title: Dried Blood Spot Thyroglobulin as a Biomarker of Iodine Status in Pregnant Women.
abstract: Thyroglobulin (Tg) could be a sensitive biomarker of iodine nutrition in pregnant women (PW). A dried blood spot (DBS) assay would simplify collection and transport in field studies.
  
  
  
  Our aims were to (1) establish and test a reference range for DBS-Tg in PW; (2) determine whether co-measurement of Tg antibodies (Abs) is necessary to define population iodine status.
  
  
  
  Standardized cross-sectional studies of 3870 PW from 11 countries. For the DBS-Tg reference range, we included TgAb-negative PW (n = 599) from 3 countries with sufficient iodine intake.
  
  
  
  We measured the urinary iodine concentration and DBS thyroid-stimulating hormone, total thyroxin, Tg, and TgAb.
  
  
  
  In the reference population, the median DBS-Tg was 9.2 μg/L (95% confidence interval, 8.7 to 9.8 μg/L) and was not significantly different among trimesters. The reference range was 0.3 to 43.5 μg/L. Over a range of iodine intake, the Tg concentrations were U-shaped. Within countries, the median DBS-Tg and the presence of elevated DBS-Tg did not differ significantly between all PW and PW who were TgAb-negative.
  
  
  
  A median DBS-Tg of ∼10 μg/L with <3% of values ≥44 μg/L indicated population iodine sufficiency. Concurrent measurement of TgAb did not appear necessary to assess the population iodine status.
authors.affiliation: Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland.
authors.forename: Sara
authors.initials: S
authors.lastname: Stinca
authors.affiliation: Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland.
authors.forename: Maria
authors.initials: M
authors.lastname: Andersson
authors.affiliation: Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland.
authors.forename: Sandra
authors.initials: S
authors.lastname: Weibel
authors.affiliation: Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Herter-Aeberli
authors.affiliation: Swiss Newborn Screening Laboratory, Children's Research Center (CRC), University Children's Hospital of Zurich, Zurich 8032, Switzerland.
authors.forename: Ralph
authors.initials: R
authors.lastname: Fingerhut
authors.affiliation: Institute of Nutrition, Mahidol University, Nakhon Pathom 73170, Thailand.
authors.forename: Sueppong
authors.initials: S
authors.lastname: Gowachirapant
authors.affiliation: Department of Nutrition, University of California, Davis, Davis, California 95616.
authors.forename: Sonja Y
authors.initials: SY
authors.lastname: Hess
authors.affiliation: St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore 560034, India.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Jaiswal
authors.affiliation: Department of Oncology and Nuclear Medicine, University of Zagreb School of Medicine, Sisters of Charity University Hospital Centre, Zagreb 10,000, Croatia.
authors.forename: Tomislav
authors.initials: T
authors.lastname: Jukic
authors.affiliation: Department of Oncology and Nuclear Medicine, University of Zagreb School of Medicine, Sisters of Charity University Hospital Centre, Zagreb 10,000, Croatia.
authors.forename: Zvonko
authors.initials: Z
authors.lastname: Kusic
authors.affiliation: Department of Nutrition, University of Venda, Thohoyandou 0950, South Africa.
authors.forename: Ngoako Solomon
authors.initials: NS
authors.lastname: Mabapa
authors.affiliation: Department of Biochemistry, B.P. Koirala Institute of Health Sciences, Ghopa, Dharan 56700, Nepal.
authors.forename: Ashwini Kumar
authors.initials: AK
authors.lastname: Nepal
authors.affiliation: Iodine Global Network (IGN), Manila 1102, Philippines; and.
authors.forename: Teofilo O L
authors.initials: TO
authors.lastname: San Luis
authors.affiliation: Shanxi Institute for Endemic Disease Prevention and Treatment, LinFen 041000, China.
authors.forename: Jia Qing
authors.initials: JQ
authors.lastname: Zhen
authors.affiliation: Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland.
authors.forename: Michael Bruce
authors.initials: MB
authors.lastname: Zimmermann
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood; D015415:Biomarkers / Q000097:blood*; D003430:Cross-Sectional Studies; D059788:Dried Blood Spot Testing / Q000379:methods* / Q000592:standards*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007455:Iodine / Q000097:blood / Q000172:deficiency*; D011247:Pregnancy; D011264:Pregnancy Trimesters / Q000097:blood*; D011379:Prognosis; D012016:Reference Values; D013954:Thyroglobulin / Q000097:blood*; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D013954:Thyroglobulin; D007455:Iodine