Parental pre-pregnancy BMI influences on offspring BMI and waist circumference at 21 years

Influence of parental weight change on the incidence of overweight and obesity in offspring

BACKGROUND

There is limited information on the association of parental weight change with overweight and obesity in offspring. This study aimed to investigate the association between parental weight change and incident overweight and obesity in offspring.

METHODS

This longitudinal cohort study included 2,963 parent-offspring trios who participated in at least two waves of the China Health and Nutrition Survey. The children without overweight and obesity defined by the International Obesity Task Force were included at the initial survey. Parental overweight and obesity were defined as body mass index ≥ 25 kg/m².

RESULTS

The incidence of overweight and obesity in offspring was 5.8% during a mean follow-up of 5.4 years. Paternal and maternal overweight and obesity at baseline were associated with this condition in offspring at follow-up (both P_s < 0.05). Compared with the persistent normal group, the persistent overweight and obesity group and incident overweight and obesity group (normal weight to overweight and obesity), but not the reversion group (overweight and obesity to normal weight), were more likely to report overweight and obesity in offspring at follow-up, regardless of father's or mother's condition. Additionally, compared with offspring whose both parents remained normal weight, those whose both parents changed from overweight and obesity to normal weight or whose one parent changed from overweight and obesity to normal weight while the other remained normal weight had no higher risks of overweight and obesity.

CONCLUSION

This study highlights the importance of parental weight management in the prevention of overweight/obesity in offspring.

Exploring the causal effect of maternal pregnancy adiposity on offspring adiposity: Mendelian randomisation using polygenic risk scores

BACKGROUND

Greater maternal adiposity before or during pregnancy is associated with greater offspring adiposity throughout childhood, but the extent to which this is due to causal intrauterine or periconceptional mechanisms remains unclear. Here, we use Mendelian randomisation (MR) with polygenic risk scores (PRS) to investigate whether associations between maternal pre-/early pregnancy body mass index (BMI) and offspring adiposity from birth to adolescence are causal.

METHODS

We undertook confounder adjusted multivariable (MV) regression and MR using mother-offspring pairs from two UK cohorts: Avon Longitudinal Study of Parents and Children (ALSPAC) and Born in Bradford (BiB). In ALSPAC and BiB, the outcomes were birthweight (BW; N = 9339) and BMI at age 1 and 4 years (N = 8659 to 7575). In ALSPAC only we investigated BMI at 10 and 15 years (N = 4476 to 4112) and dual-energy X-ray absorptiometry (DXA) determined fat mass index (FMI) from age 10-18 years (N = 2659 to 3855). We compared MR results from several PRS, calculated from maternal non-transmitted alleles at between 29 and 80,939 single nucleotide polymorphisms (SNPs).

RESULTS

MV and MR consistently showed a positive association between maternal BMI and BW, supporting a moderate causal effect. For adiposity at most older ages, although MV estimates indicated a strong positive association, MR estimates did not support a causal effect. For the PRS with few SNPs, MR estimates were statistically consistent with the null, but had wide confidence intervals so were often also statistically consistent with the MV estimates. In contrast, the largest PRS yielded MR estimates with narrower confidence intervals, providing strong evidence that the true causal effect on adolescent adiposity is smaller than the MV estimates (Pdifference = 0.001 for 15-year BMI). This suggests that the MV estimates are affected by residual confounding, therefore do not provide an accurate indication of the causal effect size.

CONCLUSIONS

Our results suggest that higher maternal pre-/early-pregnancy BMI is not a key driver of higher adiposity in the next generation. Thus, they support interventions that target the whole population for reducing overweight and obesity, rather than a specific focus on women of reproductive age.

