Does physiological distribution of blood parameters in children depend on socioeconomic status? Results of a German cross-sectional study

Abstract

ObjectivesIn the present study, we examined the relation between socioeconomic status (SES) and the physiological distribution of iron-related blood parameters.DesignThis is a cross-sectional analysis of longitudinal population-based cohort study.SettingBased on a sample of healthy participants from a German research centre, various blood parameters and values of clinical examinations and questionnaires were collected.ParticipantsA total of 1206 healthy volunteers aged 2.5 to 19 years, one child per family randomly selected, were included.Primary and secondary outcome measuresAssociations between the SES of children by Winkler-Stolzenberg Index (WSI) and its dimensions (income, education, occupation) and iron-related blood parameters (haemoglobin, ferritin and transferrin) were analysed by linear regression analyses. Gender and pubertal stage were included as covariables. Additionally, associations between SES of children by WSI and physical activity (side-to-side jumps, push-ups) as well as body mass index (BMI) were analysed by linear regression analyses.ResultsChildren with high WSI or family income showed significantly increased z-scores for haemoglobin (P=0.046; P<0.001). Children with increased WSI or family income showed significantly lower z-scores for transferrin (P<0.001). There was a significant correlation between haemoglobin and gender (P<0.001) and between transferrin and pubertal stage (P=0.024). Furthermore, physical activity was positively correlated and BMI was negatively correlated with WSI (P<0.001).DiscussionOur data show an association between SES and the distribution of iron-dependent parameters. Lower SES is correlated with lower values for haemoglobin and higher values for transferrin. Furthermore, we demonstrate that physical activity and BMI are associated with SES. Whereas higher SES is correlated with higher values for physical activity and lower BMI. Our parameters are standardised as z-scores with the advantages that the results are comparable across different age groups and present physiological courses.Trial registration numberNCT02550236; Results.

Socioeconomic Status Is Related to Pubertal Development in a German Cohort

“…Results from the German KiGGS study suggest that children and adolescents with low SES are half as likely as those with high SES to have good general health; they were significantly more affected by psychological and behavioral difficulties [11]. Exposures to stress could influence physiological and psychological processes, resulting, for example, in cell/molecular damage [36], poorer emotional health [12], and health behavior, like reduced physical activity and poor diet [13]. Moreover, exposure to early life stress could influence both the hypothalamic-pituitary-gonadal and hypothalamic-pituitary-adrenal axes and thus provide a link to advanced pubertal maturation [40].…”

“…The SES of children was assessed at their first visit recorded in the data using the “Winkler-Stolzenberg-Index” [9, 12, 13, 23]. This index comprises 3 scales measuring parental education, occupational status and household equivalized disposable income (for more information see [23]).…”

“…There may be other environmental, behavioral, and physiological effects by which SES influences early pubertal development. An alternative pathway by which SES might mediate puberty onset is through increased exposure to stress associated with lower SES [2,13,[35][36][37][38][39]. Results from the German KiGGS study suggest that children and adolescents with low SES are half as likely as those with high SES to have good general health; they were significantly more affected by psychological and behavioral difficulties [11].…”

“…We could recently demonstrate a strong association between SES and child health and development [9]. A low SES was, for example, associated with emotional disorders, behavioral problems, a less healthy lifestyle, and less physical activity [9, 12, 13]. Despite the strong link between SES and different aspects of child health, research results are inconclusive with regard to the influence of SES on pubertal timing.…”

Associations Between Socio-Economic Status and Child Health: Findings of a Large German Cohort Study

“…Previous studies showed that children growing up in families with a lower SES have a higher body mass index (BMI) [ 9 , 10 , 11 , 12 ], report more behavioral problems [ 13 , 14 , 15 ], more psychosomatic symptoms [ 16 ], a lower quality of life [ 17 , 18 ], less healthy nutrition [ 19 , 20 ], less physical activity [ 16 , 21 , 22 , 23 ], a higher media consumption [ 22 , 23 , 24 , 25 , 26 ], and experience more critical life events than children growing up in families with a higher SES [ 27 ]. There is further evidence of associations between SES and laboratory parameters, e.g., serum lipid levels [ 28 ] and hemoglobin [ 29 ]. Some studies reported smaller associations between SES and health outcomes in adolescents compared to children or adults [ 30 , 31 , 32 ].…”