Height, zinc and soil-transmitted helminth infections in schoolchildren: a study in Cuba and Cambodia.

Brechje De Gier,Kuong Khov,Maiza Ponce,Suzanne Van Der Werff,Mariano Gorbea,Marlene Perignon,Katja Polman,Patrick D'Haese,Lázara Rivero,Chhoun Chamnan,Colleen Doak,Megan Parker,Marion Fiorentino,Kim Vereecken,Raquel Díaz,Liliane Mpabanzi,Fidel Núñez,Jacques Berger,Frank Wieringa

doi:10.3390/nu7043000

Abstract

Soil-transmitted helminth (STH) infections and zinc deficiency are often found in low- and middle-income countries and are both known to affect child growth. However, studies combining data on zinc and STH are lacking. In two studies in schoolchildren in Cuba and Cambodia, we collected data on height, STH infection and zinc concentration in either plasma (Cambodia) or hair (Cuba). We analyzed whether STH and/or zinc were associated with height for age z-scores and whether STH and zinc were associated. In Cuba, STH prevalence was 8.4%; these were mainly Ascaris lumbricoides and Trichuris trichiura infections. In Cambodia, STH prevalence was 16.8%, mostly caused by hookworm. In Cuban children, STH infection had a strong association with height for age (aB-0.438, p = 0.001), while hair zinc was significantly associated with height for age only in STH uninfected children. In Cambodian children, plasma zinc was associated with height for age (aB-0.033, p = 0.029), but STH infection was not. Only in Cambodia, STH infection showed an association with zinc concentration (aB-0.233, p = 0.051). Factors influencing child growth differ between populations and may depend on prevalences of STH species and zinc deficiency. Further research is needed to elucidate these relationships and their underlying mechanisms.

Highlights

Height for age, expressed as z-scores of internationally accepted reference curves, is recommended by the World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF) and Food and Agriculture Organization (FAO) as an indicator of chronic undernutrition [1]
The mean height for age z-score (0.06) of the Cuban children was significantly higher than the median of the reference population (z-score = 0) (p = 0.03)
Zinc deficiency was highly prevalent in Cambodia (92.8%), whereas zinc deficiency was found in only 12.2% of the Cuban children

Summary

Introduction

Height for age, expressed as z-scores of internationally accepted reference curves, is recommended by the World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF) and Food and Agriculture Organization (FAO) as an indicator of chronic undernutrition [1]. Undernutrition can be caused by insufficient intake of macronutrients, micronutrients or both. Poor growth has been associated with insufficient intake and/or absorption of micronutrients [2]. An important micronutrient deficiency prevalent in many middle- and low-income countries is zinc deficiency, for which over 20% of the world’s population is estimated to be at risk [3]. Deficiency in zinc is recognized as a major cause of morbidity and mortality in developing countries [6,7]. Though generally accepted as a public health concern, documentation on zinc deficiency at the population level remains challenging, as there is no gold standard for the measurement of zinc levels [8,9]. Plasma/serum zinc concentration, dietary intake, and stunting prevalence are the best-known indicators of zinc deficiency [6]

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Discussion

Conclusion