Effects of paternal overnutrition and interventions on future generations

In the last two decades, evidence from human and animal studies suggests that paternal obesity around the time of conception can have adverse effects on offspring health through developmental programming. This may make significant contributions to the current epidemic of obesity and related metabolic and reproductive complications like diabetes, cardiovascular disease, and subfertility/infertility. To date, changes in seminal fluid composition, sperm DNA methylation, histone composition, small non-coding RNAs, and sperm DNA damage have been proposed as potential underpinning mechanism to program offspring health. In this review, we discuss current human and rodent evidence on the impact of paternal obesity/overnutrition on offspring health, followed by the proposed mechanisms, with a focus on sperm DNA damage underpinning paternal programming. We also summarize the different intervention strategies implemented to minimize effects of paternal obesity. Upon critical review of literature, we find that obesity-induced altered sperm quality in father is linked with compromised offspring health. Paternal exercise intervention before conception has been shown to improve metabolic health. Further work to explore the mechanisms underlying benefits of paternal exercise on offspring are warranted. Conversion to healthy diets and micronutrient supplementation during pre-conception have shown some positive impacts towards minimizing the impact of paternal obesity on offspring. Pharmacological approaches e.g., metformin are also being applied. Thus, interventions in the obese father may ameliorate the potential detrimental impacts of paternal obesity on offspring.

Higher maternal BMI early in pregnancy is associated with overweight and obesity in young adult offspring in Thailand

Background

Rates of overweight and obesity among women of reproductive age have been steadily increasing worldwide and in Thailand. There is mounting evidence that maternal obesity during pregnancy is associated with an increased risk of obesity and other adverse health outcomes in the offspring, but such data are lacking for Thailand. We examined the associations between maternal body mass index (BMI) and anthropometry (particularly the likelihood of obesity) and cardiometabolic parameters in young adult offspring.

Methods

This was a prospective follow-up study of a birth cohort in Chiang Mai (Thailand). Pregnant women carrying singletons were recruited at their first antenatal visit (< 24 weeks of gestation) and followed until delivery in 1989–1990. Participants were their young adult offspring followed up in 2010. Maternal BMI was recorded at the first antenatal visit. The offspring underwent clinical assessments, including anthropometry, lipid profile, insulin sensitivity (HOMA-IR), blood pressure, and carotid intima-media thickness. The primary outcome of interest was the likelihood of obesity in the offspring.

Results

We assessed 628 young adults (54% were females) at 20.6 ± 0.5 years of age (range 19.1–22.1 years). The young adult offspring of mothers with overweight/obesity was 14.1 kg (95%CI 9.7, 18.5; p < 0.0001) and 9.4 kg (95% CI 6.1, 12.8; p < 0.0001) heavier than those born to mothers with underweight or normal weight, respectively, and had BMI 3.46 kg/m² (95%CI 2.26, 4.67; p < 0.0001) and 5.27 kg/m² (95%CI 3.67, 8.68; p < 0.0001) greater, respectively. For every 1-kg/m² increase in maternal BMI, the adjusted odds ratio (aOR) of offspring obesity was 25% greater (95%CI 1.10, 1.42; p < 0.001). Thus, the aOR of obesity in offspring of mothers with overweight/obesity was 4.6 times greater (95%CI 1.86, 11.26; p < 0.001) and nearly 17-fold greater (95%CI 1.96, 146.4; p = 0.010) compared to young adults born to mothers with normal weight or underweight, respectively. There were no observed associations between maternal BMI status and offspring metabolism or blood pressure.

Discussion

Maternal overweight/obesity early in pregnancy was associated with increased BMI and greater odds of obesity in their young adult offspring in Thailand. These findings highlight the public health importance of fostering healthier lifestyle choices among women of reproductive age.

Paternal metabolic and cardiovascular programming of their offspring: A systematic scoping review

BACKGROUND

There is lots of evidence that maternal peri-gestational metabolic, genomic and environmental conditions are closely linked to metabolic and cardiovascular outcomes in their offspring later in life. Moreover, there is also lotsof evidence that underlining mechanisms, such as molecular as well as epigenetic changes may alter the intrauterine environment leading to cardio-metabolic diseases in their offspring postnatal. But, there is also increasing evidence that cardio-metabolic diseases may be closely linked to their paternal metabolic risk factors, such as obesity, Type 2 Diabetes and other risk factors.

OBJECTIVE

To analyse the evidence as well as specific risk factors of paternal trans-generational programming of cardio-metabolic diseases in their offspring.

METHODS

Within a systematic scoping review, we performed a literature search in MEDLINE (PubMed) and EMBASE databases in August 2020 considering original research articles (2000-2020) that examined the impact of paternal programming on metabolic and cardiovascular offspring health. Epidemiological, clinical and experimental studies as well as human and animal model studies were included.

