Relation of daily urinary hormone patterns to vasomotor symptoms in a racially/ethnically diverse sample of midlife women: Study of women's health across the nation

The associations of urinary pregnanediol-glucuronide (PdG) levels and menstrual bleeding and their modification of associations of other risk factors with vasomotor symptoms (VMS) are examined. Daily urine samples were collected for 1 menstrual cycle or 50 days if no bleeding occurred. Participants (n = 742) were aged 43 to 54 years, not using exogenous hormones, not pregnant, had an intact uterus and > 1 ovary, and menstruated in the prior 3 months. Multivariate analyses were performed of urinary hormone metabolites and within-woman proportion of days reporting VMS. VMS reporting was 4-fold greater (P =.0005) in women whose urine collections ended without bleeding. In collections with PdG levels suggestive of ovulatory activity according to the work of Kassam et al, VMS are significantly associated with obesity, early perimenopause, and increasing PdG levels. In collections with lower PdG concentrations, VMS are significantly increased with no bleeding, smoking, higher age, physical activity, follicle-stimulating hormone, and luteinizing hormone and are significantly reduced with increasing estrogen concentrations.