Severe iodine deficiency in two endemic goitre areas of Zimbabwe

The purpose of the study was to investigate the iodine status of the population and the possible role of goitregens (that are metabolised to thiocyanate), in two endemic goitre areas of Zimbabwe. This was done through estimation of iodine (I) and thiocyanate (SCN) levels in spot urine samples collected from goitrous and non-goitrous subjects. Mean and median urine iodine concentrations respectively for Wedza (n = 50) were 1.4 micrograms/dl and 1.0 micrograms/dl and for Chiweshe (n = 60) were 2.1 micrograms/dl and 1.65 micrograms/dl. The differences between the two districts are significant (P = 0.005) and mirror the overall differences in goitre rates found. Urine I levels were generally lower in goitrous than non-goitrous subjects, but the difference was not significant. Mean urine SCN concentrations and mean I/SCN ratios respectively for Wedza were 0.5 micrograms/dl and 2.9 micrograms/dl and for Chiweshe were 0.7 micrograms/dl and 3.4 micrograms/dl. These results indicate that the populations studied are affected by severe iodine deficiency, but that thiocyanate does not have a significant goitrogenic effect. The implications of the results, and the reasons for the discrepancies between them and ones obtained in earlier studies, are discussed.