The contribution of parental and grandparental childhood social disadvantage to circulatory disease diagnosis in young Swedish men

Transgenerational health effects of in utero exposure to economic hardship: Evidence from preindustrial Southern Norway

We studied whether in utero exposure to economic hardship during a grandmother's pregnancy has a transgenerational effect on her grandchildren's health condition. We used an individual-level three-generation data set covering people born between 1734 and 1840 in the municipality of Rendalen in Norway. We found a culling effect in which grandchildren whose grandmothers gave birth in years of economic hardship lived approximately ten years longer than grandchildren whose mothers were born in years of economic well-being. This impact was only observed among the grandmothers who belong to the lowest social classes. Our results also showed that in higher social classes, economic hardship during a grandmother's pregnancy deteriorated her grandchildren's health by "scarring" the mother's health.

Paternal grandfather's access to food predicts all-cause and cancer mortality in grandsons

Studies of animals and plants suggest that nutritional conditions in one generation may affect phenotypic characteristics in subsequent generations. A small number of human studies claim to show that pre-pubertal nutritional experience trigger a sex-specific transgenerational response along the male line. A single historical dataset, the Överkalix cohorts in northern Sweden, is often quoted as evidence. To test this hypothesis on an almost 40 times larger dataset we collect harvest data during the pre-pubertal period of grandparents (G0, n = 9,039) to examine its potential association with mortality in children (G1, n = 7,280) and grandchildren (G2, n = 11,561) in the Uppsala Multigeneration Study. We find support for the main Överkalix finding: paternal grandfather's food access in pre-puberty predicts his male, but not female, grandchildren's all-cause mortality. In our study, cancer mortality contributes strongly to this pattern. We are unable to reproduce previous results for diabetes and cardiovascular mortality.

Social class, social mobility and alcohol-related disorders in Swedish men and women: A study of four generations

Objectives

To investigate whether and how social class and social mobility in grandparents and parents predict alcohol-related disorders (ARDs) in males and females aged 12+ years, and whether intergenerational social prediction of ARDs varies across time periods.

Methods

The study sample included four successive generations (G) of Swedish families from the Uppsala Birth Cohort Multigenerational Study: G0 born 1851–1912; G1 born 1915–1929; G2 born 1940–1964 and G3 born 1965–1989. Two study populations were created, each consisting of grandparents, parents and offspring: population I ‘G0-G1-G2’ (offspring n = 18 430) and population II ‘G1-G2-G3’ (offspring n = 26 469). Registers and archives provided data on ancestors’ socio-demographic factors and ARD history, together with offspring ARD development between 1964–2008. Cox regression models examined the hazard of offspring ARD development according to grandparental social class and grandparental-to-parental social trajectories, controlling for offspring birth year, grandmother’s and mother’s marital status and parental ARDs.

Results

Disadvantaged grandparental social class predicted increased ARD risk in offspring in population I, although the effect attenuated and became non-significant in males after adjusting for parental characteristics (adjusted hazard ratio (HR) = 1.80 (95%CI; 1.07, 3.03) in females, HR = 1.32 (95%CI; 0.93, 1.89) in males). In population II, no increase in ARD risk by grandparental social was evident. In both populations, males were at the highest ARD risk if both parents and grandparents belonged to disadvantaged social class (population I: HR = 1.82 (95%CI; 1.22–2.72); population II: HR = 1.68 (95%CI; 1.02–2.76)).

Conclusions

Intergenerational social patterning of ARDs appears to be time-contextual and gender-specific. The role of grandparental social class in developing ARDs in grandchildren seems to decline over time, while persistent grandparental-to-parental social disadvantage remains associated with higher ARD risk in males. When targeting higher risk groups, continuity of familial social disadvantage, particularly among males, should be considered.

Why is parental lifespan linked to children's chances of reaching a high age? A transgenerational hypothesis

Purpose

Transgenerational determinants of longevity are poorly understood. We used data from four linked generations (G0, G1, G2 and G3) of the Uppsala Birth Cohort Multigeneration Study to address this issue.

Methods

Mortality in G1 (N = 9565) was followed from 1961–2015 and analysed in relation to tertiles of their parents’ (G0) age-at-death using Cox regression. Parental social class and marital status were adjusted for in the analyses, as was G1’s birth order and adult social class. For an almost entirely deceased segment of G1 (n = 1149), born 1915–1917, we compared exact age-at-death with G0 parents’ age-at-death. Finally, we explored ‘resilience’ as a potentially important mechanism for intergenerational transmission of longevity, using conscript information from psychological interviews of G2 and G3 men.

