Evaluation of Carotid Intima-Media Thickness in Sub-clinical Hypothyroid Patients
Keywords:Subclinical hypothyroidism, intima-media thickness, atherosclerosis
Objective: Endothelial dysfunction and atherosclerosis may be associated with subclinical hypothyroidism (SCH) in multiple ways. The intima-media thickness of the common carotid artery (CIMT) is an important parameter for early atherosclerotic change. Previously several studies addressed the association between SCH and CIMT. Some studies indicate that SCH might be related to increase CIMT, while other studies revealed no significant association. The aim of the study was to further examine the relationship between CIMT and SCH patients in our own laboratory setting in Bangladesh.
Patients and Methods: This cross sectional study was carried out at the Institute of Nuclear Medicine and Allied Sciences (INMAS), Dhaka Medical College Hospital Campus, Dhaka during the period of January 2016 to October 2016. The study included 56 consecutive patients. Out of 56 patients, 26 were in SCH group and 30 were in euthyroid control group. CIMT was measured in each subject via High resolution B-mode ultrasonography. Data were analyzed between these two groups in respect to age, sex, BMI, and mean CIMT.
Results: Out of 56 subjects, 26 were SCH group and 30 were euthyroid control group. Male to female ratio was 3:23 and 9:21 in SCH and control groups respectively. The mean age was 30±7.4 and 32±8.7 years in SCH and control groups respectively. The mean BMI was 25.6±4.7 kg/m2 in SCH and 25.1±4.1 kg/m2 in control group. The mean CIMT was significantly (p≤0.05) higher in SCH group (Right-0.80±0.05 mm, Left-0.80±0.07 mm) than control group (Right-0.60±0.05 mm, Left- 0.61±0.05 mm). SCH group was further subdivided into two groups with a cut off value of serum TSH at 10 mIU/L. The mean CIMT was significantly higher in SCH with TSH above 10 mIU/L than SCH group with TSH less than 10 mIU/L (p≤0.05). Pearson’s rank correlation test showed significant positive correlation between both CIMT and TSH values.
Conclusion: Our study showed that CIMT was significantly higher in SCH group than euthyroid control group. The CIMT values were positively correlated with the TSH values. Therefore we may conclude that SCH is an independent risk factor for atherosclerosis in addition to other classical risk factors.
Bangladesh J. Nuclear Med. 19(2): 123-127, July 2016