It is recommended to identify populations at risk of iodine deficiency by assessing urinary iodine concentration (UIC) in school-age children (SAC). However, pregnant women and young infants are the most vulnerable population groups. The study objective was to assess iodine status among SAC in rural Zinder, Niger and to compare their status with the iodine status of pregnant women from the same households.
Villages (n=73) in the catchment area of 16 health centers were randomly selected. A urine spot sample was collected from randomly selected pregnant women and one SAC living in the same household and sharing meals. UIC was assessed as indicator of iodine status. Salt samples (n=110) were collected at homes of randomly selected participants for assessment of iodine content by titration.
Mean iodine content of salt samples was 7±5ppm (range 1-41ppm). 96% had an iodine content <15ppm. Mean age of pregnant women (n=645) and SAC (n=580) was 27.3±6.3 yrs and 7.6±2.1 yrs, respectively. Although UIC of pregnant women and SAC were correlated (rs=0.23; <0.0001), the proportion of deficiency did not agree between pregnant women and their SAC (p=0.002). Median UIC of pregnant women was 69.3 µg/L (range 0-1037.8 µg/L), 84.6% had low UIC. Median UIC of SAC was 104.9 µg/L (range 8.0-788.8 µg/L), 47.0% had low UIC.
UIC in pregnant women indicated moderate to severe iodine deficiency, whereas UIC of SAC suggested marginally adequate iodine status. Monitoring iodine status among SAC may underestimate the risk of iodine deficiency in the most vulnerable population groups.Funded by Global Affairs Canada (GAC), the Micronutrient Initiative and UNICEF.