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Zhou D, Yan M, Cheng Q, Feng X, Tang S, Feng Y. Prevalence and prognosis of left ventricular diastolic dysfunction in community hypertension patients. BMC Cardiovasc Disord 2022; 22:265. [PMID: 35698035 PMCID: PMC9195252 DOI: 10.1186/s12872-022-02709-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/08/2022] [Indexed: 11/10/2022] Open
Abstract
Left ventricular diastolic dysfunction (LVDD) is common in hypertension and is a predictor of increased cardiovascular risk, however the effect of LVDD, detected by new guideline, on major adverse cardiac events (MACE) is unknown in hypertensive patients without known cardiovascular disease. The present study aims to evaluate LVDD in a community hypertension cohort study and assess the effect of LVDD on MACE. we studied 283 asymptomatic nonischemic patients with hypertension who had baseline echocardiogram between 2012 and 2014. Patients were followed for MACE (myocardial infarction, coronary revascularization procedures, heart failure, stroke, all-cause mortality) with mean follow-up of 5.4 years. A Cox proportional hazards model was used to assess the association of LVDD with MACE. At baseline, 35 of the 283 hypertensions were diagnosed with LVDD (12.3%) and 25 patients were women (15.5%). Women had higher frequency of LVDD than men (8%). During follow-up, there were 26.6% patients occurring MACE in the LVDD group at baseline, 9.9% patients occurring MACE in the group with normal diastolic function. In multivariable Cox regression analyses, LVDD was a stronger predictor of MACE (HR: 2.5; 95% CI: 1.20 to 5.25; c- statistics 0.805) than E/e' ratio (HR: 1.13; 95% CI: 1.04 to 1.22). LVDD was strongly associated with MACE in hypertension patients.
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Affiliation(s)
- Dan Zhou
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106 Zhongshan 2nd Road, Yuexiu District, Guangzhou, 510080, People's Republic of China
| | - Mengqi Yan
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106 Zhongshan 2nd Road, Yuexiu District, Guangzhou, 510080, People's Republic of China
| | - Qi Cheng
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106 Zhongshan 2nd Road, Yuexiu District, Guangzhou, 510080, People's Republic of China
| | - Xiaoxuan Feng
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106 Zhongshan 2nd Road, Yuexiu District, Guangzhou, 510080, People's Republic of China
| | - Songtao Tang
- Department of Internal Medicine, Community Health Center of Liaobu Community, Dongguan, 523411, China
| | - Yingqing Feng
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106 Zhongshan 2nd Road, Yuexiu District, Guangzhou, 510080, People's Republic of China.
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Ying W, Post WS, Michos ED, Subramanya V, Ndumele CE, Ouyang P, Ambale-Venkatesh B, Doria De Vasconcellos H, Nwabuo CC, Schreiner PJ, Lewis CE, Reis J, Lloyd-Jones D, Sidney S, Lima JAC, Vaidya D. Associations between menopause, cardiac remodeling, and diastolic function: the CARDIA study. Menopause 2021; 28:1166-1175. [PMID: 34127631 DOI: 10.1097/gme.0000000000001815] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Heart failure with preserved ejection fraction (HFpEF) affects more women than men. Menopause may influence HFpEF development in women. We assessed cross-sectional and longitudinal associations between menopause and echocardiographic measures of left ventricular (LV) function and cardiac remodeling. METHODS We studied 1,723 women with available echo data from at least two of: year 5 (Y5) (1990-1991), Y25 (2010-2011), or Y30 (2015-2016) in the Coronary Artery Risk Development in Young Adults study. Cardiac structure and function were measured using 2D and Doppler echocardiography. Cross-sectional associations between menopausal status and repeated echo measures at Y25 and Y30 were analyzed using linear mixed models. Two-segmented models were used to compare longitudinal changes in echocardiographic measures in the premenopausal period to changes in the postmenopausal period. RESULTS Mean ± SD age (years) at enrollment was 27 ± 3 in those with menopause by Y25, 25 ± 3 in those with menopause between Y25 and Y30, and 21 ± 3 in those premenopausal at Y30. There were no significant differences in race, body mass index, systolic blood pressure, or diabetes between the groups. Postmenopausal women had higher early diastolic mitral inflow (E) to annular (e') velocity ratio than premenopausal after adjusting for demographics and risk factors (P < 0.05). Menopause was associated with relative increases in the rates of change in LV mass and left atrial volume, even after adjustment. Change in E/e' ratio was similar before and after menopause. CONCLUSIONS Menopause is associated cross-sectionally with worse diastolic function and longitudinally with adverse LV and left atrial remodeling. This may contribute to the increased HFpEF risk in postmenopausal women.
