First national iodine survey in Madagascar demonstrates iodine deficiency

Abstract

Universal salt iodization (USI) was adopted in Madagascar in 1995 within the framework of a worldwide policy to eliminate iodine deficiency disorders. Despite early USI adoption, there are no representative data on the iodine status of the Malagasy population. The aims of this study were to determine the iodine status of the Malagasy population and to assess the use of adequately iodized salt among households. We randomly sampled women of reproductive age (WRA) using a national, two-stage, stratified cross-sectional survey in 2014. Casual urine from WRA and salt samples from the household containing WRA were collected to measure urinary iodine concentration (UIC) and to assess household salt iodine content. Data from 1,721 WRA in 1,128 households were collected and analysed. The national median UIC was 46μgL-1 (interquartile range [IQR]: 13-98μgL-1 ), indicating a moderate iodine deficiency. The median UIC was 53μgL-1 (IQR: 9-89μgL-1 ) in pregnant women and 46μgL-1 (IQR: 13-98μgL-1 ) in non-pregnant women. The national median iodine concentration of household salt was 10mgkg-1 (IQR: 6.3-15.8mgkg-1 ) and 26.2% (95% CI [22.1, 31.0]) of households containing WRA used adequately iodized salt (≥15mgkg-1 ). Women living in households with adequately iodized salt had higher median UIC (72 vs. 50μgL-1 ). Iodine status was significantly lower among women from low socio-economic households. Madagascar's USI program needs to be revitalized. Implementing strategies to provide adequately iodized salt and enhancing iodized salt legislation to prevent severe complications resulting from iodine deficiency in the Malagasy population are essential.