The Association between Sleep and Bone Mineral Density: Cross-Sectional Study Using Health Check-up Data in a Local...

Area of Science:

• Bone and Mineral Research
• Sleep Medicine
• Public Health

Background:

• Bone mineral density (BMD) is crucial for skeletal health.
• Sleep duration is a modifiable lifestyle factor with potential health implications.
• Previous research suggests links between sleep disturbances and various health outcomes, but the specific association with BMD requires further investigation.

Purpose of the Study:

• To examine the association between daily sleep duration and bone mineral density (BMD) in a Japanese population.
• To determine if sleeping less than 7 hours daily is associated with lower BMD.
• To explore the relationship between insomnia and BMD.

Main Methods:

• Utilized data from annual health check-ups in Japan (2020-2022).
• Employed multivariate regression models with BMD as the outcome and sleep duration (<5, 5 to <7, 7 to <9 [reference], ≥9 hours) as the exposure.
• Adjusted for age, BMI, physical activity, smoking, alcohol intake, and menopausal status (for women). BMD was measured by calcaneal quantitative ultrasound (%YAM).

Main Results:

• Included 896 men and 821 women; median age 54-55 years.
• Approximately 80% reported sleeping <7 hours daily.
• No association between sleep duration and BMD was found in men. Women sleeping 5 to <7 hours showed significantly higher BMD (+3.9%, p=0.004) versus 7 to <9 hours. Insomnia showed no association with BMD.

Conclusions:

• Daily sleep duration <7 hours was not independently associated with lower BMD in men and women compared to 7 to <9 hours.
• A potential protective effect of 5 to <7 hours sleep on BMD was observed in women.
• Given potential risks associated with both short and long sleep durations, findings should be interpreted cautiously.