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Affiliation(s)
- Wendy Ying
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Wendy S Post
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
- Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Erin D Michos
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
- Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Vinita Subramanya
- Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, GA
| | - Chiadi E Ndumele
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
- Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Pamela Ouyang
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | | | | | - Chike C Nwabuo
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Pamela J Schreiner
- Division of Epidemiology and Community Health, University of Minnesota School of Public Health, Minneapolis, MN
| | - Cora E Lewis
- Department of Epidemiology, University of Alabama at Birmingham School of Public Health, Birmingham, AL
| | - Jared Reis
- National Heart, Lung, and Blood Institute, Bethesda, MD
| | - Donald Lloyd-Jones
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL
| | | | - Joao A C Lima
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Dhananjay Vaidya
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
- Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
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Cai A, Zhou D, Liu L, Zhou Y, Tang S, Feng Y. Age-related alterations in cardiac and arterial structure and function in hypertensive women and men. J Clin Hypertens (Greenwich) 2021; 23:1322-1334. [PMID: 33960629 PMCID: PMC8678835 DOI: 10.1111/jch.14262] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/29/2021] [Accepted: 04/15/2021] [Indexed: 01/21/2023]
Abstract
The study was to compare age‐related alterations in cardiac and arterial structure and function by sex and to explore the impacts of achieved systolic blood pressure (SBP; <130 mm Hg vs. <140 mm Hg) level on age‐related alterations in cardiac and arterial structure and function in hypertensive women and men. Community hypertensive individuals without cardiovascular disease who had echocardiographic examination were included. Age‐related alterations in cardiac and arterial structure and function were compared by sex, and interplay between age and sex was analyzed according to achieved SBP level. The mean age of the cohort was 66.5 years, and women accounted for 62% (n = 602) of the cohort (n = 971). Compared to men, women had worse left ventricular (LV) diastolic function and greater LV and arterial stiffness. After adjusting for covariates, the magnitude of the associations between age with septal E/e′ ratio, septal S′ velocity, effective arterial elastance (Ea) and LV end‐diastolic elastance (Eed) were greater in women. Sex differences in the magnitude of association between age with these four indices varied according to achieved SBP level. When achieved SBP <130 mm Hg, the magnitude of the associations between age with septal E/e′ ratio, septal S′ velocity, Ea and Eed did not differ by sex. Since age and sex are non‐modifiable, achieving SBP target, especially at a lower level, might be beneficial to attenuate sex differences in age‐related alterations in cardiac and arterial structure and function.
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Affiliation(s)
- Anping Cai
- Department of Cardiology, Hypertension Research Laboratory, Guangdong Provincial People's Hospital, Guangdong Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Dan Zhou
- Department of Cardiology, Hypertension Research Laboratory, Guangdong Provincial People's Hospital, Guangdong Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Lin Liu
- Department of Cardiology, Hypertension Research Laboratory, Guangdong Provincial People's Hospital, Guangdong Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Yingling Zhou
- Department of Cardiology, Hypertension Research Laboratory, Guangdong Provincial People's Hospital, Guangdong Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Songtao Tang
- Community Health Center of the Liaobu County, Dongguan, China
| | - Yingqing Feng
- Department of Cardiology, Hypertension Research Laboratory, Guangdong Provincial People's Hospital, Guangdong Cardiovascular Institute, Guangdong Academy of Medical Sciences, Guangzhou, China
