Ascertainment of risk factors for osteoporosis: comparison of interview data with medical record review

Is there an association between peptic ulcer disease and osteoporosis: a systematic review and cumulative analysis

BACKGROUND

Mounting studies have emerged indicating that patients with peptic ulcer disease (PUD) are at a high risk of developing osteoporosis, but the evidence has not been previously synthesized. The present study aims to examine whether patients with PUD have a significantly higher prevalence of osteoporosis than the healthy normal subjects.

METHODS

Four electronic databases were systematically searched for eligible studies up to February 2020. The association between PUD and osteoporosis was evaluated by calculating the relative risk (RR) with a 95% confidence interval (CI).

RESULTS

Six observational studies were finally included, enrolling a total of 216 122 individuals. Synthetic results from the six included studies providing the number of cases for both sexes demonstrated that PUD was significantly associated with an increased risk of osteoporosis (95% CI, 1.37-1.89; P < 0.001). In line with this finding, the combined effect from the three studies independently reporting the male subjects also yielded to a positive relationship between PUD and osteoporosis (RR = 2.08; 95% CI,1.10-3.93; P = 0.023). However, when restricted to female participants, pooled results indicated that women patients with PUD would not suffer significantly more risk of osteoporosis than the general women population (RR = 1.36; 95% CI, 0.84-2.21, P = 0.212).

CONCLUSIONS

This is the first study for quantifying the positive association between PUD and the risk of osteoporosis by conducting a meta-analysis. In clinical practice, assessment of the bone mineral density and antiosteoporosis treatments are recommended for those potential patients with PUD.

What is the validity of self-reported fractures?

We assessed the validity of self-reported fractures, over a median follow-up period of 6.2 years, in a well characterized population-based cohort of 3560 postmenopausal women, aged 60-85 years, from the Fracture Risk Brussels Epidemiological Enquiry (FRISBEE) study. Incident low-traumatic (falls from a standing height or less) or non-traumatic fractures, including peripheral fractures, were registered during each annual follow-up telephone interview. A self-reported fracture was considered as a true positive if it was validated by written reliable medical reports (radiographs, CT scans or surgical report). False positives fractures were considered to be those for which the radiology report indicated that there was no fracture at the reported site. Among self-reported fractures, false positive rates were 14.4% for all fractures. The rate of false positives of 11.2% (n = 48/429) was not negligible for the four classical major osteoporotic fractures (MOFs: hip, clinical spine, forearm or shoulder fractures). In terms of fracture site, we found the lowest false positive rate (4.4%) at the hip, and the highest (16.8%) at the spine, with the proximal humerus and the wrist in between, at about 10% each. The global rates of false positives were 12.5% (n = 22/176) for other major fractures and 22.3% (n = 49/220) for minor fractures. Younger subjects, individuals with fractures at sites other than the hip, with a lower education level, or with a higher BMI were more likely to report false positive fractures. Our data indicate that the inaccuracy of self-reported fractures is clinically relevant for several major fractures, which could influence any fracture risk prediction model.

A comparison of self-reported oral contraceptive use and automated pharmacy data in perimenopausal and early postmenopausal women

PURPOSE

Oral contraceptive (OC) use can occur throughout a woman's reproductive life span with the potential for long-term impacts on health. To assess potential measurement error in prior OC use, this study compared level of agreement between self-reported prior OC use and pharmacy dispensing data in perimenopausal and/or early postmenopausal women.

METHODS

The study's 1399 women (ages, 45-59 years) were participants in a population-based case-control study of the association between OC use and fracture risk. Episodes of lifetime self-reported OC use (in months) were collected, by telephone interview, for January 1, 2008 through November 25, 2012. Pharmacy fills, back to 1980, were collected from automated data. Agreement was measured using the prevalence-adjusted and bias-adjusted kappa index.

RESULTS

The number of women with OC pharmacy fills was 11% to 45% higher than those who reported OC use during each time period. Between-measures agreement was better for more recent use. Prevalence-adjusted and bias-adjusted kappa index values ranged from 0.88 (95% confidence interval, 0.85-0.90) within 5 years from the reference date to 0.65 (95% confidence interval, 0.59-0.71) within 15 to 20 years.

