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Biomedical subjects

F van der Haar

Publications and source records attributed to F van der Haar.

13 recordsLinked to original sources

Newborn thyrotropin screening confirms iodine deficiency in Latvia.

OBJECTIVE AND SETTING: The national neonatal thyrotropin (TSH) screening data for 2000-2002 were analysed to assess the extent and severity of iodine deficiency in Latvia. RESULTS: Elevated newborn TSH (>5 mIU/l) decreased from 16.5 to 10.4% and 8.4% in 2000, 2001 and 2002, respectively. For each year and in all regions, the prevalence of elevated newborn TSH was above the cut-off level indicative for a public health problem. A positive correlation (r=0.82, P<0.05) existed between elevated newborn TSH and low urinary iodine excretion among a nationwide sample of school children in 2000. CONCLUSION: Latvia is iodine deficient, putting each new generation at risk of preventable brain damage.

Biomarkers↗

Endemic goiter associated with high iodine intake.

OBJECTIVES: This study assessed the relation of iodine content of household water to thyroid size and urinary iodine excretion in an area with high iodine concentration in the water. METHODS: The iodine content of household water and indicators of iodine status (thyroid size and urinary iodine level) were assessed in selected villages in Jiangsu Province, China. RESULTS: Water iodine levels were positively correlated with urinary iodine levels and indicators of thyroid size at the township level. CONCLUSIONS: Excess iodine in household water was the likely cause of endemic goiter and elevated urinary iodine levels in the study area. This finding affects public health policy on the institution of universal salt iodization for the elimination of iodine deficiency disorders.

China↗

Effect of intestinal parasite treatment on the efficacy of oral iodized oil for correcting iodine deficiency in schoolchildren.

Oral supplementation with iodized oil for correction of iodine deficiency in a population has advantages over intramuscular injection but the duration of effect is shorter. The relation of intestinal parasite treatment and efficacy of oral iodized oil was examined in an intervention study in 8-10-y-old schoolchildren in Malawi. Severely iodine-deficient schoolchildren with a single parasitic infestation of Ascaris lumbricoides (n = 44), hookworm (n = 42), or Entamoeba histolytica (n = 24) were randomly allocated to receive or not receive treatment before taking a 1-mL oral supplement (490 mg I) of iodized ethyl esters from poppy seed oil. The urinary iodine concentration was measured at various time points after supplementation to define the time intervals before urinary iodine concentrations returned to 0.40 mumol/L, indicating moderate iodine deficiency. Treatment with metronidazole for E. histolytica increased the protection period from 2.0 to 21.0 wk (P < 0.05). For all untreated children together, the duration of effect was 9.2 wk shorter (P < 0.001) than that for their treated peers (16.8 wk). We conclude that intestinal parasitic infestations reduce the efficacy of oral supplementation with iodized ethyl esters by interfering with absorption.

Administration, Oral↗

The challenge of the global elimination of iodine deficiency disorders.

Most nations of the world are well positioned for success in their pursuit of the virtual elimination of iodine deficiency disorders (IDD) by the year 2000. In 1990 at the World Summit for Children, Heads of State and Government had agreed on this global goal and in 1992 at the International Conference on Nutrition, multi-sector country delegations from all over the world developed the prototype framework for national action. Following a special recommendation of the United Nations Joint Committee on Health Policy, universal salt iodization (USI) is now being applied in almost all countries with an IDD problem recognized as being of public health significance. The core components of national IDD programmes based on USI are presented in this paper, and examples are given of effective actions ongoing in a number of countries. While in principle all components such as communications, information management and laboratory support should integrate and complement with ongoing efforts for general nutritional improvement, national IDD programmes also have specific needs which require separate arrangements. Sources of support and information, available from the international public nutrition community are indicated. The global conquest of IDD provides an example for other effective public nutrition practices from the important lessons that are being learned. Particularly, the role of the private food sector as full partner in national programmes is relevant to ongoing and future attempts to reduce and eliminate other major global malnutrition problems.

Humans↗

New model for describing urinary iodine excretion: its use for comparing different oral preparations of iodized oil.