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Hayashi S, Yamada H, Nishio S, Hotchi J, Bando M, Takagawa Y, Saijo Y, Hirata Y, Sata M. Age- and gender-specific changes of tricuspid annular motion velocities in normal hearts. J Cardiol 2015; 65:397-402. [DOI: 10.1016/j.jjcc.2014.06.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 06/20/2014] [Accepted: 06/25/2014] [Indexed: 01/04/2023]
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Wirakiat W, Udomuksorn W, Vongvatcharanon S, Vongvatcharanon U. Effects of estrogen via estrogen receptors on parvalbumin levels in cardiac myocytes of ovariectomized rats. Acta Histochem 2012; 114:46-54. [PMID: 21411124 DOI: 10.1016/j.acthis.2011.02.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 02/07/2011] [Accepted: 02/10/2011] [Indexed: 11/26/2022]
Abstract
The study investigated the effects of estrogen on parvalbumin (PV) levels in cardiac myocytes of ovariectomized rats, which is a model system for postmenopausal woman. Parvalbumin acts as a relaxing factor in cardiac myocytes. Adult female Wistar rats, 12 weeks old, were randomly divided into 5 groups of 10: sham-operated (SHAM), ovariectomized (OVX), and OVX receiving estrogen replacement of 10 μg/kg (Es10), 20 μg/kg (Es20) and 40 μg/kg (Es40). After 10 weeks, serum estrogen levels were measured and the α and β estrogen receptors in cardiac myocytes were investigated by immunohistochemistry. PV levels were examined by immunohistochemistry and Western blot analysis. Cardiac myocytes of all animals showed strong staining intensities for α immunoreactive (Es α-ir), but weak staining for β immunoreactive (Es β-ir) estrogen receptors. The Es α-ir was reduced in the cardiac myocytes of the OVX groups, but increased in the Es10, Es20 and Es40 groups. We therefore suggest that estrogen effects are mediated via Es α receptors rather than Es β receptors in female rat hearts. Estrogen and PV immunoreactive (PV-ir) levels and the intensity of the PV band observed in the OVX group were less than those of the SHAM group. In the Es10, Es20 and Es40 groups, the increased intensity of the PV-ir and PV bands correlated with the increased estrogen levels. The low PV levels in cardiac myocytes induced by low estrogen were restored by estrogen replacement therapy. Therefore a reduction of PV may lead to diastolic dysfunction in menopause.
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Khoo SK, O'Neill S, Scalia G, Tripcony L. Effect of lifestyle factors and hormone therapy on heart function by serial echocardiography in postmenopausal women. Aust N Z J Obstet Gynaecol 2010; 50:87-92. [PMID: 20219004 DOI: 10.1111/j.1479-828x.2009.01112.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND There is conflicting information on the effects of oestrogen on the heart in women, especially those using postmenopausal hormone therapy. Whilst some studies reported a beneficial effect, others showed adverse outcomes. The interplay of lifestyle factors and type/timing of therapy remains to be clarified. AIM The aim of this study was to determine the effects of lifestyle and hormone therapy on heart function and structure in postmenopausal women. METHOD As part of a large longitudinal study of women randomly recruited from an urban population, the study assessed 410 suitable women by echocardiography in Year 1 and Year 5 of the study by two independent cardiologists. RESULTS In lifestyle characteristics, the difference in age and body mass (as markers of cardiovascular risk) was in favour of never-users versus hormone therapy-users. Using an arbitrary cut-off > or =15% change for an effect, we found lifestyle factors had minimal effect on the two measured parameters - ejection fraction, left ventricular mass. Effects of hormone therapy were variable and mixed; greatest effect was found for an 'early start' of hormone therapy with oestrogen-only preparation - the risk of reduced ejection fraction was decreased [hazard ratio (HR) 0.42, confidence interval = 0.17-1.03, P = 0.06] and risk of increased left ventricular mass was increased (HR 2.21, 1.09-4.49, P = 0.03). CONCLUSION Our findings add to the evidence that oestrogen given to postmenopausal women has a mixed effect on the heart, with effect best shown when started early.
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Affiliation(s)
- Soo-Keat Khoo
- Betty Byrne Henderson Women's Health Research Centre, University of Queensland and Royal Brisbane and Women's Hospital, Australia.