RESULTS

From n = 3.199 citations, n = 66 eligible studies were included. We selected n = 45 epidemiological as well as clinical studies and n = 21 experimental studies. In brief, pre-conceptional paternal risk factors, such as obesity, own birth weight, high-fat and low-protein diet, undernutrition, diabetes mellitus, hyperglycaemia, advanced age, smoking as well as environmental chemical exposure affect clearly metabolic and cardiovascular health of their offspring later in life.

CONCLUSIONS

There is emerging evidence that paternal risk factors, such as paternal obesity, diabetes mellitus, nutritional habits, advanced age and exposure to environmental chemicals or cigarette smoke, are clearly associated with adverse effects in metabolic and cardiovascular health in their offspring. Compared to maternal programming, pre-conceptional paternal factors might also have also a substantial effect in the sense of trans-generational programming of their offspring and need further research.

Exploring the role of genetic confounding in the association between maternal and offspring body mass index: evidence from three birth cohorts

BACKGROUND

Maternal pre-pregnancy body mass index (BMI) is positively associated with offspring birth weight (BW) and BMI in childhood and adulthood. Each of these associations could be due to causal intrauterine effects, or confounding (genetic or environmental), or some combination of these. Here we estimate the extent to which the association between maternal BMI and offspring body size is explained by offspring genotype, as a first step towards establishing the importance of genetic confounding.

METHODS

We examined the associations of maternal pre-pregnancy BMI with offspring BW and BMI at 1, 5, 10 and 15 years, in three European birth cohorts (n ≤11 498). Bivariate Genomic-relatedness-based Restricted Maximum Likelihood implemented in the GCTA software (GCTA-GREML) was used to estimate the extent to which phenotypic covariance was explained by offspring genotype as captured by common imputed single nucleotide polymorphisms (SNPs). We merged individual participant data from all cohorts, enabling calculation of pooled estimates.

RESULTS

Phenotypic covariance (equivalent here to Pearson's correlation coefficient) between maternal BMI and offspring phenotype was 0.15 [95% confidence interval (CI): 0.13, 0.17] for offspring BW, increasing to 0.29 (95% CI: 0.26, 0.31) for offspring 15 year BMI. Covariance explained by offspring genotype was negligible for BW [-0.04 (95% CI: -0.09, 0.01)], but increased to 0.12 (95% CI: 0.04, 0.21) at 15 years, which is equivalent to 43% (95% CI: 15%, 72%) of the phenotypic covariance. Sensitivity analyses using weight, BMI and ponderal index as the offspring phenotype at all ages showed similar results.

CONCLUSIONS

Offspring genotype explains a substantial fraction of the covariance between maternal BMI and offspring adolescent BMI. This is consistent with a potentially important role for genetic confounding as a driver of the maternal BMI-offspring BMI association.

Influence of post-partum BMI change on childhood obesity and energy intake

Introduction

Association between parent’s Body Mass Index (BMI) and their children, has been widely documented. Individual, familiar and structural factors play a role in this relation. We analyzed the association between maternal BMI change during the first year post-partum and their offspring’s growth-trajectories and energy intake in their first five years of life.

Objective

Compare growth-trajectories and children’s caloric intake according to post-partum mother´s BMI classification.

Methods

The anthropometric assessment was taken in 935 mother-child pairs along the study period. Mothers were classified into four groups according to their BMI-trajectories in the post-partum. Children’s weight for height z-scores (WHZ) was compared among groups using random-effects regression models. A longitudinal comparison of children’s caloric intake by the maternal group was carried out.

Results

At 42 months of age, infants from mothers that remained overweight during the first year post-partum had, on average, 0.61 SD higher WHZ than those from mothers who remained in a recommended BMI group (R-BMI) in the same period. At 60 months of age, children´s prevalence of obesity was almost twice in the maternal overweight group vs R-BMI group (14.2% and 7.3% respectively). Chances for a child of having an over caloric intake were 36.5% (95% IC: 6.6%, 74.8%) and significantly higher among children from overweight mothers than those from R-BMI mothers. The difference in children’s WHZ trajectory remained significant after adjusting for caloric intake, suggesting that contextual factors play a role in shaping children’s obesity. A concurrent ethnographic study with the study subjects provides suggestions as to what these factors might be, including changes in the food landscape.