CONCLUSIONS

For studies designed to assess the long-term effects of OC use, the current results are reassuring in noting moderate agreement between self-reported OC use and pharmacy data for up to 15 to 20 years before the interview.

Prediction models of prevalent radiographic vertebral fractures among older men

No studies have compared how well different prediction models discriminate older men who have a radiographic prevalent vertebral fracture (PVFx) from those who do not. We used area under receiver operating characteristic curves and a net reclassification index to compare how well regression-derived prediction models and nonregression prediction tools identify PVFx among men age ≥65 yr with femoral neck T-score of -1.0 or less enrolled in the Osteoporotic Fractures in Men Study. The area under receiver operating characteristic for a model with age, bone mineral density, and historical height loss (HHL) was 0.682 compared with 0.692 for a complex model with age, bone mineral density, HHL, prior non-spine fracture, body mass index, back pain, grip strength, smoking, and glucocorticoid use (p values for difference in 5 bootstrapped samples 0.14-0.92). This complex model, using a cutpoint prevalence of 5%, correctly reclassified only a net 5.7% (p = 0.13) of men as having or not having a PVFx compared with a simple criteria list (age ≥ 80 yr, HHL >4 cm, or glucocorticoid use). In conclusion, simple criteria identify older men with PVFx and regression-based models. Future research to identify additional risk factors that more accurately identify older men with PVFx is needed.

Magnitude and consequences of misclassification of incident hip fractures in large cohort studies: the Study of Osteoporotic Fractures and Medicare claims data

In the Study of Osteoporotic Fractures (SOF), 18.5 % of incident hip fractures identified in Medicare Fee-for-Service claims data were not reported to or confirmed by the cohort. Cognitive impairment was a modest risk factor for false-negative hip fracture ascertainment via self-report.

INTRODUCTION

Prospective cohort studies of fractures that rely on participant self-report to be the initial signal of an incident fracture could be prone to bias if a significant proportion of fractures are not self-reported.

METHODS

We used data from the SOF merged with Medicare Fee-for-Service claims data to estimate the proportion of participants who had an incident hip fracture identified in Medicare claims that was either not self-reported or confirmed (by review of radiographic reports) in SOF.

RESULTS

Between 1/1/1991 and 12/31/2007, 647 SOF participants had a hip fracture identified in Medicare claims, but 120 (18.5 %) were either not reported to or confirmed by the cohort. False-negative hip fracture ascertainment was associated with a reduced modified Mini-Mental State Exam (MMSE) score (odds ratio 1.31 per SD decrease, 95 % C.I. 1.06-1.63). Point estimates of associations of predictors of incident hip fracture were changed minimally when the misclassification of incident hip fracture status was corrected with use of claims data.

CONCLUSIONS

A substantial minority of incident hip fractures were not reported to or confirmed in the SOF. Cognitive impairment was modestly associated with false-negative hip fracture ascertainment. While there was no evidence to suggest that misclassification of incident hip fracture status resulted in biased associations of potential predictors with hip fracture in this study, false-negative incident fracture ascertainment in smaller cohort studies with limited power may increase the risk of type 2 error (not finding significant associations of predictors with incident fractures).

Utility of automated data in identifying femoral shaft and subtrochanteric (diaphyseal) fractures

In women age 45 years and older, enrolled in an integrated group practice in 2007, use of ICD9 diagnostic codes, including the "not otherwise specified" code (821.00) resulted in a high false-positive rate for identifying femoral diaphyseal fractures. Restriction to more specific site-codes missed 36% of these rare fractures.

INTRODUCTION

The aim of this study was to assess the utility of automated data in identifying the occurrence of femoral diaphyseal fractures.

METHODS

We identified all women age 45 years and older enrolled in a Pacific Northwest integrated group practice during 2007. Using the computerized database we selected all ICD9 codes that could be related to a femur fracture occurring in the diaphyseal region. We then quantified the percent of codes confirmed by medical record review to have occurred in the correct anatomic location during the year of interest (positive predictive value).

RESULTS

Of the 95,765 eligible women, 161 (0.17%) had an ICD9 diagnostic code potentially related to a femoral diaphyseal fracture in 2007; of these 58 (36%) had a fracture of the femoral diaphysis, and 38 (24%) of the fractures occurred in 2007. The most frequent code was 821.00, described as "femur fracture not otherwise specified", applied to 107 women; 21 of the 58 diaphyseal fractures had this code.

