Trends in the incidence of hip fracture in Gran Canaria, Canary Islands, Spain: 2007-2011 versus 1989-1993

Hip fracture incidence in the Canaries was studied in two 5-year periods (1989-1993 and 2008-2011). The incidence in 2007-2011 was 24 % higher than in 1989, but did not differ between 2007-2011 and 1993. These findings suggest a trend to stabilize the incidence of hip fracture.

INTRODUCTION

A dramatic increase in hip fractures between 1988 and 2002 was reported in Northern Spain. We performed the present study in Gran Canaria, the Canary Islands, to compare changes in the incidence of hip fracture between 1989-1993 and 2007-2011.

METHODS

We recorded every osteoporotic hip fracture admitted to any hospital in Gran Canaria in the population 50 years of age or older.

RESULTS

In 1989-1993, we collected 1175 hip fractures (72 % women; mean age 78.2 ± 9.9 years), and the total incidence rate was 152.1 cases/100,000 population/year. In 2007-2011, we collected 2222 hip fracture cases (71 % women; mean age 79 ± 9.8 years). The total incidence was 180.9/100,000/year. A Poisson model showed that the incidence of fractures increased by 7.1 % (95 % CI = 3.1 %; 11.8 %) each year in 1989-1993, while there was no statistically significant variation (p = 0.515) during the period 2007-2011. The incidence in 2007-2011 was 24 % higher than in 1989 (first year in the first period) but did not differ between 2007-2011 and 1993 (the last year of the first period). Incidence rates were 76.7 % (95 % CI = 63.9 %; 90.5 %) higher in women than in men, but the female/male ratio remained unchanged. The age-adjusted incidence of hip fractures increased by 7.3 % each year from 1989 to 1993. The proportions of trochanter and cervical fractures were similar in the two time periods, but the mean hospital stay was reduced from 11 days in 1989-1993 to 7 days in 2007-2011.

CONCLUSIONS

These findings suggest a trend to stabilize the incidence of hip fracture in the Canary Islands due to a decrease in men, while in women, the incidence increased.

Impact of femoral neck and lumbar spine BMD discordances on FRAX probabilities in women: a meta-analysis of international cohorts

There are occasional marked discordances in BMD T-scores at the lumbar spine (LS) and femoral neck (FN). We investigated whether such discordances could contribute independently to fracture prediction using FRAX. We studied 21,158 women, average age 63 years, from 10 prospective cohorts with baseline FRAX variables as well as FN and LS BMD. Incident fractures were collected by self-report and/or radiographic reports. Extended Poisson regression examined the relationship between differences in LS and FN T-scores (ΔLS-FN) and fracture risk, adjusted for age, time since baseline and other factors including FRAX 10-year probability for major osteoporotic fracture calculated using FN BMD. To examine the effect of an adjustment for ΔLS-FN on reclassification, women were separated into risk categories by their FRAX major fracture probability. High risk was classified using two approaches: being above the National Osteoporosis Guideline Group intervention threshold or, separately, being in the highest third of each cohort. The absolute ΔLS-FN was greater than 2 SD for 2.5% of women and between 1 and 2 SD for 21%. ΔLS-FN was associated with a significant risk of fracture adjusted for baseline FRAX (HR per SD change = 1.09; 95% CI = 1.04-1.15). In reclassification analyses, only 2.3-3.2% of the women moved to a higher or lower risk category when using FRAX with ΔLS-FN compared with FN-derived FRAX alone. Adjustment of estimated fracture risk for a large LS/FN discrepancy (>2SD) impacts to a large extent on only a relatively small number of individuals. More moderate (1-2SD) discordances in FN and LS T-scores have a small impact on FRAX probabilities. This might still improve clinical decision-making, particularly in women with probabilities close to an intervention threshold.

Fracture risk following bariatric surgery: a population-based study

The effects of bariatric surgery on skeletal health are poorly understood. We found that bariatric surgery patients are more prone to fracture when compared to the general population. While further studies of fracture risk in this population are needed, bone health should be discussed in bariatric surgery clinics.

INTRODUCTION

Bariatric surgery is an increasingly common treatment for medically complicated obesity. Adverse skeletal changes after bariatric surgery have been reported, but their clinical importance remains unknown. We hypothesized that bariatric surgery patients are at increased risk of fracture.

METHODS

We conducted a historical cohort study of fracture incidence among 258 Olmsted County, Minnesota, residents who underwent a first bariatric surgery in 1985-2004. Relative fracture risk was expressed as standardized incidence ratios (SIRs), while potential risk factors were evaluated by hazard ratios (HR) obtained from a time-to-fracture regression model.

RESULTS

The mean (±SD) body mass index at bariatric surgery was 49.0 ± 8.4 kg/m(2), with an average age of 44 ± 10 years and 82% (212) females. Gastric bypass surgery was performed in 94% of cases. Median follow-up was 7.7 years (range, 6 days to 25 years), during which 79 subjects experienced 132 fractures. Relative risk for any fracture was increased 2.3-fold (95% confidence interval (CI), 1.8-2.8) and was elevated for a first fracture at the hip, spine, wrist, or humerus (SIR, 1.9; 95% CI, 1.1-2.9), as well as for a first fracture at any other site (SIR, 2.5; 95% CI, 2.0-3.2). Better preoperative activity status was associated with a lower age-adjusted risk (HR, 0.4; 95% CI, 0.2-0.8) while prior fracture history was not associated with postoperative fracture risk.

CONCLUSIONS

Bariatric surgery, which is accompanied by substantial biochemical, hormonal, and mechanical changes, is associated with an increased risk of fracture.

Long-term mortality following fractures at different skeletal sites: a population-based cohort study

Adjusting for age, sex, and precipitating cause, the relative risk of death was increased following fractures at most skeletal sites.

INTRODUCTION

This study aims to determine long-term survival following fractures due to any cause at each skeletal site.

METHODS

In a historical cohort study, 2,901 Olmsted County, MN, USA, residents ≥35 years old who experienced any fracture in 1989-1991 were followed passively for up to 22 years for death from any cause. Standardized mortality ratios (SMRs) compared observed to expected deaths.

RESULTS

During 38,818 person-years of follow-up, 1,420 deaths were observed when 1,191 were expected (SMR, 1.2; 95 % CI, 1.1-1.3). The overall SMR was greatest soon after fracture, especially among the men, but remained elevated for over a decade thereafter. Adjusting for age and sex, relative death rates were greater for pathological fractures and less for severe trauma fractures compared to the fractures due to no more than moderate trauma. In the latter group, long-term mortality was increased following fractures at many skeletal sites. After further adjustment for precipitating cause, overall SMRs were elevated not only following fractures at the traditional major osteoporotic sites (i.e., distal forearm, proximal humerus, thoracic/lumbar vertebrae, and proximal femur) combined (SMR, 1.2; 95 % CI, 1.1-1.3) but also following all other fracture types combined (SMR 1.2; 95 % CI, 1.1-1.4), excluding the hand and foot fractures not associated with any increased mortality.

CONCLUSIONS

The persistence of increased mortality long after the occurrence of a fracture has generally been attributed to underlying comorbidity, but this needs to be defined in much greater detail if specific opportunities are to be identified for reducing the excess deaths observed.

Cost-effectiveness of bone densitometry among Caucasian women and men without a prior fracture according to age and body weight

We used a microsimulation model to estimate the threshold body weights at which screening bone densitometry is cost-effective. Among women aged 55-65 years and men aged 55-75 years without a prior fracture, body weight can be used to identify those for whom bone densitometry is cost-effective.

INTRODUCTION

Bone densitometry may be more cost-effective for those with lower body weight since the prevalence of osteoporosis is higher for those with low body weight. Our purpose was to estimate weight thresholds below which bone densitometry is cost-effective for women and men without a prior clinical fracture at ages 55, 60, 65, 75, and 80 years.

METHODS

We used a microsimulation model to estimate the costs and health benefits of bone densitometry and 5 years of fracture prevention therapy for those without prior fracture but with femoral neck osteoporosis (T-score ≤ -2.5) and a 10-year hip fracture risk of ≥3%. Threshold pre-test probabilities of low BMD warranting drug therapy at which bone densitometry is cost-effective were calculated. Corresponding body weight thresholds were estimated using data from the Study of Osteoporotic Fractures (SOF), the Osteoporotic Fractures in Men (MrOS) study, and the National Health and Nutrition Examination Survey (NHANES) for 2005-2006.

RESULTS

Assuming a willingness to pay of $75,000 per quality adjusted life year (QALY) and drug cost of $500/year, body weight thresholds below which bone densitometry is cost-effective for those without a prior fracture were 74, 90, and 100 kg, respectively, for women aged 55, 65, and 80 years; and were 67, 101, and 108 kg, respectively, for men aged 55, 75, and 80 years.

CONCLUSIONS

For women aged 55-65 years and men aged 55-75 years without a prior fracture, body weight can be used to select those for whom bone densitometry is cost-effective.

