CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 2, March/April 2022 AFRICA 65 Interleukin-6 and its correlations with maternal characteristics and echocardiographic parameters in pre-eclampsia, gestational hypertension and normotensive pregnancy Dolina Gencheva, Fedya Nikolov, Ekaterina Uchikova, Rosen Mihaylov, Blagovesta Pencheva, Maria Vasileva Abstract Background: Pre-eclampsia and gestational hypertension are pregnancy-related disorders with major maternal cardiovascular implications later in life. Objectives: The aim of this study was to determine interleukin-6 levels in women with pre-eclampsia and gestational hypertension and in healthy pregnant controls, and to examine their correlations with characteristics of the women and echocardiographic findings. Methods: The ELISA method was used to determine serum interleukin-6 in 36 women with gestational hypertension, 37 women with pre-eclampsia and 50 pregnant controls. The echocardiographic examination was performed according to current recommendations by the European Association of Cardiovascular Imaging and the American Society of Echocardiography. Results: Mean serum interleukin-6 levels were 2.77 pg/ml in the controls, 5.08 pg/ml in the gestational hypertension group and 8.06 pg/ml in the pre-eclampsia group. A significant difference in these levels was present between the controls and both hypertensive groups, but not between the two hypertensive groups. Higher levels correlated with heart chamber enlargement and worse ventricular function. Conclusion: Interleukin-6 levels in gestational hypertension and pre-eclampsia were significantly elevated compared to those in healthy pregnancy. Higher levels also corresponded to echocardiographical changes. Keywords: pregnancy, interleukin-6, pre-eclampsia, gestational hypertension, echocardiography, inflammation Submitted 6/9/20, accepted 26/8/21 Published online 20/9/21 Cardiovasc J Afr 2022; 33: 65–73 www.cvja.co.za DOI: 10.5830/CVJA-2021-040 Hypertensive disorders of pregnancy (HDP) complicate approximately 5–10% of human pregnancies,1 and are one of the leading causes of maternal mortality in the modern world.2 There is also increasing evidence of elevated cardiovascular risk after pregnancy-induced hypertension – women have a long-term risk of developing arterial hypertension, coronary atherosclerosis, ischaemic heart disease, stroke, type 2 diabetes mellitus, venous thromboembolism and heart failure.3-6 It is hypothesised that the hypertensive disorders of pregnancy, in addition to common risk factors, share some similar mechanisms with heart disease, such as endothelial dysfunction, inflammation, oxidative stress and thrombophilia.7-9 The inflammatory component of pre-eclampsia is characterised by elevated cytokine levels and activated leucocytes as well as stimulation of the angiotensin II type 1 receptor, leading to vasoconstriction. Tumour necrosis factor (TNF)-alpha, interleukin-6 and interleukin-8 are elevated, while antiinflammatory factors such as interleukin-10 are decreased.10-12 Interleukin-6 is a pro-inflammatory cytokine with an established role in the inflammatory response, hypertension and atherosclerosis.13 It has been proven in a rat model that interleukin-6 is involved in elevation of blood pressure in pregnancy due to the reduction of uterine perfusion pressure and it mediates worsening of renal function.14 In another study it was found that it impaired endothelium-dependent relaxation and enhanced constriction of systemic vessels in pregnant rats. This, in turn, suggested its direct role in the vascular resistance in hypertension-complicated pregnancy.15 In humans, higher interleukin-6 levels were measured in the umbilical vein and plasma of 12 women with pre-eclampsia compared to 12 women with normotensive pregnancies.16 Similarly, in another study, higher levels of interleukin-6, interleukin-8 and TNF-alpha were present in maternal and placental blood, adding evidence to the hypothesis of the cytokine’s significant role in the pathogenesis of pre-eclampsia.17 There is also evidence of higher interleukin-6 levels inwomenwith anamnesis of pre-eclampsia, years after the pregnancy, which is Section of Cardiology, First Department of Internal Diseases, Medical University – Plovdiv; Clinic of Cardiology, UMHAT Sveti Georgi, Plovdiv, Bulgaria Dolina Gencheva, MD, Dolina.Gencheva@mu-plovdiv.bg Fedya Nikolov, MD, PhD Department of Obstetrics and Gynaecology, Medical University – Plovdiv; Clinic of Obstetrics and Gynaecology, UMHAT Sveti Georgi, Plovdiv, Bulgaria Ekaterina Uchikova, MD, PhD Maria Vasileva, MD RAMUS Independent Medical Diagnostic Laboratory and Jordanka Filaretova Medical College, Sofia, Bulgaria Rosen Mihaylov, MD, PhD RAMUS Independent Medical Diagnostic Laboratory, Sofia, Bulgaria Blagovesta Pencheva, MD, PhD
RkJQdWJsaXNoZXIy NDIzNzc=