Obesity Is Not Protective against Fracture in Postmenopausal Women: GLOW

Fractures may be associated with higher morbidity in obese postmenopausal women than in nonobese women. We compared health-care utilization, functional status, and health-related quality of life (HRQL) in obese, nonobese, and underweight women with fractures. Information from the GLOW study, started in 2006, was collected at baseline and at 1, 2, and 3 years. In this subanalysis, self-reported incident clinical fractures, health-care utilization, HRQL, and functional status were recorded and examined. Women in GLOW (n = 60,393) were aged ≥55 years, from 723 physician practices at 17 sites in 10 countries. Complete data for fracture and body mass index were available for 90 underweight, 3,270 nonobese, and 941 obese women with one or more incident clinical fractures during the 3-year follow-up. The median hospital length of stay, adjusted for age, comorbidities, and fracture type, was significantly greater in obese than nonobese women (6 vs. 5 days, p = 0.017). Physical function and vitality score were significantly worse in obese than in nonobese women, both before and after fracture; but changes after fracture were similar across groups. Use of antiosteoporosis medication was significantly lower in obese than in nonobese or underweight women. In conclusion, obese women with fracture undergo a longer period of hospitalization for treatment and have poorer functional status and HRQL than nonobese women. Whether these differences translate into higher economic costs and adverse effects on longer-term outcomes remains to be established.

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 at 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 nonlinear 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/m(2) 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 nonlinear 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.

We examined variations in proportions of hip fractures and major fractures among postmenopausal women using the Global Longitudinal Study of Osteoporosis in Women (GLOW). The proportion of major fractures that were hip fractures varied with age and region, whereas variations in the proportion of fractures that were major fractures appeared modest. In many countries, the World Health Organization fracture risk assessment tool calculates the probability of major fractures by assuming a uniform age-associated proportion of major fractures that are hip fractures in different countries. We further explored this assumption, using data from the GLOW. GLOW is an observational population-based study of 60,393 non-institutionalized women aged ≥55years who had visited practices within the previous 2years. Main outcome measures were self-reported prevalent fractures after the age of 45years and incident fractures during the 2years of follow-up. The adjusted proportion of prevalent and incident major fractures after the age of 45years that were hip fractures was higher in North America (16%, 17%) than in northern (13%, 12%) and southern Europe (10%, 10%), respectively. The proportion of incident major fractures that were hip fractures increased more than five-fold with age, from 6.6% among 55-59-year-olds to 34% among those aged ≥85years. Regional and age-associated variations in the proportion of all incident fractures that were major fractures were less marked, not exceeding 16% and 28%, respectively. The data suggest that there may be regional differences in the proportion of major fractures that are hip fractures in postmenopausal women. In contrast, the regional and age-related variations in the proportion of fractures that are major fractures appear to be modest. However, because of the limited number of fractures in our sample, further studies are necessary to confirm these findings.

Antiosteoporosis medication (AOM) does not abolish fracture risk, and some individuals experience multiple fractures while on treatment. Therefore, criteria for treatment failure have recently been defined. Using data from the Global Longitudinal Study of Osteoporosis in Women (GLOW), we analyzed risk factors for treatment failure, defined as sustaining two or more fractures while on AOM. GLOW is a prospective, observational cohort study of women aged ≥55 years sampled from primary care practices in 10 countries. Self-administered questionnaires collected data on patient characteristics, fracture risk factors, previous fractures, AOM use, and health status. Data were analyzed from women who used the same class of AOM continuously over 3 survey years and had data available on fracture occurrence. Multivariable logistic regression was used to identify independent predictors of treatment failure. Data from 26,918 women were available, of whom 5550 were on AOM. During follow-up, 73 of 5550 women in the AOM group (1.3%) and 123 of 21,368 in the non-AOM group (0.6%) reported occurrence of two or more fractures. The following variables were associated with treatment failure: lower Short Form 36 Health Survey (SF-36) score (physical function and vitality) at baseline, higher Fracture Risk Assessment Tool (FRAX) score, falls in the past 12 months, selected comorbid conditions, prior fracture, current use of glucocorticoids, need of arms to assist to standing, and unexplained weight loss ≥10 lb (≥4.5 kg). Three variables remained predictive of treatment failure after multivariable analysis: worse SF-36 vitality score (odds ratio [OR] per 10-point increase, 0.85; 95% confidence interval [CI], 0.76-0.95; p = 0.004); two or more falls in the past year (OR, 2.40; 95% CI, 1.34-4.29; p = 0.011), and prior fracture (OR, 2.93; 95% CI, 1.81-4.75; p < 0.0001). The C statistic for the model was 0.712. Specific strategies for fracture prevention should therefore be developed for this subgroup of patients.