Suppression of uninvolved immunoglobulins defined by heavy/light chain pair suppression is a risk factor for progression of MGUS

We hypothesized that the suppression of uninvolved immunoglobulin in monoclonal gammopathy of undetermined significance (MGUS) as detected by suppression of the isotype-specific heavy and light chain (HLC-pair suppression) increases the risk of progression to malignancy. This approach required quantitation of individual heavy/light chains (for example, IgGλ in IgGκ MGUS patients). Of 1384 MGUS patients from Southeastern Minnesota seen at the Mayo Clinic from 1960 to 1994, baseline serum samples obtained within 30 days of diagnosis were available in 999 persons. We identified HLC-pair suppression in 27% of MGUS patient samples compared with 11% of patients with suppression of uninvolved IgG, IgA or IgM. HLC-pair suppression was a significant risk factor for progression (hazard ratio (HR), 2.3; 95% confidence interval (CI) 1.5-3.7; P<0.001). On multivariate analysis, HLC-pair suppression was an independent risk factor for progression to malignancy in combination with serum M-spike size, heavy chain isotype and free light chain ratio (HR, 1.8; 95% CI, 1.1-3.00; P=0.018). The finding that HLC-pair suppression predicts progression in MGUS and occurs several years before malignant transformation has implications for myeloma biology.

Trends in subtrochanteric, diaphyseal, and distal femur fractures, 1984-2007

The incidence of non-hip femur fractures increased between 1984 and 2007, with an increase in the rates for women after 1996.

INTRODUCTION

Recent reports have suggested that non-hip femur fractures may be decreasing over time, similar to proximal femur fractures.

METHODS

Incidence rates for non-hip femur fractures among Olmsted County, Minnesota, residents were assessed before and after 1995 when the oral bisphosphonate, alendronate, was approved in the USA.

RESULTS

From 1984 to 2007, 727 non-hip femur fractures were observed in 690 Olmsted County residents (51% female [median age, 71.6 years] and 49% male [21.4 years]). Altogether, 20% of the fractures were subtrochanteric, 51% were diaphyseal, and 29% involved the distal femur. Causes included severe trauma in 51%, minimal to moderate trauma in 34%, and pathologic causes in 15%. The overall age- and sex-adjusted annual incidence of first non-hip femur fracture was 26.7 per 100,000 (25.0 per 100,000 for women and 26.6 per 100,000 for men). Incidence rates increased with age and were greater in women than men. Between 1984-1995 and 1996-2007, age-adjusted rates increased significantly for women (20.4 vs. 28.7 per 100,000; p = 0.002) but not for men (22.4 vs. 29.5 per 100,000; p = 0.202).

CONCLUSION

The incidence of first non-hip femur fractures rose between 1984 and 2007, with an increase in the rates for women after 1995.

Lumbar spine bone mineral density in US adults: demographic patterns and relationship with femur neck skeletal status

This analysis examines lumbar spine bone mineral density (BMD) of US adults from NHANES 2005-2008 by age, sex, and race/ethnicity. Prevalence of low spine BMD and agreement between the prevalence of low BMD at the spine and femur neck in older adults are also assessed.

INTRODUCTION

Lumbar spine BMD data from a representative sample of the US population have not been previously available.

METHODS

We used data from the National Health and Nutrition Examination Survey 2005-2008 to examine demographic patterns in lumbar spine BMD among US adults age ≥20 years and the prevalence of low lumbar spine BMD in adults age ≥50 years. Agreement between the prevalence of low BMD at the femur neck and spine in older adults was also assessed. Dual-energy X-ray absorptiometry was used to measure lumbar spine and femur neck BMD. World Health Organization definitions were used to categorize skeletal status as normal, osteopenia, or osteoporosis.

RESULTS

Compared to non-Hispanic whites, non-Hispanic blacks had higher and Mexican Americans had lower lumbar spine BMD. Lumbar spine BMD declined with age in women, but not in men. Approximately 4.7 million (10%) older US women and 1 million (3%) older men had lumbar spine osteoporosis in 2005-2008. Roughly one third of them differed in skeletal status at the spine and hip but most were normal at one site and osteopenic at the other. Only 3-10%, depending on sex, had osteoporosis at one skeletal site but not at the other skeletal site. Between 76% and 87% with discordant skeletal status had lumbar spine T-scores within 1 unit of the category threshold.

CONCLUSIONS

These findings suggest that measuring either the femur neck or the lumbar spine will correctly classify the majority of individuals who present for care as osteoporotic or not.

The potential impact of the National Osteoporosis Foundation guidance on treatment eligibility in the USA: an update in NHANES 2005-2008

This analysis of National Health and Nutrition Examination Survey (NHANES) 2005-2008 data describes the prevalence of risk factors for osteoporosis and the proportions of men and postmenopausal women age 50 years and older who are candidates for treatment to lower fracture risk, according to the new Fracture Risk Assessment Tool (FRAX)-based National Osteoporosis Foundation Clinician's Guide.

INTRODUCTION

It is important to update estimates of the proportions of the older US population considered eligible for pharmacologic treatment for osteoporosis for purposes of understanding the health care burden of this disease.

METHODS

This is a cross-sectional study of the NHANES 2005-2008 data in 3,608 men and women aged 50 years and older. Variables in the analysis included race/ethnicity, age, lumbar spine and femoral neck bone mineral density, risk factor profiles, and FRAX 10-year fracture probabilities.

RESULTS

The prevalence of osteoporosis of the femoral neck ranged from 6.0% in non-Hispanic black to 12.6% in Mexican American women. Spinal osteoporosis was more prevalent among Mexican American women (24.4%) than among either non-Hispanic blacks (5.3%) or non-Hispanic whites (10.9%). Treatment eligibility was similar in Mexican American and non-Hispanic white women (32.0% and 32.8%) and higher than it was in non-Hispanic black women (11.0%). Treatment eligibility among men was 21.1% in non-Hispanic whites, 12.6% in Mexican Americans, and 3.0% in non-Hispanic blacks.

CONCLUSIONS

Nineteen percent of older men and 30% of older women in the USA are at sufficient risk for fracture to warrant consideration for pharmacotherapy.

Changes in femur neck bone density in US adults between 1988-1994 and 2005-2008: demographic patterns and possible determinants

SUMMARY

This analysis compares femur neck bone mineral density (FNBMD) and bone determinants in adults between National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and NHANES 2005-2008. FNBMD was higher in NHANES 2005-2008 than in NHANES III, but between-survey differences varied by age, sex, and race/ethnicity. The likelihood that FNBMD has improved appears strongest for older white women.

INTRODUCTION

Recent data on hip fracture incidence and femur neck osteoporosis suggest that the skeletal status of older US adults has improved since the 1990s, but the explanation for these changes remains uncertain.

METHODS

The present study compares mean FNBMD of adults ages 20 years and older between the third (NHANES III, 1988-1994) and NHANES 2005-2008. Dual-energy X-ray absorptiometry systems (pencil beam in NHANES III, fan beam in NHANES 2005-2008) were used to measure hip BMD, and several bone determinants are compared between surveys to assess their potential role in explaining observed FNBMD differences.

RESULTS

FNBMD was higher overall in NHANES 2005-2008 than in NHANES III, but between-survey differences varied by age, sex, and race/ethnicity. Although FNBMD differences in several groups were small enough (≤3%) to be attributable to use of different dual-energy X-ray absorptiometry (DXA) systems in the two surveys, variability in size and direction of the differences does not support artifactual differences in DXA methodology as the sole explanation. Several FNBMD determinants (body size, smoking, selected bone-active medications, self-reported health status, calcium intake, and caffeine consumption) changed in a bone-improving direction in older adults, but FNBMD in older non-Hispanic white women remained significantly higher in 2005-2008 even after adjusting for DXA methodology or for the selected bone determinants.

CONCLUSION

The likelihood that FNBMD has improved appears strongest for older white women, but the reason for the improvement in this group remains unclear.

Determinants of forearm strength in postmenopausal women

Bone strength at the ultradistal radius, quantified by micro-finite element modeling, can be predicted by variables obtained from high-resolution peripheral quantitative computed tomography scans. The specific formula for this bone strength surrogate (-555.2 + 8.1 × [trabecular vBMD] + 19.6 × [cortical area] + 4.2 × [total cross-sectional area]) should be validated and tested in fracture risk assessment.

INTRODUCTION

The purpose of this study was to identify key determinants of ultradistal radius (UDR) strength and evaluate their relationships with age, sex steroid levels, and measures of habitual skeletal loading.

METHODS

UDR failure load (~strength) was assessed by micro-finite element (μFE) modeling in 105 postmenopausal controls from an earlier forearm fracture case-control study. Predictors of bone strength obtained by high-resolution peripheral quantitative computed tomography (HRpQCT) in this group were then evaluated in a population-based cohort of 214 postmenopausal women. Sex steroids were measured by mass spectrometry.

RESULTS

A surrogate variable (-555.2 + 8.1 × [trabecular vBMD] + 19.6 × [cortical area] + 4.2 × [total cross-sectional area]) predicted UDR strength modeled by μFE (R(2) = 0.81), and all parameters except total cross-sectional area declined with age. Evaluated cross-sectionally, the 21% fall in predicted bone strength between ages 40-49 years and 80+ years more resembled the change in trabecular volumetric bone mineral density (vBMD) (-15%) than that in cortical area (-41%). In multivariable analyses, measures of body composition and physical activity were stronger predictors of UDR trabecular vBMD, cortical area, total cross-sectional area, and predicted bone strength than were sex steroid levels, but bio-available estradiol and testosterone were correlated with body mass.

