier birthweights than fresh embryos [P = 0.02, 95% confidence interval (CI) fresh minus thawed: -1.047 to -0.006]. Birthweight SDS was positively associated with mid-parental corrected BMI SDS (P = 0.003, slope 0.339 ± 0.100). Four factors were related (P < 0.05) to mid-parental corrected height SDS. In particular, child height was inversely associated with the diameter of lead follicles at oocyte retrieval (P < 0.0001, slope -0.144 ± 0.040) and with the quality score of embryos at transfer (P = 0.0008, slope -0.425 ± 0.157), and directly associated with the number of follicles retrieved (P = 0.05, slope 1.011 ± 0.497). Child height was also positively associated with the transfer of a fresh as opposed to thawed embryo (P < 0.001, 95% CI 0.275-0.750).

LIMITATIONS, REASONS FOR CAUTION

More than one embryo was transferred in most cycles so mean development and quality data were used. The large number of variables measured was on a relatively small sample size. Large cohorts from multiple clinics using a variety of treatment protocols and embryology methods are needed to confirm the associations identified and ultimately to test these factors as possible predictors of phenotype.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study to directly associate peri-conception measures of IVF treatment with a pre-pubertal child's phenotype. Demonstration that peri-conception measures relate to a pre-pubertal child's phenotype extends the range of factors that may influence growth and development. These findings, if corroborated by larger studies, would provide invaluable information for practitioners, who may want to consider the impact of ovarian stimulation protocols as well as the quality of the embryo transferred on a child's growth and development, in addition to their impact on pregnancy rate.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants from the National Research Centre of Growth and Development New Zealand (grant 3682065) and the Australasian Paediatric Endocrine Group (APEG; grant 3621994), as well as a fellowship from Fertility Associates New Zealand awarded to M.P.G. In terms of competing interest, J.C.P is a shareholder of Fertility Associates. M.P.G. currently holds the position of Merck Serono Lecturer in Reproductive Biology. W.S.C. and P.L.H. have also received grants and non-financial support from Novo Nordisk, as well as personal fees from Pfizer that are unrelated to the current study. The other authors have no conflict of interest to declare.

The failure of cancer chemoprevention

Chemoprevention is proposed as a clinical analogue of population prevention, aimed at reducing likelihood of disease progression, not across the population, but in identified high-risk individuals and not by behavioral or lifestyle modification, but by the use of pharmaceutical agents. Cardiovascular chemoprevention is successful via control of hyperlipidemias and hypertension. However, chemoprevention of cancer is an almost universal failure: not only are some results null; even more frequently, there is an excess of disease, including disease that the agents were chosen specifically to reduce. A brief introduction is followed by the evidence for a wide variety of agents and their largely deleterious, sometimes null, and in one case, largely beneficial, consequences as possible chemopreventives. The agents include (i) those that are food derived and their synthetic analogues: β-carotene, folic acid, retinol and retinoids, vitamin E, multivitamin supplements, vitamin C, calcium and selenium and (ii) agents targeted at metabolic and hormonal pathways: statins, estrogen and antagonists, 5α-reductase inhibitors. There are two agents for which there is good evidence of benefit when the strategy is focused on those at defined high risk but where wider application is much more problematic: aspirin and tamoxifen. The major problems with cancer chemoprevention are presented. This is followed by a hypothesis to explain the failure of cancer chemoprevention as an enterprise, arguing that the central tenets that underpin it are flawed and showing why, far from doing good, cancer chemoprevention causes harm.

Among overweight middle-aged men, first-borns have lower insulin sensitivity than second-borns

We aimed to assess whether birth order affects metabolism and body composition in overweight middle-aged men. We studied 50 men aged 45.6 ± 5.5 years, who were overweight (BMI 27.5 ± 1.7 kg/m(2)) but otherwise healthy in Auckland, New Zealand. These included 26 first-borns and 24 second-borns. Insulin sensitivity was assessed by the Matsuda method from an oral glucose tolerance test. Other assessments included DXA-derived body composition, lipid profiles, 24-hour ambulatory blood pressure, and carotid intima-media thickness. First-born men were 6.9 kg heavier (p = 0.013) and had greater BMI (29.1 vs 27.5 kg/m(2); p = 0.004) than second-borns. Insulin sensitivity in first-born men was 33% lower than in second-borns (4.38 vs 6.51; p = 0.014), despite adjustment for fat mass. There were no significant differences in ambulatory blood pressure, lipid profile or carotid intima-media thickness between first- and second-borns. Thus, first-born adults may be at a greater risk of metabolic and cardiovascular diseases.

Increasing paternal age at childbirth is associated with taller stature and less favourable lipid profiles in their children

BACKGROUND

Paternal age at childbirth has been increasing worldwide, and we assessed whether this increase affects growth, body composition and metabolism in their children.

METHODS

We studied 277 children (aged 3-12 years) born to fathers aged 19·8-51·8 years. Clinical assessments were height and weight adjusted for parental measurements, DEXA-derived body composition, fasting lipids, glucose homoeostasis and hormonal profiles.

RESULTS

Children born to fathers aged 31-35 (P = 0·009) and >35 years (P = 0·021) were 2 cm taller than those of fathers aged ≤30 years. Children of fathers aged >35 years at childbirth had a lower body mass index (BMI) (-0·32 SDS) than offspring of fathers aged 31-35 (-0·01 SDS; P = 0·043) and ≤30 (0·22 SDS; P = 0·019). There were marked effects of paternal age at childbirth on childhood blood lipids. LDL-C concentrations in children born to fathers aged >35 years were 11% and 21% higher than in children of fathers aged 31-35 and ≤30 years, respectively (P < 0·01). Total cholesterol to HDL-C ratio was also higher among the children of fathers aged 31-35 (12%; P = 0·014) and >35 (16%; P = 0·004) years at childbirth compared with the ≤30 group. In addition, HOMA-IR in girls (but not boys) born of fathers aged 31-35 (0·99) and >35 years (1·11) indicated better insulin sensitivity compared with offspring in the ≤30 group (1·63; P < 0·05).

CONCLUSIONS

Increasing paternal age at childbirth is associated with a more favourable phenotype in their children (taller and slimmer, with better insulin sensitivity in girls) but with a less favourable lipid profile.