The Effects of Season of Birth on the Inflammatory Response to Psychological Stress in Hainan Island, China.

Aki Yazawa,Yosuke Inoue,Dandan Li,Andrew Stickley,Jianwei Du,Chiho Watanabe,Amanda Bruce

doi:10.1371/journal.pone.0139602

Abstract

Season of birth (SOB) has been investigated as one of the environmental factors that might epigenetically determine the physiology of individuals. This study investigated the role of SOB in the association between Quality of Life (QOL), a proxy of psychological stress status, and C-reactive protein (CRP) concentration (i.e., inflammatory status) among 1,085 adults (aged 20–57 years old) in Hainan Island, China. High sensitivity CRP concentration was measured in dried blood spot samples, while the abbreviated version of the World Health Organization’s QOL questionnaire was used to gather information on six QOL domains. Analysis stratified by three historically distinct age groups revealed a significant association between CRP concentration, SOB, QOL and an interaction between SOB and QOL among the youngest and oldest groups. In the oldest group, those born in the dry season had a higher CRP concentration with worse QOL whereas in the youngest group, there was a higher CRP concentration with better QOL. Annual per capita rice production, a proxy of population nutritional status in the year of birth, was found to predict CRP concentration only among the second oldest group. These findings suggest that the early environment might affect the immune response to psychological stress in adulthood and that its effect may differ by the time period in which people were born.

Highlights

Research has shown that the early life environment can epigenetically determine the physiology of individuals and have a life-long effect on health [1]
Economic and political events that occurred during that period, and the possibility that they may have impacted on the early life environment in different ways, we examined the Season of birth (SOB)—C-reactive protein (CRP) association for participants born in three distinct historical epochs: (i) after World War II to the end of the Great Leap Forward (1953–1962), (ii) the Cultural Revolution (1963–1977) and (iii) the period of early economic reforms (1978–1990) [14,15]
Analyses conducted separately by age group revealed that the inflammatory reaction to psychological stress in adulthood differed by SOB

Summary

Introduction

Research has shown that the early life environment (i.e., in the fetal period, infancy and childhood) can epigenetically determine the physiology of individuals and have a life-long effect on health [1]. Season of birth (SOB) is one of the environmental factors that has been previously investigated as it can reflect ecological differences in conditions in early life, such as temperature, precipitation and humidity, and pathogen exposure or experience of food shortage that can have a substantial effect on human physiological development [2]. Season of Birth and CRP in Hainan Island, China

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