Secular trends in growth

Abstract

Since the 19th century there have been clearly documented secular trends to increasing adult height in most European countries, with current rates of 10–30 mm / decade. Over the same period menarcheal age has also fallen steeply, but has now stabilized at approximately 13 years and may be rising again. Height trends tend to be greater in childhood than in adulthood due to the associated advance in maturation, but no trends are apparent before the age of 2 years. In particular, birth-weight trends are small and different in shape from height trends. The adult height trend matches that at age 2 years, so that the increment in adult height has already been achieved by age 2 years. To try to identify factors relating to the secular trend, increased height gain in late infancy is hypothesized to be equivalent to a reduction in stunting, and stunting is thought to be caused by impaired growth in the long bones of the leg in later infancy. Leg growth may be regulated by the expression of growth-hormone receptors on the growth plates, which it is hypothesized are susceptible to the interaction between concurrent nutrition and the nominal growth rate set during pregnancy. The timing of menarche is also likely to be determined by some growth factor operating near the time of birth, which also affects later weight, but not height.

Secular changes in body height and weight of Portuguese boys over one century

“…Colégio Militar boys experienced the greatest increase in body size after [1961][1962][1963][1964][1965][1966], indicating that the children who were born after the late 1960s and 1970s were the ones who were growing better. Several studies suggest that early life is the critical period where environmental influences have their greatest impact (Cole, 2000;Golden, 1994;Schmidt et al, 1995;Tanner, 1992;Zellner et al, 1996). Therefore, these children were the ones who benefited first from improvements in social and economic conditions that initiated in the 1960s, and then by political changes in the 1970s that promoted further progress and were responsible for further increases in body size.…”

Association of antioxidant vitamins and oxidative stress levels in pregnancy with infant growth during the first year of life

“…An optimal maternal nutritional status has been shown to reduce the risks of a preterm birth and low birth weight (1)(2)(3) , improve postnatal growth (4,5) , and reduce both maternal and infant morbidity and mortality (6)(7)(8)(9) . Despite a trend of improved infant growth in most countries due to enhanced intakes of macronutrients (10) , a low maternal nutritional status during the critical stage of foetal development subsequently contributes to growth retardation in the offspring and adverse health outcomes in later life (11) . In particular, macronutrients and associated foetal growth have been widely emphasised, but deficiencies in maternal micronutrients and induced oxidative stress have not received much attention.…”

True height and variability in estimates thereof across race and gender

“…Secular change refers to a group of undefined height-determining factors that are interrelated, and in so doing, move as a single force, giving rise to a decrease or increase in height, 10,11 as illustrated in Figure 1. Secular trends appear if the growth conditions occur repetitively within the same population, and give rise to the same effect.…”

“…Secular trends appear if the growth conditions occur repetitively within the same population, and give rise to the same effect. 10,11 Ageing process A decrease in height is part of the ageing process. 12 Height loss occurs from the age of 30 years, with females showing an average decrease in height of 1.25 cm every decade, while males lose an average of 0.75 cm of height per decade.…”