Minimal research has addressed effects of postmenopausal hormone replacement therapy (HRT) on heart rate variability (HRV), a measure of cardiovascular autonomic balance and a predictor of cardiac morbidity/mortality. Using an exploratory, pre-test/post-test design to describe HRV in postmenopausal women (PMW) before/after six weeks of HRT, twenty-four Black (n=15) and White (n=9) women, (mean age=55±4 years), were recruited from two primary care clinics (n=20) and one church population (n=4) in a large urban midsouth community. Cardiovascular risk factors for the sample included chronic illnesses of DM (n=8), HRT (n=11), both DM and HRT (n=4), smoking (n=9), non-exercise (n=11), and obesity quantified by sample mean BMI (mean=28±7.5). Twenty-four hour Holter monitoring and HRV analyses were done at first visit and following six weeks of oral self-administration of PremPro™ (estrogen: 0.625 mg; medroxyprogesterone acetate: 2.5 mg).
PMW demonstrated lower, but normal, HRV mean values than those for healthy female controls (n=118; age=35.6±11.8 years), Mean values were within normal limits established for the laboratory. Paired t-tests with significance at p? .10 demonstrated total group improvement for LowHertz (p=.06) and pNN50 (p=.10). HRV values improved for PMW with selected risk factors, consistently for values of TotalHertz and HighHertz, and, to a lesser extent, for values of PNN50 and rMSSD. Decreases in SDNN and SDANN were unexpected and merit further investigation.
White PMW showed no significant differences before/after HRT ; Black PMW demonstrated significant improvement in TotalHertz (p=.01), LowHertz (p=.03), HighHertz (p=.01), and rMSSD (p=.05. Correlational analyses of relationship for pre-/post-test HRV values to CV risk factors demonstrated significant (p?.10) relationships across HTN and years of menopause. Pre-/post-test significant differences were found for PMW with HTN for TotalHertz (p=.08), HighHertz (p=.04), pNN50 (p=.03), and rMSSD (p=.006), and PMW * 9 years menopausal for TotalHertz (p=.07), LowHertz (p=.01), pNN50 (p=.08), and SD (p=.07). Previous research findings suggested that PMW not on estrogen have a higher sympathetic mediation of autonomic function. Blacks and PMW < 55 years of age, following six-weeks of HRT, demonstrated a mediation in sympathetic/parasympathetic balance in post-test values. Because the study was exploratory with numerous analyses at p-value?.10, findings must be interpreted with caution.
","abstract_html":"<p>Minimal research has addressed effects of postmenopausal hormone replacement therapy (HRT) on heart rate variability (HRV), a measure of cardiovascular autonomic balance and a predictor of cardiac morbidity/mortality. Using an exploratory, pre-test/post-test design to describe HRV in postmenopausal women (PMW) before/after six weeks of HRT, twenty-four Black (n=15) and White (n=9) women, (mean age=55±4 years), were recruited from two primary care clinics (n=20) and one church population (n=4) in a large urban midsouth community. Cardiovascular risk factors for the sample included chronic illnesses of DM (n=8), HRT (n=11), both DM and HRT (n=4), smoking (n=9), non-exercise (n=11), and obesity quantified by sample mean BMI (mean=28±7.5). Twenty-four hour Holter monitoring and HRV analyses were done at first visit and following six weeks of oral self-administration of PremPro™ (estrogen: 0.625 mg; medroxyprogesterone acetate: 2.5 mg).</p> <p>PMW demonstrated lower, but normal, HRV mean values than those for healthy female controls (n=118; age=35.6±11.8 years), Mean values were within normal limits established for the laboratory. Paired t-tests with significance at p? .10 demonstrated total group improvement for LowHertz (p=.06) and pNN50 (p=.10). HRV values improved for PMW with selected risk factors, consistently for values of TotalHertz and HighHertz, and, to a lesser extent, for values of PNN50 and rMSSD. Decreases in SDNN and SDANN were unexpected and merit further investigation.</p> <p>White PMW showed no significant differences before/after HRT ; Black PMW demonstrated significant improvement in TotalHertz (p=.01), LowHertz (p=.03), HighHertz (p=.01), and rMSSD (p=.05. Correlational analyses of relationship for pre-/post-test HRV values to CV risk factors demonstrated significant (p?.10) relationships across HTN and years of menopause. Pre-/post-test significant differences were found for PMW with HTN for TotalHertz (p=.08), HighHertz (p=.04), pNN50 (p=.03), and rMSSD (p=.006), and PMW * 9 years menopausal for TotalHertz (p=.07), LowHertz (p=.01), pNN50 (p=.08), and SD (p=.07). Previous research findings suggested that PMW not on estrogen have a higher sympathetic mediation of autonomic function. Blacks and PMW < 55 years of age, following six-weeks of HRT, demonstrated a mediation in sympathetic/parasympathetic balance in post-test values. Because the study was exploratory with numerous analyses at p-value?.10, findings must be interpreted with caution. </p>","abstract_has_math":false,"creators":["Pace, Diane Todd"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Nursing","degree_department":null,"school":null,"contributors":["Kay F. Engelhardt"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1998,"date_issued":"1998-06-01T07:00:00Z","date_published":"1998-06-01T07:00:00Z","updated_at":"2026-07-24T05:00:11Z","subjects":["Cardiovascular rish factors","cardiac autonomic function","estrogen","heart","hypertension","Medicine and Health Sciences","Nursing"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://dc.uthsc.edu/dissertations/188","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Kay F. Engelhardt"]},{"key":"dc:creator","label":"Author","values":["Pace, Diane Todd"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2016-06-09T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Nursing"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Cardiovascular rish factors","cardiac autonomic function","estrogen","heart","hypertension","Medicine and Health Sciences","Nursing"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://dc.uthsc.edu/dissertations/188"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Minimal research has addressed effects of postmenopausal hormone replacement therapy (HRT) on heart rate variability (HRV), a measure of cardiovascular autonomic balance and a predictor of cardiac morbidity/mortality. Using an exploratory, pre-test/post-test design to describe HRV in postmenopausal women (PMW) before/after six weeks of HRT, twenty-four Black (n=15) and White (n=9) women, (mean age=55±4 years), were recruited from two primary care clinics (n=20) and one church population (n=4) in a large urban midsouth community. Cardiovascular risk factors for the sample included chronic illnesses of DM (n=8), HRT (n=11), both DM and HRT (n=4), smoking (n=9), non-exercise (n=11), and obesity quantified by sample mean BMI (mean=28±7.5). Twenty-four hour Holter monitoring and HRV analyses were done at first visit and following six weeks of oral self-administration of PremPro™ (estrogen: 0.625 mg; medroxyprogesterone acetate: 2.5 mg).