CONCLUSIONS

Bone strength at the UDR, as quantified by μFE, can be predicted from variables obtained by HRpQCT. Predicted bone strength declines with age with changes in UDR trabecular vBMD and cortical area, related in turn to reduced skeletal loading and sex steroid levels. The predicted bone strength formula should be validated and tested in fracture risk assessment.

Mortality in the vertebroplasty population

BACKGROUND AND PURPOSE

Vertebroplasty is an effective treatment for painful compression fractures refractory to conservative management. Because there are limited data regarding the survival characteristics of this patient population, we compared the survival of a treated with an untreated vertebral fracture cohort to determine whether vertebroplasty affects mortality rates.

MATERIALS AND METHODS

The survival of a treated cohort, comprising 524 vertebroplasty recipients with refractory osteoporotic vertebral compression fractures, was compared with a separate historical cohort of 589 subjects with fractures not treated by vertebroplasty who were identified from the Rochester Epidemiology Project. Mortality was compared between cohorts by using Cox proportional hazards models adjusting for age, sex, and Charlson indices of comorbidity. Mortality was also correlated with pre-, peri-, and postprocedural clinical metrics (eg, cement volume use, RDQ score, analog pain scales, frequency of narcotic use, and improvement in mobility) within the treated cohort.

RESULTS

Vertebroplasty recipients demonstrated 77% of the survival expected for individuals of similar age, ethnicity, and sex within the US population. Compared with individuals with both symptomatic and asymptomatic untreated vertebral fractures, vertebroplasty recipients retained a 17% greater mortality risk. However, compared with symptomatic untreated vertebral fractures, vertebroplasty recipients had no increased mortality following adjustment for differences in age, sex, and comorbidity (HR, 1.02; 95% CI, 0.82-1.25). In addition, no clinical metrics used to assess the efficacy of vertebroplasty were predictive of survival.

CONCLUSIONS

Vertebroplasty recipients have mortality rates similar to those of individuals with untreated symptomatic fractures but have worse mortality compared with those with asymptomatic vertebral fractures.

Secular trends in the incidence of hip and other osteoporotic fractures

Osteoporosis constitutes a major public health problem through its association with age-related fractures, most notably those of the proximal femur. Substantial geographic variation has been noted in the incidence of hip fracture throughout the world, and estimates of recent incidence trends have varied widely. Studies in the published literature have reported an increase, plateau, and decrease in age-adjusted incidence rates for hip fracture among both men and women. Accurate characterisation of these temporal trends is important in predicting the health care burden attributable to hip fracture in future decades. We therefore conducted a review of studies worldwide, addressing secular trends in the incidence of hip and other fractures. Studies in western populations, whether in North America, Europe or Oceania, have generally reported increases in hip fracture incidence through the second half of the last century, but those continuing to follow trends over the last two decades have found that rates stabilise with age-adjusted decreases being observed in certain centres. In contrast, some studies suggest that the rate is rising in Asia. This synthesis of temporal trends in the published literature will provide an important resource for preventing fractures. Understanding the reasons for the recent declines in rates of hip fracture may help understand ways to reduce rates of hip fracture worldwide.

Trabecular bone deficits among Vietnamese immigrants

SUMMARY

Compared to white women, lower areal bone mineral density (aBMD) in middle-aged Vietnamese immigrants is due to reduced trabecular volumetric bone mineral density (vBMD), which in turn is associated with greater trabecular separation along with lower estrogen levels.

INTRODUCTION

The epidemiology of osteoporosis in Asian populations is still poorly known, but we previously found a deficit in lumbar spine aBMD among postmenopausal Southeast Asian women, compared to white women, that persisted after correction for bone size. This issue was revisited using more sophisticated imaging techniques.

METHODS

Twenty Vietnamese immigrants (age, 44-79 years) were compared to 162 same-aged white women with respect to aBMD at the hip, spine and wrist, vBMD at the hip and spine by quantitative computed tomography and vBMD and bone microstructure at the ultradistal radius by high-resolution pQCT. Bone turnover and sex steroid levels were assessed in a subset (20 Vietnamese and 40 white women).

RESULTS

The aBMD was lower at all sites among the Vietnamese women, but femoral neck vBMD did not differ from middle-aged white women. Significant differences in lumbar spine and ultradistal radius vBMD in the Vietnamese immigrants were due to lower trabecular vBMD, which was associated with increased trabecular separation. Bone resorption was elevated and bone formation depressed among the Vietnamese immigrants, although trends were not statistically significant. Serum estradiol was positively associated with trabecular vBMD in the Vietnamese women, but their estrogen levels were dramatically lower compared to white women.

CONCLUSIONS

Although reported discrepancies in aBMD among Asian women are mainly an artifact of smaller bone size, we identified a specific deficit in the trabecular bone among a sample of Vietnamese immigrants that may be related to low estrogen levels and which needs further study.

Hip fracture risk in older US adults by treatment eligibility status based on new National Osteoporosis Foundation guidance

This analysis of National Health and Nutrition Examination Survey III data found a significant risk of incident hip fracture in adults aged 65 years and older who are candidates for treatment to lower fracture risk, according to the new National Osteoporosis Foundation Clinician's Guide.

INTRODUCTION

The relationship between treatment eligibility by the new National Osteoporosis Foundation (NOF) Guide to the Prevention and Treatment of Osteoporosis and the risk of subsequent hip fracture is unknown.

METHODS

The study sample consisted of 3,208 men and women ages 65 years and older who were examined in the third National Health and Nutrition Examination Survey (NHANES III, 1988-1994), a nationally representative survey. Risk factors used to define treatment eligibility at baseline were measured in NHANES III or were simulated using World Health Organization study cohorts. Incident hip fractures were ascertained using linked mortality and Medicare records that were obtained for NHANES III participants through December 31, 2000. Cox proportional hazards models were used to estimate the relative risk (RR) of hip fracture by treatment eligibility status.

RESULTS

The RR for subsequent hip fracture was 4.9 (95% CI 3.30, 7.94) in treatment-eligible vs treatment-ineligible persons. The increased risk for treatment-eligible persons remained statistically significant when examined by sex or age: RR(men) = 5.5 (2.6, 11.4) and RR(women) = 4.3 (2.2, 8.4); RR(65-79 y) = 4.8 (2.6, 8.7) and RR(80+ y) = 4.6 (2.1, 10.1).

CONCLUSIONS

Treatment-eligible persons were about five times more likely to experience a subsequent hip fracture than the non-eligible persons. The new NOF guidelines appear to predict future hip fracture risk equally in men as in women, and fracture risk prediction did not appear to diminish with age.

Assessing forearm fracture risk in postmenopausal women

A diverse array of bone density, structure, and strength parameters were significantly associated with distal forearm fractures in postmenopausal women, but most of them were also correlated with femoral neck areal bone mineral density (aBMD), which provides an adequate measure of bone fragility at the wrist for routine clinical purposes.

INTRODUCTION

This study seeks to test the clinical utility of approaches for assessing forearm fracture risk.

METHODS

Among 100 postmenopausal women with a distal forearm fracture (cases) and 105 with no osteoporotic fracture (controls), we measured aBMD and assessed radius volumetric bone mineral density, geometry, and microstructure; ultradistal radius failure load was evaluated in microfinite element (microFE) models.

RESULTS

Fracture cases had inferior bone density, geometry, microstructure, and strength. The most significant determinant of fracture in five categories were bone density (femoral neck aBMD; odds ratio (OR) per standard deviation (SD), 2.0; 95% confidence interval (CI), 1.4-2.8), geometry (cortical thickness; OR, 1.5; 95% CI, 1.1-2.1), microstructure (structure model index (SMI); OR, 0.5; 95% CI, 0.4-0.7), and strength (microFE failure load; OR, 1.8; 95% CI, 1.3-2.5); the factor-of-risk (applied load in a forward fall / microFE failure load) was 15% worse in cases (OR, 1.9; 95% CI, 1.4-2.6). Areas under receiver operating characteristic curves (AUC) ranged from 0.62 to 0.68. The predictors of forearm fracture risk that entered a multivariable model were femoral neck aBMD and SMI (combined AUC, 0.71).

CONCLUSIONS

Detailed bone structure and strength measurements provide insight into forearm fracture pathogenesis, but femoral neck aBMD performs adequately for routine clinical risk assessment.

The potential impact of new National Osteoporosis Foundation guidance on treatment patterns

This analysis of National Health and Nutrition Examination Survey III data describes the prevalence of risk factors for osteoporosis and the proportions of men and postmenopausal women age 50 years and older who are candidates for treatment to lower fracture risk, according to the new FRAX-based National Osteoporosis Foundation Clinician's Guide.

INTRODUCTION

Little information is available on prevalence of osteoporosis risk factors or proportions of US men and women who are potential candidates for treatment.

METHODS

The prevalence of risk factors used in the new National Osteoporosis Foundation (NOF) FRAX-based Guide to the Prevention and Treatment of Osteoporosis was estimated using data from the third National Health and Nutrition Examination Survey (NHANES III). Risk factors not measured in NHANES III were simulated using World Health Organization cohorts. The proportion of US men and postmenopausal women age 50+ years who are treatment candidates by the new NOF Guide were calculated; for non-Hispanic white (NHW) women, the proportion eligible by the new NOF Guide was compared with that based on an earlier NOF Guide.

RESULTS

Twenty percent of men and 37% of women were potential candidates for treatment to prevent fractures by the new NOF Guide. Among NHW women, 53% were potential candidates by the previous NOF Guide compared with 41% by the new guide.

