Abstract
According to current recommendations, a TSH value of <2.5 mIU/l should be maintained
during preconception and pregnancy. The same recommendation, however, does not relate
to all women of childbearing age. The aim of the study was to evaluate relationship
between lipid peroxidation (LPO; index of oxidative damage to membrane lipids) and
thyroid tests and other parameters, which may be affected by thyroid dysfunction,
in euthyroid women of childbearing age. Ninety nine female inpatients with normal
thyroid tests (TSH 0.27–4.2 mIU/l), aged 18–48 years, were prospectively enrolled.
Blood concentrations of malondialdehyde+4-hydroxyalkenals (LPO index) were measured
spectrophotometrically. Thyroid tests (TSH, FT4, FT3), thyroid antibodies and other
laboratory parameters [cholesterol, HDL cholesterol (HDLC), LDL cholesterol, HDLC/cholesterol
ratio, triglycerides, glucose, CRP, iron] were measured with standard methods. Blood
LPO level was higher in women with TSH≥2.5 mIU/l than in women with TSH<2.5 mIU/l.
Positive correlation was found between TSH concentration and LPO level (r=0.210, p=0.037).
In the univariate regression analysis, blood LPO level did constitute the only independent
factor associated with TSH≥2.5 mIU/l. Abnormal HDLC/cholesterol ratio occurred more
frequently in subjects with TSH≥2.5 mIU/l. Additionally, LPO level correlated positively
with triglyceride concentration (r=0.340, p=0.001), whereas it correlated negatively
with HDLC concentration (r=–0.335, p=0.001) and with HDL/cholesterol ratio (r=–0.331,
p=0.001). In conclusion, in women of childbearing age with normal thyroid tests, TSH≥2.5 mIU/l
is associated with higher oxidative damage to membrane lipids and less favorable lipid
profile, which supports our standpoint that TSH of less than 2.5 mIU/l should be maintained
in all women of childbearing age.
Key words
thyroid tests - euthyroid - reproductive age - lipid peroxidation - oxidative damage
- lipid profile
