Iodine status in Danish pregnant and breastfeeding women including studies of some challenges in urinary iodine status evaluation

Denmark was previously iodine deficient with regional differences. Moderate iodine deficiency appeared in West Denmark and mild iodine deficiency in East Denmark and also Danish pregnant and breastfeeding women suffered from iodine deficiency. The Danish mandatory iodine fortification of salt was introduced in the year 2000 and has increased iodine intake in the Danish population. However, median urinary iodine concentration in the general population and in pregnant and breastfeeding women is still below the level recommended, corresponding to mild iodine deficiency. Certain characteristics may challenge the evaluation of urinary iodine status in pregnancy and during breastfeeding. This review also addresses methodological challenges related to spot urine sampling conditions and the use of iodine supplement and discusses the use of non-pregnant population groups as a proxy for iodine intake in pregnant women.

[Basic registration of risk factors in medical records. Malnutrition, overweight, physical inactivity, smoking and alcohol]

INTRODUCTION

Lifestyle factors are important for clinical outcome. Systematic and early identification of these factors is important in order to offer relevant lifestyle intervention programmes. The objective was to evaluate whether basic registration of risk factors was understandable, applicable and sufficient in the clinical workday.

MATERIALS AND METHODS

Eleven clinical specialists participated from a broad range of departments. They performed identification and registration of malnutrition, overweight, physical inactivity, smoking and harmful alcohol consumption based on medical records from own departments (in total 2420 times). The specialists then evaluated the understanding, applicability and sufficiency (363 times). Their comments were noted.

RESULTS

Identification and registration was accomplished for 85% (0-100%) of the records. Except for two fields--"measurements of waist" and "other training programs"--the specialists found the basic registration understandable, applicable and sufficient. They lacked more details regarding stress-response in the information material and pointed out inconsistencies in the wording. Ten specialists found that the recommended clinical approach was possible to implement in the present routines.

CONCLUSION

Basic registration of lifestyle factors for adult patients is possible and clinical relevant. It is recommended that the Danish National Board of Health uses the results in future.

Biologic variation is important for interpretation of thyroid function tests

Large variations exist in thyrotropin (TSH) and thyroid hormones in serum. The components of variation include preanalytical, analytical, and biologic variation. This is divided into between- and within-individual variation. The latter consists of circadian and seasonal differences although there are indicators of a genetically determined starting point. The ratio of within- to between-individual variation describes the reliability of population-based reference ranges. This ratio is low for serum TSH, thyroxine (T(4)) and triiodothyronine (T(3)) indicating that laboratory reference ranges are relatively insensitive to aberrations from normality in the individual. Solutions are considered but reducing the analytical variation below the calculated analytical goals of 7%, 5% and 12% for serum T(3), T(4), and TSH does not improve diagnostic performance. Neither does determination of the individual set-point and reference range. In practice this means that population-based reference ranges are necessary but that it is important to recognize their limitations for use in individuals. Serum TSH responds with amplification to minor alterations in T(4) and T(3). A consistently abnormal TSH probably indicates that T(4) and T(3) are not normal for the individual even when inside the laboratory reference range. This underlines the importance of TSH in diagnosis and monitoring of thyroid dysfunctions. Also, it implies that subclinical thyroid disease may be defined in purely biochemical terms. Under critical circumstances such as pregnancy where normal thyroid function is of importance for fetal brain development, subclinical thyroid disease should be treated. Even TSH within the reference range may be associated with slightly abnormal thyroid function of the individual. The clinical importance of such small abnormalities in thyroid function in small children and pregnant women for brain development remains to be elucidated.

Accuracy of diagnostic ultrasound for detection of cystic lesions: determination using receiver operating characteristic curve analysis of findings in phantom studies

Anechoic, spherical cystic lesions are important findings on ultrasound examination. In polycystic renal disease of cats, they may be the only ultrasonographic sign of disease. This study assesses the accuracy of ultrasound, as used in a veterinary setting, for the detection of cysts. Using a spherical lesion ultrasound imaging phantom and 7.5- to 8-MHz linear array transducers, images of cysts of 2- and 4-mm diameter were created at various imaging depths from 0 to 6 cm. These were digitized and given to a panel of readers for interpretation. Area under receiver operating characteristic curves were used to evaluate test accuracy. It was shown that test accuracy was different at different imaging depths and differed with machines of differing price category. It is suggested that when setting standards for quality control in ultrasound, criteria used might be better related to imaging outcome studies rather than to aspects of machine specification.

Narrow individual variations in serum T(4) and T(3) in normal subjects: a clue to the understanding of subclinical thyroid disease

High individuality causes laboratory reference ranges to be insensitive to changes in test results that are significant for the individual. We undertook a longitudinal study of variation in thyroid function tests in 16 healthy men with monthly sampling for 12 months using standard procedures. We measured serum T(4), T(3), free T(4) index, and TSH. All individuals had different variations of thyroid function tests (P < 0.001 for all variables) around individual mean values (set points) (P < 0.001 for all variables). The width of the individual 95% confidence intervals were approximately half that of the group for all variables. Accordingly, the index of individuality was low: T(4) = 0.58; T(3) = 0.54; free T(4) index = 0.59; TSH = 0.49. One test result described the individual set point with a precision of +/- 25% for T(4), T(3), free T(4) index, and +/- 50% for TSH. The differences required to be 95% confident of significant changes in repeated testing were (average, range): T(4) = 28, 11-62 nmol/liter; T(3) = 0.55, 0.3--0.9 nmol/liter; free T4 index = 33, 15-61 nmol/liter; TSH = 0.75, 0.2-1.6 mU/liter. Our data indicate that each individual had a unique thyroid function. The individual reference ranges for test results were narrow, compared with group reference ranges used to develop laboratory reference ranges. Accordingly, a test result within laboratory reference limits is not necessarily normal for an individual. Because serum TSH responds with logarithmically amplified variation to minor changes in serum T(4) and T(3), abnormal serum TSH may indicate that serum T(4) and T(3) are not normal for an individual. A condition with abnormal serum TSH but with serum T(4) and T(3) within laboratory reference ranges is labeled subclinical thyroid disease. Our data indicate that the distinction between subclinical and overt thyroid disease (abnormal serum TSH and abnormal T(4) and/or T(3)) is somewhat arbitrary. For the same degree of thyroid function abnormality, the diagnosis depends to a considerable extent on the position of the patient's normal set point for T(4) and T(3) within the laboratory reference range.