Conclusion

Children from overweight mothers tended to have a more caloric diet yielding a higher propensity to obesity. Contextual factors such as food landscape might contribute to childhood obesity beyond having an overweight mother. Pregnancy and post-partum is a window of opportunity for interventions to decrease the incidence of children’s overweight.

Intergenerational Effects of Health Issues Among Women of Childbearing Age: a Review of the Recent Literature

PURPOSE OF REVIEW

This review summarizes the latest scientific evidence, primarily from systematic reviews/meta-analyses and large cohort studies, on the impact of health issues among women of childbearing age and their effect on their offspring during pregnancy and from birth to adulthood.

RECENT FINDINGS

Women of childbearing age with overweight/obesity, diabetes, and hypertension prior to pregnancy are at increased risk for adverse outcomes during pregnancy, such as excessive gestational weight gain, gestational diabetes mellitus, and hypertensive disorders of pregnancy. These adverse outcomes could complicate delivery and put their offspring at risk of developing overweight/obesity, diabetes, and hypertension (i.e., intergenerational transmission of health issues). Interventions should target women of childbearing age, especially those who wish to conceive, in order to possibly stop the transmission of women's health issues to the offspring and favor a healthy pregnancy from the start. This could be one of the best strategies to promote both maternal and child health.

Maternal smoking early in pregnancy is associated with increased risk of short stature and obesity in adult daughters

We assessed anthropometry in 22,421 adult daughters in association with their mothers’ tobacco smoking early in pregnancy (at their first antenatal visit) in Sweden, particularly their risk of short stature and obesity. Adult daughters were grouped by maternal smoking levels during pregnancy: Non-smokers (58.5%), Light smokers (24.1%; smoked 1–9 cigarettes/day), and Heavier smokers (17.4%; smoked ≥10 cigarettes/day). Anthropometry was recorded on the adult daughters at approximately 26.0 years of age. Obesity was defined as BMI ≥30 kg/m², and short stature as height more than two standard deviations below the population mean. Daughters whose mothers were Light and Heavier smokers in early pregnancy were 0.8 cm and 1.0 cm shorter, 2.3 kg and 2.6 kg heavier, and had BMI 0.84 kg/m² and 1.15 kg/m² greater, respectively, than daughters of Non-smokers. The adjusted relative risk of short stature was 55% higher in women born to smokers, irrespectively of smoking levels. Maternal smoking had a dose-dependent association with obesity risk, with offspring of Heavier smokers 61% and of Light smokers 37% more likely to be obese than the daughters of Non-smokers. In conclusion, maternal smoking in pregnancy was associated with an increased risk of short stature and obesity in their adult daughters.

An Exercise-Only Intervention in Obese Fathers Restores Glucose and Insulin Regulation in Conjunction with the Rescue of Pancreatic Islet Cell Morphology and MicroRNA Expression in Male Offspring

Paternal obesity programs metabolic syndrome in offspring. Low-impact exercise in obese males improves the metabolic health of female offspring, however whether this occurred in male offspring remained unknown. C57BL/6NHsd (Harlan) mice were fed a control diet (CD; 6% fat, n = 7) or a high-fat diet (HFD; 21% fat, n = 16) for 18 weeks. After 9 weeks, HFD-fed mice either remained sedentary (HH, n = 8) or undertook low–moderate exercise (HE, n = 8) for another 9 weeks. Male offspring were assessed for glucose/insulin tolerance, body composition, plasma lipids, pancreatic islet cell morphology and microRNA expression. Founder HH induced glucose intolerance, insulin insensitivity, and hyperlipidaemia in male offspring (p < 0.05). Metabolic health was fully restored in male offspring by founder exercise to control levels. Founder HH reduced pancreatic β-cell area and islet cell size in male offspring, and altered the expression of 13 pancreatic microRNAs (p < 0.05). Founder HE led to partial restoration of pancreatic islet cell morphology and the expression of two pancreatic microRNAs (let7d-5p, 194-5p) in male offspring. Founder HE reduced male offspring adiposity, increased muscle mass, reduced plasma free fatty acids (FFAs), and further altered pancreatic microRNAs (35 vs. HH; 32 vs. CD) (p < 0.05). Low-impact exercise in obese fathers prior to conception, without dietary change, may be a viable intervention strategy to reduce the ill-effects of obesity-induced paternal programming in male offspring.