Existence of iodine deficiency in Hong Kong--a coastal city in southern China.
OBJECTIVE
Iodine deficiency is a serious public health problem worldwide which is associated with mental retardation and cretinism. In view of a high incidence of transient neonatal hypothyroidism and a relatively high mean cord blood thyrotropin (TSH) concentration, a pilot study was carried out to analyse the urine iodine excretion in Hong Kong, a coastal city in the southern part of China.


METHODS
Early morning urine was collected from healthy volunteers including children (n = 104), adults (n = 112) and elderly subjects (n = 349). A semi-quantitative questionnaire survey on the pattern of food intake was conducted in the adults and elderly.


RESULTS
45.3% of the children, 51.7% of the adults and 55.3% of the elderly had urine iodine concentration below the criteria for iodine sufficiency (< 0.79 mumol/l). Iodine content in the drinking water and salt was low. A dietary survey revealed that seafood was not commonly consumed. 50-80% of the subjects never consumed high-iodine containing food such as seaweed, kelp or laver, and only 50% consumed seawater fish daily.


CONCLUSIONS
We confirmed that although Hong Kong is a non-goitrous area, iodine insufficiency exists. It is unsafe to assume that iodine deficiency does not exist in coastal urban areas.
Kung
A W
AW
Department of Medicine, University of Hong Kong.
Chan
L W
LW
Low
L C
LC
Robinson
J D
JD
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003677:Deficiency Diseases / Q000453:epidemiology*; D004034:Diet Surveys; D006042:Goiter / Q000517:prevention & control*; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D007455:Iodine / Q000172:deficiency* / Q000652:urine; D010865:Pilot Projects; D012965:Sodium Chloride / Q000737:chemistry; D011795:Surveys and Questionnaires; D014867:Water / Q000737:chemistry
D014867:Water; D012965:Sodium Chloride; D007455:Iodine