Variations in urinary iodine excretion and thyroid function. A 1-year study in healthy men

OBJECTIVE

The iodine intake level in a population is determined in cross-sectional studies. A fraction of samples with iodine content below a certain level, e.g. 25 microg/l, may suggest iodine deficiency in part of the population. However, urinary iodine varies considerably from day to day and the fraction of low samples caused by dispersion remains unsettled.

DESIGN

A longitudinal study of 16 healthy men living in an area of mild to moderate iodine deficiency.

METHODS

We measured urinary iodine and creatinine concentrations, and serum TSH, total thyroxine (T4), free T4 index and total tri-iodothyronine (T3) in samples collected monthly for 1 year.

RESULTS

Average urinary iodine excretion was 57.0 microg/l (49.1 microg/24 h (corrected for creatinine excretion)) and varied from 29 to 81 microg/l (28 to 81 microg/24 h) between participants. Individual samples varied between 10 and 260 microg/l, and the variation around the mean was 2.4 times larger when calculated for the 180 individual samples compared with the 15 average annual values (1.7 times larger for estimated 24 h iodine excretion values). The fraction of individual samples below 25 microg/l was 6.7% (7.2% < 25 microg/24 h), whereas none of the participants had average iodine excretion below 25 microg/l or 25 microg/24 h. Participants with average annual iodine excretion below 50 microg/24 h had a negative correlation between iodine excretion and TSH, whereas a positive correlation was observed when average annual iodine excretion was above this level.

CONCLUSIONS

Seven per cent of individual urine samples indicated severe iodine deficiency without this being present in the group studied. Dispersion was reduced by 24% when using estimated 24 h urinary iodine excretion rather than urinary iodine concentration. Participants with moderate iodine deficiency (average annual urinary iodine excretion 25-50 microg/24 h) showed clear signs of substrate deficiency for thyroid hormone synthesis while participants with mild iodine deficiency (50-100 microg/24 h) did not.

Thyroid disorders in mild iodine deficiency

Comparative epidemiologic studies in areas with low and high iodine intake and controlled studies of iodine supplementation have demonstrated that the major consequence of mild-to-moderate iodine deficiency for the health of the population is an extraordinarily high occurrence of hyperthyroidism in elderly subjects, especially women, with risk of cardiac arrhythmias, osteoporosis, and muscle wasting. The hyperthyroidism is caused by autonomous nodular growth and function of the thyroid gland and it is accompanied by a high frequency of goiter. Pregnant women and small children are not immediately endangered but the consequences of severe iodine deficiency for brain development are grave and a considerable safety margin is advisable. Moreover, a shift toward less malignant types of thyroid cancer and a lower radiation dose to the thyroid in case of nuclear fallout support that mild-to-moderate iodine deficiency should be corrected. However, there is evidence that a high iodine intake may be associated with more autoimmune hypothyroidism, and that Graves' disease may manifest at a younger age and be more difficult to treat. Hence, the iodine intake should be brought to a level at which iodine deficiency disorders are avoided but not higher. Iodine supplementation programs should aim at relatively uniform iodine intake, avoiding deficient or excessive iodine intake in subpopulations. To adopt such a strategy, surveillance programs are needed.

Postpartum thyroid dysfunction in pregnant thyroid peroxidase antibody-positive women living in an area with mild to moderate iodine deficiency: is iodine supplementation safe?

In moderately iodine-deficient, pregnant, thyroid peroxidase antibody (TPO-Ab)-positive women the role of iodine supplementation in the development of postpartum thyroid dysfunction (PPTD) was studied in a placebo-controlled, randomized, double blind trial. Screening for TPO-Ab was performed in early pregnancy in a population of healthy pregnant Danish women with no previous diagnosed thyroid disease (prevalence, 117 of 1,284; 9.1%). The participants were randomized, stratified according to TPO-Ab level, to three groups. All participants received a daily vitamin and mineral tablet with 150 microg iodine or no iodine. The +/+ group received iodine during pregnancy and the postpartum period, the +/- group received iodine during pregnancy only, and the -/- group received no iodine supplementation. A total of 66 TPO-Ab positive women were followed, and in the postpartum period sera were collected at 8-week interval for biochemical evaluation of thyroid function and antibody level. Compliance was evaluated by 24-h urinary iodine measurements. PPTD developed in 55% of the participants. In 67% of the cases abnormal TSH was accompanied by abnormalities in thyroid hormones, whereas 33% had abnormal serum TSH only. There was no statistically significant difference in the frequency of PPTD in the three groups: +/+ group, 59% (95% confidence interval, 36-79%); +/- group, 60% (36-81%); and -/- group, 46% (26-67%). There were also no differences in the severity of the PPTD, as evaluated by duration and grade of deviation of TSH and thyroid hormones from normality. The occurrence, severity, and type of PPTD predominantly depended on the TPO-Ab level: TPO-Ab below 200 U/L at screening, 35% developed PPTD; TPO-Ab of 200-900 U/L, 54%; and TPO-Ab above 900 U/L, 75% developed PPTD. Women with low levels of antibodies predominantly remained euthyroid or had hyperthyroidism only, whereas women with high antibody levels had hyperthyroidism followed by hypothyroidism or hypothyroidism only. We conclude that iodine supplementation (150 microg) during pregnancy and the postpartum period to TPO-Ab-positive women living in an area with mild to moderate iodine deficiency did not induce or worsen PPTD. The study confirmed that screening for TPO-Ab in early pregnancy can predict women at high risk for development of PPTD.

