Monthly haemostatic factor variability in women and men
Article first published online: 12 FEB 2014
© 2014 Stichting European Society for Clinical Investigation Journal Foundation
European Journal of Clinical Investigation
Volume 44, Issue 3, pages 309–318, March 2014
How to Cite
Eur J Clin Invest 2014; 44 (3): 309–318
- Issue published online: 12 FEB 2014
- Article first published online: 12 FEB 2014
- Accepted manuscript online: 2 JAN 2014 06:52AM EST
- Manuscript Accepted: 22 DEC 2013
- Manuscript Received: 27 FEB 2013
- NIH. Grant Numbers: 5-U01-HL 049644, HL 049648, HL 049649, HL 049651, HL 049659, M01-NCRR 00645
- NIH Office for Research on Women's Health
- Controlled dietary intervention;
- factor VII;
- menstrual cycle;
- plasminogen activator inhibitor
Hormonal status influences haemostatic factors including fibrinogen, factor VII and plasminogen activator inhibitor (PAI-1), and concentrations differ among men, premenopausal and postmenopausal women. This study examines how phases of the menstrual cycle influence variability of fibrinogen, factor VII and PAI-1.
We studied 103 subjects (39 premenopausal women, 18 postmenopausal women and 46 men) during three, randomized, 8-week energy- and nutrient-controlled experimental diets in the Dietary Effects on Lipids and Thrombogenic Activity (DELTA) Study. Fasting blood samples were collected weekly during the last 4 weeks of each diet period, and haemostatic factors were quantified. Two linear mixed-effects models were used for fibrinogen, factor VII and PAI-1: one to estimate and compare group-specific components of variance, and the other to estimate additional fixed effects representing cyclical functions of day of menstrual cycle in premenopausal women.
Systematic cyclical variation with day of menstrual cycle was observed for fibrinogen (P < 0·0001), factor VII (P = 0·0012) and PAI-1 (P = 0·0024) in premenopausal women. However, the amplitude of cycling was small relative to the total magnitude of intra-individual variability. In addition, the intra-individual variance and corresponding coefficient of variation observed in premenopausal women did not differ from postmenopausal women and men.
The variability in haemostatic factors in premenopausal women is no greater than for postmenopausal women or men. Consequently, premenopausal women can be included in studies investigating haemostatic factor responses without controlling for stage of menstrual cycle.