Subclinical thyroid dysfunction and blood pressure: a community-based study.
OBJECTIVE
Overt hypothyroidism and hyperthyroidism are associated with hypertension, but it is uncertain whether the same is true of subclinical hypothyroidism and hyperthyroidism.


METHODS
Cross-sectional study of 2033 participants (aged 17-89 years) in the Busselton Thyroid Study who did not have a history of thyroid disease. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and the prevalence of hypertension (defined as SBP >or=140 mmHg, DBP >or=90 mmHg or on treatment for hypertension) in subjects with thyroid dysfunction and euthyroid subjects were compared using linear regression models. Subjects with treated hypertension (N = 299) were excluded from analyses of SBP and DBP but included in analyses of hypertension prevalence.


RESULTS
Mean SBP, DBP and the prevalence of hypertension did not differ significantly between subjects with subclinical hypothyroidism (N = 105) and euthyroid subjects (N = 1859), nor did they differ between subjects with serum TSH concentrations in the upper reference range (2.0-4.0 mU/l; N = 418) and those with TSH concentrations in the lower reference range (0.4-2.0 mU/l; N = 1441). The prevalence of hypertension was higher in subjects with subclinical hyperthyroidism than euthyroid subjects (prevalence odds ratio 2.8, 95% confidence interval 1.3-6.0 adjusted for age, age(2) and sex), but this was based on a small number of subjects with subclinical hyperthyroidism (N = 35).


CONCLUSIONS
Subclinical hypothyroidism is not associated with hypertension. The observed association between subclinical hyperthyroidism and hypertension requires confirmation in a larger sample.
Walsh
John P
JP
Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia. john.walsh@health.wa.gov.au
Bremner
Alexandra P
AP
Bulsara
Max K
MK
O'Leary
Peter
P
Leedman
Peter J
PJ
Feddema
Peter
P
Michelangeli
Valdo
V
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003971:Diastole; D005260:Female; D006306:Health Surveys; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000150:complications*; D006980:Hyperthyroidism / Q000097:blood / Q000150:complications; D007037:Hypothyroidism / Q000097:blood / Q000150:complications; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012306:Risk; D013599:Systole; D013959:Thyroid Diseases / Q000097:blood / Q000150:complications*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014904:Western Australia
D013972:Thyrotropin; D013974:Thyroxine