Relationship of body mass index with main limb fragility fractures in postmenopausal women.
ABSTRACT Body mass index (BMI) has been found to be related to the risk of osteoporotic hip fractures in women, regardless of bone mineral density (BMD). The same relationship is under debate for other limb fragility fractures. Very few studies have investigated the comparison of fracture risk among BMI categories, classified according to the WHO criteria, despite the potential usefulness of such information for clinical purposes. To address these issues we studied 2,235 postmenopausal women including those with fragility fractures of the hip (187), ankle (108), wrist (226) and humerus (85). Statistical analyses were performed by logistic regression by treating the fracture status as the dependent variable and age, age at menopause, femoral neck BMD and BMI as covariates. BMI was tested as a continuous or categorical variable. As a continuous variable, increased BMI had a protective effect against hip fracture: OR 0.949 (95% CI, 0.900-0.999), but carried a higher risk of humerus fracture: OR 1.077 (95% CI, 1.017-1.141). Among the BMI categories, only leanness: OR 3.819 (95% CI, 2.035-7.168) and obesity: OR 3.481 (95% CI, 1.815-6.678) showed a significantly higher fracture risk for hip and humerus fractures, respectively. There was no relationship between ankle and wrist fractures and BMI. In conclusion, decreasing BMI increases the risk for hip fracture, whereas increasing BMI increases the risk for humerus fractures. Leanness-related low BMD and obesity-related body instability might explain the different BMI relationships with these two types of fracture.
- Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research 02/2014; 29(2). · 6.04 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Obesity was commonly thought to be advantageous for maintaining healthy bones due to the higher bone mineral density observed in overweight individuals. However, several recent studies have challenged the widespread belief that obesity is protective against fracture and have suggested that obesity is a risk factor for certain fractures. The effect of obesity on fracture risk is site-dependent, the risk being increased for some fractures (humerus, ankle, upper arm) and decreased for others (hip, pelvis, wrist). Moreover, the relationship between obesity and fracture may also vary by sex, age, and ethnicity. Risk factors for fracture in obese individuals appear to be similar to those in nonobese populations, although patterns of falling are particularly important in the obese. Research is needed to determine if and how visceral fat and metabolic complications of obesity (type 2 diabetes mellitus, insulin resistance, chronic inflammation, etc) are causally associated with bone status and fragility fracture risk. Vitamin D deficiency and hypogonadism may also influence fracture risk in obese individuals. Fracture algorithms such as FRAX(®) might be expected to underestimate fracture probability. Studies specifically designed to evaluate the antifracture efficacy of different drugs in obese patients are not available; however, literature data may suggest that in obese patients higher doses of the bisphosphonates might be required in order to maintain efficacy against nonvertebral fractures. Therefore, the search for better methods for the identification of fragility fracture risk in the growing population of adult and elderly subjects with obesity might be considered a clinical priority which could improve the prevention of fracture in obese individuals.Clinical Interventions in Aging 01/2014; 9:1629-1636. · 2.65 Impact Factor
Article: Obesity and fracture risk.[Show abstract] [Hide abstract]
ABSTRACT: Obesity and osteoporosis are two common diseases with an increasing prevalence and a high impact on morbidity and mortality. Obese women have always been considered protected against osteoporosis and osteoporotic fractures. However, several recent studies have challenged the widespread belief that obesity is protective against fracture and have suggested that obesity is a risk factor for certain fractures. Fat and bone are linked by many pathways, which ultimately serve the function of providing a skeleton appropriate to the mass of adipose tissue it is carrying. Leptin, adiponectin, adipocytic estrogens and insulin/amylin are involved in this connection. However, excessive body fat, and particularly abdominal fat, produces inflammatory cytokines which may stimulate bone resorption and reduce bone strength. This review aimed to examine the literature data on the relationships of BMI and fat mass with factures in adult and elderly subjects. Even though the more recent studies have shown conflicting results, there is growing evidence that obesity, and particularly severe obesity, may be related to an increased risk of fracture at different skeletal sites which is partially independent from BMD. Moreover, the relationship between obesity and fracture appears to be markedly influenced by ethnicity, gender and fat distribution. Even though the incidence and the pathogenesis of fracture in obese individuals has not yet been clearly defined, the growing evidence that obesity may be related to an increased risk of fracture has important public health implications and emphasizes the need to develop effective strategies to reduce fracture risk in obese subjects.01/2014; 11(1):9-14.