Socioeconomic factors and intergenerational differences in height of Portuguese adults born in 1990: results from the EPITeen cohort.

Average adult height is an indicator of population health and a marker of socioeconomic inequalities. This study aimed to assess how socioeconomic differences affect intergenerational height increase between adults born in 1990 and their parents. Data from a population-based cohort of subjects born in 1990 (EPITeen) were analysed. Participants' adult height was objectively measured. Parental height, education, and occupation were reported by the parents. The height difference between daughters and their mothers (n=707), and sons and their fathers (n=647) was calculated. A generalised linear model was used to assess the association between parental education and occupation, separately, and the intergenerational height difference, adjusted for maternal age at birth, smoking during pregnancy, birthweight adjusted for gestational age, and birth order. Females were on average 1.46cm (SD=6.62) taller than their mothers, and males 3.00cm (SD=7.26) taller than their fathers. The highest height gain was shown in those with less advantaged socioeconomic background. In the adjusted model, sons whose mothers had 0-6 years of education grew 3.9cm taller (β=3.894; 95%CI:2.345;5.443) and daughters 1.5cm taller (β=1.529; 95%CI:0.180;2.878) (compared to >12y maternal education); for paternal education, sons and daughters grew 3.5cm (β=3.480; 95%CI:1.913;5.047) and 1.9cm taller (β=1.895; 95%CI:0.526;3.265), respectively. A higher height increase was found in participants with less advantaged maternal and paternal occupational level. Adults born in 1990 are taller than their parents, and height gain was higher in males than females. Adults from a lower socioeconomic status experienced the highest height gain, suggesting a reduction in height inequality.