2.2 Study protocol
In addition to determining the association between SCH and carotid
intima-media thickness, we studied the influence of levothyroxine
hormone replacement at short- and long-term follow up on carotid
intima-media thickness, as a secondary endpoint. We also evaluated the
correlation between the carotid intima-media thickness and age, body
mass index (BMI), waist circumference, waist-hip ratio (WHR), systolic
and diastolic arterial pressure (BP), level of anti-thyroid peroxidase
antibodies (anti-TPO), fasting glycemia, and lipid levels.
A blood sample for a biochemical profile, thyroid hormone levels,
anti-TPO, and a lipid profile was obtained in all participants. On
physical examination, a particular emphasis was given to weight, height,
body mass index (BMI), antrophometric measures, and blood pressure.
Carotid assessment by ultrasound included the intima-media thickness of
the right common carotid artery (RCCA) and the left common carotid
artery (LCCA). After the baseline assessment, thyroid hormone
replacement was started in PH and PSH participants. In PSH participants,
a carotid assessment follow-up was carried out 3 and 6 months after the
baseline visit. Complete blood sampling and physical examination, as in
the first visit, were repeated in this group at 3 and 6 months.