Thyrotropin levels and their relationship with cardiovascular risk factors in the island of Gran Canaria, Spain. Implications of lowering the upper reference limit of thyrotropin stimulating hormone.
OBJECTIVE
To characterize the cardiovascular risk profile of subjects with high and normal-high concentrations of serum TSH in a sample of adult Spanish subjects from the island of Gran Canaria.


METHODS
Cross-sectional population-based study.


METHODS
After excluding 28 individuals on current treatment with levothyroxine and 9 others with TSH levels below the range of normality (0.3-4.9 mU/l), 704 randomly selected subjects (412 women; age range: 30-82 yr) belonging to the Telde Study were assessed.


METHODS
Participants underwent physical examination and fasting blood analyses to determinate TSH, serum lipids, homocysteine, fibrinogen, von Willebrand factor, plasminogen activator inhibitor- 1, C-reactive protein, and insulin.


RESULTS
Twenty-nine participants had serum TSH concentrations above the normal range of normality. Among all the studied variables, only female sex and diastolic blood pressure were significantly associated with TSH levels > or =5 mU/l in a multivariate logistic regression analysis. If the upper normal limit of TSH was reduced up to 2.4 mU/l, an additional group of 106 subjects would be considered to have elevated TSH levels. A serum TSH > or =2.5 mU/l was positive and independently associated with female sex, body mass index, total cholesterol, and homocysteine, and negatively associated with smoking.


CONCLUSIONS
Although the impact of serum TSH levels on cardiovascular risk cannot be established from these findings, TSH values within the upper part of the usually accepted normal range were demonstrated to be associated with well-recognized risk factors for cardiovascular disease.
Alberiche
M
M
Section of Endocrinology and Nutrition, Insular University Hospital, 35016 Las Palmas de Gran Canaria, Spain. malberiche@hotmail.com
Boronat
M
M
Saavedra
P
P
Pérez
N
N
Marrero
D
D
López-Plasencia
Y
Y
Varillas
V F
VF
Ríos
M
M
Nóvoa
F J
FJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D002318:Cardiovascular Diseases / Q000209:etiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008055:Lipids / Q000097:blood; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D013030:Spain; D013972:Thyrotropin / Q000097:blood*
D008055:Lipids; D013972:Thyrotropin