CONCLUSIONS

One fifth of men and 37% of postmenopausal women are eligible for osteoporosis treatment consideration by the new NOF Guide. However, fewer NHW women are eligible by the new guide than by the previous NOF Guide.

Referral and ascertainment bias in patients with synchronous and metachronous endometrial malignancy

The purpose of this study was to evaluate the frequency in patients with endometrial cancer of other malignancies and the influence of referral and ascertainment biases on these associations. Analysis of 1,028 local and referred patients who had a hysterectomy for endometrial cancer was based on residence at the time of diagnosis. Altogether, 208 patients had a history of another malignancy, most frequently breast, colon, and ovary. At the time of surgery for endometrial cancer, the prevalence of lymphoma and breast and ovarian cancers was greater than expected although the higher prevalence of lymphoma was limited to referred patients. During follow-up after hysterectomy, the incidence of lung cancer was lower than expected, whereas the incidence of lymphoma was higher. Breast, colorectal, and bladder cancers were more common than expected although this finding was limited to local patients. We concluded that results of epidemiologic studies from tertiary care centers may be misleading if they do not account for referral and ascertainment biases.

Updated fracture incidence rates for the US version of FRAX

On the basis of updated fracture and mortality data, we recommend that the base population values used in the US version of FRAX be revised. The impact of suggested changes is likely to be a lowering of 10-year fracture probabilities.

INTRODUCTION

Evaluation of results produced by the US version of FRAX indicates that this tool overestimates the likelihood of major osteoporotic fracture. In an attempt to correct this, we updated underlying fracture and mortality rates for the model.

METHODS

We used US hospital discharge data from 2006 to calculate annual age- and sex-specific hip fracture rates and age-specific ratios to estimate clinical vertebral fracture rates. To estimate the incidence of any one of four major osteoporotic fractures, we first summed these newly derived hip and vertebral fracture estimates with Olmsted County, MN, wrist and upper humerus fracture rates, and then applied 10-20% discounts for overlap.

RESULTS

Compared with rates used in the current FRAX tool, 2006 hip fracture rates are about 16% lower, with greatest reductions observed among those below age 65 years; major osteoporotic fracture rates are about one quarter lower, with similar reductions across all ages.

CONCLUSIONS

We recommend revising the US-FRAX by updating current base population values for hip fracture and major osteoporotic fracture. The impact of these revisions on FRAX is likely to be lowering of 10-year fracture probabilities, but more precise estimates of the impact of these changes will be available after these new rates are incorporated into the FRAX tool.

The effects of a FRAX revision for the USA

A revision (version 3.0) of the fracture risk assessment tool (FRAX) is developed based on an update of epidemiological information for the USA. With the revised tool, there were strong correlations (r > 0.99) between versions 2.0 and 3.0 for FRAX estimates of fracture probability, but the revised models gave lower probability estimates.

INTRODUCTION

The aim of this study was to determine the effects of a revision of the epidemiological data used to compute fracture probabilities in the USA with FRAX.

METHODS

Models were constructed to compute fracture probabilities based on updated fracture incidence and mortality rates in the USA. The models comprised the ten-year probability of hip fracture and the ten-year probability of a major osteoporotic fracture, both including femoral neck bone mineral density (BMD). For each model, fracture and death hazards were computed as continuous functions. The effect of the revised rates on fracture probability was examined by piecewise linear regression using multiple combinations of clinical risk factors and BMD.

RESULTS

At all ages, there was a strong correlation (r > 0.99) between version 2.0 and revised FRAX estimates of fracture probability. For a major osteoporotic fracture, the revised model gave lower median probabilities by 13% to 24% in men, depending on age, and by 19% to 24% in women. For hip fracture probability, the revised model gave lower median fracture probabilities by 40% and 27% at the ages of 50 and 60 years in men and by 43% and 30%, respectively, in women. At the ages of 70 years and older the revised model gave similar hip fracture probabilities as version 2.0 in both men and women.

CONCLUSION

The revised FRAX model for the USA (version 3.0) does not alter the ranking of fracture probabilities but provides lower probability estimates than version 2.0, particularly, in younger women and men.

Incidence and prevalence of CIDP and the association of diabetes mellitus

BACKGROUND

The reported prevalence of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) varies greatly, from 1.9 to 7.7 per 100,000. CIDP is reported to occur more commonly in patients with diabetes mellitus (DM) but has not been rigorously tested.

OBJECTIVES

To determine the incidence (1982-2001) and prevalence (on January 1, 2000) of CIDP in Olmsted County, Minnesota, and whether DM is more frequent in CIDP.

METHODS

CIDP was diagnosed by clinical criteria followed by review of electrophysiology. Cases were coded as definite, probable, or possible. DM was ascertained by clinical diagnosis or current American Diabetes Association glycemia criteria.

RESULTS

One thousand five hundred eighty-one medical records were reviewed, and 23 patients (10 women and 13 men) were identified as having CIDP (19 definite and 4 probable). The median age was 58 years (range 4-83 years), with a median disease duration at diagnosis of 10 months (range 2-64 months). The incidence of CIDP was 1.6/100,000/year. The prevalence was 8.9/100,000 persons on January 1, 2000. Only 1 of the 23 CIDP patients (4%) also had DM, whereas 14 of 115 age- and sex-matched controls (12%) had DM.

CONCLUSIONS

1) The incidence (1.6/100,000/year) and prevalence (8.9/100,000) of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are similar to or higher than previous estimates. 2) The incidence of CIDP is similar to that of acute inflammatory demyelinating polyradiculoneuropathy within the same population. 3) Diabetes mellitus (DM) is unlikely to be a major risk covariate for CIDP, but we cannot exclude a small effect. 4) The perceived association of DM with CIDP may be due to misclassification of other forms of diabetic neuropathies and excessive emphasis on electrophysiologic criteria.

Age, gender, and race/ethnic differences in total body and subregional bone density

SUMMARY

Total body bone density of adults from National Health and Nutrition Examination Survey (NHANES) 1999-2004 differed as expected for some groups (men>women and blacks>whites) but not others (whites>Mexican Americans). Cross-sectional age patterns in bone mineral density (BMD) of older adults differed at skeletal sites that varied by degree of weight-bearing.

INTRODUCTION

Total body dual-energy X-ray absorptiometry (DXA) data offer the opportunity to compare bone density of demographic groups across the entire skeleton.

METHODS

The present study uses total body DXA data (Hologic QDR 4500A, Hologic, Bedford MA, USA) from the NHANES 1999-2004 to examine BMD of the total body and selected skeletal subregions in a wide age range of adult men and women from three race/ethnic groups. Total body, lumbar spine, pelvis, right leg, and left arm BMD and lean mass from 13,091 adults aged 20 years and older were used. The subregions were chosen to represent sites with different degrees of weight-bearing.

RESULTS

Mean BMD varied in expected ways for some demographic characteristics (men>women and non-Hispanic blacks>non-Hispanic whites) but not others (non-Hispanic whites>Mexican Americans). Differences in age patterns in BMD also emerged for some characteristics (sex) but not others (race/ethnicity). Differences in cross-sectional age patterns in BMD and lean mass by degree of weight-bearing in older adults were observed for the pelvis, leg, and arm.

CONCLUSION

This information may be useful for generating hypotheses about age, race, and sex differences in fracture risk in the population.

Secular trends in hip fracture incidence and recurrence

The decline in hip fracture incidence is now accompanied by a further reduction in the likelihood of a recurrent hip fracture among survivors of the first fracture.

INTRODUCTION

Hip fracture incidence is declining in North America, but trends in hip fracture recurrence have not been described.

METHODS

All hip fracture events among Olmsted County, Minnesota residents in 1980-2006 were identified. Secular trends were assessed using Poisson regression, and predictors of recurrence were evaluated with Andersen-Gill time-to-fracture regression models.

RESULTS

Altogether, 2,752 hip fractures (median age, 83 years; 76% female) were observed, including 311 recurrences. Between 1980 and 2006, the incidence of a first-ever hip fracture declined by 1.37%/year for women (p < 0.001) and 0.06%/year for men (p = 0.917). Among 2,434 residents with a first-ever hip fracture, the cumulative incidence of a second hip fracture after 10 years was 11% in women and 6% in men with death treated as a competing risk. Age and calendar year of fracture were independently associated with hip fracture recurrence. Accounting for the reduction in first-ever hip fracture rates over time, hip fracture recurrence appeared to decline after 1997.

CONCLUSION

A recent reduction in hip fracture recurrence is somewhat greater than expected from the declining incidence of hip fractures generally. Additional research is needed to determine the extent to which this can be attributed to improved patient management.

Long-term trends in carpal tunnel syndrome

OBJECTIVE

To assess temporal trends in carpal tunnel syndrome (CTS) incidence, surgical treatment, and work-related lost time.

METHODS

Incident CTS and first-time carpal tunnel release among Olmsted County, Minnesota, residents were identified using the medical records linkage system of the Rochester Epidemiology Project; 80% of a sample were confirmed by medical record review. Work-related CTS was identified from the Minnesota Department of Labor and Industry.

