Incidence of congenital hypothyroidism in the Autonomous Province of Bolzano: benefit of increased iodine intake

PURPOSE: Although a nation-wide salt iodization program on voluntary basis was implemented in 2005, many areas in our country are still characterized by mild iodine deficiency. Differently from the rest of Italy, an efficient program of iodine prophylaxis was implemented in 1981 in the Autonomous Province of Bolzano. The aim of this study was to investigate whether an adequate iodine intake in the population may affect the incidence of permanent congenital hypothyroidism (CH). METHODS: The incidence trends of permanent CH between 1987 and 2006 in Bolzano Province and in the rest of Italy were estimated. RESULTS: Over the years, the CH incidence has remained steadily lower in Bolzano than in the rest of the country. CONCLUSIONS: Primary prevention of permanent CH may be possible by assuring an adequate nutritional iodine intake in the population. However, the time needed to observe a decrease in the incidence of CH is about a decade under conditions of iodine sufficiency.