The Sleep-Entrained Slowing of Lh Pulses Persists in the Early Follicular Phase of Older Ovulatory Women, but Amplitude Fails to Rise

2.50
Hdl Handle:
http://hdl.handle.net/10755/160608
Type:
Presentation
Title:
The Sleep-Entrained Slowing of Lh Pulses Persists in the Early Follicular Phase of Older Ovulatory Women, but Amplitude Fails to Rise
Abstract:
The Sleep-Entrained Slowing of Lh Pulses Persists in the Early Follicular Phase of Older Ovulatory Women, but Amplitude Fails to Rise
Conference Sponsor:Midwest Nursing Research Society
Conference Year:2002
Author:Reame, Nancy, PhD
P.I. Institution Name:University of Michigan
Title:Professor
Contact Address:School of Nursing, 400 North Ingalls Building, Rm 2240, Ann Arbor, MI, 48109-0482, USA
Contact Telephone:734.647.0134
Some studies in older cycling women have identified age-related changes in pulsatile LH secretion and altered pituitary responsiveness to GnRH, while others have not. To determine age effects on GnRH pacemaker activity, we compared the sleep-entrained slowing of LH pulsatility as a marker of hypothalamic drive in the early follicular phase (cycle day 4-6) in young (YC, <30 yrs, n=15) and older cycling (OC, ages 40-50, n=11) volunteers to that of age-matched postmenopausal women (PM, n=10) and ovariectomized (OVX, n=8) women using ERT. All subjects underwent a day-time stimulation test (25 mg) at the end of the 24-hour q 10 min blood sampling. Day- night differences (11am-7pm vs. 11pm-7am) in mean estradiol, mean FSH and LH pulse parameters were determined. Mean estradiol was highest in the OVX+ERT group (59±20, 28±4, 39±7, 7±2 pg/ml; OVX, YC, OC, respectively; p<0.001). ). FSH differed by study group (4.7±0.3, 8.8±1.7, 65.0±5.9, 29.3±4.8 mIU/mL; YC, OC,, OVX+ERT respectively; p<0.001). YC women showed the characteristic slowing and high amplitude LH pulses at night (p<0.01 day vs. night). While LH pulse frequency slowed (8.1±0.7 vs. 5.0±0.4 pulses/8hr; day vs. night, p <0.01) in OC women, amplitude did not increase with sleep (1.5±0.2 vs. 1.7±0.3 mIU/ml; day vs. night, NS) and was lower than in controls (1.7±0.3 vs. 2.6±0.3 mIU/ml; OC vs. YC, p<0.05). women showed no day-night difference in LH pulse frequency or amplitude. OVX+ERT women tended to have lower night-time LH pulse frequency (p=0.086). The sleep-entrained slowing of LH pulse frequency requires estrogen and is not influenced by central aging deficits in middle-aged women. The ability to increase LH pulse amplitude at night is lost prior to menopause and is not dependent on the ovary. Failure to increase amplitude at night in OC women is not due to reduced daytime pituitary sensitivity.
Repository Posting Date:
26-Oct-2011
Date of Publication:
17-Oct-2011
Sponsors:
Midwest Nursing Research Society

Full metadata record

DC FieldValue Language
dc.typePresentationen_GB
dc.titleThe Sleep-Entrained Slowing of Lh Pulses Persists in the Early Follicular Phase of Older Ovulatory Women, but Amplitude Fails to Riseen_GB
dc.identifier.urihttp://hdl.handle.net/10755/160608-
dc.description.abstract<table><tr><td colspan="2" class="item-title">The Sleep-Entrained Slowing of Lh Pulses Persists in the Early Follicular Phase of Older Ovulatory Women, but Amplitude Fails to Rise</td></tr><tr class="item-sponsor"><td class="label">Conference Sponsor:</td><td class="value">Midwest Nursing Research Society</td></tr><tr class="item-year"><td class="label">Conference Year:</td><td class="value">2002</td></tr><tr class="item-author"><td class="label">Author:</td><td class="value">Reame, Nancy, PhD</td></tr><tr class="item-institute"><td class="label">P.I. Institution Name:</td><td class="value">University of Michigan</td></tr><tr class="item-author-title"><td class="label">Title:</td><td class="value">Professor</td></tr><tr class="item-address"><td class="label">Contact Address:</td><td class="value">School of Nursing, 400 North Ingalls Building, Rm 2240, Ann Arbor, MI, 48109-0482, USA</td></tr><tr class="item-phone"><td class="label">Contact Telephone:</td><td class="value">734.647.0134</td></tr><tr class="item-email"><td class="label">Email:</td><td class="value">nreame@umich.edu</td></tr><tr><td colspan="2" class="item-abstract">Some studies in older cycling women have identified age-related changes in pulsatile LH secretion and altered pituitary responsiveness to GnRH, while others have not. To determine age effects on GnRH pacemaker activity, we compared the sleep-entrained slowing of LH pulsatility as a marker of hypothalamic drive in the early follicular phase (cycle day 4-6) in young (YC, &lt;30 yrs, n=15) and older cycling (OC, ages 40-50, n=11) volunteers to that of age-matched postmenopausal women (PM, n=10) and ovariectomized (OVX, n=8) women using ERT. All subjects underwent a day-time stimulation test (25 mg) at the end of the 24-hour q 10 min blood sampling. Day- night differences (11am-7pm vs. 11pm-7am) in mean estradiol, mean FSH and LH pulse parameters were determined. Mean estradiol was highest in the OVX+ERT group (59&plusmn;20, 28&plusmn;4, 39&plusmn;7, 7&plusmn;2 pg/ml; OVX, YC, OC, respectively; p&lt;0.001). ). FSH differed by study group (4.7&plusmn;0.3, 8.8&plusmn;1.7, 65.0&plusmn;5.9, 29.3&plusmn;4.8 mIU/mL; YC, OC,, OVX+ERT respectively; p&lt;0.001). YC women showed the characteristic slowing and high amplitude LH pulses at night (p&lt;0.01 day vs. night). While LH pulse frequency slowed (8.1&plusmn;0.7 vs. 5.0&plusmn;0.4 pulses/8hr; day vs. night, p &lt;0.01) in OC women, amplitude did not increase with sleep (1.5&plusmn;0.2 vs. 1.7&plusmn;0.3 mIU/ml; day vs. night, NS) and was lower than in controls (1.7&plusmn;0.3 vs. 2.6&plusmn;0.3 mIU/ml; OC vs. YC, p&lt;0.05). women showed no day-night difference in LH pulse frequency or amplitude. OVX+ERT women tended to have lower night-time LH pulse frequency (p=0.086). The sleep-entrained slowing of LH pulse frequency requires estrogen and is not influenced by central aging deficits in middle-aged women. The ability to increase LH pulse amplitude at night is lost prior to menopause and is not dependent on the ovary. Failure to increase amplitude at night in OC women is not due to reduced daytime pituitary sensitivity.</td></tr></table>en_GB
dc.date.available2011-10-26T23:06:25Z-
dc.date.issued2011-10-17en_GB
dc.date.accessioned2011-10-26T23:06:25Z-
dc.description.sponsorshipMidwest Nursing Research Societyen_GB
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