RESULTS

Altogether, 10,069 Olmsted County residents were initially diagnosed with CTS in 1981-2005. Overall incidence (adjusted to the 2000 US population) was 491 and 258 per 100,000 person-years for women vs men (p < 0.0001) and 376 per 100,000 for both sexes combined. Adjusted annual rates increased from 258 per 100,000 in 1981-1985 to 424 in 2000-2005 (p < 0.0001). The average annual incidence of carpal tunnel release surgery was 109 per 100,000, while that for work-related CTS was 11 per 100,000. An increase in young, working-age individuals seeking medical attention for symptoms of less severe CTS in the early to mid-1980s was followed in the 1990s by an increasing incidence in elderly people.

CONCLUSIONS

The incidence of medically diagnosed carpal tunnel syndrome (CTS) accelerated in the 1980s. The cause of the increase is unclear, but it corresponds to an epidemic of CTS cases resulting in lost work days that began in the mid-1980s and lasted through the mid-1990s. The elderly present with more severe disease and are more likely to have carpal tunnel surgery, which may have significant health policy implications given the aging population.

Long-term effects of bilateral oophorectomy on brain aging: unanswered questions from the Mayo Clinic Cohort Study of Oophorectomy and Aging

In the Mayo Clinic Cohort Study of Oophorectomy and Aging, women who had both ovaries removed before reaching natural menopause experienced a long-term increased risk of parkinsonism, cognitive impairment or dementia, and depressive and anxiety symptoms. Here, we discuss five possible mechanistic interpretations of the observed associations; first, the associations may be non-causal because they result from the confounding effect of genetic variants or of other risk factors; second, the associations may be mediated by an abrupt reduction in levels of circulating estrogen; third, the associations may be mediated by an abrupt reduction in levels of circulating progesterone or testosterone; fourth, the associations may be mediated by an increased release of gonadotropins by the pituitary gland; and fifth, genetic variants may modify the hormonal effects of bilateral oophorectomy through simple or more complex interactions. Results from other studies are cited as evidence for or against each possible mechanism. These putative causal mechanisms are probably intertwined, and their clarification is a research priority.

Comparison of sex steroid measurements in men by immunoassay versus mass spectroscopy and relationships with cortical and trabecular volumetric bone mineral density

In men, measurement of serum testosterone and estradiol levels with immunoassays correlated with mass spectroscopic measurements, and correlations of sex steroids with volumetric bone mineral density were similar.

INTRODUCTION

While immunoassays have been used extensively for measurement of serum testosterone (T) and estradiol (E(2)) levels, there is concern about their specificity, particularly at low E(2) levels as present in men.

METHODS

We compared T and E(2) measured by mass spectroscopy to levels measured by immunoassay in men (n = 313, age 22 to 91 years) and related these to volumetric bone mineral density (vBMD) at various skeletal sites.

RESULTS

Serum T and non-SHBG bound (or bioavailable) T levels by immunoassay correlated well with the corresponding mass spectroscopy measurements (R = 0.90 and 0.95, respectively, P < 0.001); the correlations for serum E(2) measured using the two techniques were less robust (R = 0.63 for total E(2) and 0.84 for bioavailable E(2), P < 0.001). Overall relationships between serum bioavailable T and E(2) levels with vBMD at various skeletal sites were similar for the immunoassay and mass spectroscopic measures.

CONCLUSIONS

Although E(2) levels with immunoassay correlate less well with the mass spectroscopic measurements than do the T measurements in men, our findings indicate that the fundamental relationships observed previously between vBMD and the sex steroids by immunoassay are also present with the mass spectroscopic measurements.

Prognostic value of the serum free light chain ratio in newly diagnosed myeloma: proposed incorporation into the international staging system

To determine if the serum free light chain (FLC) ratio has prognostic value in patients with symptomatic multiple myeloma (MM), baseline serum samples from a well-characterized cohort of 790 newly diagnosed MM patients were tested with the FLC assay. FLC ratio was calculated as kappa/lambda (reference range 0.26-1.65). On the basis of the distribution of values, a cutpoint kappa/lambda FLC ratio of <0.03 or >32 was chosen for further analysis. Overall survival was significantly inferior in patients with an abnormal FLC ratio of <0.03 or >32 (n=479) compared with those with an FLC ratio between 0.03 and 32 (n=311), with median survival of 30 versus 39 months, respectively. We incorporated abnormal FLC ratio with the International Staging System (ISS) risk factors (that is, albumin <3.5 g/dl and serum beta(2)-microglobulin >or=3.5 g/l), to create a risk stratification model with improved prognostic capabilities. Patients with 0, 1, 2 or 3 adverse risk factors had significantly different overall survival, with median survival times of 51, 39, 30 and 22 months, respectively (P<0.001). These findings suggest that the serum FLC ratio at initial diagnosis is an important predictor of prognosis in myeloma, and can be incorporated into the ISS for improved risk stratification.

Cost-effective osteoporosis treatment thresholds: the United States perspective

A United States-specific cost-effectiveness analysis, which incorporated the cost and health consequences of clinical fractures of the hip, spine, forearm, shoulder, rib, pelvis and lower leg, was undertaken to identify the 10-year hip fracture probability required for osteoporosis treatment to be cost-effective for cohorts defined by age, sex, and race/ethnicity. A 3% 10-year risk of hip fracture was generally required for osteoporosis treatment to cost less than $60,000 per QALY gained.

INTRODUCTION

Rapid growth of the elderly United States population will result in so many at risk of osteoporosis that economically efficient approaches to osteoporosis care warrant consideration.

METHODS

A Markov-cohort model of annual United States age-specific incidence of clinical hip, spine, forearm, shoulder, rib, pelvis and lower leg fractures, costs (2005 US dollars), and quality-adjusted life years (QALYs) was used to assess the cost-effectiveness of osteoporosis treatment ($600/yr drug cost for 5 years with 35% fracture reduction) by gender and race/ethnicity groups. To determine the 10-year hip fracture probability at which treatment became cost-effective, average annual age-specific probabilities for all fractures were multiplied by a relative risk (RR) that was systematically varied from 0 to 10 until a cost of $60,000 per QALY gained was observed for treatment relative to no intervention.

RESULTS

Osteoporosis treatment was cost-effective when the 10-year hip fracture probability reached approximately 3%. Although the RR at which treatment became cost-effective varied markedly between genders and by race/ethnicity, the absolute 10-year hip fracture probability at which intervention became cost-effective was similar across race/ethnicity groups, but tended to be slightly higher for men than for women.

CONCLUSIONS

Application of the WHO risk prediction algorithm to identify individuals with a 3% 10-year hip fracture probability may facilitate efficient osteoporosis treatment.

Implications of absolute fracture risk assessment for osteoporosis practice guidelines in the USA

Application of the WHO fracture prediction algorithm in conjunction with an updated US economic analysis indicates that osteoporosis treatment is cost-effective in patients with fragility fractures or osteoporosis, in older individuals at average risk and in younger persons with additional clinical risk factors for fracture, supporting existing practice recommendations.

INTRODUCTION

The new WHO fracture prediction algorithm was combined with an updated economic analysis to evaluate existing NOF guidance for osteoporosis prevention and treatment.

METHODS

The WHO fracture prediction algorithm was calibrated to the US population using national age-, sex- and race-specific death rates and age- and sex-specific hip fracture incidence rates from the largely white population of Olmsted County, MN. Fracture incidence for other races was estimated by ratios to white women and men. The WHO algorithm estimated the probability (%) of a hip fracture (or a major osteoporotic fracture) over 10 years, given specific age, gender, race and clinical profiles. The updated economic model suggested that osteoporosis treatment was cost-effective when the 10-year probability of hip fracture reached 3%.

RESULTS

It is cost-effective to treat patients with a fragility fracture and those with osteoporosis by WHO criteria, as well as older individuals at average risk and osteopenic patients with additional risk factors. However, the estimated 10-year fracture probability was lower in men and nonwhite women compared to postmenopausal white women.

CONCLUSIONS

This analysis generally endorsed existing clinical practice recommendations, but specific treatment decisions must be individualized. An estimate of the patient's 10-year fracture risk should facilitate shared decision-making.

Excess mortality following hip fracture: the role of underlying health status

We evaluated the long-term excess mortality associated with hip fracture, using prospectively collected data on pre-fracture health and function from a nationally representative sample of U.S. elders. Although mortality was elevated for the first six months following hip fracture, we found no evidence of long-term excess mortality.

INTRODUCTION

The long-term excess mortality associated with hip fracture remains controversial.

METHODS

To assess the association between hip fracture and mortality, we used prospectively collected data on pre-fracture health and function from a representative sample of U.S. elders in the Medicare Current Beneficiary Survey (MCBS) to perform survival analyses with time-varying covariates.

RESULTS

Among 25,178 MCBS participants followed for a median duration of 3.8 years, 730 sustained a hip fracture during follow-up. Both early (within 6 months) and subsequent mortality showed significant elevations in models adjusted only for age, sex and race. With additional adjustment for pre-fracture health status, functional impairments, comorbid conditions and socioeconomic status, however, increased mortality was limited to the first six months after fracture (hazard ratio [HR]: 6.28, 95% CI: 4.82, 8.19). No increased mortality was evident during subsequent follow-up (HR: 1.04, 95% CI: 0.88, 1.23). Hip-fracture-attributable population mortality ranged from 0.5% at age 65 among men to 6% at age 85 among women.

CONCLUSIONS

Hip fracture was associated with substantially increased mortality, but much of the short-term risk and all of the long-term risk was explained by the greater frailty of those experiencing hip fracture.

