title: Iodine Supplementation Decreases Hypercholesterolemia in Iodine-Deficient, Overweight Women: A Randomized Controlled Trial.
abstract: BACKGROUND
  In iodine deficiency, thyrotropin (TSH) may increase to stimulate thyroidal iodine uptake. In iodine-sufficient populations, higher TSH predicts higher total cholesterol. Whether higher TSH caused by iodine deficiency affects serum lipids is uncertain.
  
  
  OBJECTIVE
  Our aim was to determine if iodine repletion decreases serum TSH and improves the lipid profile.
  
  
  METHODS
  In this randomized controlled intervention, iodine-deficient, overweight or obese Moroccan women (n = 163) received 200 μg oral iodine or a placebo daily for 6 mo. Main outcomes were serum TSH and plasma total and LDL cholesterol. Secondary outcomes included thyroid hormones and measures of lipid and glucose metabolism and urinary iodine concentration (UIC). Data were compared by using mixed-model analysis.
  
  
  RESULTS
  In the intervention group, median UIC increased from 38 (95% CI: 34, 45) μg/L to 77 (95% CI: 59, 89) μg/L (P < 0.001). After 6 mo of intervention, TSH was 33% lower in the treatment group than in the placebo group (P = 0.024). The triiodothyronine (T3) to thyroxine (T4) ratio and thyroglobulin decreased with treatment [-15% (P = 0.002) and -32% (P < 0.001), respectively], whereas T4 concentrations were higher in the treatment group (P < 0.001). Total cholesterol in subjects with elevated baseline cholesterol (>5 mmol/L) was reduced by 11% after the intervention (P = 0.034). At 6 mo, only 21.5% of treated women remained hypercholesterolemic (total cholesterol >5 mmol/L) vs. 34.8% of controls (baseline: 44.2% in the intervention and 36.8% in the control group; P = 0.015). The reduction in the prevalence of elevated LDL cholesterol (>3 mmol/L) in the intervention group (50.6% to 35.4% compared with 47.4% to 44.9% in the control group) was not significant (P-interaction = 0.23).
  
  
  CONCLUSIONS
  Our findings suggest that moderate to severe iodine deficiency in overweight women elevates serum TSH and produces a more atherogenic lipid profile and that iodine supplementation in this group reduces the prevalence of hypercholesterolemia. Thus, iodine prophylaxis may reduce cardiovascular disease risk in overweight adults. This trial was registered at clinicaltrials.gov as NCT01985204.
authors.affiliation: Human Nutrition Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland; isabelle.herter@hest.ethz.ch.
authors.forename: Isabelle
authors.identifier: http://orcid.org/0000-0003-0134-6217
authors.initials: I
authors.lastname: Herter-Aeberli
authors.affiliation: Laboratory of Human Ecology, Faculty of Sciences Semlalia, and.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Cherkaoui
authors.affiliation: Medical and Pharmaceutical Faculty, University Cady Ayyad, Marrakesh, Morocco; Mohammed VI University Hospital, Marrakesh, Morocco;
authors.forename: Nawal
authors.initials: N
authors.lastname: El Ansari
authors.affiliation: Human Nutrition Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland;
authors.forename: Riccarda
authors.initials: R
authors.lastname: Rohner
authors.affiliation: Human Nutrition Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland;
authors.forename: Sara
authors.initials: S
authors.lastname: Stinca
authors.affiliation: Mohammed VI University Hospital, Marrakesh, Morocco;
authors.forename: Laila
authors.initials: L
authors.lastname: Chabaa
authors.affiliation: Institute for Clinical Chemistry, University Hospital Zurich, Zurich, Switzerland; and.
authors.forename: Arnold
authors.initials: A
authors.lastname: von Eckardstein
authors.affiliation: Medical and Pharmaceutical Faculty, University Cady Ayyad, Marrakesh, Morocco; Mohammed VI University Hospital, Marrakesh, Morocco;
authors.forename: Abdelmounaim
authors.initials: A
authors.lastname: Aboussad
authors.affiliation: Human Nutrition Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland; Iodine Global Network, Zurich, Switzerland.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Zimmermann
mesh_terms: D000284:Administration, Oral; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000150:complications / Q000188:drug therapy*; D007037:Hypothyroidism / Q000188:drug therapy; D007328:Insulin / Q000097:blood; D007455:Iodine / Q000008:administration & dosage* / Q000097:blood / Q000172:deficiency*; D016015:Logistic Models; D008875:Middle Aged; D009018:Morocco; D009765:Obesity / Q000097:blood / Q000150:complications; D050177:Overweight / Q000097:blood* / Q000150:complications; D013954:Thyroglobulin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D016896:Treatment Outcome; D014284:Triiodothyronine / Q000097:blood; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D007328:Insulin; D014284:Triiodothyronine; D013954:Thyroglobulin; D007455:Iodine; D013974:Thyroxine
keywords: Morocco; cardiovascular disease; cholesterol; double burden; iodine deficiency; lipid profile; obesity; subclinical hypothyroidism