Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 7-Day Trial for You or Your Team.

Learn More →

A Comparison of Two Methods for Detecting Hormone Peaks: The Effect of Sampling Interval on Gonadotropin Peak Frequency

A Comparison of Two Methods for Detecting Hormone Peaks: The Effect of Sampling Interval on... Abstract There is no consensus on the optimum method to identify gonadotropin pulses in serum. We compared two approaches for detecting gonadotropin peaks. The first employed the conventional criterion of an increment from nadir to peak of 3 times the intraassay coefficient of variation (3 CV). The second identified peaks by Student's t test to quadruplicate measurements at each time point. We obtained blood samples every 5 min for 6 h from four women in the follicular phase. We also constructed control or noise series by subdividing single serum pools into consecutively labeled aliquots. Any variations in hormone concentration in the noise series that were identified as peaks were, by definition, false positive peaks. We evaluated the effect of sampling interval on gonadotropin peak detection by omitting data to simulate sampling every 10, 15, or 20 min. The 3 CV approach identified numerous false positive peaks in the noise series and detected as many peaks in the noise series as it did in the patient series. Increasing the sampling frequency from every 20 to every 5 min nearly doubled the apparent peak frequencies in both the patient and the noise series (P < 0.025). By contrast, the t test method detected far fewer false positive peaks and significantly more peaks in the patient series than in the noise series. Increasing the sampling frequency from every 20 to every 5 min resulted in a 50-75% increase in peak frequency by the t test method. This increase in peak frequency appeared to result from improved detection of small peaks, because samples were obtained nearer the true peaks and nadirs. The resulting increase in the nadir to peak increment made it more likely that a small peak would achieve statistical significance. We conclude that increasingly stringent criteria for pulse detection should be applied as one increases the sampling frequency, and that the t test approach is a more valid method than the 3 CV approach because it yields significantly fewer false positive peaks. This content is only available as a PDF. Copyright © 1984 by The Endocrine Society http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Clinical Endocrinology and Metabolism Oxford University Press

A Comparison of Two Methods for Detecting Hormone Peaks: The Effect of Sampling Interval on Gonadotropin Peak Frequency

Download PDF
5 pages

Loading next page...
 
/lp/oxford-university-press/a-comparison-of-two-methods-for-detecting-hormone-peaks-the-effect-of-2tVpzykNN7

References (9)

Publisher
Oxford University Press
Copyright
Copyright © 1984 by The Endocrine Society
ISSN
0021-972X
eISSN
1945-7197
DOI
10.1210/jcem-59-6-1159
Publisher site
See Article on Publisher Site

Abstract

Abstract There is no consensus on the optimum method to identify gonadotropin pulses in serum. We compared two approaches for detecting gonadotropin peaks. The first employed the conventional criterion of an increment from nadir to peak of 3 times the intraassay coefficient of variation (3 CV). The second identified peaks by Student's t test to quadruplicate measurements at each time point. We obtained blood samples every 5 min for 6 h from four women in the follicular phase. We also constructed control or noise series by subdividing single serum pools into consecutively labeled aliquots. Any variations in hormone concentration in the noise series that were identified as peaks were, by definition, false positive peaks. We evaluated the effect of sampling interval on gonadotropin peak detection by omitting data to simulate sampling every 10, 15, or 20 min. The 3 CV approach identified numerous false positive peaks in the noise series and detected as many peaks in the noise series as it did in the patient series. Increasing the sampling frequency from every 20 to every 5 min nearly doubled the apparent peak frequencies in both the patient and the noise series (P < 0.025). By contrast, the t test method detected far fewer false positive peaks and significantly more peaks in the patient series than in the noise series. Increasing the sampling frequency from every 20 to every 5 min resulted in a 50-75% increase in peak frequency by the t test method. This increase in peak frequency appeared to result from improved detection of small peaks, because samples were obtained nearer the true peaks and nadirs. The resulting increase in the nadir to peak increment made it more likely that a small peak would achieve statistical significance. We conclude that increasingly stringent criteria for pulse detection should be applied as one increases the sampling frequency, and that the t test approach is a more valid method than the 3 CV approach because it yields significantly fewer false positive peaks. This content is only available as a PDF. Copyright © 1984 by The Endocrine Society

Journal

Journal of Clinical Endocrinology and Metabolism – Oxford University Press

Published: Dec 1, 1984

There are no references for this article.