Osteoporosis and age-related fracture syndromes

Osteoporosis is one of the most important age-related diseases. Each year in the United States it causes at least 1.2 million fractures and costs 7 to 10 billion dollars. The main cause of the fractures is increased bone fragility due to low bone density, although in the elderly an increase in the frequency of falls and in the trauma produced by the falls also contributes to fractures. Low bone density in osteoporosis has multiple causes which can be grouped into the categories of low initial bone mass and bone loss due to ageing, menopause, and sporadic factors. Given the magnitude of the problem, prevention is the only cost-effective approach. Enough is known about causes of bone loss leading to osteoporosis that an effective programme of prevention can be designed. Its implementation in the population should substantially reduce the incidence of this major public health problem.

Increased risk of parkinsonism in women who underwent oophorectomy before menopause

OBJECTIVE

There is increasing laboratory evidence for a neuroprotective effect of estrogen on the nigrostriatal pathway; however, the epidemiologic evidence remains limited and conflicting. We studied the association of oophorectomy performed before the onset of menopause with the risk of subsequent parkinsonism.

METHODS

We included all women who underwent either unilateral or bilateral oophorectomy before the onset of menopause for a noncancer indication from 1950 through 1987 while residing in Olmsted County, MN. Each member of the oophorectomy cohort was matched by age to a referent woman in the same population who had not undergone oophorectomy. In total, we studied 1,252 women with unilateral oophorectomy, 1,075 women with bilateral oophorectomy, and 2,368 referent women. Women were followed through death or end of study using a combination of direct or proxy interviews, neurologic examinations, medical records in a records-linkage system, and death certificates.

RESULTS

Women who underwent either unilateral or bilateral oophorectomy before the onset of menopause had an increased risk of parkinsonism compared with referent women (HR 1.68; 95% CI 1.06 to 2.67; p = 0.03), and the risk increased with younger age at oophorectomy (test for linear trend; p = 0.01). The findings were similar regardless of the indication for the oophorectomy, and for unilateral or bilateral oophorectomy considered separately. The findings were also consistent for Parkinson disease alone, but did not reach significance.

CONCLUSIONS

Both unilateral and bilateral oophorectomy performed prior to menopause may be associated with an increased risk of parkinsonism and the effect may be age-dependent. However, our findings await independent replication.

Increased risk of cognitive impairment or dementia in women who underwent oophorectomy before menopause

OBJECTIVE

There is increasing laboratory evidence for a neuroprotective effect of estrogen; however, the clinical and epidemiologic evidence remains limited and conflicting. We studied the association of oophorectomy performed before the onset of menopause with the risk of subsequent cognitive impairment or dementia.

METHODS

We included all women who underwent unilateral or bilateral oophorectomy before the onset of menopause for a non-cancer indication while residing in Olmsted County, MN, from 1950 through 1987. Each member of the oophorectomy cohort was matched by age to a referent woman from the same population who had not undergone oophorectomy. In total, we studied 813 women with unilateral oophorectomy, 676 women with bilateral oophorectomy, and 1,472 referent women. Women were followed through death or end of study using either direct or proxy interviews.

RESULTS

Women who underwent either unilateral or bilateral oophorectomy before the onset of menopause had an increased risk of cognitive impairment or dementia compared to referent women (hazard ratio [HR] = 1.46; 95% CI 1.13 to 1.90; adjusted for education, type of interview, and history of depression). The risk increased with younger age at oophorectomy (test for linear trend; adjusted p < 0.0001). These associations were similar regardless of the indication for the oophorectomy, and for women who underwent unilateral or bilateral oophorectomy considered separately.

CONCLUSIONS

Both unilateral and bilateral oophorectomy preceding the onset of menopause are associated with an increased risk of cognitive impairment or dementia. The effect is age-dependent and suggests a critical age window for neuroprotection.

The use of clinical risk factors enhances the performance of BMD in the prediction of hip and osteoporotic fractures in men and women

BMD and clinical risk factors predict hip and other osteoporotic fractures. The combination of clinical risk factors and BMD provide higher specificity and sensitivity than either alone. INTRODUCTION AND HYPOTHESES: To develop a risk assessment tool based on clinical risk factors (CRFs) with and without BMD.

METHODS

Nine population-based studies were studied in which BMD and CRFs were documented at baseline. Poisson regression models were developed for hip fracture and other osteoporotic fractures, with and without hip BMD. Fracture risk was expressed as gradient of risk (GR, risk ratio/SD change in risk score).

RESULTS

CRFs alone predicted hip fracture with a GR of 2.1/SD at the age of 50 years and decreased with age. The use of BMD alone provided a higher GR (3.7/SD), and was improved further with the combined use of CRFs and BMD (4.2/SD). For other osteoporotic fractures, the GRs were lower than for hip fracture. The GR with CRFs alone was 1.4/SD at the age of 50 years, similar to that provided by BMD (GR = 1.4/SD) and was not markedly increased by the combination (GR = 1.4/SD). The performance characteristics of clinical risk factors with and without BMD were validated in eleven independent population-based cohorts.

CONCLUSIONS

The models developed provide the basis for the integrated use of validated clinical risk factors in men and women to aid in fracture risk prediction.

Impact of increased overweight on the projected prevalence of osteoporosis in older women

INTRODUCTION

Overweight is increasing worldwide, but particularly in the United States of America. Higher body weight is associated with higher bone density, so our goal was to estimate whether the higher prevalence of overweight is likely to reduce osteoporosis among older women.

METHODS

We calculated the prevalence of osteoporosis by weight status in older women using data from the third National Health and Nutrition Examination Survey (NHANES III, 1988-94). We defined overweight as a body mass index (BMI) >or=25 and osteoporosis as a femur neck bone mineral density (BMD) value 2.5 standard deviations or more below the mean of that of young women. To estimate the expected prevalence of osteoporosis, we applied the prevalence of osteoporosis by weight status from NHANES III to the corresponding weight status prevalence from NHANES 1999-2002.

RESULTS

Of older women in NHANES 1999-2002, 68% were overweight compared to 62% in NHANES III. Overweight status was significantly related to osteoporosis prevalence (P < 0.001). However, the expected prevalence of osteoporosis in NHANES 1999-2002 was only slightly lower than that seen in NHANES III (16.8% vs 18.1%, respectively).

CONCLUSIONS

The increasing prevalence of overweight among older US women appears unlikely to be accompanied by a significant reduction in osteoporosis.

Potential for bone turnover markers to cost-effectively identify and select post-menopausal osteopenic women at high risk of fracture for bisphosphonate therapy

INTRODUCTION AND HYPOTHESIS

Over half of all fractures among post-menopausal women occur in those who do not have osteoporosis by bone density criteria. Measurement of bone turnover may cost-effectively identify a subset of women with T-score >-2.5 for whom anti-resorptive drug therapy is cost-effective.

METHODS

Using a Markov model, we estimated the cost per quality adjusted life year (QALY) for five years of oral bisphosphonate compared to no drug therapy for osteopenic post-menopausal women aged 60 to 80 years with a high (top quartile) or low (bottom 3 quartiles) level of a bone turnover marker.

RESULTS

For women with high bone turnover, the cost per QALY gained with alendronate compared to no drug therapy among women aged 70 years with T-scores of -2.0 or -1.5 were $58,000 and $80,000 (U.S. 2004 dollars), respectively. If bisphosphonates therapy also reduced the risk of non-vertebral fractures by 20% among osteopenic women with high bone turnover, then the costs per QALY gained were $34,000 and $50,000 for women age 70 with high bone turnover and T-scores of -2.0 and -1.5, respectively.

CONCLUSION

Measurement of bone turnover markers has the potential to identify a subset of post-menopausal women without osteoporosis by bone density criteria for whom bisphosphonate therapy to prevent fracture is cost-effective. The size of that subset highly depends on the assumed efficacy of bisphosphonates for fracture risk reduction among women with both a T-score >-2.5 and high bone turnover and the cost of bisphosphonate treatment.

Survival and cause specific mortality in patients with inflammatory bowel disease: a long term outcome study in Olmsted County, Minnesota, 1940-2004

BACKGROUND AND AIMS

We followed a population based cohort of patients with inflammatory bowel disease (IBD) from Olmsted County, Minnesota, in order to analyse long term survival and cause specific mortality.

MATERIAL AND METHODS

A total of 692 patients were followed for a median of 14 years. Standardised mortality ratios (SMRs, observed/expected deaths) were calculated for specific causes of death. Cox proportional hazards regression was used to determine if clinical variables were independently associated with mortality.

RESULTS

Fifty six of 314 Crohn's disease patients died compared with 46.0 expected (SMR 1.2 (95% confidence interval (CI) 0.9-1.6)), and 62 of 378 ulcerative colitis (UC) patients died compared with 79.2 expected (SMR 0.8 (95% CI 0.6-1.0)). Eighteen patients with Crohn's disease (32%) died from disease related complications, and 12 patients (19%) died from causes related to UC. In Crohn's disease, an increased risk of dying from non-malignant gastrointestinal causes (SMR 6.4 (95% CI 3.2-11.5)), gastrointestinal malignancies (SMR 4.7 (95% CI 1.7-10.2)), and chronic obstructive pulmonary disease (COPD) (SMR 3.5 (95% CI 1.3-7.5)) was observed. In UC, cardiovascular death was reduced (SMR 0.6 (95% CI 0.4-0.9)). Increased age at diagnosis and male sex were associated with mortality in both subtypes. In UC but not Crohn's disease, a diagnosis after 1980 was associated with decreased mortality.

