Menstrual Cycle Patterns and Their Determinants during the Menopausal Transition among a ...

150 Pages·2012·0.98 MB·English

Menstrual Cycle Patterns and Their Determinants during the
Menopausal Transition among a Multiethnic Cohort of Women

by

Pangaja Paramsothy

A dissertation submitted in partial fulfillment
of the requirements for the degree of
Doctor of Philosophy
(Epidemiological Science)
in The University of Michigan
2012

Doctoral Committee:

Professor Siobán D. Harlow, Chair
Professor John F. Randolph Jr.
Associate Professor Michael R. Elliott
Associate Professor Lynda D. Lisabeth
© Pangaja Paramsothy
2012
ACKNOWLEDGEMENTS

I first like to thank my academic advisor and dissertation committee chair, Dr.
Harlow for her mentorship, encouragement, and support during my time here at the
University of Michigan. I would also like to thank my dissertation committee: Dr.
Randolph, Dr. Elliott, and Dr. Lisabeth for their support, guidance, and feedback. Their
involvement strengthened this work.
I would like to thank Matheos Yosef for sharing his statistical expertise with
quantile regression. His patience and kindness is very much appreciated.
I would also like to thank Nancy Vander Kuyl for her administrative support and most
importantly her moral support and her cheerleading throughout my time here.
I would like to thank my SWAN site coauthors: Dr. Crawford, Dr. Gold, and Dr.
Greendale for their timely feedback and suggestions.
I am indebted to the SWAN staff at all study sites for their years of hard work. I
would also like to express my gratitude to the SWAN participants. Their steadfast
dedication in filling out the SWAN Menstrual Calendar made this research possible.
I gratefully acknowledge funding support from the Rackham Graduate School of
University of Michigan as well as the Department of Epidemiology, University of
Michigan School of Public Health. Their financial support made it possible for me to
achieve my degree.

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On a personal note, I would like to thank my fellow doctoral students for their
friendship and support. I would especially like to acknowledge Sandra Albrecht, Kristin
King Sznajder, and Mariana Rosenthal for sharing their wisdom and helping me navigate
through the doctoral program.
Finally, I would like to thank my family for their love and support, especially my
mother for her many sacrifices. I would not have achieved my dreams without her
support.

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TABLE OF CONTENTS

ACKNOWLEDGEMENTS ................................................................................................ ii
LIST OF FIGURES .......................................................................................................... vii
LIST OF TABLES ........................................................................................................... viii
LIST of APPENDICIES .................................................................................................... ix
ABSTRACT ........................................................................................................................ x
CHAPTER I ........................................................................................................................ 1
Introduction ............................................................................................................. 1
Dissertation Aims.................................................................................................... 5
Background ............................................................................................................. 6
Questionnaires vs. Menstrual Diaries ................................................................... 15
Factors that Influence Menstrual Cycle Characteristics ....................................... 17
Summary and Chapter Overview .......................................................................... 24
References ............................................................................................................. 26
CHAPTER II ..................................................................................................................... 37
Poor Agreement Found Between Staging the Menopausal Transition Using
Annual Interview Questions or Annual Follicle-Stimulating Hormone Measures
and Menstrual Calendars....................................................................................... 37
Introduction ........................................................................................................... 37
Methods................................................................................................................. 38
Results ................................................................................................................... 44
iv
Discussion ............................................................................................................. 50
References ............................................................................................................. 61
CHAPTER III ................................................................................................................... 63
Quantile Regression Models of Factors Associated with Menstrual Cycle Length
During the Menopausal Transition ....................................................................... 63
Introduction ........................................................................................................... 63
Methods................................................................................................................. 64
Results ................................................................................................................... 70
Discussion ............................................................................................................. 73
References ............................................................................................................. 85
CHAPTER IV ................................................................................................................... 89
Abnormal Uterine Bleeding Common during the Menopausal Transition ........... 89
Introduction ........................................................................................................... 89
Methods................................................................................................................. 91
Results ................................................................................................................... 97
Discussion ........................................................................................................... 101
References ........................................................................................................... 113
CHAPTER V .................................................................................................................. 117
Summary of Findings .......................................................................................... 117
Strength and Limitations ..................................................................................... 121
Future Research .................................................................................................. 123
v
Clinical Implications ........................................................................................... 126
Conclusions ......................................................................................................... 127
References ........................................................................................................... 129
APPENDICIES ............................................................................................................... 133
Appendix A ......................................................................................................... 133
Appendix B ......................................................................................................... 135
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LIST OF FIGURES

2.1 An Example of the Comparison Between the Annual Interviews (Baseline and
Visits) to the Menstrual Calendar. ..............................................................................55

2.2 The 2 by 2 Table for Calculation of Cohen’s Kappa Statistic ....................................56

3.1 Kernel Density Plot of Menstrual Cycle Length.........................................................77

3.2 Estimated Cycle Length by Time since the Start of Transition from Multivariate
Quantile Regressions for Four Percentiles: 25th, 50th, 75th and 90th. .................................. 78

3.3 Estimated Cycle Length by Time until FMP from Multivariable Quantile Regressions
for Four Percentiles: 25th, 50th, 75th and 90th. ..................................................................... 79

4.1 Venn Diagram of Potential Abnormal Bleeding Events ........................................................ 106
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LIST OF TABLES

2.1a Baseline Demographics of Women Participating in the SWAN Menstrual Calendar
Study .................................................................................................................................... 57

2.1b Baseline Demographics of Women Participating in the SWAN Menstrual Calendar
Study with at least 10 Consecutive Untreated Non-Missing Cycles Observed by
FMP Status .......................................................................................................................... 58

2.2 Menopausal Transition (MT) Stage by Menstrual Calendar Compared to MT Stage
by Annual Interview among Those with Observed FMP in the Menstrual Calendar .......... 59

2.3 MT Stage by Menstrual Calendar Compared to MT Stage by FSH Level among
Those with Observed FMP in the Menstrual Calendar ....................................................... 60

3.1 Number of Cycles for the Start of the Menopausal Transition Models and the FMP
Models by Exclusion Criteria. ............................................................................................. 80

3.2 Baseline Demographics of Women in SWAN by Eligibility............................................... 81

3.3 Adjusted Menstrual Cycle Length Differences in Days among Women Since Start of
the Menopausal Transition, by Percentile ........................................................................... 83

3.4 Adjusted Menstrual Cycle Length Differences in Days among Women until the FMP
by Percentile ........................................................................................................................ 84

4.1 Baseline Demographics of Women in SWAN by Participation in
Menstrual Calendar Substudy ............................................................................................. 107

4.2 Number of Menstrual Cycles (51,606) by Bleeding Characteristic .................................... 108

4.3 Cumulative Percent of Women with at least 1, 2, or 3 Episodes of Bleeding Event
Observed ............................................................................................................................ 109

4.4 Logistic Regression Models for Menses Duration of 10 or More Days ............................. 110

4.5 Logistic Regression Models for Menses with Spotting of 6 or More days ......................... 111

4.6 Logistic Regression Models for Menses with Heavy bleeding of 3 or More Days ............ 112

viii
LIST of APPENDICIES

Appendix A .................................................................................................................................. 133

Appendix B .................................................................................................................................. 135

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