Mothers' behaviour contributes to suboptimal iodine status of family members: findings from an iodine-sufficient area.

OBJECTIVE

Iodine deficiency still remains a major public health concern worldwide despite global progress in its elimination. The aims of the present study were to evaluate dietary iodine status in the mother and one adult member of each family and the association between mothers' knowledge, attitude and behaviour and the dietary iodine status of adult family members in Tehran.

DESIGN

In this cross-sectional study, 24 h urinary iodine and Na concentrations and the iodine content of household salt were measured. Mothers' knowledge, attitude and behaviour were assessed using a questionnaire administered in face-to-face interviews.

SETTING

Health-care centres from four distinct areas of Tehran.

SUBJECTS

Mother-adult family member pairs aged ≥ 19 years (n 290), enrolled through randomized cluster sampling.

RESULTS

In mothers and adult family members, median 24 h urinary iodine concentration was 73 (interquartile range (IQR) 36-141) µg/l and 70 (IQR 34-131) µg/l, dietary iodine intake was 143 (IQR 28-249) µg/d and 130 (IQR 26-250) µg/d and dietary salt intake was 8.0 (IQR 5.9-10.2) g/d and 7.5 (IQR 5.3-10.0) g/d, respectively. Significant correlations were observed between mothers' attitude and behaviour and the 24 h urinary iodine concentration, dietary iodine intake and iodine content of salt of adult family members. In multiple analysis, lower quartiles of salt iodine content and salt intake and inappropriate behaviour scores in mothers increased the risk of urinary iodine concentration <100 µg/l in adult family members.

CONCLUSIONS

The present study showed that mothers' behaviour, but not knowledge and attitude, was among major contributors to the suboptimal dietary iodine status observed in adult family members.