CONCLUSIONS

In this population based study of IBD patients from North America, overall survival was similar to that expected in the US White population. Crohn's disease patients were at increased risk of dying from gastrointestinal disease and COPD whereas UC patients had a decreased risk of cardiovascular death.

Alternating bowel pattern: what do people mean?

BACKGROUND

With the introduction of new therapies, the subgrouping of patients based on bowel pattern has become important. However, the appropriate definition of an alternating bowel pattern remains unclear.

AIM

To determine if specific symptoms are reported by people with an alternating bowel pattern.

METHODS

Using the Rochester Epidemiology Project, a series of population-based surveys were undertaken in which valid self-report gastrointestinal symptom questionnaires were mailed to 4029 randomly selected members of the community. One question asked was 'How would you describe your usual bowel pattern in the last year'?

RESULTS

3022 subjects (74%) provided questionnaire data and 2718 were eligible for this analysis, the mean age was 57 years, with a range of 20-98 years (median = 61). Of these, 9.2%, 2.5% and 7.6% reported their usual bowel pattern as being constipated, diarrhoea, or alternating respectively. At least 50% of those reporting alternating bowel pattern reported incomplete evacuation (63%), urgency (57%), straining (55%) and loose stool (50%). The proportion of alternators reporting each individual symptom was between that of diarrhoea and constipation except for mucus and incomplete evacuation; however, no symptom was unique to alternators.

CONCLUSION

People who self-report an alternating bowel pattern appear to represent a blend of constipation and diarrhoea symptoms, rather than a distinct subgroup.

The use of multiple sites for the diagnosis of osteoporosis

INTRODUCTION

It has been suggested that bone mineral density (BMD) measurements should be made at multiple sites, and that the lowest T-score should be taken for the purpose of diagnosing osteoporosis.

PURPOSE

The aim of this study was to examine the use of BMD measurements at the femoral neck and lumbar spine alone and in combination for fracture prediction.

METHODS

We studied 19,071 individuals (68% women) from six prospective population-based cohorts in whom BMD was measured at both sites and fracture outcomes documented over 73,499 patient years. BMD values were converted to Z-scores, and the gradient of risk for any osteoporotic fracture and for hip fracture was examined by using a Poisson model in each cohort and each gender separately. Results of the different studies were merged using weighted beta-coefficients.

RESULTS

The gradients of risk for osteoporotic fracture and for hip fracture were similar in men and women. In men and women combined, the risk of any osteoporotic fracture increased by 1.51 [95% confidence interval (CI)=1.42-1.61] per standard deviation (SD) decrease in femoral-neck BMD. For measurements made at the lumbar spine, the gradient of risk was 1.47 (95% CI=1.38-1.56). Where the minimum of the two values was used, the gradient of risk was similar (1.55; 95% CI=1.45-1.64). Higher gradients of risk were observed for hip fracture outcomes: with BMD at the femoral neck, the gradient of risk was 2.45 (95% CI=2.10-2.87), with lumbar BMD was 1.57 (95% CI=1.36-1.82), and with the minimum value of either femoral neck and lumbar spine was 2.11 (95% CI=1.81-2.45). Thus, selecting the lowest value for BMD at either the femoral neck or lumbar spine did not increase the predictive ability of BMD tests. By contrast, the sensitivity increased so that more individuals were identified but at the expense of specificity. Thus, the same effect could be achieved by using a less stringent T-score for the diagnosis of osteoporosis.

CONCLUSIONS

Since taking the minimum value of the two measurements does not improve predictive ability, its clinical utility for the diagnosis of osteoporosis is low.

Influence of baseline deformity definition on subsequent vertebral fracture risk in postmenopausal women

INTRODUCTION

Approaches for recognizing vertebral fractures remain controversial.

METHODS

An age-stratified population sample of 512 postmenopausal women was followed with serial radiographs for up to 12 years (4455 person-years).

RESULTS

112 women experienced a new vertebral fracture (20% reduction in any vertebral height from baseline) within this study period, for an annual age-adjusted (to US white women > or =50 years of age in 2000) incidence of 23 per 1000. Depending on the morphometric definition used, the prevalence of vertebral deformities at baseline ranged from 3 to 90%. A recent method to standardize vertebral heights produced the best agreement with a qualitative clinical reading of the films [kappa (kappa), 0.53]. Almost all of the different baseline definitions predicted future vertebral fractures, but most of the predictive power was attributable to the severe (e.g., 4 SD) deformities included within more generous (e.g., 3 SD) classifications. Whereas the generous definitions were more sensitive, and the restrictive ones more specific, their overall abilities to predict a new vertebral fracture were roughly comparable as evaluated by the c-index (analogous to the area under an ROC curve).

CONCLUSION

This result suggests that the choice of a morphometry definition depends on the particular application and, in particular, on whether it is more important to maximize sensitivity or specificity.

Body mass index as a predictor of fracture risk: a meta-analysis

Low body mass index (BMI) is a well-documented risk factor for future fracture. The aim of this study was to quantify this effect and to explore the association of BMI with fracture risk in relation to age, gender and bone mineral density (BMD) from an international perspective using worldwide data. We studied individual participant data from almost 60,000 men and women from 12 prospective population-based cohorts comprising Rotterdam, EVOS/EPOS, CaMos, Rochester, Sheffield, Dubbo, EPIDOS, OFELY, Kuopio, Hiroshima, and two cohorts from Gothenburg, with a total follow-up of over 250,000 person years. The effects of BMI, BMD, age and gender on the risk of any fracture, any osteoporotic fracture, and hip fracture alone was examined using a Poisson regression model in each cohort separately. The results of the different studies were then merged. Without information on BMD, the age-adjusted risk for any type of fracture increased significantly with lower BMI. Overall, the risk ratio (RR) per unit higher BMI was 0.98 (95% confidence interval [CI], 0.97-0.99) for any fracture, 0.97 (95% CI, 0.96-0.98) for osteoporotic fracture and 0.93 (95% CI, 0.91-0.94) for hip fracture (all p <0.001). The RR per unit change in BMI was very similar in men and women ( p >0.30). After adjusting for BMD, these RR became 1 for any fracture or osteoporotic fracture and 0.98 for hip fracture (significant in women). The gradient of fracture risk without adjustment for BMD was not linearly distributed across values for BMI. Instead, the contribution to fracture risk was much more marked at low values of BMI than at values above the median. This nonlinear relation of risk with BMI was most evident for hip fracture risk. When compared with a BMI of 25 kg/m(2), a BMI of 20 kg/m(2) was associated with a nearly twofold increase in risk ratio (RR=1.95; 95% CI, 1.71-2.22) for hip fracture. In contrast, a BMI of 30 kg/m(2), when compared with a BMI of 25 kg/m(2), was associated with only a 17% reduction in hip fracture risk (RR=0.83; 95% CI, 0.69-0.99). We conclude that low BMI confers a risk of substantial importance for all fractures that is largely independent of age and sex, but dependent on BMD. The significance of BMI as a risk factor varies according to the level of BMI. Its validation on an international basis permits the use of this risk factor in case-finding strategies.

Overlap of gastrointestinal symptom complexes in a US community

BACKGROUND

Although the Rome criteria define a number of individual functional gastrointestinal disorders, people may have symptoms of multiple disorders at the same time. In addition, therapies may be effective in subsets of people with specific disorders, yet at the same time help people with multiple disorders.

AIM

To estimate the prevalence of combinations of gastrointestional (GI) symptom complexes.

METHODS

A valid self report questionnaire which records GI symptoms was mailed to an age- and gender-stratified random sample of Olmsted County, MN residents aged 30-64 years. Standard definitions were used to identify people with gastro-oesophageal reflux, dyspepsia, irritable bowel syndrome (IBS), constipation and diarrhoea. The prevalence of people meeting multiple symptom complexes was estimated. Specifically, combinations of dyspepsia, IBS and constipation were compared to dyspepsia, IBS and diarrhoea.

RESULTS

A total of 657 (69%) of 943 eligible subjects responded; 643 provided data for each of the necessary symptom questions. Each two-way combination of symptom group was present in between 4 and 9% of the population; each three-way combination was present in 1-4% of the population. The overlap between dyspepsia, IBS and constipation was similar to dyspepsia, IBS and diarrhoea, except body mass index was higher in the diarrhoea overlap group (P = 0.03).

CONCLUSION

Symptom complex overlap is common in the community; for each condition, the majority of sufferers reported an additional symptom complex. This overlap of symptoms challenges the current paradigm that functional GI disorders represent multiple discreet entities.