CONCLUSION

In this study, use of ICD9 codes that included the "not otherwise specified" code (821.00) resulted in a high false-positive rate for identifying diaphyseal fractures. However, restriction to more specific site codes would have missed at least 36% of the diaphyseal fractures. Furthermore, the codes did not provide any information about the characteristics of the fracture. Our findings support validating cases selected using ICD codes before they are used as a surrogate for the occurrence of femoral diaphyseal fractures.

The Rochester Epidemiology Project: exploiting the capabilities for population-based research in rheumatic diseases

The Rochester Epidemiology Project (REP) is a patient record-based database based upon a medical records-linkage system for all residents of the Olmsted County, MN, USA. This comprehensive system includes all health-care providers of patients resident in this geographically defined region. It uniquely enables long-term population-based studies of all medical conditions occurring in this population; their incidence and prevalence; permits examination of disease risk and protective factors, health resource utilization and cost as well as translational studies in rheumatic diseases.

Increased cardiovascular mortality after early bilateral oophorectomy

OBJECTIVE

To investigate the mortality associated with cardiovascular diseases and the effect of estrogen treatment in women who underwent unilateral or bilateral oophorectomy before menopause.

DESIGN

We conducted a cohort study with long-term follow-up of women in Olmsted County, MN, who underwent either unilateral or bilateral oophorectomy before the onset of menopause 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 any oophorectomy. We studied the mortality associated with cardiovascular disease in a total of 1,274 women with unilateral oophorectomy, 1,091 women with bilateral oophorectomy, and 2,383 referent women.

RESULTS

Women who underwent unilateral oophorectomy experienced a reduced mortality associated with cardiovascular disease compared with referent women (hazard ratio [HR], 0.82; 95% CI, 0.67-0.99; P = 0.04). In contrast, women who underwent bilateral oophorectomy before age 45 years experienced an increased mortality associated with cardiovascular disease compared with referent women (HR, 1.44; 95% CI, 1.01-2.05; P = 0.04). Within this age stratum, the HR for mortality was significantly increased in women who were not treated with estrogen through age 45 years or longer (HR, 1.84; 95% CI, 1.27-2.68; P = 0.001) but not in women treated with estrogen (HR, 0.65; 95% CI, 0.30-1.41; P = 0.28; test of interaction, P = 0.01). Mortality was further increased after deaths associated with cerebrovascular causes were excluded.

CONCLUSIONS

Bilateral oophorectomy performed before age 45 years is associated with increased cardiovascular mortality, especially with cardiac mortality. However, estrogen treatment may reduce this risk.

Increased mortality for neurological and mental diseases following early bilateral oophorectomy

BACKGROUND

The effects of oophorectomy on brain aging remain uncertain.

METHODS

We conducted a cohort study with long-term follow-up of women in Olmsted County, Minn., USA, who underwent either unilateral or bilateral oophorectomy before the onset of menopause 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 any oophorectomy. We studied underlying and contributory causes of death in 1,274 women with unilateral oophorectomy, 1,091 women with bilateral oophorectomy, and 2,383 referent women.

RESULTS

Mortality for neurological or mental diseases was increased in women who underwent bilateral oophorectomy before age 45 years compared with referent women (hazard ratio = 5.24; 95% confidence interval = 2.02-13.6; p < 0.001). Within this age stratum, mortality was similar in women who were or were not treated with estrogen from the time of oophorectomy through age 45 years, and in women who had bilateral oophorectomy for prophylaxis or for treatment of a benign ovarian condition. Mortality was also increased in women who underwent unilateral oophorectomy before age 45 years without concurrent hysterectomy.

CONCLUSIONS

Bilateral oophorectomy performed before age 45 years is associated with increased mortality for neurological or mental diseases.

Use of renal function measurements for assessing fracture risk in postmenopausal women

OBJECTIVE

To determine whether factors associated with moderate chronic kidney disease can be used to independently predict fracture risk in postmenopausal white women by analyzing the effect of adding renal function measurements to traditional risk factors (eg, age, body weight, bone mineral density) for fracture risk assessment.

