1. Iodine Supplementation Decreases Hypercholesterolemia in Iodine-Deficient, Overweight Women: A Randomized Controlled Trial
- Author
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Mohamed Cherkaoui, Arnold von Eckardstein, Michael B. Zimmermann, Laila Chabaa, Isabelle Herter-Aeberli, Abdelmounaim Aboussad, Nawal El Ansari, Riccarda Rohner, Sara Stinca, University of Zurich, and Herter-Aeberli, Isabelle
- Subjects
Blood Glucose ,Medicine (miscellaneous) ,Blood lipids ,Administration, Oral ,Overweight ,Body Mass Index ,chemistry.chemical_compound ,Blood serum ,540 Chemistry ,Insulin ,10038 Institute of Clinical Chemistry ,Nutrition and Dietetics ,medicine.diagnostic_test ,Thyroid ,2701 Medicine (miscellaneous) ,Middle Aged ,Morocco ,medicine.anatomical_structure ,Treatment Outcome ,2916 Nutrition and Dietetics ,Triiodothyronine ,Female ,medicine.symptom ,Iodine ,Adult ,medicine.medical_specialty ,Hypercholesterolemia ,chemistry.chemical_element ,610 Medicine & health ,Thyroglobulin ,Young Adult ,Hypothyroidism ,Internal medicine ,medicine ,Humans ,Obesity ,business.industry ,Cholesterol ,Cholesterol, HDL ,Cholesterol, LDL ,medicine.disease ,Iodine deficiency ,Thyroxine ,Endocrinology ,Logistic Models ,chemistry ,Dietary Supplements ,business ,Lipid profile - Abstract
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.Our aim was to determine if iodine repletion decreases serum TSH and improves the lipid profile.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.In the intervention group, median UIC increased from 38 (95% CI: 34, 45) μg/L to 77 (95% CI: 59, 89) μg/L (P0.001). 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% (P0.001), respectively], whereas T4 concentrations were higher in the treatment group (P0.001). 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 cholesterol5 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).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.
- Published
- 2015