A family history of fracture and fracture risk: a meta-analysis

The aims of the present study were to determine whether a parental history of any fracture or hip fracture specifically are significant risk factors for future fracture in an international setting, and to explore the effects of age, sex and bone mineral density (BMD) on this risk. We studied 34,928 men and women from seven prospectively studied cohorts followed for 134,374 person-years. The cohorts comprised the EPOS/EVOS study, CaMos, the Rotterdam Study, DOES and cohorts at Sheffield, Rochester and Gothenburg. The effect of family history of osteoporotic fracture or of hip fracture in first-degree relatives, BMD and age on all clinical fracture, osteoporotic fracture and hip fracture risk alone was examined using Poisson regression in each cohort and for each sex. The results of the different studies were merged from the weighted beta coefficients. A parental history of fracture was associated with a modest but significantly increased risk of any fracture, osteoporotic fracture and hip fracture in men and women combined. The risk ratio (RR) for any fracture was 1.17 (95% CI=1.07-1.28), for any osteoporotic fracture was 1.18 (95% CI=1.06-1.31), and for hip fracture was 1.49 (95% CI=1.17-1.89). The risk ratio was higher at younger ages but not significantly so. No significant difference in risk was seen between men and women with a parental history for any fracture (RR=1.17 and 1.17, respectively) or for an osteoporotic fracture (RR=1.17 and 1.18, respectively). For hip fracture, the risk ratios were somewhat higher, but not significantly higher, in men than in women (RR=2.02 and 1.38, respectively). A family history of hip fracture in parents was associated with a significant risk both of all osteoporotic fracture (RR 1.54; 95CI=1.25-1.88) and of hip fracture (RR=2.27; 95% CI=1.47-3.49). The risk was not significantly changed when BMD was added to the model. We conclude that a parental history of fracture (particularly a family history of hip fracture) confers an increased risk of fracture that is independent of BMD. Its identification on an international basis supports the use of this risk factor in case-finding strategies.

A meta-analysis of previous fracture and subsequent fracture risk

Previous fracture is a well-documented risk factor for future fracture. The aim of this study was to quantify this risk on an international basis and to explore the relationship of this risk with age, sex, and bone mineral density (BMD). We studied 15259 men and 44902 women from 11 cohorts comprising EVOS/EPOS, OFELY, CaMos, Rochester, Sheffield, Rotterdam, Kuopio, DOES, Hiroshima, and two cohorts from Gothenburg. Cohorts were followed for a total of 250000 person-years. The effect of a prior history of fracture on the risk of any fracture, any osteoporotic fracture, and hip fracture alone was examined using a Poisson model for each sex from each cohort. Covariates examined were age, sex, and BMD. The results of the different studies were merged by using the weighted beta-coefficients. A previous fracture history was associated with a significantly increased risk of any fracture compared with individuals without a prior fracture (RR = 1.86; 95% CI = 1.75-1.98). The risk ratio was similar for the outcome of osteoporotic fracture or for hip fracture. There was no significant difference in risk ratio between men and women. Risk ratio (RR) was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any fracture (8%) and for hip fracture (22%). The risk ratio was stable with age except in the case of hip fracture outcome where the risk ratio decreased significantly with age. We conclude that previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by measurement of BMD. Its validation on an international basis permits the use of this risk factor in case finding strategies.

Incidence of a clinical diagnosis of the irritable bowel syndrome in a United States population

BACKGROUND

The incidence of irritable bowel syndrome is uncertain. We aimed to determine the incidence of clinically diagnosed irritable bowel syndrome in the community.

METHODS

Using the Rochester Epidemiology Project, all diagnoses of irritable bowel syndrome made among adult residents of Olmsted County, Minnesota, over a 3-year period were identified. The complete medical records of a random sample of the potential subjects were reviewed for the 10 years prior to the irritable bowel syndrome diagnosis and any patient who had received a previous diagnosis of irritable bowel syndrome was excluded (prevalent cases).

RESULTS

The diagnostic index listed 1245 possible irritable bowel syndrome patients; 416 patient charts were reviewed and, of these, 149 were physician diagnosed incident cases of irritable bowel syndrome. The age- and sex-adjusted incidence rate was 196 per 100,000 person-years and increased with age (P = 0.006). The age-adjusted annual incidence per 100,000 in women was higher than in men: 238 vs. 141 (ratio 3:2; P = 0.005). The overall symptom frequency at the time of diagnosis was abdominal pain (73%), diarrhoea (41%) and constipation (16%).

CONCLUSIONS

The incidence of a clinical diagnosis of irritable bowel syndrome in adults was estimated to be two per 1000 per year, increased with age and was higher in women than men. As many people with irritable bowel syndrome do not seek care, the true incidence of irritable bowel syndrome is likely to be higher.

Impact of functional gastrointestinal disorders on health-related quality of life: a population-based case-control study

BACKGROUND

The health-related quality of life is impaired in patients with functional gastrointestinal disorders seen in referral centres.

AIM

To determine whether the health-related quality of life is impaired in subjects with functional disorders in the community and whether any differences can be explained by psychological co-morbidity.

METHODS

In a population-based, nested, case-control study, subjects reporting symptoms of either dyspepsia or irritable bowel syndrome and healthy controls were interviewed and completed a battery of psychological measures plus a validated, generic, health-related quality of life measure (Medical Outcomes Study 36-item short form health survey, SF-36). The association between irritable bowel syndrome and dyspepsia and the physical and mental composite scores of SF-36 were assessed with and without adjustment for psychological state.

RESULTS

One hundred and twelve cases (30 dyspepsia, 39 irritable bowel syndrome, 32 dyspepsia and irritable bowel syndrome and 11 gastrointestinal symptoms but not dyspepsia or irritable bowel syndrome) and 110 controls were enrolled. In the unadjusted linear regression models, irritable bowel syndrome (but not dyspepsia) was negatively associated with the physical composite score (P < 0.05); in an adjusted model, the association between the physical health-related quality of life and irritable bowel syndrome was explained by the Symptom Checklist-90 somatization score alone. In unadjusted models, irritable bowel syndrome and dyspepsia were each negatively associated with the mental composite score (P < 0.05). The association between the mental health-related quality of life and dyspepsia remained after adjusting for psychological covariates, but the association between this and irritable bowel syndrome was not significant after adjustment.

CONCLUSIONS

In the community, health-related quality of life is impaired in subjects with irritable bowel syndrome and dyspepsia; however, much of this association can be explained by psychological factors.

Is early colonoscopy after admission for acute diverticular bleeding needed?

OBJECTIVES

Urgent colonoscopy has been proposed for the diagnosis and management of acute colonic diverticular bleeding. Identification of active bleeding and nonbleeding stigmata facilitates diagnosis and endoscopic therapy, but it is unclear whether urgent colonoscopy after presentation increases the diagnostic yield. This study evaluated the association between timing of colonoscopy and diagnostic yield in patients admitted with acute colonic diverticular bleeding.

METHODS

Patients admitted for hematochezia and receiving a diagnosis of diverticular hemorrhage were identified using the Mayo Clinic GI Bleeding Team and Emergency Room Admissions Databases for the years 1998-2000. Timing of colonoscopy was determined from the time of admission. Logistic regression analysis was used to assess whether the timing of colonoscopy was associated with an endoscopic finding of active bleeding or nonbleeding stigmata (or both).

RESULTS

A diagnosis of definitive or presumptive diverticular bleeding was made in 78 patients (39 men and 39 women, mean age 78 yr, range 49-96 yr). Twelve patients (15%) had active bleeding or stigmata. Colonoscopies were performed a mean of 18 +/- 11 h after admission. The association between a definitive diagnosis of acute diverticular bleeding and the timing of colonoscopy was not significant (p > 0.46).

CONCLUSIONS

No significant association is apparent between the timing of colonoscopy after admission and encountering active bleeding or nonbleeding stigmata. Based on these observations, urgent colonoscopy for these patients does not seem advantageous.

Areal and volumetric bone density in Hong Kong Chinese: a comparison with Caucasians living in the United States

It is a common perception that Asians have lower bone density than Caucasians. However, such relationships could be confounded by bone size. In this study, the skeletal status of a convenience sample of 482 men and 887 women living in Hong Kong is compared with published data for Caucasians living in Rochester, Minnesota. Areal bone mineral density (BMD, g/cm(2)) and volumetric bone mineral apparent density (BMAD, g/cm(3)) were determined for the lumbar spine and proximal femur, using the Hologic QDR 2000 instrument. Cross-calibration was performed by measuring a common phantom, and the Hong Kong data were adjusted by a multiplication factor. Lumbar spine and femoral neck BMD and BMAD of Chinese men and women were all significantly lower ( P<0.001 by t-test) than those of Caucasians, but the differences in BMAD were on average only about half the size of the differences in BMD. For instance, in postmenopausal Chinese women, BMD at the femoral neck and lumbar spine were 15.2% and 18.8% lower respectively, but BMAD at the femoral neck and lumbar spine were only 7.8% and 12.4% lower respectively. Similar trends were observed in men. After adjusting for age, body height and weight, the difference in BMAD between Caucasians and Chinese was further reduced and only statistically significant among postmenopausal women and among men younger than age 50 years for the lumbar spine. For instance, the adjusted BMAD in postmenopausal Chinese women at the femoral neck and lumbar spine were 3.9% ( P=0.03 by ANCOVA) and 7.3% ( P<0.001 by ANCOVA) lower respectively, while the adjusted BMAD at the lumbar spine for Chinese men younger than 50 years was 11.7% lower ( P<0.01 by ANCOVA). Predictors of BMAD in Hong Kong Chinese women include body weight, age at menarche, cigarette smoking, and oral contraceptive use ( P<0.001), while body weight was the only independent predictor of BMAD in Hong Kong Chinese men ( P<0.001). We conclude that bone density is lower in Hong Kong Chinese men and women than in Caucasians, although such differences were attenuated by adjustments for bone size, body weight and height.