Iodine excretion in urine after oral dosing with iodized oil is influenced by various factors involved in the retention and elimination of iodine by the body. In a study comparing different treatments of severely iodine-deficient schoolchildren from Malawi, a hyperbolic function was found to describe changes in urinary iodine concentration over time more adequately than a simple exponential function. Compared with oil A, comprising ethyl esters of iodized fatty acids, the retention and elimination of iodine from oil B, comprising triacylglycerol esters of iodized fatty acids, were significantly greater. The mean duration of effectiveness of oral iodized oil, based on urinary iodine concentrations > 0.40 mumol/L, was estimated to be 13.7, 9.9, and 52.5 wk for a single dose of iodized oil A (490 mg I), a split dose of iodized oil A (2 x 245 mg I), and a single dose of iodized oil B (675 mg I), respectively. Dividing the dose of oil A into two equal amounts given on consecutive days did not improve its efficacy.

Administration, Oral↗

A critical appraisal of goiter assessment and the ratio of urinary iodine to creatinine for evaluating iodine status.

Iodine status can be evaluated by goiter assessment and measurement of urinary iodine concentration in either 24-h urine collections or in casual samples. It is often impossible to make 24-h collections. Therefore, iodine concentration in casual samples is often expressed in terms of urinary creatinine, assuming creatinine excretion to be constant between and within individuals. In this study large inter- and intraindividual variations were observed in the creatinine content of casual samples ranging from 0.6 to 9.87 mmol/L. Further, the urinary iodine-creatinine ratio correlated significantly with the creatinine concentration; Spearman's rank-order correlation coefficient, rs = 0.39 (P < 0.001). If creatinine is a suitable index to correct for variations in iodine excretion, no correlation would be expected. We conclude that the iodine-creatinine ratio in casual urine samples is an unsuitable indicator for evaluating iodine status in areas where large inter- and intraindividual variations in urinary creatinine excretion exist.

Child↗

Goitre in Ethiopia.

A stratified goitre survey was conducted on 35,635 schoolchildren and 19,158 household members in all Regions of Ethiopia except Eritrea and Tigrai. The gross goitre prevalence (mean of male and female values) among schoolchildren and household members was 30.6 and 18.7% respectively, while that of visible goitre was 1.6 and 3.2% respectively. Prevalence was higher in females (27.3% in household members and 36.1% in schoolchildren) than in males (10.1% in household members and 25.1% in schoolchildren) and increased with age more in females than in males. The prevalence rates at higher altitudes were higher than those at lower altitudes in both schoolchildren and household members. Using an epidemiological model the consequences of iodine deficiency, including cretinism and maternal wastage, have been estimated.

Adolescent↗

Standardization of serum cholesterol assays by use of serum calibrators and direct addition of Liebermann-Burchard reagent.

Serum cholesterol concentrations of subjects in epidemiological studies were measured after direct addition of Liebermann-Burchard reagent; results were calibrated with human serum pools assayed according to Abell et al. (J. Biol. Chem. 195:357-366, 1952). Accuracy and precision were monitored for six years by analysis of internal-control pools and blind external-control pools. For various internal-control pools, the imprecision (CV) of the long-term averages of run means ranged from 0.5 to 0.9%. The within-run CV for internal control and patients' sera was about 1%. For blind control sera with different concentrations (provided by the Centers for Disease Control, Atlanta, GA, over the same period), the average difference per three-month period between the values found and the target values was usually between -0.5% and +0.7% for medium-concentration pools and between -2% and +2% for low- and high-concentration pools (extreme values: -2.4% and +2.5%). The CV per three-month period ranged from 0.6 to 2.7%. Sera from subjects on diets of high or low linoleic acid content were analyzed to study the effect of the fatty acid portion of serum cholesterol esters; the differences between values obtained with the comparison method and the direct method was insignificant on both diets. We conclude that the use of serum calibrators eliminates the bias inherent in the direct method.

Autoanalysis↗

Methods for the estimation of high density cholesterol, comparison between two laboratories.

The determination of HDL by quantification of HDL-cholesterol was investigated using different methods and employing the Abell method as reference. The routinely applied direct method of Huang (calibrated on Abell standardized sera) and the enzymatic method of Röschlau were tested. Results show that with the Huang method, as compared to Abell values, a total laboratory error of less than 4.5 mg/100 can be achieved in 95% of the cases. The enzymatic method gave rise to erroneous results. Comparisons between two laboratories in experiments using random and pool sera are presented.

Chemical Phenomena↗