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Duygu H, Akman L, Ozerkan F, Akercan F, Zoghi M, Nalbantgil S, Erturk U, Akilli A, Onder R, Akin M. Comparison of the effects of new and conventional hormone replacement therapies on left ventricular diastolic function in healthy postmenopausal women: a Doppler and ultrasonic backscatter study. Int J Cardiovasc Imaging 2009; 25:387-96. [DOI: 10.1007/s10554-009-9429-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2008] [Accepted: 01/09/2009] [Indexed: 11/28/2022]
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Chu SH, Goldspink P, Kowalski J, Beck J, Schwertz DW. Effect of estrogen on calcium-handling proteins, β-adrenergic receptors, and function in rat heart. Life Sci 2006; 79:1257-67. [PMID: 16647722 DOI: 10.1016/j.lfs.2006.03.037] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Revised: 03/06/2006] [Accepted: 03/27/2006] [Indexed: 11/30/2022]
Abstract
Regulation of cellular Ca(2+) cycling is central to myocardial contractile function. Loss of Ca(2+) regulation is associated with cardiac dysfunction and pathology. Estrogen has been shown to modify contractile function and to confer cardioprotection. Therefore, we investigated the effect of estrogen on expression of rat heart myocardial Ca(2+)-handling proteins and beta-adrenergic receptor (beta(1)-AR) and examined functional correlates. Female rats were sham-operated (SHAM) or ovariectomized. Two weeks after ovariectomy rats were injected (i.p.) daily with estradiol benozoate (OVX+EB) or sesame oil (OVX) for 2 weeks. Protein abundance was measured by immunoblotting and mRNA was quantified by real-time RT-PCR. OVX significantly decreased estrogen and progesterone levels and EB replacement returned both estrogen and progesterone to physiological levels. OVX induced a 75% reduction of uterine weight and a gain in body weight. Replacement restored weights to SHAM level. OVX increased and estrogen-replacement normalized abundance of beta(1)-AR and L-type Ca(2+) channel (Cav1.2) protein. OVX decreased sodium-Ca(2+) exchange protein (NCX) and estrogen restored protein abundance to SHAM levels. Sarcoplasmic reticular ATPase (SERCA), phospholamban (PLB), and ryanodine receptor (RyR) abundance was not altered by hormone status. Levels of mRNA encoding for beta(1)-AR, Cav1.2, and NCX were not influenced by OVX or estrogen replacement. OVX had no effect on SERCA and PLB mRNA level but estrogen replacement elicited a significant increase compared to OVX and SHAM. Estrogen-dependent changes in Ca(2+)-handling proteins and beta(1)-AR are theoretically consistent reduced myocellular Ca(2+) load. However, hormone-dependent alterations in protein were not associated with changes in contractile function.
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Affiliation(s)
- Sang Hui Chu
- Department of Clinical Nursing Science, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-752, Korea
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Ozdemir K, Celik C, Altunkeser BB, Içli A, Albeni H, Düzenli A, Akyürek C, Gök H. Effect of postmenopausal hormone replacement therapy on cardiovascular performance. Maturitas 2004; 47:107-13. [PMID: 14757269 DOI: 10.1016/s0378-5122(03)00248-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
UNLABELLED Postmenopausal hormone replacement therapy (HRT) has usually been evaluated the relationship with atherosclerotic disease, whereas its effect on direct cardiac functions hasn't been investigated in detail. This study was planned to investigate the long-term effects of HRT on cardiac functions and exercise performance. METHODS Thirty-six postmenopausal women (mean age: 51 +/- 4 years, 39-60 years) were prospectively analyzed with pulsed wave Doppler echocardiography and symptom-limited exercise stress test before HRT (oral 0.625 mg conjugated estrogen and 2.5 mg medroxyprogesteron acetate/day), and at the third and the sixth months. The effect of HRT on left ventricular ejection fraction (EF), early filling velocity (E wave) and late filling velocity (A wave), E wave deceleration time (EDT), E/A ratio, myocardial performance index (MPI), exercise duration and METS changes were examined. RESULTS HRT did not significantly alter the left ventricular EF. At the third month of HRT, there was an insignificant increase in E wave, EDT, and E/A ratio, whereas an insignificant decrease was noted in MPI (P > 0.05). However, at the sixth month of HRT, these changes became significant (68 +/- 12 vs. 75 +/- 13 cm/s, P < 0.01; 171 +/- 24 vs. 184 +/- 14 ms, P < 0.01; 1.01 +/- 0.23 vs. 1.11 +/- 0.27, P < 0.01, and 44 +/- 9 vs. 39 +/- 8%, P < 0.001, respectively). On the other hand, exercise duration and exercise METS values showed significant improvements at the third month of HRT (423 +/- 104 vs. 482 +/- 104 s, P < 0.001; 8.2 +/- 1.7 vs. 9.1 +/- 2 METS, P < 0.001). These improvements also continued at the sixth month of HRT. In conclusion, postmenopausal HRT leads to a progressive improvement on left ventricular function parameters, and in parallel, in exercise performance.
