[The radioiodine test for the evaluation of iodine deficiency in the district of Karl-Marx-Stadt and in East Germany].

The values of the per cent 24 h radioiodine uptake in the GDR are above 60--70% and speak for a low alimentary intake of iodine or renal excretion of iodine below 40 micrograms J/d. Like the struma prevalences they show a tendency increasing from north to south and characterize the whole European situation of iodine deficiency including its decrease from west to east. The mean values of radioiodine uptake of 71.7 +/- 13.2% (n = 110) in euthyroids of the district of Karl-Marx-Stadt correspond to the iodine deficiency as it occurs approximately in the districts of Erfurt, Dresden, Munich or Freiburg/B. The alimentary iodine intake of 38.4 +/- 17.2 micrograms J/d and the renal iodine excretion of 29.9 +/- 16.1 micrograms J/d, calculated from the 24 h radioiodine accumulation values of 40 euthyroid persons by means of a mathematical model developed by Oddie and co-workers were low. The latter only slightly differed (P less than 0.05) from its chemically estimated excretion of iodine in the urine: 23.1 +/- 16.9 micrograms J/g creatinine (n = 73). Between the calculated and chemically estimated excretion of iodine there was a relatively strict correlation of r = 0.68 (n = 26; P less than 0.001). The introduction of an iodine prophylaxis is regarded as an urgent necessity. Later on a new estimation of the regional "normal values" is necessary for the per cent radioiodine uptake.