Regional differences in treatment for osteoporosis. The Global Longitudinal Study of Osteoporosis in Women (GLOW)

Characteristics associated with anti-osteoporosis medication use: Data from the Global Longitudinal Study of Osteoporosis in Women (GLOW) USA cohort

This study aimed to assess how well self-perception of fracture risk, and fracture risk as estimated by the fracture prediction tool FRAX, related to fracture incidence and uptake and persistence of anti-osteoporosis medication among women participating in the Global Longitudinal study of Osteoporosis in Women (GLOW). GLOW is an international cohort study involving 723 physician practices across 10 countries in Europe, North America and Australia. Aged ≥ 55years, 60,393 women completed baseline questionnaires detailing medical history, including co-morbidities, fractures and self-perceived fracture risk (SPR). Annual follow-up included self-reported incident fractures and anti-osteoporosis medication (AOM) use. We calculated FRAX risk without bone mineral density measurement. Of the 39,241 women with at least 1year of follow-up data, 2132 (5.4%) sustained an incident major osteoporotic fracture over 5years of follow-up. Within each SPR category, risk of fracture increased as the FRAX categorisation of risk increased. In GLOW, only 11% of women with a lower baseline SPR were taking AOM at baseline, compared with 46% of women with a higher SPR. AOM use tended to increase in the years after a reported fracture. However, women with a lower SPR who were fractured still reported lower AOM rates than women with or without a fracture but had a higher SPR. These results suggest that SPR captures some aspect of fracture risk not currently measured using conventional fracture prediction tools and is also associated with improved medication uptake.

The role of obesity in fracture risk remains uncertain and inconclusive in postmenopausal women. Our study aimed to assess the relationship between obesity and risk of major osteoporotic fracture (MOF; ie, a clinical fracture of upper arm or shoulder, hip, spine, or wrist) in postmenopausal women, after taking frailty into consideration. We used the data from the Global Longitudinal Study of Osteoporosis in Women (GLOW) 5-year Hamilton cohort for this study. Frailty was measured by a frailty index (FI) of deficit accumulation at baseline. We incorporated an interaction term (obesity × FI) in the Cox proportional hazards regression model. We included 3985 women (mean age 69.4 years) for analyses, among which 29% were obese (n = 1118). There were 200 (5.02%) MOF events documented during follow-up: 48 (4.29%) in obese women and 152 (5.65%) in the nonobese group. Significant relationships between obesity, frailty, and MOF risk were found: hazard ratio (HR) = 0.72 (95% confidence interval [CI] 0.67-0.78) for those with an FI of zero regarding MOF risk among obese women, and HR = 1.34 (95% CI 1.11-1.62) per SD increase in the FI among nonobese women. The interaction term was also significant: HR = 1.16 (95% CI 1.02-1.34) per SD increase in the FI among obese women. Increased HRs were found with higher FIs regarding the relationship between obesity and MOF risk, indicating increasing frailty attenuated the protective effect of obesity. For example, although the HR for obesity and MOF risk among those who were not frail (FI = 0) was 0.72 (95% CI 0.67-0.78), among those who were very frail (FI = 0.70), the HR was 0.91 (95% CI 0.85-0.98). To conclude, after taking frailty into consideration, obesity was significantly associated with decreased risk of MOF in postmenopausal women among those who were not frail; however, increasing frailty attenuated this protective effect of obesity. Evaluating frailty status may aid in understanding of the complex relationship between obesity and fracture risk. © 2020 American Society for Bone and Mineral Research (ASBMR).

