Secular trends in male adult height 1904-1996 in relation to place of residence and parent's educational level in Portugal

The records of height of 22841 18-year-old Portuguese males were analysed a s well as their parents educational level and localities of subject's resid ence (districts). The sample includes all the Portuguese 18-year-old males, born in 1978 and examined in 1996, in central and southern Portugal, repre senting all the social strata. Statistically significant differences (p les s than or equal to 0.001) among the districts were found: males from Setuba l (172.75 cm) and Lisboa (172.64 cm), the most developed districts, are the tallest, and those from C. Branco (170.79 cm) and Coimbra (171.19 cm) are the shortest. Comparing to published data from 1904, a positive secular tre nd in height was found. The average increase was 8.99 cm, which yields a ra te of 0.99 cm per decade. This positive trend must be related to the genera l improvement in the population's standard living conditions, as the striki ng drop of post-neonatal mortality rate shows after the 1960s and 1970s. De spite this positive trend, great social difference still exists: the gap be tween the two extremes of parents' educational level is almost 4 cm for hei ght. Analysis of variance (ANOVA) showed significant effects of father's an d mother's educational level as well as subject's locality of residence, bu t the influence of parents' educational level was stronger than that of geo graphic residence. These results suggest that the secular trend in height w ill continue for the Portuguese population in the future decade.