Thyroid function, brain bioelectrical activity and heart rate variability in patients with hypertension

Aim. To study the levels of thyroid-stimulating hormone (TSH) and thyroid hormones (TH), frequency and amplitude parameters of alpha wave, parameters of heart rate variability, hemodynamics and their relationship in patients with hypertension (HTN) and healthy individuals.

Material and methods. We studied 75 patients with stage 2 HTN and 70 healthy individuals. All patients underwent an electroencephalography, 24-hour blood pressure monitoring. Weighted average heart rate variability was calculated. We determined blood plasma levels of TSH and TH. Statistical processing, multiple regression and correlation analysis were carried out using the Statistica v. 10.0.1 software package (StatSoft Inc).

Results. In patients with HTN, TSH and TH were lower than in the control group by 50% and 38%, respectively. The а-index was also 40% lower. Patients with HTN were characterized by lower amplitude, frequency and power of а-wave, and weighted average heart rate variability by 35%, 13-35%, and 30%, respectively. Pulse wave velocity in patients with HTN exceeded the control group by 18%, and the systemic dynamic response was 2,2 times higher. The groups differed in the characteristics of the relationship of а-wave between the brain lobes and hemispheres with TSH, TH, heart rate variability and hemodynamics.

Conclusion. The concentration of TSH and TH is interrelated with the frequency and amplitude parameters of alpha wave, heart rate variability and hemodynamic parameters in hypertensive patients.

1. World Health Organization. A global brief on hypertension: 9. Silent killer, global public health crisis: World Health Day 2013. WHO/DCO/WHD/2013.2: 40 p. https://apps.who.int/iris/handle/10665/79059.

2. Razvi S, Jabbar A, Pingitore A, et al. Thyroid Hormones and Cardiovascular Function and Diseases. J Am Coll Cardiol. 2018;71(16):1781-96. doi:10.1016/j.jacc.2018.02.045.

3. Cole SR, Voytek B. Brain Oscillations and the Importance of Waveform Shape. Trends Cogn Sci. 2017;21 (2): 137-49. doi:10.1016/j.tics.2016.12.008.

4. Bazanova O. M. Modern interpretation of EEG alpha activity. Mezhdunarodnyj nevrologicheskij zhurnal. 2011;8(46):96-104. (In Russ.)

5. Montagnese S, Schiff S, Realdi A, et al. Abnormal cerebral electrogenesis is associated with impaired cognitive performance in hypertensive patients. J Human Hypertens. 2013;27:463-4. doi:10.1038/jhh.2013.21.

6. Mullur R, Yan-Yun Liu, Brent GA. Thyroid Hormone Regulation of Metabolism. Physiol Rev. 2014;94(2):355-82. doi:10.1152/physrev.00030.2013.

7. Prezioso G, Giannini C, Chiarelli F. Effect of Thyroid Hormones on Neurons and Neurodevelopment. Horm Res Paediatr. 2018;90:73-81. doi:10.1159/000492129.

8. Dyomin DB. Effects of thyroid hormones in the development of the nervous system (review). Zhurnal medico-biologicheskich issledovanij. 2018;6(2): 115-27 (In Russ.) doi:10.17238/issn2542-1298.2018.6.2.115.

9. Langen VL, Niiranen TJ, Puukka P, et al. Association between thyroid­stimulating hormone and blood pressure in adults: an 11­year longitudinal study. Clin. Endocrinol (Oxford). 2016;84(5):741­47. doi:10.1111/cen.12876.

10. Williams B, Mancia G, Spiering W, et al. 2018 ESC/ESH Guidelines for the management of arterial hypertension. Eur Heart J. 2018;39(33):3021-104. doi:10.1093/eurheartj/ehy339.

11. Bazanova OM, Vernon D. Interpreting EEG alpha activity. Neurosci Biobehav Rev. 2014;44:94-110. doi:10.1016/j.neubiorev.2013.05.007.

12. Jennings JR, Christie IC, Muldoon MF, et al. Brain function, cognition, and the blood pressure response to pharmacological treatment. Psychosom Med. 2010;72(7):702-11. doi: 10.1097/PSY.0b013e3181e7c1a2.

13. Mahashabde M, Munjal D, Dugad A. Study of Electroencephalogram changes in Hypothyroidism. Appl Physiol Anat Digest. 2016;(1)02:20-7. http://apad.co.in/upload_pdf/APAD_,_september_2016_,_20-271.pdf

14. Gordan R, Gwathmey JK, Xie LH. Autonomic and endocrine control of cardiovascular function. World J Cardiol. 2015;7(4):204-14. doi:10.4330/wjc.v7.i4.204.

15. Baevskiy RM, Chernikova AG. To the problem of physiological norm: mathematical model of functional states because of the analysis of heart rate variability. Aviakosmicheskaya i ekologicheskaya meditsina. 2002;36(6):11-7 (In Russ.)