Previous fractures of the hip, spine, or wrist are well-recognized predictors of future fracture, but the role of other fracture sites is less clear. We sought to assess the relationship between prior fracture at 10 skeletal locations and incident fracture. The Global Longitudinal Study of Osteoporosis in Women (GLOW) is an observational cohort study being conducted in 17 physician practices in 10 countries. Women aged ≥55 years answered questionnaires at baseline and at 1 and/or 2 years (fractures in previous year). Of 60,393 women enrolled, follow-up data were available for 51,762. Of these, 17.6%, 4.0%, and 1.6% had suffered 1, 2, or ≥3 fractures, respectively, since age 45 years. During the first 2 years of follow-up, 3149 women suffered 3683 incident fractures. Compared with women with no previous fractures, women with 1, 2, or ≥3 prior fractures were 1.8-, 3.0-, and 4.8-fold more likely to have any incident fracture; those with ≥3 prior fractures were 9.1-fold more likely to sustain a new vertebral fracture. Nine of 10 prior fracture locations were associated with an incident fracture. The strongest predictors of incident spine and hip fractures were prior spine fracture (hazard ratio [HR] = 7.3) and hip (HR = 3.5). Prior rib fractures were associated with a 2.3-fold risk of subsequent vertebral fracture, and previous upper leg fracture predicted a 2.2-fold increased risk of hip fracture. Women with a history of ankle fracture were at 1.8-fold risk of future fracture of a weight-bearing bone. Our findings suggest that a broad range of prior fracture sites are associated with an increased risk of incident fractures, with important implications for clinical assessments and risk model development.

Increased fracture risk has been associated with weight loss in postmenopausal women, but the time course over which this occurs has not been established. The aim of this study was to examine the effects of unintentional weight loss of ≥10 lb (4.5 kg) in postmenopausal women on fracture risk at multiple sites up to 5 years after weight loss. Using data from the Global Longitudinal Study of Osteoporosis in Women (GLOW), we analyzed the relationships between self-reported unintentional weight loss of ≥10 lb at baseline, year 2, or year 3 and incident clinical fracture in the years after weight loss. Complete data were available in 40,179 women (mean age ± SD 68 ± 8.3 years). Five-year cumulative fracture rate was estimated using the Kaplan-Meier method, and adjusted hazard ratios for weight loss as a time-varying covariate were calculated from Cox multiple regression models. Unintentional weight loss at baseline was associated with a significantly increased risk of fracture of the clavicle, wrist, spine, rib, hip, and pelvis for up to 5 years after weight loss. Adjusted hazard ratios showed a significant association between unintentional weight loss and fracture of the hip, spine, and clavicle within 1 year of weight loss, and these associations were still present at 5 years. These findings demonstrate increased fracture risk at several sites after unintentional weight loss in postmenopausal women. This increase is found as early as 1 year after weight loss, emphasizing the need for prompt fracture risk assessment and appropriate management to reduce fracture risk in this population. © 2016 American Society for Bone and Mineral Research.

SummaryWe compared self-perception of fracture risk with actual risk among 60,393 postmenopausal women aged ≥55 years, using data from the Global Longitudinal Study of Osteoporosis in Women (GLOW). Most postmenopausal women with risk factors failed to appreciate their actual risk for fracture. Improved education about osteoporosis risk factors is needed.IntroductionThis study seeks to compare self-perception of fracture risk with actual risk among postmenopausal women using data from GLOW.MethodsGLOW is an international, observational, cohort study involving 723 physician practices in 17 sites in ten countries in Europe, North America, and Australia. Participants included 60,393 women ≥55 years attended by their physician during the previous 24 months. The sample was enriched so that two thirds were ≥65 years. Baseline surveys were mailed October 2006 to February 2008. Main outcome measures were self-perception of fracture risk in women with elevated risk vs women of the same age and frequency of risk factors for fragility fracture.ResultsIn the overall study population, 19% (10,951/58,434) of women rated their risk of fracture as a little/much higher than that of women of the same age; 46% (27,138/58,434) said it was similar; 35% (20,345/58,434) believed it to be a little/much lower. Among women whose actual risk was increased based on the presence of any one of seven risk factors for fracture, the proportion who recognized their increased risk ranged from 19% for smokers to 39% for current users of glucocorticoid medication. Only 33% (4,185/12,612) of those with ≥2 risk factors perceived themselves as being at higher risk. Among women reporting a diagnosis of osteopenia or osteoporosis, only 25% and 43%, respectively, thought their risk was increased.ConclusionIn this international, observational study, most postmenopausal women with risk factors failed to appreciate their actual risk for fracture.