PMW demonstrated lower, but normal, HRV mean values than those for healthy female controls (n=118; age=35.6±11.8 years), Mean values were within normal limits established for the laboratory. Paired t-tests with significance at p? .10 demonstrated total group improvement for LowHertz (p=.06) and pNN50 (p=.10). HRV values improved for PMW with selected risk factors, consistently for values of TotalHertz and HighHertz, and, to a lesser extent, for values of PNN50 and rMSSD. Decreases in SDNN and SDANN were unexpected and merit further investigation.
White PMW showed no significant differences before/after HRT ; Black PMW demonstrated significant improvement in TotalHertz (p=.01), LowHertz (p=.03), HighHertz (p=.01), and rMSSD (p=.05. Correlational analyses of relationship for pre-/post-test HRV values to CV risk factors demonstrated significant (p?.10) relationships across HTN and years of menopause. Pre-/post-test significant differences were found for PMW with HTN for TotalHertz (p=.08), HighHertz (p=.04), pNN50 (p=.03), and rMSSD (p=.006), and PMW * 9 years menopausal for TotalHertz (p=.07), LowHertz (p=.01), pNN50 (p=.08), and SD (p=.07). Previous research findings suggested that PMW not on estrogen have a higher sympathetic mediation of autonomic function. Blacks and PMW < 55 years of age, following six-weeks of HRT, demonstrated a mediation in sympathetic/parasympathetic balance in post-test values. Because the study was exploratory with numerous analyses at p-value?.10, findings must be interpreted with caution.
"]},{"key":"dc:title","label":"Title","values":["Effect of Postmenopausal Hormone Replacement Therapy on Heart Rate Variability"]}]}],"canonical_facts":{"dc:contributor":["Kay F. Engelhardt"],"dc:creator":["Pace, Diane Todd"],"dc:date.available":["2016-06-09T07:00:00Z"],"dc:description.abstract":["Minimal research has addressed effects of postmenopausal hormone replacement therapy (HRT) on heart rate variability (HRV), a measure of cardiovascular autonomic balance and a predictor of cardiac morbidity/mortality. Using an exploratory, pre-test/post-test design to describe HRV in postmenopausal women (PMW) before/after six weeks of HRT, twenty-four Black (n=15) and White (n=9) women, (mean age=55±4 years), were recruited from two primary care clinics (n=20) and one church population (n=4) in a large urban midsouth community. Cardiovascular risk factors for the sample included chronic illnesses of DM (n=8), HRT (n=11), both DM and HRT (n=4), smoking (n=9), non-exercise (n=11), and obesity quantified by sample mean BMI (mean=28±7.5). Twenty-four hour Holter monitoring and HRV analyses were done at first visit and following six weeks of oral self-administration of PremPro™ (estrogen: 0.625 mg; medroxyprogesterone acetate: 2.5 mg).
PMW demonstrated lower, but normal, HRV mean values than those for healthy female controls (n=118; age=35.6±11.8 years), Mean values were within normal limits established for the laboratory. Paired t-tests with significance at p? .10 demonstrated total group improvement for LowHertz (p=.06) and pNN50 (p=.10). HRV values improved for PMW with selected risk factors, consistently for values of TotalHertz and HighHertz, and, to a lesser extent, for values of PNN50 and rMSSD. Decreases in SDNN and SDANN were unexpected and merit further investigation.
White PMW showed no significant differences before/after HRT ; Black PMW demonstrated significant improvement in TotalHertz (p=.01), LowHertz (p=.03), HighHertz (p=.01), and rMSSD (p=.05. Correlational analyses of relationship for pre-/post-test HRV values to CV risk factors demonstrated significant (p?.10) relationships across HTN and years of menopause. Pre-/post-test significant differences were found for PMW with HTN for TotalHertz (p=.08), HighHertz (p=.04), pNN50 (p=.03), and rMSSD (p=.006), and PMW * 9 years menopausal for TotalHertz (p=.07), LowHertz (p=.01), pNN50 (p=.08), and SD (p=.07). Previous research findings suggested that PMW not on estrogen have a higher sympathetic mediation of autonomic function. Blacks and PMW < 55 years of age, following six-weeks of HRT, demonstrated a mediation in sympathetic/parasympathetic balance in post-test values. Because the study was exploratory with numerous analyses at p-value?.10, findings must be interpreted with caution.
"],"dc:identifier":["https://dc.uthsc.edu/dissertations/188"],"dc:subject":["Cardiovascular rish factors","cardiac autonomic function","estrogen","heart","hypertension","Medicine and Health Sciences","Nursing"],"dc:title":["Effect of Postmenopausal Hormone Replacement Therapy on Heart Rate Variability"],"thesis:degree_discipline":["Nursing"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T05:00:11Z"}