Hormone-replacement therapy use, but not race, impacts the resting and exercise-induced GH response in postmenopausal women

Objective: This study examined the effect of hormone-replacement therapy (HRT) use on the incremental GH response to aerobic exercise in postmenopausal women and established whether racial differences in the GH response were seen at rest and in response to exercise. Methods: 13 white (n = 6, HRT; n = 7, no HRT) and seven black women (no HRT) were studied on two occasions, a control day and an exercise day (30 min at 70% VO2max on a cycle ergometer). Blood was sampled every 10 min for a 4-h period and analyzed for GH using an ultrasensitive chemiluminescent assay. Results: The mean 4-h GH concentration was higher on both study days in the HRT women than the non-HRT users. The integrated GH concentrations were greater in the HRT women both at rest and in response to exercise (rest, 352 ± 53 min μg l−1; exercise, 711 ± 57 min μg l−1; P < 0.01) than in the non-HRT women (rest, 157 ± 87 min μg l−1; exercise, 248 ± 94 min μg l−1). The incremental GH response was greater in the HRT users than in the non-HRT women (358 ± 130 versus 90.8 ± 94 min μg l−1, respectively; P < 0.05). GH-production rate during the 4-h period was greater in the HRT women than in the non-HRT women (P < 0.01), due to an increase in the GH mass secreted/pulse (P < 0.05), with no change in GH pulse number or GH half-life. No racial differences in the mean 4-h GH concentrations or integrated GH concentrations were found at rest or in response to exercise. Conclusion: HRT use resulted in a greater incremental exercise response compared with non-HRT users, due to changes in the secretory pulse characteristics in the HRT users. This study also demonstrated that no racial differences exist at rest and in response to exercise in the morning hours.

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Effect of Hormone Replacement Therapy on Ocular Hemodynamics in Postmenopausal Women

European Journal of Ophthalmology ◽

10.1177/112067210101100311 ◽

2001 ◽

Vol 11 (3) ◽

pp. 277-280 ◽

Cited By ~ 10

Author(s):

H. Atílla ◽

A. Arslanpençe ◽

F. Batioğlu ◽

T. Eryilmaz ◽

S. Aytaç ◽

...

Keyword(s):

Hormone Replacement Therapy ◽

Replacement Therapy ◽

Postmenopausal Women ◽

Doppler Ultrasonography ◽

Hormone Replacement ◽

Control Group ◽

Medication History ◽

The Mean ◽

Ocular Hemodynamics ◽

Flow Velocities

Purpose To evaluate the effect of hormone replacement therapy on ocular hemodynamics in postmenopausal women. Methods Ocular Doppler ultrasonography was performed in 20 postmenopausal women on hormone replacement therapy (HRT) and in 20 women without treatment, as the control group. Central retinal artery (CRA), posterior ciliary artery (PCA) and ophthalmic artery (OA) flow velocities and vascular resistances were measured prospectively by a radiologist blinded to the therapy. There were no associated systemic or ocular diseases or any medication history. Results The mean age of the patients on HRT was 50.05 ± 4.5 yrs (range 44 - 62). The mean age of the control group was 52.8 ± 4.09 yrs (range 46 - 65). The mean duration of HRT was 1.6 ± 1.4 yrs (range 3 months - 5 years). There were no differences between the groups in terms of flow velocities, vascular resistivities or pulsatility indices of OA, CRA and PCA (p>0.05). Conclusions HRT is essential in postmenopausal women for relief of vasomotor symptoms, cardioprotection and prevention of osteoporosis. Even though vaso-occlusive complications of hormone preparations have been reported, we did not observe any changes in ocular hemodynamics detectable with Doppler ultrasonography.

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Chronic hormone replacement therapy alters thermoregulatory and vasomotor function in postmenopausal women

Journal of Applied Physiology ◽

10.1152/jappl.1997.83.2.477 ◽

1997 ◽

Vol 83 (2) ◽

pp. 477-484 ◽

Cited By ~ 76

Author(s):

E. M. Brooks ◽

A. L. Morgan ◽

J. M. Pierzga ◽

S. L. Wladkowski ◽

J. T. O’Gorman ◽

...

Keyword(s):

Hormone Replacement Therapy ◽

Replacement Therapy ◽

Postmenopausal Women ◽

Hormone Replacement ◽

Venous Occlusion ◽

Cycle Ergometer ◽

Vascular Conductance ◽

Mean Body Temperature ◽

Doppler Flowmetry ◽

Vasomotor Function

Brooks, E. M., A. L. Morgan, J. M. Pierzga, S. L. Wladkowski, J. T. O’Gorman, J. A. Derr, and W. L. Kenney. Chronic hormone replacement therapy alters thermoregulatory and vasomotor function in postmenopausal women. J. Appl. Physiol. 83(2): 477–484, 1997.—This investigation examined effects of chronic (≥2 yr) hormone replacement therapy (HRT), both estrogen replacement therapy (ERT) and estrogen plus progesterone therapy (E+P), on core temperature and skin blood flow responses of postmenopausal women. Twenty-five postmenopausal women [9 not on HRT (NO), 8 on ERT, 8 on E+P] exercised on a cycle ergometer for 1 h at an ambient temperature of 36°C. Cutaneous vascular conductance (CVC) was monitored by laser-Doppler flowmetry, and forearm vascular conductance (FVC) was measured by using venous occlusion plethysmography. Iontophoresis of bretylium tosylate was performed before exercise to block local vasoconstrictor (VC) activity at one skin site on the forearm. Rectal temperature (Tre) was ∼0.5°C lower for the ERT group ( P < 0.01) compared with E+P and NO groups at rest and throughout exercise. FVC: mean body temperature (Tb) and CVC: Tb curves were shifted ∼0.5°C leftward for the ERT group ( P < 0.0001). Baseline CVC was significantly higher in the ERT group ( P < 0.05), but there was no interaction between bretylium treatment and groups once exercise was initiated. These results suggest that 1) chronic ERT likely acts centrally to decrease Tre, 2) ERT lowers the Tre at which heat-loss effector mechanisms are initiated, primarily by actions on active cutaneous vasodilation, and 3) addition of exogenous progestins in HRT effectively blocks these effects.

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