PARTICIPANTS AND METHODS

In a prospective, population-based cohort study, postmenopausal women residing in Rochester, MN, with baseline measurements of bone mineral density and renal function were followed up for as long as 25 years for occurrence of fractures. Participants were enrolled in 1980-1984 or 1991-1993, and outcomes were analyzed in 2007. Standardized incidence ratios were used to compare the number of observed fractures with the number of predicted fractures, and potential risk factors were evaluated with Andersen-Gill time-to-fracture regression models.

RESULTS

During 5948 person-years of follow-up of 427 women, 254 women (59.5%) experienced a total of 563 fractures, 394 (70.0%) of which resulted from moderate trauma. Excluding incidentally diagnosed fractures, the 186 clinically diagnosed fractures were statistically undifferentiated from the 195 predicted fractures (standardized incidence ratio, 0.95; 95% confidence interval, 0.82-1.10). No significant trends were observed toward increasing fracture risk with inclusion of quintiles of declining renal function (P>.10). In univariate analyses, serum creatinine concentration, creatinine clearance rate, and estimated glomerular filtration rate were associated with greater risk of some fractures. In multivariate analyses, however, decreasing renal function was not found to be a significant risk factor, after adjusting for age, body weight, and bone mineral density.

CONCLUSION

The addition of serum creatinine concentration, creatinine clearance rate, or estimated glomerular filtration rate does not improve fracture risk prediction in postmenopausal white women who have moderate chronic kidney disease. This result can be partly explained by the fact that important risk factors for decreased renal function (eg, advanced age, lower body weight) are already accounted for in most fracture prediction models.

Rates of fracture in participants and non-participants in the Osteoporosis Prospective Risk Assessment study

We invited 1604 randomly selected women, all 75 years of age, to participate in a study on the risk factors for fracture. The women were divided into three groups consisting of 1044 (65%) who attended the complete study, 308 (19%) respondents to the study questionnaire only and 252 (16%) who did not respond. The occurrence of the life-time fracture was ascertained from radiological records in all groups and by questionnaires from the attendees and respondents. According to the radiological records, fewer of the questionnaire respondents (88 of 308, 28.6%) and non-respondents (68 of 252, 27%) had sustained at least one fracture when compared with the attendees (435 of 1044, 41.7%; chi-squared test, p < 0.001). According to the questionnaire, fewer of the respondents (96 of 308, 31.1%) had sustained at least one previous fracture when compared with the attendees (457 of 1044, 43.7%; chi-squared test, p < 0.001). Any study concerning the risk of fracture may attract those with experience of a fracture which explains the higher previous life-time incidence among the attendees. This factor may cause bias in epidemiological studies.

Glucocorticoid-Induced osteoporosis: clinical and therapeutic aspects

Glucocorticoid-induced osteoporosis (GIO) is the most common form of secondary osteoporosis. Fractures, which are often asymptomatic, may occur in as many as 30_50% of patients receiving chronic glucocorticoid therapy. Vertebral fractures occur early after exposure to glucocorticoids, at a time when bone mineral density (BMD) declines rapidly. Fractures tend to occur at higher BMD levels than in women with postmenopausal osteoporosis. Glucocorticoids have direct and indirect effects on the skeleton. They impair the replication, differentiation, and function of osteoblasts and induce the apoptosis of mature osteoblasts and osteocytes. These effects lead to a suppression of bone formation, a central feature in the pathogenesis of GIO. Glucocorticoids also favor osteoclastogenesis and as a consequence increase bone resorption. Bisphosphonates are the most effective of the various therapies that have been assessed for the management of GIO. Anabolic therapeutic strategies are under investigation. Teriparatide seems to be also efficacious for the treatment of patients with GIO.

Inaccuracy in self-report of fractures may underestimate association with health outcomes when compared with medical record based fracture registry

INTRODUCTION AND OBJECTIVE

Misreporting fractures in questionnaires is known. However, the effect of misreporting on the association of fractures with subsequent health outcomes has not been examined.

METHODS

Data from a fracture registry (FR) developed from an extensive review of radiographic and medical records were related to self-report of fracture for 2,255 participants from the AGES Reykjavik Study. This data was used to determine false negative and false positive rates of self-reported fractures, correlates of misreporting, and the potential effect of the misreporting on estimates of health outcomes following fractures.