Molecular cloning, genomic organization, developmental regulation, and a knock-out mutant of a novel leu-rich repeats-containing G protein-coupled receptor (DLGR-2) from Drosophila melanogaster

After screening the Berkeley Drosophila Genome Project database with sequences from a recently characterized Leu-rich repeats-containing G protein-coupled receptor (LGR) from Drosophila (DLGR-1), we identified a second gene for a different LGR (DLGR-2) and cloned its cDNA. DLGR-2 is 1360 amino acid residues long and shows a striking structural homology with members of the glycoprotein hormone [thyroid-stimulating hormone (TSH); follicle-stimulating hormone (FSH); luteinizing hormone/choriogonadotropin (LH/CG)] receptor family from mammals and with two additional, recently identified mammalian orphan LGRs (LGR-4 and LGR-5). This homology includes the seven transmembrane region (e.g., 49% amino acid identity with the human TSH receptor) and the very large extracellular amino terminus. This amino terminus contains 18 Leu-rich repeats-in contrast with the 3 mammalian glycoprotein hormone receptors and DLGR-1 that contain 9 Leu-rich repeats, but resembling the mammalian LGR-4 and LGR-5 that each have 17 Leu-rich repeats in their amino termini. The DLGR-2 gene is >18.6 kb pairs long and contains 15 exons and 14 introns. Four intron positions coincide with the intron positions of the three mammalian glycoprotein hormone receptors and have the same intron phasing, showing that DLGR-2 is evolutionarily related to these mammalian receptors. The DLGR-2 gene is located at position 34E-F on the left arm of the second chromosome and is expressed in embryos and pupae but not in larvae and adult flies. Homozygous knock-out mutants, where the DLGR-2 gene is interrupted by a P element insertion, die around the time of hatching. This finding, together with the expression data, strongly suggests that DLGR-2 is exclusively involved in development.

[Health care systems in the Nordic countries--more similarities than differences?]

The aim of this paper is to explore similarities and differences of the Nordic health care systems. The analysis is based on a three-part model involving patients, providers and the financing third party. In all Nordic countries, about 80% of the funding come from public sources. In Iceland, central government is providing most of the health care services, while the county councils are central in Denmark, Norway and Sweden. In Finland, the municipalities are providing most of the health care. Salary is the only payment system for general practitioners in Iceland, while it is used for some GPs in Finland, Norway and Sweden. Capitation in combination with service fees is used for all Danish GPs and the majority of the Finnish, while various fee-for-service systems are used for the others. All Nordic countries had global hospital budgeting in the 1980s; since then, Finland, Norway and Sweden have implemented others systems, predominantly combinations of diagnosis-related group financing and global budgets. The amounts of resources devoted to health care are about the same in all five countries whether measured by the proportion of GDP devoted to health care, or by hospital beds or doctor/patient ratios. In monetary terms, Denmark, Iceland and Norway spend more than Finland and Sweden. Despite similar amounts of resources, they are quite differently used across the countries. Differences of a factor of two or more are observed for hip operations, gal bladder operations and pharmaceuticals. Danes and Finns are very satisfied with their health care system; the Swedes are not. All the Nordic countries have increased patient co-payments during the 1990s. Finnish patients may pay an extra free to get a one-bed room. Finland also has the greatest number of private hospitals. Despite all these differences, the Nordic health care systems are quite similar when seen in a global perspective.

Iodine in drinking water varies by more than 100-fold in Denmark. Importance for iodine content of infant formulas

The iodine intake level of the population is of major importance for the occurrence of thyroid disorders in an area. The aim of the present study was to evaluate the importance of drinking water iodine content for the known regional differences in iodine intake in Denmark and for the iodine content of infant formulas. Iodine in tap water obtained from 55 different locations in Denmark varied from <1.0 to 139 microg/l. In general the iodine content was low in Jutland (median 4.1 microg/l) with higher values on Sealand (23 microg/l) and other islands. Preparation of coffee or tea did not reduce the iodine content of tap water with a high initial iodine concentration. A statistically significant correlation was found between tap water iodine content today and the urinary iodine excretion measured in 41 towns in 1967 (r=0.68, P<0.001). The correlation corresponded to a basic urinary iodine excretion in Denmark of 43 microg/24h excluding iodine in water and a daily water intake of 1.7 l. The iodine content of infant formulas prepared by addition of demineralized water varied from 37 to 138 microg/l (median 57 microg/l, n=18). Hence the final iodine content would depend heavily on the source of water used for preparation. We found that iodine in tap water was a major determinant of regional differences in iodine intake in Denmark. Changes in water supply and possibly water purification methods may influence the population iodine intake level and the occurrence of thyroid disorders.

muFKBP38: a novel murine immunophilin homolog differentially expressed in Schwannoma cells and central nervous system neurons in vivo

To better understand the process of multistage carcinogenesis in Schwann cells, we have attempted to isolate novel candidate genes involved in neoplastic progression of mouse malignant Schwannoma cells. The semi-differentiated Schwannoma cell line 56-24 and the less differentiated Schwannoma cell line 64-39 were established from peripheral nerve sheath tumors arising in transgenic mice of the MBP/SV40 large T strain Tg29. By using the chemical cross-linking subtraction technique, we have cloned a novel murine cDNA that detects pronounced expression in 56-24 cells but not in 64-39 cells. The longest open reading frame of the cDNA predicts a peptide showing 95% amino acid sequence homology to the recorded sequence of the human immunophilin homolog huFKBPr38, one of a family of proteins that are thought to interface with a wide range of intracellular signal transduction systems. The predicted open reading frame of the corresponding gene, named muFKBP38, encodes a 38 kDa protein that harbors an FK-binding protein (FKBP) domain that is 36% identical to that of muFKBP52, a three-unit tetratricopeptide repeat and a consensus leucine-zipper repeat. Although muFKBP38 mRNA was detected in both neurons and glial cells, pronounced expression of the immunophilin homolog appeared in various classes of neurons associated with the hippocampal formation, as shown by in situ hybridization analysis of adult mouse brains. Taken together, these data indicate that muFKBP38 is (i) a novel potential marker for semi-differentiated Schwannomas, (ii) may form homomultimers and/or interact with other proteins, and (iii) may have a role in neurons associated with memory function.

