TITLE:
The Relationship between Thyroid Hormone Levels and Corrected QT Interval and QT Dispersion in Non-Diabetic Hemodialysis Patients
AUTHORS:
Heo-Yeong Kim, Ji Soo Kim, Seung Eun Suh, Yu Kyung Hyun, Kyeong Mi Park, Hyung-Jong Kim
KEYWORDS:
Thyroid Hormone; Hemodialysis; Cardiovascular Disease
JOURNAL NAME:
Open Journal of Nephrology,
Vol.4 No.1,
March
24,
2014
ABSTRACT: Background: Cardiovascular
disease and sudden cardiac death are common in hemodialysis patients. These
cardiac complications are often associated with prolonged QTc interval (QTc)
and QTc dispersion (QTcd). Subclinical hypothyroidism (SH) can alter autonomic
modulation of heart rate and cause increased inhomogeneity of ventricular
recovery time. We aimed to evaluate the relationship between thyroid hormone
levels and QTc and QTcd in non-diabetic hemodialysis patients. Methods: We
enrolled 29 non-diabetic hemodialysis patients without thyroid disease. After
each hemodialysis session, a 12-lead ECG was recorded. Before each hemodialysis
session, routine laboratory tests and measurement of thyroid hormone levels
were performed. Patients were divided into 2 groups according to QTc (group
1 QTc ms, group 2 QTc ≥ 430 ms).
We examined the relationship between QTc or QTcd and thyroid hormone in the
respective groups and then compared the results from the 2 groups. Results: The
mean age was 54.06 ± 14.72 years and the means of QTc and QTcd were 433.82 ± 22.03 ms, 59.10 ± 28.29 ms, respectively.
Homocysteine levels were significant higher in group 2 than group 1 (p 0.05)
and QTcd was comparable between groups. In group 1, QTc
and QTcd were not significant correlated with TSH, T3, fT4 and biochemical
parameters. In group 2, QTc was significant positively correlated with TSH (p 0.05)
and QTcd was not significant correlated with thyroid hormone levels. Conclusion:
The results of this study showed that TSH is associated with prolonged QTc
interval and hyperhomocysteinemia in non-diabetic
hemodialysis patients. Moreover, we suggest that SH may be associated with
prolonged QTc in non-diabetic hemodialysis patients. However, further studies
are required to elucidate the role of the L-thyroxine doses and TSH target levels
in hemodialysis patients.