Vitamin D Deficiency, Iodine Deficiency and Lead Levels in Haitian Infants and Children.
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 299
- 试验地点
- 2
- 主要终点
- serum 25OHD levels
研究概览
简要总结
Vitamin D deficiency is common worldwide, including in infants and children, and rickets remains a public health concern in many developing countries. The vitamin D status and prevalence of vitamin D deficiency in the Haitian population has not been studied. There is currently no approved point-of-care testing device for vitamin D deficiency. Iodine deficiency and resulting hypothyroidism is the leading cause of preventable neuro-developmental delay and cognitive impairment worldwide. Young infants and children are especially susceptible to sequelae of disruption in thyroid function given the dependence of the developing brain on sufficient levels of thyroid hormone. Perchlorate and thiocyanate have been described as potential environmental disrupters of thyroid function. Lead intoxication is a significant cause of disease throughout the world. Millions of people have suffered the effects of lead poisoning. Although most developed countries have taken drastic measures to limit the environmental lead levels, many countries in the developing world have not been able to address, or even assess, the problem.
Our objectives are to study the following three components in 300 Haitian children between 9 months and 6 years of age in three different geographical areas of Haiti: 1) Vitamin D status and prevalence of rickets, environmental factors associated with low vitamin D levels, and the accuracy and efficacy of a vitamin D point-of-care testing (POCT) device for the screening of vitamin D insufficiency. 2) Iodine status and thyroid function, and environmental disruptors such as perchlorate and thiocyanate as potential risk factors for abnormal thyroid function. 3) Lead levels and the extent of childhood lead poisoning.
详细描述
BACKGROUND:
- Vitamin D Deficiency
Vitamin D deficiency is common in the United States and worldwide, including in infants and children 1,2. Moderate to severe deficiency in children can manifest as rickets, a skeletal disease which results from a failure of mineralization of developing bones and cartilage. In most industrialized countries, infantile vitamin D supplementation represents the standard of care and has lead to a dramatic reduction in the incidence of rickets. However, in many developing countries, rickets remains a public health problem 3.In addition, recent literature indicates that there may be a resurgence of rickets even in industrialized countries 4, especially among immigrant populations 5. Potential extraskeletal effects of vitamin D deficiency are also being increasingly recognized, including an increased susceptibility to type 1 diabetes, insulin resistance and the metabolic syndrome, pulmonary disease such as asthma, pneumonia and tuberculosis, and possible modulation of the innate immune system 6.
Growing children with severe vitamin D deficiency, most commonly defined as serum 25-hydroxy-vitamin D (25OHD) levels less than 8 ng/ml, are at greatest risk for rickets and should undergo a diagnostic evaluation. When physical exam findings such as bowing of weight-bearing extremities, rachitic rosary, or frontal bossing are not evident, the level of serum alkaline phosphatase as an indicator for increased bone turnover and calcium mobilization from bone can be used as a screening test 4,7. X-rays of knees and wrists are typically obtained to confirm the diagnosis and establish a baseline for follow up.
The vitamin D status and prevalence of vitamin D deficiency in the Haitian population has not been studied. The prevalence of rickets is also unknown. Two studies conducted in Puerto Rican children 8 and in newly immigrated adults of Caribbean background 9 found prevalence rates of 47% and 59%, respectively, suggesting the possibility of moderate to high prevalence rates in Haiti.
研究设计
- 研究类型
- Observational
- 观察模型
- Ecologic Or Community
- 时间视角
- Cross Sectional
入排标准
- 年龄范围
- 9 Months 至 6 Years（Child）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Haitian ethnicity
- •Age between nine months and six years
排除标准
- •Presence of a chronic medical condition other than malnutrition
- •Residence outside of Haiti (i.e. visiting children who usually live abroad).
结局指标
主要结局
serum 25OHD levels
时间窗: Baseline
Measure serum 25OHD levels, including the proportion of children found to be vitamin D insufficient, deficient and severely deficient.
urinary iodine levels
时间窗: Baseline
Urinary iodine levels, including the proportion of children found to be iodine deficient
serum lead levels
时间窗: Baseline
Serum lead levels in Haitian infants and children
次要结局
- Determine the accuracy of the POCT device(Baseline)
- Number of children found to have elevated alkaline phosphatase levels(Baseline)
- Dietary and sun exposure effect on vitamin D level(Baseline)
- Goiter and abnormal thyroid function tests(Baseline)
- Lead intoxication(Baseline)
- Environmental disruptors of thyroid function(Baseline)
研究者
Julia Von Oettingen
Fellow in Pediatric Endocrinology
Boston Children's Hospital