Low incidence rate of overt hypothyroidism compared with hyperthyroidism in an area with moderately low iodine intake

In areas with relatively high iodine intake, the incidence rate of hypothyroidism is several-fold higher than that of hyperthyroidism. Recently, we found a similarly high prevalence rate of subclinical hypothyroidism compared with hyperthyroidism in a high iodine intake area, while a relatively low prevalence of subclinical hypothyroidism was observed in a low iodine intake area. In the present study we compared the incidence rate (newly diagnosed in primary care and at hospital) of overt hypothyroidism with that of hyperthyroidism in a well-defined geographical area in Jutland, Denmark, with an iodine intake around 60 microg/day. The number of personsxyears studied was 569,108. Data on hyperthyroidism have been published previously. The overall incidence of hypothyroidism was 13.5/100,000 per year (F/M 22.9/3.6), hyperthyroidism 38.7/100.000 per year (F/M 63.0/13.0). The incidence of hypothyroidism was steadily increasing with age up to 80/100,000 per year in subjects older than 70 years of age, but apart from congenital hypothyroidism it was lower than that of hyperthyroidism at all ages. The majority of patients (79%) was diagnosed to have spontaneous autoimmune hypothyroidism (16% with goiter, 84% with no thyroid visible or palpable). In conclusion, in an area with moderately low iodine intake, hypothyroidism was considerably less common than hyperthyroidism. This is in contrast to findings in high iodine intake areas. The iodine intake of an area seems to be of major importance for the pattern of thyroid disorders observed.

Expression of a novel murine phospholipase D homolog coincides with late neuronal development in the forebrain

Members of the phospholipase D (PLD) superfamily are defined by the conserved HXKXXXXD motif, which is essential for the catalytic function of mammalian PLD. PLD enzymes are thought to play roles in signal transduction and membrane vesicular trafficking in mammalian cells. Here we describe a 54-kDa novel murine polypeptide (designated SAM-9) that is predicted to be a membrane-associated member of the PLD superfamily. SAM-9 shares 40, 30, and 29% amino acid identity with potential orthologs, in vaccinia virus, Caenorhabditis elegans, and Dictyostelium discoideum, respectively, and belongs to a subclass of PLD homologs in which the second HXKXXXXD motif is imperfect and harbors a conserved Asp to Glu substitution. The sam-9 gene has more than eight exons, and the two HXKXXXXD motifs are encoded by two highly conserved exons. The expression of the sam-9 gene is greater in the brain than in non-nervous tissue and appears to be predominantly of neuronal origin. sam-9 expression is pronounced in mature neurons of the forebrain and appears to be turned on at late stages of neurogenesis as revealed by in situ hybridization analysis of sam-9 expression during postnatal development of the hippocampal formation and the primary somatosensory cortex.

[A young woman with metabolic acidosis and recently discovered IDDM without ketonuria. A rare autoimmune (?) combination of hypothyroidism, diabetes mellitus and distal renal tubular acidosis]

A case of a 29-year-old woman with a multiple autoimmune disorder is reported. She had a history of hypothyroidism since the age of 18. She was admitted to hospital due to hyperglycaemia. At admission she had hyperglycaemia, metabolic acidosis, but no urinary ketone bodies. Further laboratory studies revealed that the acidosis was due to distal renal tubular acidosis rather than diabetic ketoacidosis (although the patient had type 1 diabetes mellitus). Blood tests revealed antibodies to glutamic acid decarboxylase (GAD-65; associated with type 1 diabetes mellitus), thyroid and adrenal tissue, and gastric parietal cells. The patient had not developed pernicious anaemia or Addison's disease. The multiple positive antibody titres in this patient indicate that the diabetes, hypothyroidism and distal renal tubular acidosis are part of an autoimmune syndrome.

Failure of central nervous system myelination in MBP/c-myc transgenic mice: evidence for c-myc cytotoxicity

c-myc is a member of the helix-loop-helix/leucine zipper family of proteins that modulate the transcriptional activity of specific target genes. Although aberrant c-myc expression has been reported to play a role in multistage carcinogenesis in astrocytic gliomas, little is known about the effects of the expression of c-myc on oligodendrocytes. Using transgenic animals expressing a human c-myc oncogene under transcriptional control of the myelin basic protein gene, we investigated the effect of overexpression of this oncogene in oligodendrocytes. The MBP/c-myc transgenic mice developed severe neurological disturbances characterized by action tremors and recurrent seizures, and premature death during postnatal weeks three to five. Affected transgenic mice of various strains had severely hypomyelinated central nervous systems and expressed low levels of c-myc, myelin basic protein (MBP) and proteolipid protein (PLP) mRNAs in the brain. These c-myc transgenic mice also exhibited an increased number of TUNEL positive nuclei, which in most cases were located in cells that expressed c-myc, as judged by double immunohistochemistry. There was no evidence of brain tumors in the c-myc transgenic mice, including heterozygous mice from two strains that had normal lifespans. These observations indicate that the myelin deficiency observed in the MBP/c-myc transgenic animals results from a cytotoxic effect of the c-myc transgene.

Neurological disturbances, premature lethality, and central myelination deficiency in transgenic mice overexpressing the homeo domain transcription factor Oct-6

Pit, Oct, Unc (POU) homeo domain transcription factors have been implicated in various developmental processes, including cell division, differentiation, specification, and survival of specific cell types. Although expression of the transcription factor Oct-6 in oligodendroglia is confined to the promyelin stage and is downregulated at the myelin stage of development, the effect of Oct-6 overexpression on oligodendrocyte development has not been established. Here we show that transgenic animals overexpressing Oct-6 at late oligodendrocyte development develop a severe neurologic syndrome characterized by action tremors, recurrent seizures, and premature death. Axons in the central nervous system of Oct-6 transgenics were hypomyelinated, hypermyelinated, or dysmyelinated, and ultrastructural analyses suggested that myelin formation was premature. The vulnerability of developing oligodendroglia to Oct-6 deregulation provides evidence that the POU factor may play a direct role in myelin disease pathogenesis in the mammalian CNS.