RESULTS

In women, the false positive rate decreased with age as the false negative rate increased with no clear trend with age in men. Kappa values for agreement between FR and self-report were generally higher in women than men with the best agreement for forearm fracture (men 0.64 and women 0.82) and the least for rib (men 0.28 and women 0.25). Impaired cognition was a major factor associated with discordant answers between FR and self-report, OR 1.7 (95% CI: 1.3-2.1) (P < 0.0001). We estimated the effect of misreporting on health after fracture by comparison of the association of the self-report of fracture and fracture from the FR, adjusting for those factors associated with discordance. The weighted attenuation factor measured by mobility and muscle strength was 11% (95% CI: 0-24%) when adjusted for age and sex but reduced to 6% (95% CI: -10-22%) when adjusted for cognitive impairment.

CONCLUSION

Studies of hip fractures should include an independent ascertainment of fracture but for other fractures this study supports the use of self-report.

Osteoporosis assessment by whole body region vs. site-specific DXA

The ability of regional data from whole body scans to provide an accurate assessment of site-specific BMD, osteoporosis prevalence and fracture risk has not been fully explored. To address these issues, we measured total body (TBBD) and site-specific BMD in an age-stratified population sample of 351 women (21-93 years) and 348 men (22-90 years). We found an excellent correlation between AP lumbar spine and total body lumbar spine subregion BMD (r2=0.92), but weaker ones for total hip compared to pelvis region (r2=0.72) or between total wrist and left arm subregion from the whole body scan (r2=0.83). The error in estimating site-specific BMD from total body regions ranged from 4.3% (lumbar spine) to 11.2% (femoral neck) in women and from 4.9 to 11.1%, respectively, in men. Site-specific versus regional measurements at the lumbar spine and total hip/pelvis provided comparable overall estimates of osteoporosis prevalence, but disagreed on the status of individuals; measurements at whole body regions underestimated osteoporosis as assessed at the femoral neck or total wrist. All measurements were associated with a history of various fractures [age adjusted odds ratios (OR), 1.3 to 2.1 in women and 1.2 to 1.5 in men] and were generally interchangeable, but femoral neck BMD provided the best estimate of osteoporotic fracture risk in women (OR, 2.9; 95% CI, 1.7-5.0). Although there are strong correlations between BMD from dedicated scans of the hip, spine and distal forearm and corresponding regions on the whole body scan, the measurements provide somewhat different estimates of osteoporosis prevalence and fracture risk.

Menstrual and Reproductive Factors and Fracture Risk: The Leisure World Cohort Study

BACKGROUND

Because menopausal estrogen is related to the development of osteoporosis, we investigated the potential associations of the estrogen-related events of menarche, pregnancy, and menopause with fracture risk in a population-based, prospective study of older women.

METHODS

The Leisure World Cohort was established in the early 1980s when residents of a California retirement community, including 8877 women, completed a health survey. Incident fractures of the hip (n = 1220), wrist (n = 463), and spine (n = 613) incurred over two decades were identified from four follow-up questionnaires, hospital discharge records, and (for hip fracture) death certificates. Hazard ratios (HR) adjusted for age and other potential confounders were calculated using proportional hazards regression.

RESULTS

Late age at menarche was associated with decreased hip fracture risk (HR = 0.84, 95% CI 0.72-0.98, for age > or = 14 vs. < or = 12 years) but was unrelated to fractures at other sites. Hip fracture risk was also reduced in women who had been pregnant (HR = 0.83, 95% CI 0.72- 0.95). Women who reported menopause at age 45+ had a lower risk of wrist fracture compared with those with menopause at age < or = 44 (HR = 0.74, 95% CI 0.58-0.95 for ages 45-54; HR = 0.71, 95% CI 0.49-1.04 for ages 55+). Although fracture risks did not differ between ever and never users of menopausal estrogen, recency since last use was related to wrist fractures (HR = 1.09, 95% CI 1.03-1.16 for each 5 years since last years).

CONCLUSIONS

The estrogen-related events of menarche, pregnancy, and menopause were not associated with osteoporotic fracture risk in a consistent manner. Other factors related to these events may be influencing development of osteoporosis and the likelihood of sustaining a fracture in older women.