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Affiliation(s)
- Kurtulus Ozdemir
- Cardiology Department, Medical Faculty, Selçuk University, Aybüke Sitesi 83/14, 42080 Selçuklu, Konya, Turkey.
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Fenkci V, Yilmazer M, Alpaslan M, Onrat E, Fenkci S. The short-term effects of different regimens of hormone replacement therapy on left ventricular structure and performance in healthy postmenopausal women. A prospective, controlled echocardiographic study. Gynecol Obstet Invest 2003; 55:139-44. [PMID: 12865592 DOI: 10.1159/000071527] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2002] [Accepted: 03/03/2003] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To compare the short-term effects of different hormone replacement therapy (HRT) regimens on left ventricular structure and function in healthy postmenopausal women. METHODS Forty-two apparently healthy postmenopausal women were evaluated prospectively in this controlled study. Subjects were divided into 4 groups. Ten subjects, who did not accept HRT or any other treatments, formed the control group. The remaining subjects were assigned to receive oral estradiol (2 mg/day) + norethisterone acetate (1 mg/day) (n = 11), transdermal estradiol (0.05 mg) + norethisterone acetate (0.25 mg) (n = 11) or tibolone (2.5 mg/day) (n = 10) therapy during 12 weeks. Echocardiography and Doppler techniques were used to assess the cardiac effects of different HRT regimens. RESULTS After 12 weeks of treatment, there were significant increases in left ventricular ejection fraction (transdermal group: p = 0.008, oral group: p = 0.003, tibolone group: p = 0.005) and cardiac output (transdermal group: p = 0.003, oral group: p = 0.003, tibolone group: p = 0.021) in all treatment groups. In addition, in the transdermal group, a slight increase in left ventricular end-diastolic volume was significant (p = 0.046). CONCLUSION These data suggest that oral and transdermal HRT regimens and tibolone may contribute to the improvement in left ventricular systolic function without having an effect on left ventricular structure after short-term administration in healthy postmenopausal women.
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Affiliation(s)
- Veysel Fenkci
- Department of Obstetrics and Gynecology, School of Medicine, Kocatepe University, Afyon, Turkey.
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Thawornkaiwong A, Preawnim S, Wattanapermpool J. Upregulation of beta 1-adrenergic receptors in ovariectomized rat hearts. Life Sci 2003; 72:1813-24. [PMID: 12586219 DOI: 10.1016/s0024-3205(02)02473-6] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Changes in cardiac myofilament Ca(2+) activation have been demonstrated in ovariectomized rats. The underlying mechanisms responsible for these changes, however, are unknown. Accordingly, we measured both density and binding affinity of cardiac beta(1)-adrenergic receptors in sarcolemmal preparations from 10-week ovariectomized rats, pair-fed ovariectomized rats, and sham-operated control rats. Receptor protein content was also measured by immunoblotting. Deprivation of ovarian sex hormones for 10 weeks induced a significant upregulation of beta(1)-adrenergic receptors without affecting binding affinity. The same magnitude of receptor upregulation was also detected in pair-fed ovariectomized hearts. To determine which hormone is responsible for the observed increase in beta(1)-adrenergic receptor density, various sex hormone supplemental regimens were administered to ovariectomized rats. Subcutaneous injection of estrogen (5 microg/rat), progesterone (1 mg/rat), or estrogen plus progesterone three times a week all effectively prevented the upregulation of the beta(1)-adrenoceptors. Western blot analyses using polyclonal antibody of beta(1)-adrenergic receptors revealed the same pattern of changes in the protein content of the receptors in these various groups of experimental hearts as those obtained from the receptor binding assay. These results suggest a possible direct suppressive effect of ovarian sex hormones on the expression of cardiac beta(1)-adrenergic receptors.
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Affiliation(s)
- Ariyaporn Thawornkaiwong
- Department of Physiology, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
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