Iodine intake and the pattern of thyroid disorders: a comparative epidemiological study of thyroid abnormalities in the elderly in Iceland and in Jutland, Denmark

Thyroid abnormalities are common in all populations, but it is difficult to compare results of epidemiological studies, because different methods have been used for evaluation. We studied the importance of the population iodine intake level for the prevalence rate of various thyroid abnormalities in elderly subjects. Random samples of elderly subjects (68 yr) were selected from the central person registers in Jutland, Denmark, with low (n = 423) and, in Iceland, with longstanding relatively high (n = 100) iodine intake. Females from Jutland had a high prevalence of goiter or previous goiter surgery (12.2%), compared with males from Jutland (3.2%) and females (1.9%) and males (2.2%) from Iceland. Abnormal thyroid function was very common in both areas, with serum TSH outside the reference range in 13.5% of subjects from Jutland and 19% of those from Iceland. In Jutland, it was mainly thyroid hyperfunction (9.7% had low, 3.8% had high serum TSH), whereas in Iceland, it was impaired thyroid function (1% had low, 18% had high serum TSH). All subjects with serum TSH more than 10 mU/L had autoantibodies in serum, but antibodies were, in general, more common in Jutland than in Iceland. Thus, thyroid abnormalities in populations with low iodine intake and those with high iodine intake develop in opposite directions: goiter and thyroid hyperfunction when iodine intake is relatively low, and impaired thyroid function when iodine intake is relatively high. Probably, mild iodine deficiency partly protects against autoimmune thyroid disease. Thyroid autoantibodies may be markers of an autoimmune process in the thyroid or secondary to the development of goiter.

[Iodine intake in Denmark]

Iodine deficiency with a high frequency of goitre and, in severely affected areas, cretinism is common in some areas of the world. In Denmark the iodine intake as evaluated by urinary iodine excretion has been at a stable low level for many years, except for the part of the population now taking iodine supplementation as part of vitamin/ mineral preparations. The iodine intake is lowest in the western part of the country where an epidemiological study of elderly subjects has demonstrated a high frequency of goitre and hyperthyroidism in women. This supports the suggestion of a controlled moderate increase in iodine intake via an iodine supplementation program.

[Cholera in Denmark--an imported case of illness]

A case of cholera imported to Denmark from the Pacific is presented. The patient was successfully treated with rehydration and antibiotics. A survey of the ongoing seventh pandemic of cholera is given and the possible emergence of a new eighth pandemic is discussed. Guidelines for prophylactic and therapeutic measures are discussed. Although V. cholerae colonies can be recognized on routine cultivation media, low numbers require selective media, and this is not included in routine investigations of stools for pathogens.

Urinary iodine excretion and individual iodine supplementation among elderly subjects: a cross-sectional investigation in the commune of Randers, Denmark

Several studies have demonstrated that the iodine intake is relatively low in Denmark. However, the results are difficult to interpret because no information has been given on the frequency of individual iodine supplementation. We performed a cross-sectional study of elderly subjects living in the commune of Randers, Denmark. Urinary iodine excretion was measured in the 423 participants (185 males, 238 females) and a careful history was taken on any possible intake of supplementary iodine. The median urinary iodine excretion was 48.3 micrograms/g creatinine for the whole population (40.8 micrograms/g creatinine in males, 53.2 micrograms/g creatinine in females). In the part of the population that did not take iodine supplementation (46.7%) the median value was 36.1 micrograms/g creatinine (males 33.8; females 38.8). Regular iodine supplementation taken as an iodine-containing vitamin/mineral tablet was found in 30.8% of the population. This increased the urinary iodine excretion to a median level of 80.5 micrograms/g creatinine (males 62.0; females 88.0). The study shows that the basic iodine intake level is overestimated if individual iodine supplementation is not taken into account. Such supplementation may lead to median iodine excretion values that seem reasonable, even if the iodine intake of the part of the population not taking iodine (in this study, nearly half of the population) is low.

Iodine status in neonates in Denmark: regional variations and dependency on maternal iodine supplementation

Iodine status of 147 neonates born in five different regions of Denmark was evaluated in relation to the iodine content of breast milk and iodine supplementation taken by the mother. Approximately two-thirds of the women had not received iodine supplementation. They had low iodine concentrations in breast milk and urinary iodine concentrations of the neonates at day 5 were low. The median values (milk/urine) were 33.6/31.7 micrograms/l (Randers 22/26, Ringkøbing 29/16, Aalborg 36/31. Arhus 54/41 and Copenhagen 55/59 micrograms/l). Higher values were found in the group where tablets containing iodine had been taken (milk/urine: 57.0/61.0 micrograms/l). In general, the values are low compared with internationally recommended levels. We suggest that mothers without autoimmune thyroid disease should receive iodine supplementation in the form of vitamin/mineral tablets containing iodine (150 micrograms per tablet).

[Knee arthroscopy under local anesthesia with or without anesthesiologic assistance. A cost-benefit analysis]

The benefit of anaesthesiological assistance during arthroscopy of the knee in local anaesthesia was evaluated in a cost-effectiveness analysis. One hundred consecutive patients had arthroscopy of the knee performed in local anaesthesia without anesthesiological assistance. In 15% of the cases the arthroscopy was insufficient because of pain reaction. Sixteen percent of the patients indicated that they would prefer general anaesthesia for a similar procedure in the future. The costs for arthroscopy of the knee in local anaesthesia without anaesthesiological assistance were calculated to Dkr. 2055. The amount includes costs for rearthroscopy in local anaesthesia with anaesthesiological assistance for 15% of the patients. Thirty-three patients had arthroscopy of the knee done in local anaesthesia with anaesthesiological assistance. General anaesthesia was needed for twelve percent of the patients. The cost for this procedure, including the costs of possible general anaesthesia were calculated to Dkr. 2458. Any significant difference in the sensation of pain during the arthroscopy could not be demonstrated between the two groups. Based on this study it is recommended that arthroscopy of the knee in local anaesthesia is planned without anaesthesiological assistance.