Resting Energy Expenditure: A Better Marker than BMI for BMD in African-American Women

PURPOSE

African-American women tend to be more overweight and to have lower resting energy expenditures (REE) compared with Caucasian women. Weight is associated with bone mineral density (BMD), but the relation between BMD and REE has not been reported.

METHODS

Four hundred postmenopausal African-American women aged 45-87 (yr) from San Diego, CA participated in this community-based cross-sectional study. Body composition (fat mass, lean body mass), bone mineral content (BMC) and BMD of the lumbar spine, hip (femoral neck, greater trochanter, intertrochanter), and total body were measured using dual energy x-ray absorptiometry (DXA). REE was calculated using the Harris-Benedict equation; grip strength was measured by isometric dynamometry.

RESULTS

REE (r range: 0.32-0.79) showed the strongest correlation with spine, total hip, and total body BMC and BMD. In stepwise multiple linear regressions adjusted for age and grip strength, REE explained 15% of the variance in spine BMD, 33% of the variance in total hip, and 32% of the total body BMD variance. REE explained 63% of the total body BMC variance. When body weight replaced REE in the models, weight became the strongest covariate of BMC and BMD but explained 1% less of the variance in spine BMD, 5% less of the variance in total hip BMD, 4% less of the variance in total body BMD, and 3% less of the variances in spine, total hip, and total body BMC than did REE.

CONCLUSION

In this cohort of African-American women, weight explained less of the BMC and BMD variance than REE. Poor energy economy may contribute to being overweight and may explain the lower rates of osteoporosis observed in African-American women.

Contributions of bone density and structure to fracture risk assessment in men and women

Although bone mineral density (BMD) is a strong predictor of fractures, it is only a surrogate for bone strength. Bone structural parameters can now be measured on BMD scans, but it is unclear whether they would be more useful for risk assessment. We measured structural parameters using the Hip Structural Analysis Program and evaluated their association, compared with standard hip BMD, with fracture risk in a population-based sample of 213 postmenopausal women and 200 men > or =50 years of age. Altogether, 38% of the women and 27% of the men had experienced a fracture due to moderate trauma (half involved hip, spine or distal forearm), while 23% and 36%, respectively, had a previous fracture due to severe trauma. In logistic regression analyses adjusted for age, the hip BMD and structural parameters were all associated with moderate trauma fractures generally, and osteoporotic fractures specifically, in women, but the best predictor in a multivariate model was femoral neck BMD (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.9-4.0). BMD and the structural parameters were strongly correlated, however, and could be interchanged with little reduction in predictive power. These variables were less predictive of moderate trauma fractures in men. The best model included age (OR per 10 years, 1.5; 95% CI, 1.1-2.1), femoral neck section modulus (OR, 1.6; 95% CI, 1.1-2.5) and intertrochanteric buckling ratio (OR, 1.6; 95% CI, 1.3-2.0). Correction for body size did not alter these relationships. Fractures due to severe trauma were best predicted by structural parameters: in women, femoral neck buckling ratio (OR, 1.2; 95% CI, 1.04-1.5) and, in men, intertrochanteric buckling ratio (OR, 1.4; 95% CI, 1.2-1.6). These data suggest that selected structural variables as assessed by dual-energy X-ray absorptiometry would be as good as standard BMD measurements for predicting fracture risk. Because of the strong correlations, however, some judgment can be used in selecting the variables easiest to measure.

Evaluation of a prediction model for long-term fracture risk

The NOF cost-effectiveness model, based on clinical risk factors and femoral neck aBMD, predicted overall fracture risk in a cohort of postmenopausal women followed for up to 22 years.

INTRODUCTION

To assess the ability of a statistical model to predict long-term fracture risk for a population of postmenopausal women, we compared observed fractures to those predicted by the National Osteoporosis Foundation's (NOF) cost-effectiveness model.

MATERIALS AND METHODS

In this population-based study, 393 postmenopausal Rochester, MN, women had baseline measurements of femoral neck areal BMD (aBMD) and assessment of the clinical risk factors (personal fracture history, family history of osteoporotic fracture, low body weight, and smoking status) that were included in the NOF model. They were then followed prospectively for up to 22 years. Fractures were ascertained by periodic interview and review of community medical records. Standardized incidence ratios (SIRs) compared observed fractures to predicted numbers.

