Iodine deficiency disorders in Gansu Province in 2014

Objective To master the situation of iodine deficiency disorders (IDD) and the people's iodine nutritional status after implementation of the new salt iodine standard in Gansu Province in 2012. Methods Totally 30 counties (cities) were selected in Gansu Province by population proportionate to size sampling (PPS) method in 2014, and one primary school was selected in each counties (cities). In each selected school, 50 children aged 8-10 years old were selected for thyroid examination by B-ultrasound, urine samples were collected for iodine determination, and salt samples were collected for iodine determination from a subset of children included in the study. Totally 20 pregnant women were selected from the towns with the sampled schools and urine samples were collected for iodine determination. Arsenic and cerium catalysis spectrophotometry (WS/T 107-2006) was used to detect urinary iodine content; direct titration (GB/T 13025.7-2012) was used to detect edible salt iodine content. Urinary iodine of children and pregnant women were compared with 2011 (before implementation of the new salt iodine standard). Results The median of salt iodine was 26.6 mg/kg, the iodized salt coverage rate was 99.5% (1 492/1 500), the qualified rate of iodized salt was 89.3% (1 333/1 492), and the consumption rate of qualified iodized salt was 88.9% (1 333/1 500). The thyroid goiter rate of children was 3.2% (48/1 500); a total of 1 499 urine samples of children were detected, the urinary iodine median was 169.8 μg/L, it was significantly lower than that in 2011 (216.0 μg/L, Z=-6.813, P < 0.05). A total of 600 urine samples of pregnant women were detected, the urinary iodine median was 161.8 μg/L, it was significantly lower than that in 2011 (168.6 μg/L, Z=-3.590, P < 0.05). Conclusion IDD has been controlled after implementation of the new standard of iodized salt and iodine nutrition condition is good. Key words: Iodine; Deficiency diseases; Goiter, endemic; Urine; Salts