Bone loss in relation to menopause: a prospective study during 16 years

Area of Science:

• Bone Metabolism and Endocrinology
• Reproductive Health and Aging

Background:

• Bone mineral density (BMD) changes significantly during the menopausal transition.
• Understanding peri- and postmenopausal bone loss is crucial for long-term skeletal health.
• Previous studies have varied in their focus on specific menopausal stages and BMD measurement techniques.

Purpose of the Study:

• To prospectively evaluate bone loss patterns in women during the peri- and postmenopausal periods.
• To determine the relationship between age at menopause and subsequent bone mineral density.
• To identify predictors of bone density at older age based on premenopausal and early menopausal bone status.

Main Methods:

• Prospective study of 156 premenopausal women, followed from age 48 to 64 years.
• Areal bone mineral density (BMD) measured using single-photon absorptiometry (SPA) of the forearm every two years.
• Menopause onset (MP) defined by WHO criteria (12 months amenorrhea and elevated FSH).

Main Results:

• No significant BMD loss was observed in the premenopausal period.
• BMD loss accelerated significantly at menopause onset, independent of chronological age.
• Bone loss rates were highest in the first 5 years post-menopause (2.4% per year) compared to later years (0.4% per year).
• Women with later menopause onset (>53.7 years) experienced greater bone loss in the initial 5 years post-menopause than those with earlier onset (<50.3 years).
• By age 64, BMD did not differ between early and late menopause groups, with no correlation found between age at menopause and BMD at 64.

Conclusions:

• Menopause onset triggers accelerated bone loss, particularly in the early postmenopausal phase.
• While initial postmenopausal bone loss rates vary with age at menopause, BMD levels tend to equalize by age 64.
• Premenopausal BMD at age 48 is a significant predictor of BMD at age 64, irrespective of menopausal timing.