Relationships Between Risk Factors and Fractures Differ by Type of Fracture: A Population-Based Study of 12192 Perimenopausal Women

Relationship between selected factors and fractures according to type of fracture were retrospectively examined in 12192 women aged 47–56 years responding to the baseline postal enquiry of the Kuopio Osteoporosis Study, Finland, in 1989. A total of 1358 women reported fractures sustained during the previous 9.4 years, i.e. at ages 38–57 years. The incidence of fractures per 1000 person-years was 17.2 after menopause and 9.5 before (p < 0.0001). The adjusted fracture risk was elevated in smokers versus non-smokers (OR: 1.5; (95%CI = 1.3–1.9) and in those with chronic health disorders versus the healthy (OR = 1.3; 95% CI 1.1–1.5). Long-term work disability was associated with fractures independently of health disorders (OR = 1.3; 95% CI 1.1–1.6). Anthropometric measures were not associated with the overall fracture risk. Menopause was strongly and linearly related to wrist fracture but not to ankle fracture. A 1 SD increase in body mass index decreased the risk of wrist fracture by 21% (p = 0.0001) but increased that of ankle fracture by 24% (p = 0.002). Smoking was related to ankle fracture (OR = 2.2; 95% CI 1.6–3.2) but not to wrist fracture (OR = 0.9; 95% CI 0.6–1.4). Health disorders were more markedly associated with fractures other than those of the wrist or ankle. Relationships between several risk factors and pre- and perimenopausal fractures vary by type of fracture. This may affect, for example, the comparability of studies with varying fracture profiles.