Results

G0 men’s and women’s ages-at-death were independently associated with G1 midlife and old age mortality. This association was robust and minimally reduced when G0 and G1 social class were adjusted for. We observed an increased lifespan in all social groups. Median difference in age-at-death for sons compared to fathers was + 3.9 years, and + 6.9 years for daughters compared to mothers.

Parents’ and maternal grandmother’s longevity were associated with resilience in subsequent generations. Resilience scores of G2 men were also associated with those of their G3 sons and with their own mortality in midlife.

Conclusions

The chance of reaching a high age is transmitted from parents to children in a modest, but robust way. Longevity inheritance is paralleled by the inheritance of individual resilience. Individual resilience, we propose, develops in the first part of life as a response to adversity and early experience in general. This gives rise to a transgenerational pathway, distinct from social class trajectories. A theory of longevity inheritance should bring together previous thinking around general susceptibility, frailty and resilience with new insights from epigenetics and social epidemiology.

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Parents’ ages-at-death predict children's midlife and old-age mortality.

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We speculate that these results reflect early programming of resilience.

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Male resilience, measured at age 18, predicts mortality between ages 50 and 65.

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Resilience is transmitted across generations, from fathers to sons.

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Male descendants to long-lived parents are somewhat more resilient than their peers.

Non-genomic transmission of longevity between generations: potential mechanisms and evidence across species

Accumulating animal and human data indicate that environmental exposures experienced during sensitive developmental periods may strongly influence risk of adult disease. Moreover, the effects triggered by developmental environmental cues can be transgenerationally transmitted, potentially affecting offspring health outcomes. Increasing evidence suggests a central role of epigenetic mechanisms (heritable alterations in gene expression occurring without changes in underlying DNA sequence) in mediating these effects. This review summarizes the findings from animal models, including worms, insects, and rodents, and also from human studies, indicating that lifespan and longevity-associated characteristics can be transmitted across generations via non-genetic factors.

Grandparental education, parental education and adolescent blood pressure

BACKGROUND

Maternal and paternal education could affect childhood blood pressure differently. Grandparental education might also play a role. Disentangling their contribution to childhood blood pressure may shed light on the persistence of disparities and potential windows of intervention.

METHODS

Using 5604 participants from a Chinese birth cohort born in 1997 and followed-up until ~13years (68% of follow-up), we examined the associations of parental education and grandparental education with age-, sex, and height-specific blood pressure z-scores or prehypertension status.

RESULTS

Parental education was inversely associated with adolescent systolic (-0.11 z-score, equivalent to -1.17mmHg, 95% confidence interval (CI) -0.19 to -0.04 for grade ≥12 compared with grade ≤9) and diastolic blood pressure (-0.07 z-score, equivalent to -0.79mmHg, 95% CI -0.11 to -0.04). The magnitude of association was similar for maternal or paternal education. Grandparental education was not associated with adolescent blood pressure. No association with prehypertension was found.

CONCLUSIONS

In an economically developed non-Western setting, both maternal and paternal, but not grandparental, education was associated with adolescent blood pressure. Blood pressure may be responsive to contemporary family socioeconomic conditions that may be scrutinized for suitable interventions.

Fathers' intelligence measured at age 18-20 years is associated with offspring smoking: linking the Swedish 1969 conscription cohort to the Swedish Survey of Living Conditions

Background

An association between lower IQ of parents, measured early in life, and smoking among their offspring has been reported. The extent to which other background factors account for this association is unknown.

Methods

Data on IQ, smoking, mental health, social class, parental divorce and social problems in a cohort of men born during 1949–1951 and conscripted for military service in 1969 were linked to smoking data on 682 offspring interviewed in the Swedish Surveys of Living Conditions 1984–2009.

Results

In an age-adjusted model, a one-step decrease on a stanine scale was associated with an OR of 1.19 (95% CI 1.04 to 1.35) for offspring smoking. Adjusting for father's socioeconomic background and smoking, mental illness and social problems in youth only marginally lowered the OR's.

Conclusions

Lower IQ among fathers measured at ages 18–20 years was associated with smoking in their offspring. The association was not explained by father's social class in childhood or a higher prevalence of mental illness, social problems or smoking measured among the fathers in their late adolescence.

