Fertility History, Children's Gender, and Post-Reproductive Survival in a Longevous Population

Regional differences regarding the occurrence of falls and associated factors in two populations of Brazilian longevous people

BACKGROUND

Few studies have explored regional asymmetries and their implications for health policies regarding episodes of falls among the population of ≥80 years old in continental and developing countries like Brazil with deep inequalities and sociocultural differences.

OBJECTIVE

To evaluate the occurrence of falls and their association with functional capacity and nutritional status in the longest oldest-old living in two municipalities in the Northeast and Southeast of Brazil.

METHODS

This is a cross-sectional study, with primary data collection in which were included in the research seniors aged 80 years or more, of both sexes, belonging to two Brazilian municipalities of discrepant socioeconomic aspects. The dependent variable was the occurrence of falls in the last year. The independent variables were grouped into demographic aspects, functional capacity and nutritional status. To identify variables that contribute to the occurrence of falls, the multiple logistic regression model, adopts a significance level of 5%.

RESULTS

The sample was composed of 415 oldest-old adults. From the total, 32.3% reported having fallen in the last year, 24.7% in Brejo dos Santos and 37.8% in São Paulo. Among the former population, the mean value of walking speed for those who had falls was 0.27 m/s and for those who had no occurrence of falls was 0.33 m/s; and, among the seniors from São Paulo, the mean values were 0.51 m/s and 0.58 m/s, respectively. Significant correlations between walking speed and falls were verified for both populations, showing that the lower the walking speed, the higher the predisposition to falls. In the final regression model, the occurrence of falls was associated with moderate balance (OR = 5.28; CI: 1.11-25.18) among the longevous people Brejo dos Santos and with very poor functional performance (OR = 16.09; CI:1.46-177.06) among those from São Paulo.

CONCLUSION

The results pointed out a lower prevalence of falls in longevous people from Brejo dos Santos than in those from São Paulo and differences regarding the associated factors, showing heterogeneity between the two populations; indicating the need for public policies and effective programmes aimed at preventing falls based on the maintenance or increase of functional capacity.

The Influence of Female Reproductive Factors on Longevity: A Systematized Narrative Review of Epidemiological Studies

Purpose: This systematized review presents a synthesis of epidemiological studies that examine the association between female reproductive factors and longevity indicators. Methods: A comprehensive literature search was conducted using four bibliographic databases: OVID Medline, Web of Science, PubMed, and Google Scholar, including English language articles published until March 2022. Results from the search strategy yielded 306 articles, 37 of which were included for review based on eligibility criteria. Results were identified within the following nine themes: endogenous androgens and estrogens, age at first childbirth, age at last childbirth, parity, reproductive lifespan, menopause-related factors, hormone therapy use, age at menarche, and offspring gender. Results: Evidence that links reproductive factors and long lifespan is limited. Several female reproductive factors are shown to be significantly associated with longevity, yet findings remain inconclusive. The most consistent association was between parity (fertility and fecundity) and increased female lifespan. Age at first birth and parity were consistently associated with increased longevity. Associations between age at menarche and menopause, premature menopause, reproductive lifespan, offspring gender and longevity are inconclusive. Conclusion: There is not enough evidence to consider sex a longevity predictor. To understand the mechanisms that predict longevity outcomes, it is imperative to consider sex-specific within-population differences.

Reconstruction of Birth Histories for the Study of Fertility in the United States, 1830-1910

This paper describes a method to reconstruct complete birth histories for women in the 1900 and 1910 U. S. census IPUMS samples. The method is an extension of an earlier method developed by Luther and Cho (1988). The basic method relies on the number of children ever born, number of children surviving, number of children coresident in the household and age-specific fertility rates for the population to probabilistically assign an "age" to deceased and unmatched children. Modifications include the addition of an iterative Poisson regression model to fine-tune age-specific fertility inputs. The potential of complete birth histories for the study of the U.S. fertility transition is illustrated with a few examples.

Selection bias in studies of human reproduction-longevity trade-offs

A shorter lifespan as a potential cost of high reproductive effort in humans has intrigued researchers for more than a century. However, the results have been inconclusive so far and despite strong theoretical expectations we do not currently have compelling evidence for the longevity costs of reproduction. Using Monte Carlo simulation, it is shown here that a common practice in human reproduction-longevity studies using historical data (the most relevant data sources for this question), the omission of women who died prior to menopausal age from the analysis, results in severe underestimation of the potential underlying trade-off between reproduction and lifespan. In other words, assuming that such a trade-off is expressed also during reproductive years, the strength of the trade-off between reproduction and lifespan is progressively weakened when women dying during reproductive ages are sequentially and non-randomly excluded from the analysis. In cases of small sample sizes (e.g. few hundreds of observations), this selection bias by reducing statistical power may even partly explain the null results commonly found in this field. Future studies in this field should thus apply statistical approaches that account for or avoid selection bias in order to recover reliable effect size estimates between reproduction and longevity.

Why were Sardinians the shortest Europeans? A journey through genes, infections, nutrition, and sex

Since ancient times the Mediterranean island of Sardinia has been known for harboring a population with an average body height shorter than almost every other ethnic group in Europe. After over a century of investigations, the cause(s) at the origin of this uniqueness are not yet clear. The shorter stature of Sardinians appears to have been documented since prehistoric times, as revealed by the analysis of skeletal remains discovered in archaeological sites on the island. Recently, a number of genetic, hormonal, environmental, infective and nutritional factors have been put forward to explain this unique anthropometric feature, which persisted for a long time, even when environmental and living conditions improved around 1960. Although some of the putative factors are supported by sound empirical evidence, weaker support is available for others. The recent advent of whole genome analysis techniques shed new light on specific variants at the origin of this short stature. However, the marked geographical variability of stature across time and space within the island, and the well-known presence of pockets of short height in the population of the southern districts, are still puzzling findings that have attracted the interest of anthropologists and geneticists. The purpose of this review is to focus on the state-of-the-art research on stature, as well as the factors that made Sardinians the shortest among Europeans.