title: Changes in metabolic and cardiovascular risk factors before and after treatment in overt hypothyroidism.
abstract: OBJECTIVE
  Overt hypothyroidism is associated with an increased risk for developing cardiovascular disease. We aimed to assess the changes in renal function, serum lipids, vitamin B12, folic acid and homocysteine levels before and after treatment in hypothyroid patients.
  
  
  METHODS
  The study included 54 patients (F/M=47/7) with overt hypothyroidism. All patients were assessed for demographic characteristics such as age, gender, body weight, and body mass index. Fasting blood samples were taken from the patients for analysis of chemical parameters including thyroid stimulating hormone (TSH), free thyroxine (fT4), homocysteine, total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), folic acid, and vitamin B12 levels before and after L-thyroxine (LT4) treatment.
  
  
  RESULTS
  Homocysteine levels in hypothyroidism (9.67 ± 5.24 mmol/l) were significantly higher than in euthyroid state (8.16 ± 3.38 mmol/L, p=0.038). Glomerular filtration rate (GFR) was lower before treatment. Following LT4 replacement, renal functions significantly improved. After achieving the euthyroid state, folic acid levels significantly increased although vitamin B12 levels were not changed. There was a significant reduction in serum lipid levels after LT4 replacement. It was demonstrated that there was a significant negative correlation between GFR and lipids and a positive correlation with homocysteine and lipids at hypothyroid state. After normalization of thyroid functions, the correlations became non-significant.
  
  
  CONCLUSIONS
  The hypothyroidism was associated with increased serum homocysteine, lipids, and creatinine concentrations. The improvement of these parameters with LT4 replacement may be associated with the lower risk for atherosclerotic cardiovascular diseases in the patients with hypothyroidism.
authors.affiliation: Department of Endocrinology and Metabolism, 2Department of Internal Medicine, 3Department of Nephrology; Gaziosmanpasa University, School of Medicine, Tokat, Turkey.
authors.forename: Faruk
authors.initials: F
authors.lastname: Kutluturk
authors.forename: Suleyman
authors.initials: S
authors.lastname: Yuce
authors.forename: Turker
authors.initials: T
authors.lastname: Tasliyurt
authors.forename: Berna Murat
authors.initials: BM
authors.lastname: Yelken
authors.forename: Pelin
authors.initials: P
authors.lastname: Aytan
authors.forename: Banu
authors.initials: B
authors.lastname: Ozturk
authors.forename: Abdulkerim
authors.initials: A
authors.lastname: Yılmaz
mesh_terms: D002318:Cardiovascular Diseases; D006801:Humans; D007037:Hypothyroidism; D012307:Risk Factors; D013972:Thyrotropin; D013974:Thyroxine
chemical_list: D013972:Thyrotropin; D013974:Thyroxine