Population-Based National Prevalence of Thyroid Dysfunction in Spain and Associated Factors: Di@bet.es Study.
The aim of this study was to investigate the national prevalence of thyroid dysfunction in Spain and its association with various clinical, environmental, and demographic variables.



The study included 4554 subjects (42.4% men) with a mean age of 50 years (range 18-93 years), who were participants in a national, cross-sectional, population-based survey conducted in 2009-2010. Data gathered included clinical and demographic characteristics, physical examination, and blood sampling. Thyrotropin, free thyroxine, free triiodothyronine, and thyroid peroxidase antibody (TPOAb) concentrations were analyzed by electrochemiluminescence. Urinary iodine (UI) levels were measured in an isolated urine sample.



The prevalence of treated hypothyroidism, untreated subclinical hypothyroidism, and untreated clinical hypothyroidism was 4.2% [confidence interval (CI) 3.6-4.9%], 4.6% [CI 4.0-5.2%], and 0.3% [CI 0.1-0.5%], respectively. The prevalence of total hypothyroidism (including all fractions) was 9.1% [CI 8.2-10.0%]. The prevalence of total hyperthyroidism was 0.8% [CI 0.6-1.1]. A total of 7.5% [CI 6.7-8.3%] of the population tested positive for TPOAbs (≥50 IU/mL). In multivariate logistic regression models, TPOAbs were strongly associated with both hypothyroidism (p < 0.001) and hyperthyroidism (p = 0.005), whereas high UI levels (>200 μg/g creatinine) were associated with hypothyroidism (p < 0.001). The positive association between UI and hypothyroidism remained for both treated (p < 0.001) and untreated (p < 0.05) hypothyroidism, whereas it was especially significant for non-autoimmune (TPOAbs negative) forms (p < 0.001). At UI levels ≥200 μg/g, there was a positive correlation between UI and thyrotropin levels (β = 0.152, p < 0.001) and a negative correlation between UI and free triiodothyronine levels (β = -0.134, p = 0.001).



According to the data, a large proportion (10%) of the Spanish population has some evidence of thyroid dysfunction. High TPOAb concentrations were associated with both hypo- and hyperthyroidism, whereas high UI concentrations were associated with hypothyroidism.
1 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III , Madrid, Spain .|2 Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga , Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain .
Sergio
S
Valdés
1 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III , Madrid, Spain .|2 Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga , Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain .
Cristina
C
Maldonado-Araque
1 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III , Madrid, Spain .|2 Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga , Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain .
Ana
A
Lago-Sampedro
3 UGC de Laboratorio (Bioquímica), Hospital Regional Universitario de Málaga , Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain .
J Antonio
JA
Lillo
2 Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga , Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain .|4 CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III , Madrid, Spain .
Eduardo
E
Garcia-Fuentes
3 UGC de Laboratorio (Bioquímica), Hospital Regional Universitario de Málaga , Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain .
Vidal
V
Perez-Valero
1 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III , Madrid, Spain .|2 Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga , Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain .
Carolina
C
Gutierrez-Repiso
3 UGC de Laboratorio (Bioquímica), Hospital Regional Universitario de Málaga , Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain .
Pilar
P
Ocon-Sanchez
5 Department of Endocrinology and Nutrition, Hospital del Mar , Barcelona, Spain .
Albert
A
Goday
1 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III , Madrid, Spain .|6 Research Unit, Hospital Universitario Cruces-UPV-EHU , Baracaldo, Spain .
Ines
I
Urrutia
2 Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga , Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain .
Laura
L
Peláez
7 Department of Endocrinology and Nutrition, Hospital Universitario S. Carlos de Madrid , Madrid, Spain .
Alfonso
A
Calle-Pascual
8 Laboratorio de Bioquímica, Hospital Universitario S. Carlos de Madrid , Madrid, Spain .
Elena
E
Bordiú
1 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III , Madrid, Spain .|6 Research Unit, Hospital Universitario Cruces-UPV-EHU , Baracaldo, Spain .
Luis
L
Castaño
9 Public Health Agency, Department of Health, Autonomous Government of Catalonia , Barcelona, Spain .
Conxa
C
Castell
10 Department of Endocrinology and Nutrition, Hospital Central de Asturias , Oviedo, Spain .
Elias
E
Delgado
10 Department of Endocrinology and Nutrition, Hospital Central de Asturias , Oviedo, Spain .
Edelmiro
E
Menendez
1 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III , Madrid, Spain .|11 EAP Raval Sud, Institut Català de la Salut, Red GEDAPS, Primary Care, Unitat de Suport a la Recerca (IDIAP-Fundació Jordi Gol) , Barcelona, Spain .
Josep
J
Franch
1 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III , Madrid, Spain .|12 Department of Endocrinology and Nutrition, Hospital Universitario Cruces-UPV-EHU , Baracaldo, Spain .
Sonia
S
Gaztambide
13 Diabetes Unit, Hospital Arnau de Vilanova , Valencia, Spain .
Joan
J
Girbés
4 CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III , Madrid, Spain .|14 Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS); Hospital Clínic de Barcelona , Barcelona, Spain .
Emilio
E
Ortega
15 Department of Endocrinology and Nutrition, Fundación Hospital de Jove , Gijón, Spain .
Alfonso
A
Lopez-Alba
1 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III , Madrid, Spain .|16 Genotyping and Genetic Diagnosis Unit, Fundación de Investigación del Hospital Clínico de Valencia-INCLIVA , Valencia, Spain .
Felipe J
FJ
Chaves
1 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III , Madrid, Spain .|17 Department of Endocrinology and Nutrition, Hospital Universitario Joan XXIII , Institut d'Investigacions Sanitaries Pere Virgili, Tarragona, Spain .
Joan
J
Vendrell
1 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III , Madrid, Spain .|17 Department of Endocrinology and Nutrition, Hospital Universitario Joan XXIII , Institut d'Investigacions Sanitaries Pere Virgili, Tarragona, Spain .
Matilde R
MR
Chacón
1 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III , Madrid, Spain .|2 Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga , Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain .
Federico
F
Soriguer
1 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III , Madrid, Spain .|2 Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga , Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain .
Gemma
G
Rojo-Martínez
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000276:immunology; D001324:Autoantigens / Q000276:immunology; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000453:epidemiology* / Q000276:immunology / Q000378:metabolism; D007037:Hypothyroidism / Q000453:epidemiology* / Q000276:immunology / Q000378:metabolism; D007453:Iodide Peroxidase / Q000276:immunology; D007455:Iodine / Q000652:urine; D033862:Iron-Binding Proteins / Q000276:immunology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015995:Prevalence; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D055815:Young Adult
D001323:Autoantibodies; D001324:Autoantigens; D033862:Iron-Binding Proteins; D014284:Triiodothyronine; D013972:Thyrotropin; D007455:Iodine; C056658:TPO protein, human; D007453:Iodide Peroxidase; D013974:Thyroxine
Spain; epidemiology; hypothyroidism; iodine; thyroid dysfunction