Obesity and fractures in postmenopausal women

Abstract

Low body mass index (BMI) is a recognized risk factor for fragility fracture, whereas obesity is widely believed to be protective. As part of a clinical audit of guidance from the National Institute of Health and Clinical Excellence (NICE), we have documented the prevalence of obesity and morbid obesity in postmenopausal women younger than 75 years of age presenting to our Fracture Liaison Service (FLS). Between January 2006 and December 2007, 1005 postmenopausal women aged less than 75 years with a low-trauma fracture were seen in the FLS. Of these women, 805 (80%) underwent assessment of bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA), and values for BMI were available in 799. The prevalence of obesity (BMI 30 to 34.9 kg/m 2 ) and morbid obesity (BMI ! 35 kg/m 2 ) in this cohort was 19.3% and 8.4%, respectively. Normal BMD was reported in 59.1% of obese and 73.1% of morbidly obese women, and only 11.7% and 4.5%, respectively, had osteoporosis ( p < .0001). Multiple regression analysis revealed significant negative associations between hip T-score and age ( p < .0001) and significant positive associations with BMI ( p < .0001) and previous fracture ( p ¼ .001). Our results demonstrate a surprisingly high prevalence of obesity in postmenopausal women presenting to the FLS with low-trauma fracture. Most of these women had normal BMD, as measured by DXA. Our findings have important public heath implications in view of the rapidly rising increase in obesity in many populations and emphasize the need for further studies to establish the pathogenesis of fractures in obese individuals and to determine appropriate preventive strategies. ß

Subtrochanteric/femoral shaft Versus hip fractures: Incidences and identification of risk factors

“…Obesity is often found to be a protective factor against hip fracture; (28,29) however, excess subcutaneous fat with less lean mass may alter the gait, thus predisposing individuals to falls. Indeed, obesity modifies the mechanical impact at the hip, which may consequently be transmitted to the diaphysis, (30) where the adipose tissue may have less shock-absorbing effect than at the hip. We also found that higher age is protective against ST/FS fractures.…”

Obesity and fracture in men and women: An epidemiologic perspective

“…In fact, the mean BMI for postmenopausal women presenting with a fracture in a UK study was 27.4 kg/m 2 , and 28% of cases were obese (BMI 30 kg/m 2 ). (30) In the Million Women Study in the UK, almost one-half of all postmenopausal hip fractures occurred in women who were overweight or obese: 40% were overweight (BMI 25-29.9 kg/m 2 ) and 9% were obese (BMI 30 kg/m 2 ). (17) In a large longitudinal study of older U.S. men, 68% of all incident clinical fractures and 62% of incident hip fractures occurred in those who were overweight or obese; 19% of all clinical fractures and 13% of hip fractures occurred in obese men.…”

Fat mass accumulation compromises bone adaptation to load in finnish women: A cross-sectional study spanning three generations

“…(20) There are strong reasons to expect a pathophysiologic linkage between fat and bone tissue. Osteoblasts and adipocytes in bone marrow originate from the same mesenchymal stem cells, (21) normal aging is associated with a high incidence of both osteoporosis and bone marrow adiposity, (22,23) and both bone remodeling and adiposity are regulated by the hypothalamus and sympathetic nervous system.…”