Anthropometrics of Estonian children in relation to family disruption: Thrifty phenotype and Trivers-Willard effects

Background and objectives

The thrifty phenotype hypothesis proposes that at resource limitation, the growth of some organs/tissues is selectively spared to preserve more critical ones, such as the brain or lungs. The Trivers–Willard hypothesis (TWH) predicts that boys are more vulnerable in the case of resource limitation than girls. Both hypotheses were tested in children from disrupted families, differing in the extent of deprivation/adversities imposed on them.

Methodology

In a retrospective cohort study in the mid-20th century Estonia (Juhan Aul’s database), different types of orphans and children of divorced parents (treatment groups; n = 106–1401) were compared with children from bi-parental families (control groups; n = 2548–8648) so that children from treatment groups were matched with control children on the basis of sex, age, year of birth, urban versus rural origin and socioeconomic position.

Results

Children in orphanages suffered strong growth suppression, best explained by psychosocial deprivation. Their feet were on average 0.5 SD shorter than the feet of the controls, followed by height, leg/torso ratio and cranial volume that differed from controls by ca 0.4 SD. Weight difference was 0.2 SD units, while body mass index did not differ from controls. The growth of boys and girls in orphanages was suppressed to the same extent. Boys whose mothers were dead were relatively smaller and less masculine than girls from such families. Fathers’ absence was unrelated to growth suppression. Sons of divorced parents had broader shoulders than boys whose fathers were dead.

Conclusions and implications

Prediction of TWH about the greater vulnerability of male growth may hold under some conditions but not universally. Predictions of the thrifty phenotype hypothesis were partly supported: trunk growth was spared at the expense of leg growth; however, no evidence for brain sparing was found. Comparison of children of divorced versus dead fathers may appear useful for indirect assessment of sexual selection on offspring quality.

Lay Summary: Boys and girls in orphanages suffered similarly strong growth suppression, best explained by psychosocial deprivation. Boys whose mothers were dead were relatively smaller and less masculine than girls from such families. The occurrence of sex-specific associations between family structure and children’s growth depends on the type of family disruption.

Testing for paternal influences on offspring telomere length in a human cohort in the Philippines

OBJECTIVES

Telomeres, emerging biomarkers of aging, are comprised of DNA repeats located at chromosomal ends that shorten with cellular replication and age in most human tissues. In contrast, spermatocyte telomeres lengthen with age. These changes in telomere length (TL) appear to be heritable, as older paternal ages of conception (PAC) predict longer offspring TL. Mouse-model studies raise questions about the potential for effects of paternal experiences on human offspring TL, as they suggest that smoking, inflammation, DNA damage, and stressors all shorten sperm TL. Here, we examined whether factors from the paternal environment predict offspring TL as well as interact with PAC to predict offspring TL.

MATERIALS AND METHODS

Using data from the Philippines, we tested if smoking, psychosocial stressors, or shorter knee height (a measure of early life adversity) predict shorter offspring TL. We also tested if these interacted with PAC in predicting offspring TL.

RESULTS

While we did not find the predicted associations, we observed a trend toward fathers with shorter knee height having offspring with longer TL. In addition, we found that knee height interacted with PAC to predict offspring TL. Specifically, fathers with shorter knee heights showed a stronger positive effect of PAC on offspring TL.

DISCUSSION

While the reasons for these associations remain uncertain, shorter knee height is characteristic of earlier puberty. Since spermatocyte TL increases with the production of sperm, we speculate that individuals with earlier puberty, and its concomitant commencement of production of sperm, had more time to accumulate longer sperm telomeres.

Childhood disadvantages and the timing of the onset of natural menopause in Latin America and the Caribbean

The aim of this study is to investigate the association of early life factors with the timing of the onset of natural menopause in Costa Rica and Puerto Rico. We use Cox proportional hazard models to estimate the risk of the onset of menopause. Our results suggest that socioeconomic disadvantages, as expressed by difficulties attending school due to economic hardships or parents never living together, increase the risk of the onset of natural menopause among Puerto Rican women. Among Costa Rican women, early life nutrition, estimated using anthropometric measures, is related to the timing of the onset of natural menopause.

