PMID- 30316182
OWN - NLM
STAT- MEDLINE
DCOM- 20190404
LR  - 20190404
IS  - 1873-6750 (Electronic)
IS  - 0160-4120 (Linking)
VI  - 121
IP  - Pt 1
DP  - 2018 Dec
TI  - Fluoride exposure and thyroid function among adults living in Canada: Effect 
      modification by iodine status.
PG  - 667-674
LID - S0160-4120(18)30833-X [pii]
LID - 10.1016/j.envint.2018.09.026 [doi]
AB  - BACKGROUND: Fluoride exposure has the potential to disrupt thyroid functioning, 
      though adequate iodine intake may mitigate this effect. This is the first 
      population-based study to examine the impact of chronic low-level fluoride 
      exposure on thyroid function, while considering iodine status. The objective of 
      this study was to determine whether urinary iodine status modifies the effect of 
      fluoride exposure on thyroid stimulating hormone (TSH) levels. METHODS: This 
      cross-sectional study utilized weighted population-based data from Cycle 3 
      (2012-2013) of the Canadian Health Measures Survey (CHMS). Information was 
      collected via a home interview and a visit to a mobile examination centre. The 
      weighted sample represented 6,914,124 adults in Canada aged 18-79 who were not 
      taking any thyroid-related medication. Urinary fluoride concentrations were 
      measured in spot samples using an ion selective electrode and adjusted for 
      specific gravity (UF(SG)). Serum TSH levels provided a measure of thyroid 
      function. Multivariable regression analyses examined the relationship between 
      UF(SG) and TSH, controlling for covariates. RESULTS: Approximately 17.8% of 
      participants fell in the moderately-to-severely iodine deficient range. The mean 
      (SD) age of the sample was 46.5 (15.6) years and the median UF(SG) concentration 
      was 0.74 mg/L. Among iodine deficient adults, a 1 mg/L increase in UF(SG) was 
      associated with a 0.35 mIU/L increase in TSH [95% CI: 0.06, 0.64; p = 0.01, 
      one-tailed]. CONCLUSIONS: Adults living in Canada who have moderate-to-severe 
      iodine deficiencies and higher levels of urinary fluoride may be at an increased 
      risk for underactive thyroid gland activity.
CI  - Copyright (c) 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.
FAU - Malin, Ashley J
AU  - Malin AJ
AD  - Department of Environmental Medicine and Public Health, Icahn School of Medicine 
      at Mount Sinai, One Gustave L. Levy Place, Box 1057, New York 10029, NY, USA; 
      Psychology Department, Faculty of Health, York University, 4700 Keele St, Toronto 
      M3J 1P3, ON, Canada. Electronic address: Ashley.malin@mssm.edu.
FAU - Riddell, Julia
AU  - Riddell J
AD  - Psychology Department, Faculty of Health, York University, 4700 Keele St, Toronto 
      M3J 1P3, ON, Canada. Electronic address: jriddell@yorku.ca.
FAU - McCague, Hugh
AU  - McCague H
AD  - Institute for Social Research, York University, 242A-4700 Keele St, Toronto, ON, 
      Canada, M3J 1P3. Electronic address: hmccague@yorku.ca.
FAU - Till, Christine
AU  - Till C
AD  - Psychology Department, Faculty of Health, York University, 4700 Keele St, Toronto 
      M3J 1P3, ON, Canada. Electronic address: ctill@yorku.ca.
LA  - eng
GR  - CIHR/Canada
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20181010
PL  - Netherlands
TA  - Environ Int
JT  - Environment international
JID - 7807270
RN  - 0 (Drinking Water)
RN  - 9002-71-5 (Thyrotropin)
RN  - 9679TC07X4 (Iodine)
RN  - Q80VPU408O (Fluorides)
SB  - IM
MH  - Adolescent
MH  - Adult
MH  - Aged
MH  - Canada
MH  - Cross-Sectional Studies
MH  - Drinking Water/chemistry
MH  - Female
MH  - Fluorides/*toxicity/urine
MH  - Health Surveys
MH  - Humans
MH  - Hypothyroidism/blood/*chemically induced
MH  - Iodine/deficiency/*urine
MH  - Male
MH  - Middle Aged
MH  - Nutritional Status
MH  - Thyroid Gland/*drug effects/physiopathology
MH  - Thyrotropin/*blood
MH  - Young Adult
OTO - NOTNLM
OT  - Fluoride
OT  - Iodine status
OT  - Thyroid
OT  - Thyroid stimulating hormone
EDAT- 2018/10/14 06:00
MHDA- 2019/04/05 06:00
CRDT- 2018/10/14 06:00
PHST- 2018/04/27 00:00 [received]
PHST- 2018/09/14 00:00 [revised]
PHST- 2018/09/14 00:00 [accepted]
PHST- 2018/10/14 06:00 [pubmed]
PHST- 2019/04/05 06:00 [medline]
PHST- 2018/10/14 06:00 [entrez]
AID - S0160-4120(18)30833-X [pii]
AID - 10.1016/j.envint.2018.09.026 [doi]
PST - ppublish
SO  - Environ Int. 2018 Dec;121(Pt 1):667-674. doi: 10.1016/j.envint.2018.09.026. Epub 
      2018 Oct 10.