Goitre epidemiology: thyroid volume, iodine excretion, thyroglobulin and thyrotropin in Germany and Sweden

Abstract

Abstract. Thyroid volume of 1397 German and 303 Swedish adults were estimated by sonography. Thyroid size of 6–16 year old Germans (n = 619) was determined and compared with findings on palpation. Thyroid volume was more than twice as great in German (21.4 ± 15.6 ml, mean ± sd) than in Swedish adults (10.1 ± 4.9 ml). The echopattern was abnormal in 16% of the Germans and in 3.6% of the Swedes. German children have a thyroid volume ranging from 1.8 ± 0.4 ml at 6 years to 10.8 ± 6.0 ml at 16 years of age. Palpation is by comparison an unreliable method for determining thyroid size. In Germany, the iodine excretion was less in children (n = 619, 39.5 ± 30.5, 34.1 μg I/g creatinine, mean ± sd, median) than in adults (n = 1193, 83.7 ± 94.4, 62.6), (P <0.001) and much lower than that observed in Sweden (adults n = 98, 170.2 ± 93.3, 141.4; 13 year olds n = 113, 172.9 ± 224.1, 124), (P < 0.0001). Serum thyrotropin concentration was significantly higher (P <0.001) in Sweden (n = 62, 1.49 ± 0.82 mU/ml), than in Germany (n = 91, 0.97 ± 0.52 mU/ml), while serum thyroglobulin was increased in Germany (n = 91, 72.6 ± 50.6 μg/l) as compared to Sweden (n = 62, 23.5 ± 17.4), (P <0.0001). These results indicate the goitrogenic effect of iodine deficiency and the continuing need for an effective iodine prophylaxis in the FRG.

Urinary iodine and thyroid status of New Zealand residents

“…Our observations of differences among the three groups are similar to, although not as pronounced as, those of Gutekunst and colleagues, who reported higher thyroid volumes in residents of Germany, where iodine intake is marginal, than those of Sweden where iodine status is adequate (Gutekunst et al, 1986). Similarly, serum thyroglobulin of the Germans was more than twice that of the Swedes.…”

“…On the other hand, thyroglobulin changes rapidly after alteration of iodine intake and thus may be a more sensitive indicator of marginal iodine status (Bourdoux, 1993;Miûler et al, 1994;World Health Organization, 1993a). Mean and median thyroid volume of our subjects were higher than those of Swedes with adequate iodine status, but lower than those of Germans (Gutekunst et al, 1986), even though the iodideacreatinine ratio of our subjects was lower than that of the Germans. This may re¯ect a lag in the response to reduced iodine intake on thyroid volume (World Health Organization, 1993a), but may also re¯ect differences in methodology (World Health Organization, 1993a).…”

“…An inverse relationship between thyroid volume and urinary iodine excretion has also been reported in European schoolchildren (Delange et al, 1997), but not in German adults where the range of marginal iodine status was narrow (Gutekunst et al, 1986), or in Dutch adults where iodine status was adequate (Berghout et al, 1987). Our study appears to be the ®rst to report an inverse relationship between urinary iodide excretion and serum thyroglobulin.…”

“…Increased serum thyroglobulin, but not TSH or T 4 , in subjects with low iodide excretion con®rms other research showing elevated thyroglobulin associated with mild iodine de®ciency and enlarged thyroid glands (Gutekunst et al, 1986;Miûler et al, 1994;Pedersen et al, 1993). Free T 4 , free T 3 and TSH levels are measures normally used to assess thyroid hormone status.…”

“…On the other hand, circulating thyroglobulin, which also re¯ects an increased stimulation arising from a borderline iodine intake, may be a more sensitive indicator of thyroid stimulation (World Health Organization, 1993a). When compared with Swedish children with adequate iodine intake, German children with marginal iodine status and increased thyroid volume showed signi®cantly higher thyroglobulin levels, whereas TSH levels were in fact lower (Gutekunst et al, 1986). The same group reported that thyroglobulin was a more sensitive indicator of iodine de®ciency than TSH in children from areas of more severe iodine de®ciency (Miûler et al, 1994).…”