SummaryThe Global Longitudinal study of Osteoporosis in Women (GLOW) is a prospective cohort study involving 723 physicians and 60,393 women subjects ≥55 years. The data will provide insights into the management of fracture risk in older women over 5 years, patient experience with prevention and treatment, and distribution of risk among older women on an international basis.IntroductionData from cohort studies describing the distribution of osteoporosis-related fractures and risk factors are not directly comparable and do not compare regional differences in patterns of patient management and fracture outcomes.MethodsThe GLOW is a prospective, multinational, observational cohort study. Practices typical of each region were identified through primary care networks organized for administrative, research, or educational purposes. Noninstitutionalized patients visiting each practice within the previous 2 years were eligible. Self-administered questionnaires were mailed, with 2:1 oversampling of women ≥65 years. Follow-up questionnaires will be sent at 12-month intervals for 5 years.ResultsA total of 723 physicians at 17 sites in ten countries agreed to participate. Baseline surveys were mailed (October 2006 to February 2008) to 140,416 subjects. After the exclusion of 3,265 women who were ineligible or had died, 60,393 agreed to participate.ConclusionsGLOW will provide contemporary information on patterns of management of fracture risk in older women over a 5-year period. The collection of data in a similar manner in ten countries will permit comparisons of patient experience with prevention and treatment and provide insights into the distribution of risk among older women on an international basis.

ObjectiveTo examine when, where and how fractures occur in postmenopausal women.MethodsWe 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.ResultsAmong 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.ConclusionIn 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.

The epidemiology and pathogenesis of fractures in postmenopausal women has previously been investigated in the Global Longitudinal study of Osteoporosis in Women (GLOW). To date, however, relationships between bone imaging outcomes and fracture have not been studied in this cohort. We examined relationships between high-resolution peripheral quantitative computed tomography (HRpQCT) parameters and fracture in the UK arm of GLOW, performing a cluster analysis to assess if our findings were similar to observations reported from older participants of the Hertfordshire Cohort Study (HCS), and extended the analysis to include tibial measurements. We recorded fracture events and performed HRpQCT of the distal radius and tibia and dual-energy X-ray absorptiometry (DXA) of the hip in 321 women, mean age 70.6 (SD 5.4) years, identifying four clusters at each site. We saw differing relationships at the radius and tibia. Two radial clusters (3 and 4) had a significantly lower hip areal bone mineral density (p < 0.001) compared to Cluster 1; only individuals in Cluster 4 had a significantly higher risk of fracture (p = 0.005). At the tibia, clusters 1, 3 and 4 had lower hip areal bone mineral density (p < 0.001) compared to Cluster 2; individuals in Cluster 3 had a significantly higher risk of fracture (p = 0.009). In GLOW our findings at the radius were very similar to those previously reported in the HCS, suggesting that combining variables derived from HRpQCT may give useful information regarding fracture risk in populations where this modality is available. Further data relating to tibial HRpQCT-phenotype and fractures are provided in this paper, and would benefit from validation in other studies. Differences observed may reflect age differences in the two cohorts.

The purpose of this study is to identify factors associated with concern and perception of risks of osteoporosis and osteoporotic fractures and determine whether bone mineral density (BMD) testing influenced concern and risk perception. Study subjects (n = 1,082, age 55-94years) were female Australian participants of the Global Longitudinal Study of Osteoporosis in Women (GLOW). Self-administered questionnaires were sent annually from 2007 to 2010. Study outcomes included 'concern about osteoporosis', 'perception of getting osteoporosis' and 'perception of fracture risk' compared to similar aged women. The closest post-BMD testing or baseline questionnaires were used for women with and without BMD testing, respectively. Multinomial logistic regression was used for the analysis. BMD testing, prior fracture after age 45, younger age and lower self-reported general health were significantly associated with being 'very' or 'somewhat concerned' about osteoporosis and having a 'much higher' or 'little higher' risk perception of osteoporosis and fractures. A poorer BMD result was associated with higher concern and higher risk perceptions. The presence of comorbidities, having ≥2 falls in the preceding year and maternal osteoporosis were associated with higher concern. Maternal osteoporosis, presence of comorbidities, weight loss of ≥5kg in the preceding year and low body mass index were associated with higher perceptions of osteoporosis risk. Women's concern and risk perception of osteoporosis and osteoporotic fractures were reasonably well founded. However, increasing age, height loss, smoking and drinking were not associated with concern and perception despite being known osteoporosis risk factors. These factors should be considered in planning for education and awareness raising programmes.