|
Knudsen et al., Copenhagen, Denmark, evaluated different types of
calculation of urinary iodine excretion, using casual urine samples from
15 males between 30 and 50 years of age, from the hospital staff. As gold
standard, 24 hours urinary iodine excretion was used. They compared 3 different
methods of calculation, i.e. only iodine concentration, iodine concentration
per gr creatinine and iodine excretion per gr creatinine multiplied by
1.55 (being the mean 24 hours creatinine excretion in adults). It appeared
that estimation of only iodine in a casual sample did not correlate at
all with 24 hours urinary iodine excretion. A good correlation was found
when iodine concentration was corrected for creatinine, however, the best
correlation was present when the ratio was multiplied by the mentioned
correction factor. (Comment: I have never understood why in many recent
publications on iodine deficiency, data of iodine excretion were based
on measurements of iodine concentration only in casual urinary samples
that were not corrected in any way for creatinine. This study shows that
it is far better to relate the findings to creatinine to have a realistic
idea about the state of iodine deficiency.)
Brix et al., Odense, Denmark, analyzed the genetic influence on the development of non-autoimmune non-toxic goiter in a well defined population of Danish twins. They studied 91 subjects (83 females) representing 81 twin pairs with past or present non-autoimmune non-toxic goiter. They measured concordance rates in monozygotic and dizygotic twins. The pairwise concordance rate for non-toxic diffuse or multinodular goiter was significantly higher in monozygotic twins compared to dizygotic twins (0.56 vs 0.18, p = 0.03). No such influence was present in the case of a solitary non-toxic nodule. Laurberg et al., Aalborg, Denmark, evaluated the incidence of newly diagnosed frank hypo- and hyperthyroidism in Jutland, Denmark, where the mean iodine intake level is around 60 µg/day in a study of 565,128 persons x years. The overall incidence of hypothyroidism was 13.6/100,000/year and of hyperthyroidism 38.7/100,000/year. Hyperthyroidism was more prevalent at all ages above 10 years. The authors conclude that the finding, that in an area of moderately low iodine intake, hypothyroidism is considerably less common than hyperthyroidism, contrasts with the findings in high iodine intake areas where hypothyroidism is more prevalent. Apparently the iodine intake level in an area is a major determinant of the type of thyroid function disorders. |