The impact of parental educational trajectories on their adult offspring's overweight/obesity status: a study of three generations of Swedish men and women

The objective of this study was to investigate the impact of grandparental and parental education and parental educational trajectory on their adult offspring's overweight/obesity. We used register data from the Uppsala Birth Cohort Multigenerational Study, based on a representative cohort born in Sweden 1915-1929 (G1). Our sample included 5122 women and 11,204 men who were grandchildren of G1 (G3), their parents (G2), and grandparents. G3's overweight/obesity (BMI≥25 kg/m2) was based on pre-pregnancy weight/height for women before their first birth (average age=26 years), and measured weight/height at conscription for men (average age=18 years). G1's, G2's, and G3's highest educational attainment was obtained from routine registers and classified as low, intermediate, or high based on respective sample distributions. Parental (G2) educational trajectory was defined as change in education between their own and their highest educated parent (G1), classified into 5 categories: always advantaged (AA), upward trajectory (UT), stable-intermediate (SI), downward trajectory (DT), and always disadvantaged (AD). We used hierarchical gender-stratified logistic regression models adjusted for G3's age, education, year of BMI collection, lineage and G2's year of birth and income. Grandparental and parental education were negatively associated with men's odds of overweight/obesity and parental education affected women's overweight/obesity risk. Furthermore, men and women whose parents belonged to the UT, SI, DT, and AD groups had greater odds of overweight/obesity compared to men and women whose parents belonged to the AA group (adjusted for G3's age, year of BMI collection, lineage, and G2's year of birth). These associations were attenuated when further adjusting for parental income and G3's own education. Socioeconomic inequalities can have long-term consequences and impact the health of future generations. For overweight/obesity in concurrent young cohorts, this inequality is not fully offset by upward educational trajectory in their parent's generation.

Human transgenerational responses to early-life experience: potential impact on development, health and biomedical research

Mammalian experiments provide clear evidence of male line transgenerational effects on health and development from paternal or ancestral early-life exposures such as diet or stress. The few human observational studies to date suggest (male line) transgenerational effects exist that cannot easily be attributed to cultural and/or genetic inheritance. Here we summarise relevant studies, drawing attention to exposure sensitive periods in early life and sex differences in transmission and offspring outcomes. Thus, variation, or changes, in the parental/ancestral environment may influence phenotypic variation for better or worse in the next generation(s), and so contribute to common, non-communicable disease risk including sex differences. We argue that life-course epidemiology should be reframed to include exposures from previous generations, keeping an open mind as to the mechanisms that transmit this information to offspring. Finally, we discuss animal experiments, including the role of epigenetic inheritance and non-coding RNAs, in terms of what lessons can be learnt for designing and interpreting human studies. This review was developed initially as a position paper by the multidisciplinary Network in Epigenetic Epidemiology to encourage transgenerational research in human cohorts.

Childhood family living arrangements and blood pressure in black men: the Howard University Family Study

Black men have higher blood pressure (BP) levels and consequently higher prevalence of hypertension compared with men from other ethnic groups in the United States. Socio-familial factors in childhood have been found to play an important role in hypertension, but few studies have examined this relationship among black men. We investigated whether childhood family living arrangements are independently associated with mean BP and hypertension in a cross-sectional sample of 515 unrelated black male participants aged ≥20 years enrolled in the Howard University Family Study between 2001 and 2008. Black men who lived with both parents compared with the reference group of men who never lived with both parents during their lifetime had lower systolic BP (-4.4 mm Hg [95% confidence interval {CI}, -7.84 to -0.96]), pulse pressure (-3.9 mm Hg [95% CI, -6.28 to -1.51]), and mean arterial BP (-2.0 mm Hg [95% CI, -4.44 to 0.51]). This protective effect was more pronounced among men who lived with both parents for 1 to 12 years of their lives; they had decreased systolic BP (-6.5 mm Hg [95% CI, -10.99 to -1.95]), pulse pressure (-5.4 mm Hg [95% CI, -8.48 to -2.28]), mean arterial pressure (-3.3 mm Hg [95% CI, -6.56 to 0.00]), and a 46% decreased odds of developing hypertension (odds ratio=0.54; 95% CI, 0.30 to 0.99). No statistically significant associations were found for diastolic BP. These results provide preliminary evidence that childhood family structure exerts a long-term influence on BP among black men.