A study on urinary iodine levels and influencing factors of urban and rural residents in some areas of Gansu Province / 中华地方病学杂志

ABSTRACT

Objective To analyze the urinary iodine status of urban and rural residents in some areas of Gansu Province and its related influencing factors,and to provide certain references for scientific iodine intake of urban and rural residents in Gansu Province.Methods Subjects in Gansu Province with normal thyroid function were recruited in the investigation of thyroid diseases and iodine nutritional status,conducted a questionnaire survey and measured height,weight,waist circumference,collected 1 urine sample,and tested their urinary iodine levels.The urinary iodine levels of different groups were compared based on different gender,region,age,body weight,the waist,and salt intaking.The affecting factors of urinary iodine levels were analyzed by multiple linear regression models.Results Totally 1 964 subjects were recruited,including 1 099 males,and 865 females.The age was (41.23 ± 14.75) years old.The median urinary iodine of the selected group was 225.60 (158.80,311.58) μg/L.The urinary iodine level of rural residents was significantly higher than that of urban residents [μg/L249.80 (180.58,336.88)vs 206.25 (148.03,280.33),Z=-8.015,P ＜ 0.05],and there was no significant difference between the urinary iodine levels of male and female [μg/L222.40 (161.60,298.90) vs 230.60 (158.00,326.40),P ＞ 0.05].The composition ratio of ＜ 100 μg/L group in rural areas was lower than that in urban areas (5.14％ vs 8.27％,x2 =7.45,P ＜0.05),and the composition ratio of ≥300 μg/L group was higher than that in urban areas (34.93％ vs 21.51％,x2 =43.87,P ＜ 0.05).The composition ratio of ≥300 μg/L group in male was lower than that in female (24.57％ vs 31.21％,x2 =10.73,P ＜ 0.05).The multiple linear regression analysis showed that lived in rural areas,age,moderate and severe salt intaking,student,and weight were independently correlated with urinary iodine levels (β =0.074,-0.001,0.059,0.034,0.096,-0.003,P ＜ 0.05).And the urinary iodine levels were decreased with age and weight increased (P ＜ 0.05).Conclusions At present,the iodine nutrition level of urban and rural residents in some areas of Gansu Province is generally over the adequate level.The urinary iodine level of rural residents is higher than that of urban residents.In the future,we should pay attention to the impact of different living areas,salt intaking and body weight on urinary iodine levels to prevent thyroid diseases.