以結構方程模型探討黃麴黴毒素與微量營養素的交互作用對尼泊爾孩童成長影響

Abstract

背景 近年來研究發現，食物中的黃麴黴毒素會影響孩童生長，且可能造成他們生長發育遲緩。黃麴黴毒素是一種黴菌毒素，由真菌產生，常因保存不當造成一些穀類作物受到黃麴黴毒素的污染。另外，研究指出黃麴黴毒素的暴露與微量營養素的缺乏有關係，當孩童攝取愈多受黃麴黴毒素汙染的食物，可能會加劇體內微量營養素缺乏的現象。在發展中國家，兒童時期營養不良和微量營養素缺乏的問題尤為嚴重，這會影響孩童生長發育和健康，嚴重時甚至會導致孩童死亡，對於這些國家而言是個沉重的負擔，同時也是引人關注的一大公共健康問題。 目的 本研究主要目的為探討孩童成長情形與黃麴黴毒素和微量營養素(維生素A和鋅)之間的關係，並且進一步探討黃麴黴毒素與微量營養素間的交互作用是否對孩童成長造成影響。 材料與方法 本研究在尼泊爾當地招募了85位剛出生的孩童參與(最後有77位孩童進入統計分析)，每位孩童共有三次測量時間點的資料，分別在其出生後的第15、24和36個月。另外，每位孩童測量資料的取得，會由訓練有素的專業人員蒐集其生長資料 (身高對年齡Z分數(LAZ)、體重對年齡Z分數(WAZ)及體重對身高Z分數(WLZ) ) 、血液中黃麴黴毒素濃度資料、血液中微量營養素濃度資料以及糞便中腸道炎症指標濃度資料等。本研究中所使用的統計分析方法，主要為線性迴歸分析、潛在成長曲線分析(LGCM)以及潛在交互作用分析，觀察孩童成長情形與黃麴黴毒素和微量營養素間的關係，且探討黃麴黴毒素和微量營養素間的交互作用對孩童成長的影響。

結果 我們發現環境性腸病對於孩童成長指標中的WAZ變化量有負面影響，而不同時間點的維生素A對於不同時間點的WAZ和WLZ有正面且顯著影響。此外，第15個月黃麴黴毒素與鋅的交互作用對於不同時間點的WAZ和WLZ有負面且顯著影響，表示黃麴黴毒素對於孩童生長的影響會因為鋅濃度增加而減少。

Background Recent research showed that dietary exposure to aflatoxin, a type of mycotoxin produced by fungi that contaminate staple cereal crops, may affect child growth, possibly through impaired gut function. On the other hand, some studies indicated that aflatoxin exposure coincided with micronutrient deficiencies in developing countries and it possibly exacerbated micronutrient deficiencies. Malnutrition and micronutrient deficiencies during childhood have been serious public health problems in developing countries, and the burden of child growth impairment, health problems, and death attributed to these factors remains high. Objective The main objective of this study is to investigate the associations of child growth with aflatoxin and micronutrients (vitamin A and zinc). We also would like to investigate whether there was interaction effect between aflatoxin and micronutrients on child growth. Materials and Methods There were 85 new born children recruited in Nepal (77 children for statistical analysis), and measurements were taken on three occasions for each child, at ages of 15, 24 and 36 months. For each child, trained researchers collected growth data (length-for-age Z score (LAZ), weight-for-age Z score (WAZ), and weight-for-length Z score (WLZ)), aflatoxin levels in blood, micronutrients levels in blood, and gut inflammation levels in stool. In the study, we used linear regression model, latent growth curve model (LGCM), and latent interaction model to investigate the associations of child growth indices with aflatoxin and micronutrients (vitamin A and zinc) and interaction effect of aflatoxin and micronutrients on child growth. Results We found that environmental enteropathy (EE) was negatively associated with changes in WAZ between 15 and 36 months. Vitamin A levels measured at ages of 15 and 24 months were positively associated with WAZ and WLZ at the same ages. On the other hand, the effect of aflatoxin on WAZ and WLZ decreased when zinc levels increased at ages of 15 months.