Relationship of Weight, Height, and Body Mass Index With Fracture Risk at Different Sites in Postmenopausal Women: The Global Longitudinal Study of Osteoporosis in Women (GLOW)

Abstract

Low body mass index (BMI) is a well-established risk factor for fracture in postmenopausal women. Height and obesity have also been associated with increased fracture risk at some sites. We investigated the relationships of weight, BMI, and height with incident clinical fracture in a practice-based cohort of postmenopausal women participating in the Global Longitudinal study of Osteoporosis in Women (GLOW). Data were collected at baseline and 1, 2, and 3 years. For hip, spine, wrist, pelvis, rib, upper arm/shoulder, clavicle, ankle, lower leg, and upper leg fractures, we modeled the time to incident self-reported fracture over a 3-year period using the Cox proportional hazards model and fitted the best linear or non-linear models containing height, weight, and BMI. Of 52,939 women, 3628 (6.9%) reported an incident clinical fracture during the 3-year follow-up period. Linear BMI showed a significant inverse association with hip, clinical spine, and wrist fractures: adjusted hazard ratios (HRs) (95% confidence intervals [CIs]) per increase of 5 kg/m2 were 0.80 (0.71–0.90), 0.83 (0.76–0.92), and 0.88 (0.83–0.94), respectively (all p < 0.001). For ankle fractures, linear weight showed a significant positive association: adjusted HR per 5-kg increase 1.05 (1.02–1.07) (p < 0.001). For upper arm/shoulder and clavicle fractures, only linear height was significantly associated: adjusted HRs per 10-cm increase were 0.85 (0.75–0.97) (p = 0.02) and 0.73 (0.57–0.92) (p = 0.009), respectively. For pelvic and rib fractures, the best models were for non-linear BMI or weight (p = 0.05 and 0.03, respectively), with inverse associations at low BMI/body weight and positive associations at high values. These data demonstrate that the relationships between fracture and weight, BMI, and height are site-specific. The different associations may be mediated, at least in part, by effects on bone mineral density, bone structure and geometry, and patterns of falling.

Current and past menstrual status is an important determinant of femoral neck geometry in exercising women

“…The lower the weight and height, the greater the odds of low BMD and low femoral neck geometry and strength, respectively. These results are not surprising, given that low body weight is a known risk factor for low BMD [49] and fracture [55]. Possible reasons for the direct relation between body weight and bone health include greater mechanical force on the bone during weight-bearing activities and greater production of hormones with higher bodyweight [49].…”

A review of lifestyle, smoking and other modifiable risk factors for osteoporotic fractures

“…79 The GLOW study recently showed that the relationship between fracture and weight, BMI and height is surprisingly site-specific. 82 Thus, whereas BMI showed a significant inverse association with hip, clinical spine and wrist fractures, weight was ignificantly associated with the risk of malleolar fractures. For upper arm/shoulder and clavicle fractures, only linear height was significantly associated.…”

“…Further suggestions are nutritional deficiencies of protein or vitamin D, decreased padding over the greater trochanter or a greater liability to fall. 15,82 The association between BMI and fracture risk is complex, differs across skeletal sites and is modified by the interaction between BMI and BMD.…”

The pathophysiological basis of bone tissue alterations associated with eating disorders

“…In particular, recent studies have shown that an increased abdominal fat tissue could be considered a risk factor for bone loss and osteoporosis [95][96][97]. Interestingly, in men obesity correlates with hypogonadism, changes in body composition, glucose tolerance alteration, increased cardiovascular risk factors, and osteoporosis [46], strongly suggesting the lack of gender-specific events.…”