Objective: To understand the status of iodine nutrition and the affective factors of urinary iodine concentration among residents over age of 15 years in Shenzhen City.
Methods: Totally 8152 residents from 73 communities were selected with stratified cluster random sampling. The morning urinary iodine was determined and the dietary assessment of iodine using a food frequency questionnaire were carried out.
Results: The range of urinary iodine was 9. 65 - 4039.09 μg/L and the median of urinary iodine was 194.59 μg/L among the residents. The percentages of the residents with urinary iodine < 50,50 - 100,100 - 199, 200 - 300, and ≥ 300 μg/L were 2.49%, 12.12%, 40.16%, 26.94% and 20.78%, respectively. There was significant difference in the medians of iodine between different gender (P = 0.0001), the medians of urinary iodine of men (201.32 μg/L) was slightly higher. There was no significant difference in urinary iodine levels (186.59 - 197.44 μg/L) among all age groups, the medians of urinary iodine of all age groups were within the recommended adequate intake. Along with the increase in age, the medians of urinary iodine of all age groups was gradually decreased. Sex, alcohol consumption and daily dietary iodine intake was significant in the final regression model.
Conclusion: The iodine nutrition of residents in Shenzhen City was in good condition, populations with low or high iodine still exist. The monitoring is needed and the influencing factors of the urine iodine levels need much exploration.