RESULTS

During 4782 person-years of follow-up, 212 women experienced 503 fractures, two-thirds of which were caused by moderate trauma. When undiagnosed (incidentally noted) vertebral and rib fractures were excluded, there was general concordance between observed and predicted fractures of the hip (SIR, 0.78; 95% CI, 0.56-1.01), distal forearm (SIR, 1.22; 95% CI, 0.86-1.68), spine (SIR, 0.76; 95% CI, 0.50-1.11), and all other sites combined (SIR, 1.18; 95% CI, 0.97-1.42). Fracture prediction by the NOF model was about as good after 10 years as it was earlier during follow-up.

CONCLUSIONS

This study validates the ability of a statistical model based on femoral neck aBMD and common clinical risk factors to predict the actual occurrence of fractures in a cohort of postmenopausal white women.

Osteoporosis and fracture risk in women of different ethnic groups

Osteoporosis and 1-year fracture risk were studied in 197,848 postmenopausal American women from five ethnic groups. Weight explained differences in BMD, except among blacks, who had the highest BMD. One SD decrease in BMD predicted a 50% increased fracture risk in each group. Despite similar relative risks, absolute fracture rates differed.

INTRODUCTION

Most information about osteoporosis comes from studies of white women. This study describes the frequency of osteoporosis and the association between BMD and fracture in women from five ethnic groups.

MATERIALS AND METHODS

This study was made up of a cohort of 197,848 community-dwelling postmenopausal women (7784 blacks, 1912 Asians, 6973 Hispanics, and 1708 Native Americans) from the United States, without known osteoporosis or a recent BMD test. Heel, forearm, or finger BMD was measured, and risk factor information was obtained; 82% were followed for 1 year for new fractures. BMD and fracture rates were compared, adjusting for differences in covariates.

RESULTS

By age 80, more than one-fifth of women in each ethnic group had peripheral BMD T scores <-2.5. Black women had the highest BMD; Asian women had the lowest. Only the BMD differences for blacks were not explained by differences in weight. After 1 year, 2414 new fractures of the spine, hip, forearm, wrist, or rib were reported. BMD at each site predicted fractures equally well within each ethnic group. After adjusting for BMD, weight, and other covariates, white and Hispanic women had the highest risk for fracture (relative risk [RR] 1.0 [referent group] and 0.95, 95% CI, 0.76, 1.20, respectively), followed by Native Americans (RR, 0.87; 95% CI, 0.57, 1.32), blacks (RR, 0.52; 95% CI, 0.38, 0.70), and Asian Americans (RR, 0.32; 95% CI, 0.15, 0.66). In age- and weight-adjusted models, each SD decrease in peripheral BMD predicted a 1.54 times increased risk of fracture in each ethnic group (95% CI, 1.48-1.61). Excluding wrist fractures, the most common fracture, did not materially change associations.

CONCLUSIONS

Ethnic differences in BMD are strongly influenced by body weight; fracture risk is strongly influenced by BMD in each group. Ethnic differences in absolute fracture risk remain, which may warrant ethnic-specific clinical recommendations.

Association between self-reported prior wrist fractures and risk of subsequent hip and radiographic vertebral fractures in older women: a prospective study

In this large prospective cohort study of elderly women, the relationships between prior wrist fracture and incident hip and radiographic vertebral fractures were significantly attenuated when adjusted for BMD. This study suggests that BMD thresholds for drug therapy to prevent osteoporotic fracture should be only modestly adjusted in those with prior wrist fracture compared with those without prior wrist fracture. Validation of such an approach would require intervention trials in patients with prior wrist fracture.

INTRODUCTION

Prior wrist fracture has been identified as a risk factor for incident hip and vertebral fractures and proposed as a criterion for determining who should be offered drug therapy to prevent osteoporotic fracture, even if their hip BMD T score is > -2.5. Previously published studies of the relationships between prior wrist fracture and incident hip and vertebral fractures did not adjust for BMD.

MATERIALS AND METHODS

We ascertained prior history of wrist fracture since age 50, measured calcaneal and hip BMD, and performed lateral spine films in a cohort of 9704 elderly community-dwelling women, and then followed them prospectively for incident vertebral and hip fractures. Incident vertebral fractures were defined by morphometry using lateral spine radiography at the first examination and an average of 3.7 years later. Incident hip fractures were confirmed with radiographic reports over a mean follow-up period of 10.1 years.