Amelioration of some pregnancy-associated variations in thyroid function by iodine supplementation

Knowledge of the effect of differences in iodine intake levels on public health in areas with no endemic goiter is limited. Groups at risk when iodine intake is relatively low are pregnant and lactating women and their newborns. A prospective randomized study was performed to evaluate the effect of iodine supplementation in an area where the median daily iodine excretion in urine is around 50 micrograms. Fifty-four normal pregnant women were randomized to be controls or to receive 200 micrograms iodine/day from weeks 17-18 of pregnancy until 12 months after delivery. In the control group, serum TSH, serum thyroglobulin (Tg), and thyroid size showed significant increases during pregnancy. These variations were ameliorated by iodine supplementation. Iodine did not induce significant variations in serum T4, T3, or free T4. Cord blood Tg was much lower when the mother had received iodine, whereas TSH, T4, T3, and free T4 levels were unaltered. The results suggest that a relatively low iodine intake during pregnancy leads to thyroidal stress, with increases in Tg release and thyroid size. However, the thyroid gland is able to adapt and keep thyroid hormones in the mother and the child normal, at least under normal circumstances, as evaluated in the present study. It is not known whether this stress is sufficient to be of importance for late development of autonomous thyroid growth and function.

Iodine deficiency in pregnancy in Denmark. Regional variations and frequency of individual iodine supplementation

Iodine requirements are increased during pregnancy and lactation and adequate iodine intake is important for normal brain development of the fetus/newborn child. The aim of the present study was to evaluate the extent to which this increase in iodine requirement is met in pregnant women living in various regions of Denmark. One hundred and fifty-two healthy pregnant women admitted to five different Danish departments of obstetrics participated in the study. Iodine status was evaluated by measurement of iodine in spot urine at day five after delivery and by careful history of the intake of iodine containing vitamin/mineral tablets. Approximately one third of the women had received tablets containing iodine. In women who had not received iodine supplementation urinary iodine was low with a median value of 39.7 micrograms/g creatinine (Aalborg 28, Randers 33, Ringkøbing 34, Arhus 43 and Copenhagen 62 micrograms/g creatinine). These values are far below internationally recommended levels. The consequences remain to be evaluated and no firm recommendations can be given. It seems reasonable, however, to recommend a high intake of food containing iodine (e.g. milk products) during pregnancy and lactation. Since nearly all the women took some kind of vitamin/mineral supplementation it could be considered to advocate intake of vitamin/mineral tablets containing iodine.

Sensitive enzyme-linked immunosorbent assay for measurement of autoantibodies to human thyroid peroxidase

The development of a sensitive assay for detection of autoantibodies against one of the major thyroid antigens, thyroid peroxidase (TPO), is described. TPO was purified from human thyroid tissue by: (1) isolation of thyroid microsomes using homogenization and differential centrifugation, (2) solubilization of membrane proteins by Zwittergent 3-14, and (3) anion exchange liquid chromatography on a FPLC Mono Q column. Autoantibodies against TPO (TPO-Ab) were measured using an enzyme-linked immunosorbent assay (ELISA) with serum samples diluted 1:100. Standards containing 70, 7, 0.7, 0.02 and 0 U ml-1 TPO-Ab were employed (reference standard code 66/387 NIBSC, London, UK). The detection limit was 0.02 U ml-1 corresponding to 2 U ml-1 in undiluted serum. The inter- and intra-assay coefficients of variation were 8.6% and 5.3%. In 109 healthy control subjects TPO-Ab was found in 9 (8.3%), while 43 (97.7%) out of 44 patients with newly diagnosed untreated Graves' disease had detectable TPO-Ab in serum. All of 16 patients with newly diagnosed spontaneously developing primary hypothyroidism had circulating TPO-Ab (range 16-7000 U ml-1). The new assay is a valuable tool for evaluation of thyroid autoimmunity in individual patients and for studying the epidemiology of thyroid autoimmunity.

High incidence of multinodular toxic goitre in the elderly population in a low iodine intake area vs. high incidence of Graves' disease in the young in a high iodine intake area: comparative surveys of thyrotoxicosis epidemiology in East-Jutland Denmark and Iceland

Little is known about the optimum level of iodine intake for iodine supplementation programmes, or about the effects of the high levels of iodine intake that are found in some countries. We compared the incidence of different types of hyperthyroidism in East-Jutland Denmark with a low average iodine intake but no endemic goitre, and the incidence in Iceland with a relatively high iodine intake. Hyperthyroidism was more common in East-Jutland than in Iceland, due to a much higher incidence of multinodular toxic goitre and also of single toxic adenoma. Most of the patients with these diseases were over 50 years of age. By contrast, the incidence of Graves' disease was significantly higher in Iceland than in East-Jutland. This difference was most marked in the younger age groups, in which hyperthyroidism was more than twice as common in Iceland as in East-Jutland. These results demonstrate that even mild iodine deficiency has a significant effect on population health, since it leads to a high incidence of autonomous thyroid nodules with hyperthyroidism in the elderly population. However, population iodine intake probably should not exceed a level much higher than that necessary to avoid iodine deficiency, otherwise Graves' disease may be induced in the young population.

Hyperfunctioning thyroid nodules

The authors describe the principal clinical and pathological aspects of the solitary hyperfunctioning adenoma or the multifocal hyperfunction of a multinodular goitre. Successively they report the incidence of these conditions in countries with different iodine intake as well as the age distribution of the examined patients. In the area with low iodine intake the incidence of hyperthyroidism caused by multinodular goitre is 10 times higher than in the high iodine intake area. Finally, the role of the laboratory in the diagnosis of hyperthyroidism and in identifying the type of hyperthyroidism is discussed; an up-todate flow-sheme is also reported.

Malignant intestinal schwannoma. Case report

Malignant schwannoma of the small intestine is rare and diagnosis often late. Histologic distinction from fibrosarcoma and leiomyosarcoma may require electron microscopy. The primary treatment is surgical. Close postoperative observation is recommended because of the tendency to recurrence. Remission after chemotherapy has been reported, but without controlled studies. The 5-year survival rate is unknown. Two cases are presented.

