[Effect of treatment with levothyroxine in the lipid profile of the patients with subclinical hypothyroidism].
OBJECTIVE
Controversy surrounds the issue of whether levothyroxine treatment improves lipid profile in patients with subclinical hypothyroidism (SHT). The objective was to detect substantial differences -> or = 20% in total cholesterol (TC) and > or = 15 mg/dl in low-density lipoprotein cholesterol (LDL-c)- in the lipid profiles of patients with subclinical hypothyroidism (SHT) after initiating levothyroxine replacement therapy (T4).


METHODS
Observational retrospective cohort study with paired data.


METHODS
Primary care center in Manresa (Barcelona).


METHODS
100 patients with SHT treated with levothyroxine.


METHODS
Demographic and clinical variables from the clinical history, as well as temporal data -SHT diagnosis, beginning of T4 treatment and thyroid-stimulating hormone (TSH) normalization, and the quantity of T4 administered to treat SHT-were gathered. Data for TSH, lipid profile and body mass index were recorded at specific moments (beginning of treatment, after 6-18 months on T4, at the euthyroidism stage, and the last value registered in the previous 12 months).


RESULTS
The mean age was 61+/-15 [95% confidence interval (CI), 46-76] years and 95% of the patients were women. Obesity was found in 40%, high blood pressure in 39%, dyslipidemia in 37%, diabetes mellitus in 10%, smoking in 7%, and cardiovascular disease in 6% of the patients. No significant differences were detected in TC or in LDL-c after treatment with levothyroxine. Nonsignificant reductions were found in TC (-4 mg/dl; p=0.77) and LDL-c (-10 mg/dl; p=0.31) when euthyroidism was achieved, as well as in TC (-10mg/dl; p=0.58) after 5+/-3 years of treatment.


CONCLUSIONS
Levothyroxine treatment in patients with SHT does not lead to substantial reductions in TC or LDL-c, independently of TSH concentrations prior to treatment.
Prats Julià
Montserrat
M
Departamento de Medicina Interna, Hospital de Terrassa, Ctra. Torrebonica s/n, 08227 Terrassa, Barcelona, España. 29665mpj@comb.cat
D000368:Aged; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000453:epidemiology; D002784:Cholesterol / Q000097:blood; D015331:Cohort Studies; D015897:Comorbidity; D050171:Dyslipidemias / Q000453:epidemiology; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000188:drug therapy*; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology; D012189:Retrospective Studies; D012907:Smoking / Q000453:epidemiology; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000627:therapeutic use*; D014280:Triglycerides / Q000097:blood
D008055:Lipids; D014280:Triglycerides; D013972:Thyrotropin; D002784:Cholesterol; D013974:Thyroxine