Healthy Aging 5 Years After a Period of Daily Supplementation With Antioxidant Nutrients: A Post Hoc Analysis of the French Randomized Trial SU.VI.MAX

This study's objective was to investigate healthy aging in older French adults 5 years after a period of daily nutritional-dose supplementation with antioxidant nutrients. The study was based on the double-blind, randomized trial, Supplementation with Antioxidant Vitamins and Minerals (SU.VI.MAX) Study (1994-2002) and the SU.VI.MAX 2 Follow-up Study (2007-2009). During 1994-2002, participants received a daily combination of vitamin C (120 mg), β-carotene (6 mg), vitamin E (30 mg), selenium (100 µg), and zinc (20 mg) or placebo. Healthy aging was assessed in 2007-2009 by using multiple criteria, including the absence of major chronic disease and good physical and cognitive functioning. Data from a subsample of the SU.VI.MAX 2 cohort, initially free of major chronic disease, with a mean age of 65.3 years in 2007-2009 (n = 3,966), were used to calculate relative risks. Supplementation was associated with a greater healthy aging probability among men (relative risk = 1.16, 95% confidence interval: 1.04, 1.29) but not among women (relative risk = 0.98, 95% confidence interval: 0.86, 1.11) or all participants (relative risk = 1.07, 95% confidence interval: 0.99, 1.16). Moreover, exploratory subgroup analyses indicated effect modification by initial serum concentrations of zinc and vitamin C. In conclusion, an adequate supply of antioxidant nutrients (equivalent to quantities provided by a balanced diet rich in fruits and vegetables) may have a beneficial role for healthy aging.

Intergenerational changes in knee height among Maya mothers and their adult daughters from Merida, Mexico

OBJECTIVES

To analyze differences in knee height (KH) between adult Maya mothers and daughters in Merida City, Mexico, and determine if these differences are associated with their childhood socioeconomic conditions.

METHODS

From September 2011 to January 2014, we measured KH and collected data on childhood conditions (place of birth, type of drinking water, family size, and fathers' occupation) from a sample of 180 Maya mother-daughter dyads. Mean KH intergenerational difference was calculated and compared for each category of socioeconomic variables and a multiple regression model was used to assess the association between childhood conditions and KH difference.

RESULTS

A relative increase of 1.05 cm (SD = 2.3 cm) or 0.45 standard deviations (effect size of difference) was observed in KH between generations. Place of birth was significantly associated with KH. With three other variables statistically adjusted for, the intergenerational KH difference was 1.5 cm greater when mothers were born outside Merida but daughters were born in the city. Piped water consumption by mother-daughter dyads was associated with 1.5 cm of increase in KH difference compared with dyads who consumed well water (P = 0.058).

CONCLUSIONS

The relative increase in KH between mothers and daughters represents a portion of the expected change in growth in a group that has experienced few substantial improvements in their living conditions. Some improvements in childhood living conditions resulting from the intergenerational transition from rural to urban environments seem to be linked to a modest, but statistically significant intergenerational increase in KH among Maya women in Merida.

Intergenerational influences on the growth of Maya children: The effect of living conditions experienced by mothers and maternal grandmothers during their childhood

OBJECTIVES

To test the hypothesis that living conditions experienced by maternal grandmothers (F1 generation) and mothers (F2 generation) during their childhood are related to height and leg length (LL: height - sitting height) of their 6-to-8 year old children (F3 generation).

METHODS

From September 2011 to June 2012 we obtained height and LL, and calculated z-score values of these measurements for 109 triads (F1 , F2 , F3 ) who are Maya living in Merida, Yucatan, Mexico. Multiple regression models were adjusted to examine the relation of anthropometric and intergenerational socioeconomic parameters of F1 (house index and family size during childhood) and F2 (paternal job loss during childhood) with the z-score values of height and LL of F3 .

RESULTS

Children's height and LL were positively associated with maternal height and LL. This association was relatively stronger in LL. Better categories of grand-maternal house index were significantly associated with higher values of height and LL in grandchildren. Grand-maternal family size was positively related with LL, but not with height.

CONCLUSIONS

Our findings partially support the hypothesis that living conditions experienced by recent maternal ancestors (F1 and F2 ) during their growth period influence the growth of descendants (F3 ). Results suggest that LL is more sensitive to intergenerational influences than is total height and that the transition from a traditional rural lifestyle to urban conditions results in new exposures for risk in human physical growth.