Factors Associated with Sleep Disturbance in Midlife Women

Purpose: The purpose of this secondary analysis is to describe factors associated with sleep disturbance in late pre-menopause and peri-menopause.

Methods: We conducted a secondary analysis of longitudinal data collected every 6 months (Time 1-8). A multiethnic sample of 158 women with a mean age of 48 (SD 2.20) remained in the study at 5 years (Time 8). Data extracted for this analysis include demographics, menopause status (determined by cycle regularity and urine FSH levels using STRAW criteria – a staging system for ovarian aging) anthropometrics (height and weight).  Self-report data used for this analysis included: 1) Pittsburgh Sleep Quality Index (PSQI), 2) perceived general health status (1 = excellent; 5 = poor) and 3) urinary symptoms checklist. 

Results: The women were similar in demographics (age, parity, education, income) despite the racial diversity. The overall sample had poor sleep quality (mean PSQI > 5.0). Nighttime awakenings were prevalent in this sample. Repeated Measures Analysis of Variance indicated that women consistently reported ‘having to get up to use the bathroom’ and ‘waking up in the middle of the night or early in the morning’ over time. At Time 8, urinary leakage was the most frequently reported urinary symptom (50%) with significant race differences (c²  = 12.87, p = 0.001). Over 33% reported waking from sleep three or more times per week regardless of race. Nighttime urinary frequency (nocturia) was correlated with PSQI interrupted sleep (r = 0.53). A linear regression model was developed to account for the variance in nighttime awakenings. Menopause status (pre-menopausal rather than peri- or post-menopausal) was a significant contributor to frequent nighttime awakenings at Time 8. General health status and body mass index (BMI) were also significant contributors. Interestingly, race and age were not significant contributors to nighttime awakenings. 

Conclusion: Sleep disturbance in the form of nighttime awakenings is a significant problem for women in midlife and these symptoms precede menopause. Nocturia was the most prevalent bladder symptom associated with nighttime awakenings. Our findings suggest that menopause stage is a significant factor in the occurrence of nocturia in late pre-menopause. Causation cannot be implied due to the nature of these analyses. Further research is needed to explore the relationship between menopause stage, nocturia and other, less frequent, reasons for nighttime awakenings. Urinary symptoms may be more relevant for women who experience menopause transition at an earlier age. Further research on this phenomenon may help to defray future healthcare costs and morbidity associated with nocturia as a cause of sleep disturbance in pre-menopausal women.