[Costs and cost analysis]

The costs of an activity is frequently the most conspicuous part in decision making when changes in health care services are considered. It is thus essential to be aware of the principles and considerations underlying the composition of costs. The concept of cost is not restricted to expenditures that have to be paid. It involves the notion of opportunity cost i.e. the cost of a service is the satisfaction or benefit foregone in not being able to use the resources involved to obtain some other service which is also desirable and therefore also provides satisfaction. Strictly, this relates to the best alternative way of using the resources. In order to estimate the costs of an activity, all costs, whether direct or indirect, tangible or intangible, ought to be taken into account. The fact that they may be difficult to measure a value is no excuse for ignoring them. In a cost analysis the result has to be assessed in the light of the types of costs employed and the aim of the analysis. Average cost is very often used, but is seldom the relevant costs. What is normally of concern is the cost of some change. Only by using marginal costs i.e. those costs that actually do change is it possible to obtain a true picture of resource consequences of that change. Regardless of the type of cost it is necessary to consider on whom the costs fall and to whom the benefits accrue. These may not be the same.

[The value of life and limb]

Assessment of the value of life and limbs is a controversial subject, not only emotionally but also theoretically. The economic starting point is based on assessment of the value of reduction or increase of the probability for an event which leads to disability or death. No concern is expressed for the single individual but for the phenomenon of probability where the person or persons who are affected by an event cannot be identified. Assessment of the value is in monetary units. The obvious discrepancy between the expression "value of life and limbs" and the theoretical content of the analysis has involved many misunderstandings. Attempts are made to elucidate and explain these. There is e.g. another method of assessing the value of life and limbs, the human capital method. In this, the disability and the premature death (compared with the current time) by means of loss of occupational income are assessed. The method is criticized and is discarded on the basis of theoretical arguments and consequences, the calculations of which are employed. Unfortunately, it has proved tempting to employ the method because it is relatively easy to make the calculations. Finally, the parts played by some recent questionnaire methods for assessment of alterations of risks are discussed. Assessment of the value of alterations in risks is an important requirement in order to carry out relevant cost-benefit analyses in the health sector. In cases where this is not possible, these analyses are meaningless.

[A review of the types of economic analyses of the health economy]

Great confusion is involved concerning health economics analyses. For example: What is the difference between cost-benefit and cost-effectiveness analyses? Is there a difference between the so-called cost-of-illness analyses? What is a financial analysis? These questions are discussed on the basis of the underlying economic theory and the use of the analyses. In order to avoid terminological confusion, the English terminology is retained. Cost-benefit and cost-effectiveness analyses are social economical analyses because they are all-embracing as regards what is understood by costs and profits based on the so-called welfare economy where cost-benefit analyses are concerned. The theoretical basis for cost-effectiveness analysis is slightly more obscure. Where both forms of analysis are concerned, no concern is shown for who obtains the profits or who pays the costs, i.e. a cross-sectional perspective. The financial analysis contrasts with this because attention is focussed directly on expenditures and revenues and the accounts responsible for the expenses and which obtain the revenues. The cost-of-illness analysis is a confusing but frequently employed and quoted form of analysis where an attempt is made to calculate the costs of a certain disease or injurious agent (alcohol, tobacco, accidents) for the various parties involved. These are subdivided into direct costs, roughly corresponding to the costs of treatment and indirect costs which include e.g. loss of income resulting from the illness, disability or death. This form of analysis is strongly warned against as the results of analysis may easily be misused frequently with absurd implications.

[What is cost effectiveness analysis?]

Cost-effectiveness analysis (CEA) is an established economical form of analysis which, in public services, replaces the marketing mechanism. The questions which CEA attempts to answer are: Which form of medical technology is most economically effective where a given disease is concerned. Where and how must the medical technology be commenced. Which group of patients can benefit from a given form of medical technology? It is a prerequisite for employment of CEA that there is unanimity in advance about the object of an activity, eg. a given treatment or procedure in the diagnostic investigation. Several strategies may be employed to ensure that the aim is sufficiently wide: the limits may be explicit; goals may be established which compare years of life with quality of life, or several goals may be present in the goal. The predominant economical expression in CEA is alternative costs which must be sacrificed in order to carry out a certain activity. In order to estimate what is obtained by carrying out an activity, an expression of effect is essential. These are most frequently both of quantitative and also of qualitative character and may be subdivided into three categories: Alterations in the employment of resources. Alterations in production by society. Alterations in the conditions of health of the individual. Doctors are important decisions-makers and distributors of resources in the health services. The questions which a CEA can provide graduated answers to, are the questions that the doctor works with in clinical practice.(ABSTRACT TRUNCATED AT 250 WORDS)

[What is cost benefit analysis?]

The practical and theoretical bases of cost-benefit analysis are reviewed systematically with particular emphasis on how an analysis can be carried out in practice. A Danish analysis about introduction of vaccination for mumps, measles and German measles is included as a common example. The great significance of elucidating the socio-economical questions to be answered before commencing an analysis is emphasized. It is therefore recommended that, among other things, as a side-effect of the actual cost-benefit analysis, a cash-analysis and a budget analysis should be carried out to identify the parties involved in the immediate expenses and incomes. This is particularly important in the cases where the same parties have a central position in the decision-making processes concerned in the project. In addition, costs and benefits are frequently distributed differently in time in different ways: Short-term expenses and long-term benefits. In connection with decision-making, this may also involve problems and should, therefore, be elucidated in detail. Similarly, the importance of including many alternatives in the analysis is emphasized and illustrated. In conclusion, it is demonstrated how well the theoretical principles have been followed, the employment and the process which led to the concrete analysis.

[What is healthy economy?]

Health economics is the branch of economics which is concerned theoretically and practically with the health sector and related subjects such as e.g. the market for medicine and medico-technical equipment. In health economics, the universal basic problem is: Distribution of scarce resources to competing ends and establishment of rules for this. In this respect, (health) economics is knowledge about priorities based on the methodical an appreciative basis of economics. The essence is the absolute or relative scarcity and the existence of alternative uses for the limited resources. Many identify health economics with societal economic analyses: cost-benefit analyses or cost-effectiveness analyses. A great many analyses of this type have been published and these have been employed to an increasing extent in connection with decisions about introduction or alteration of the existing therapeutic or diagnostic methods. Health economics is, however, much more: theoretical and empirical analysis of the demand for health and health services, including the effect of payment-for-service; supplier and producer behaviour including questions about the existence and consequence of supplier-induced demand i.e. the professional health groups may, themselves, determine the extent of the demand and employment for their services to a considerable extent. Analyses of productivity and effectiveness and methods for measuring and assessing health status are two other typical subjects. Thus, in the course of the past 15-20 years, health economy has become established as an academic subject with its own professorships and scientific journals.

