When, where and how osteoporosis-associated fractures occur: an analysis from the Global Longitudinal Study of Osteoporosis in Women (GLOW)

Abstract

Objective: To examine when, where and how fractures occur in postmenopausal women.

Methods: We analyzed data from the Global Longitudinal Study of Osteoporosis in Women (GLOW), including women aged ≥55 years from the United States of America, Canada, Australia and seven European countries. Women completed questionnaires including fracture data at baseline and years 1, 2 and 3.

Results: Among 60,393 postmenopausal women, 4122 incident fractures were reported (86% non-hip, non-vertebral [NHNV], 8% presumably clinical vertebral and 6% hip). Hip fractures were more likely to occur in spring, with little seasonal variation for NHNV or spine fractures. Hip fractures occurred equally inside or outside the home, whereas 65% of NHNV fractures occurred outside and 61% of vertebral fractures occurred inside the home. Falls preceded 68-86% of NHNV and 68-83% of hip fractures among women aged ≤64 to ≥85 years, increasing with age. About 45% of vertebral fractures were associated with falls in all age groups except those ≥85 years, when only 24% occurred after falling.

Conclusion: In this multi-national cohort, fractures occurred throughout the year, with only hip fracture having a seasonal variation, with a higher proportion in spring. Hip fractures occurred equally within and outside the home, spine fractures more often in the home, and NHNV fractures outside the home. Falls were a proximate cause of most hip and NHNV fractures. Postmenopausal women at risk for fracture need counseling about reducing potentially modifiable fracture risk factors, particularly falls both inside and outside the home and during all seasons of the year.

Figure 1. Seasonal variation of fracture rates according to fracture site.

Significant differences for each season within fracture types (P<0.05) are denoted by an asterisk. NHNV, non-hip, non-vertebral.

Figure 2. Location of occurrence of fracture by fracture type.

Significant differences for each location within fracture types (P<0.05) are denoted by an asterisk. NHNV, non-hip, non-vertebral.

Figure 3. Cause of fracture by fracture type.

Significant differences for each cause between fracture types (P<0.05) are denoted by an asterisk. Dagger denotes response only available on year 3 survey. NHNV, non-hip, non-vertebral.

Figure 4. Cause of fractures by age group.

A, For hip fractures. B, For spine fractures. C, For NHNV fractures. NHNV, non-hip, non-vertebral.