Marginal zinc deficiency (MZD) exists in children of industrialized societies and
can impair growth and development. Presently there are no data available on its global
prevalence. It is believed that MZD is one of the most common hidden deficiencies
throughout the world. This is partly because of the lack of sensitivity and specificity of
serum zinc, the most commonly used biomarker of zinc status, to detect MZD. This
deficiency in children is always accompanied by a decrease in hair zinc. Although in
research settings hair zinc is a recognized biomarker of MZD in children, health
practitioners do not presently use it.
These cross-sectional studies were designed to examine the hair zinc status of
preschoolers in Vancouver. They also aimed at exploring some dietary and non-dietary
factors associated with hair zinc status in an attempt to construct and validate a screening
tool for detection of MZD.
Our first study indicated a mean hair zinc of 75��30 ��g/g, with 46% below the
cutoff (<70��g/g) for a group (n=87) of low-income preschoolers (Chapter II). Among
these children we observed negative associations between the hair zinc and consumption
of dairy (R�� =0.09, P=0 .01) and milk (R�� =0.08, P=0.01), being described as "often sick"
(R�� =0.55, P=0 .00) and "eating unhealthy" (R�� =0.16 P=0.00), and prolonged breastfeeding
(R�� =0.11, P=0.01).
Our citywide survey (n=719) indicated a mean hair zinc of 116��43 ��g/g with 17%
below the cutoff (Chapter III). Logistic regression analysis indicated sex, age, maternal
education, the number of adults at home, consumption frequency of milk, "scores of
activity level", "being described as frequently sick" and "taking supplements containing
iron" as the significant predictors of hair zinc status. However, the final model had 16%
sensitivity while having 98 .3% specificity, indicating its lack of usefulness as a screening
tool.
Our study provides important information on the hair zinc status of Vancouver
preschoolers. Although we did not accomplish our primary goal of constructing and
validating a screening tool, we did identify some factors in children and their
environment associated with hair zinc, which may help in better understanding of hair
zinc as a biomarker of MZD.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU./924 |
| Date | 05 1900 |
| Creators | Vaghri, Ziba |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Format | 12202276 bytes, application/pdf |
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