Self-care within a model for demand for medical care

Self-care is interpreted from a health economic point of view. Various approaches are presented. It is stressed that the decision-oriented approach used by other health service researchers is an integral part of the economic approach to the topic as is the idea of a continuum of care, from self-care to professional care. A new approach is taken to the modeling of self-care, in that self-care becomes part of a four-part demand for care model. This makes it possible to model the demand for care for three different groups separately: 1--persons with zero episodes; 2--persons with pure illness episodes and illness episodes with self-care; 3--persons with episodes involving professional care or professional care combined with self-care. Another contribution is due to the so-called episodic approach to the demand for care. The natural counting units are illness and treatment episodes, i.e. instead of counting for instance number of times a general practitioner is consulted we ought to count the number of episodes involving professional care, self-care or both types of care. The episodic approach seems to be well suited for work with self-care. The empirical part is based on a unique Danish panel study using health diaries returned weekly. Data from 27 of the 52 reporting weeks are used, involving more than 14,000 episodes distributed across about 2800 persons belonging to about 1000 households. The use of health diaries seems to be very well suited to the study of self-care in that less salient events and activities than professional care are picked up far better in prospective health diary studies than in retrospective questionnaire based surveys. Descriptive and regression (logistic and ordinary) results are presented.

An investigation of the effect of regional variation in the treatment of hypertension

Over a period both a monetary and physical measure of antihypertensive drug consumption has increased in Denmark, but the consumption has varied considerably between counties in any given year. Concurrently, SMR for myocardial infarctions and cerebrovascular diseases due to hypertension has declined. The relation between intensity of treatment and outcome in terms of reduced loss of life time or healthy time is analyzed at an aggregate level within a health economic framework. The relation is analyzed by using a pooled time series cross section regression analysis. Two models, a covariance and an error component model are used. Within the range of observed drug consumption, loss of life years and loss of good health show a tendency towards negative regression on consumption of drugs when controlled for relevant variables such as occupational structure, degree of urbanization, and hardness of the drinking water.

Sensitive assay for thyroglobulin autoantibodies in serum employing polyethylene glycol for precipitation

A sensitive assay for thyroglobulin autoantibodies (Tg-ab) is described. The assay is based on prolonged incubation of [125I]Tg with serum followed by precipitation of antibody bound [125I]Tg by polyethylene glycol (PEG). The PEG concentration was chosen to give a low precipitation of free [125I]Tg while effectively precipitating Tg-ab-bound [125I]Tg. The lowest reference employed contained 19.5 MRC U/l Tg-ab. This was always different from an incubate without Tg-ab. Tg standard added to samples interfered in the assay giving spuriously low Tg-ab values as in other Tg-ab assays. Tg-ab added to samples was recovered quantitatively. The interassay coefficient of variation was 19.8% and the intra-assay coefficient of variation 11.3%. Only eight of 66 serum samples with various amounts of Tg-ab, measured with the new assay, had levels of Tg-ab detectable by the passive haemagglutination test.

Urinary iodine excretion is low and serum thyroglobulin high in pregnant women in parts of Denmark

In the Randers area of Denmark urinary iodine excretion (which reflects iodine intake) was found to be much lower than recommended intake levels, both in women in late pregnancy [52(23-118) micrograms iodine/g creatinine, median, range, n = 20] and in non-pregnant controls [42(23-71), n = 20]. Serum thyroglobulin which is high in iodine deficiency was 32.5 micrograms/l (median) (range 10.5-78.0) in the control women and considerably higher in the pregnant women [67.0 micrograms/l (9.0-385)]. This increase was probably due to the extra iodine requirement of pregnancy which was not satisfied with an adequate increase in iodine intake. The results may suggest that pregnant women in this area should receive iodine supplementation and that a general program of iodine supplementation should be considered.

A sensitive radio-immunoassay for serum thyroglobulin--including a correct screening for thyroglobulin autoantibodies

A new thyroglobulin (Tg) assay employing polyethylene glycol (PEG) for separation of free and antibody bound [125I]Tg is described. By choosing a suitable PEG concentration the non-specific precipitation of free [125I]Tg was kept low while both [125I]Tg bound to rabbit anti-Tg immunoglobulins and to human Tg autoantibodies were precipitated. For all sera a 'blank' incubation with no rabbit anti-Tg immunoglobulins was run in parallel with the assay tubes. Hence any interference of Tg autoantibodies would be detected. A two-phase incubation gave a very low detection limit of 0.2 microgram/l. The inter-assay coefficient of variation was 9.4% and the intra-assay coefficient of variation was 5.6%. Dilution curves of normal sera were parallel to the standard curve and Tg standards added to normal sera were recovered quantitatively. Twelve out of 60 normal sera from the Randers area contained Tg autoantibodies. The average serum Tg in the 48 sera without antibody was 44.6 +/- 5.2 micrograms/l (SEM).

Initial mass screening for colorectal cancer with fecal occult blood test. A prospective randomized study at Funen in Denmark

A Danish study allocated at random 30,970 persons to screening with Hemoccult-II and 30,968 as controls in a population of 140,000 between 45 and 74 years old. Persons with known colorectal cancer, adenoma, and distant spread from all types of cancer were excluded. The test was completed in 20,672 persons from August 1985 to September 1986, and 215 (1%) were found to be positive. Colonoscopy in 203 and double-contrast barium enema in 6 detected 37 persons with cancer and 86 with adenomas. Dukes A cancer was detected in 19 in the screening group, in contrast to 2 among controls. Synchronous adenomas were found in 23 with a positive test and 10 controls. Interval cancer was found in nine persons within 1-11 months after a negative test. Eighteen persons got cancer before invitation and six defectors as well. In all, colorectal cancer was detected in 70 persons in the screening group and in 38 controls; the figures for adenomas alone were 103 and 38, respectively. The study is designed to detect a possible reduction in mortality from colorectal cancer of 25% within 5 years after three screenings with intervals of 2 years. The second screening will begin in September 1987. It remains to be shown whether a reduction may be obtained both in mortality and in incidence of colorectal cancer.