1. Department of Endocrinology and Nutrition, Hospital Universitari "Germans Trias i Pujol," Badalona, Catalonia, Spain.
2. Endocrinology Unit, Hospital of Mataró, Catalonia, Spain.
3. Biochemical Department, Hospital Universitari "Germans Trias i Pujol" Badalona, Catalonia, Spain.
4. Epidemiology Department, Hospital Universitari "Germans Trias i Pujol" Badalona, Catalonia, Spain.