RESULTS

Prior wrist fracture was associated with an age-adjusted 72% increased odds of incident radiographic vertebral fracture (odds ratio [OR], 1.72; 95% CI, 1.31-2.25). After adjustment for calcaneal BMD, the association of prior wrist fracture with incident radiographic vertebral fracture was attenuated (OR, 1.39; 95% CI, 1.05-1.83). Prior wrist fracture was also associated with an age-adjusted 43% excess rate of incident hip fracture (hazards ratio [HR], 1.43; 95% CI, 1.17-1.74). After adjustment for hip BMD, the association of prior wrist fracture with rate of incident hip fracture was no longer statistically significant (HR, 1.12; 95% CI, 0.92-1.38).

CONCLUSION

In elderly women, prior wrist fracture is a risk factor for radiographic vertebral fracture independent of BMD. The association between prior wrist fracture and incident hip fracture is largely explained by hip BMD. Modest adjustment of BMD drug treatment thresholds for prevention of osteoporotic fractures in those with prior wrist fracture compared with those without prior wrist fracture may be reasonable, but validation of such an approach would require intervention trials in patients with prior wrist fracture.

Validity of self-report for fractures among a multiethnic cohort of postmenopausal women: results from the Women's Health Initiative observational study and clinical trials

OBJECTIVE

The purpose of this study is to examine the validity of, and factors associated with, the accuracy of self-report (participant-report and proxy-report) for fractures.

DESIGN

Study participants were from the Women's Health Initiative Clinical Trial and Observational Study cohorts. All women were postmenopausal; populations included American Indian, Asian/Pacific Islander, black, Hispanic, and non-Hispanic white. The average length of follow-up was 4.3 years. Self-reported fractures were adjudicated by reviewing medical records. The first adjudicated self-report of fractures for each participant was included in the analysis (n = 6,652).

RESULTS

We found substantial variations in validity of self-report by the fracture site. Agreements between self-reports for single-site fractures and medical records were high for hip (78%) and forearm/wrist (81%) but relatively lower for clinical spine fractures (51%). The average confirmation rate for all single-site fractures was 71%. Misidentification of fracture sites by participants or proxy-reporters seemed to be a cause of unconfirmed self-reports. Higher confirmation rates were observed in participant-reports than in proxy-reports. Results of the multivariate analysis indicated that multiple factors, such as ethnicity, a history of osteoporosis or fractures, body mass index, years since menopause, smoking status, and number of falls in the past year were significantly (P < 0.05) related to the validity of self-report.

CONCLUSION

The validity of self-reports for fracture varies by fracture sites and many other factors. The assessed validity in this study is likely conservative because some of the unconfirmed self-reports may be due to poor medical record systems. The validity of self-reports for hip and forearm/wrist fractures is high in this study, supporting their use in epidemiological studies among postmenopausal women.

Relative contributions of bone density, bone turnover, and clinical risk factors to long-term fracture prediction

Long-term fracture prediction using bone mineral density remains controversial, as does the additional contribution from assessing bone turnover or clinical risk factors. We measured bone mineral density at various sites, along with biochemical markers of bone turnover, sex steroid levels, and over 100 clinical variables, at baseline on an age-stratified sample of 304 Rochester, MN women in 1980. The 225 postmenopausal women were subsequently followed for 3146 person-years (median, 16.2 years per subject), wherein they experienced 302 new fractures: 81% resulted from minimal or moderate trauma and 60% of these involved the proximal femur, thoracic or lumbar vertebrae, or distal forearm. Accounting for multiple fractures per subject, these osteoporotic fractures together were best predicted by baseline femoral neck bone mineral density (age-adjusted hazard ratio [HR] per SD decrease, 1.37; 95% CI, 1.10-1.70); 19 moderate trauma forearm fractures were best predicted by distal radius bone mineral content, whereas 28 hip fractures and 100 vertebral fractures were best predicted by femoral neck bone mineral density. Femoral neck bone mineral density performed comparably in predicting osteoporotic fracture risk within the first decade of follow-up (HR, 1.38; 95% CI, 1.10-1.74) as well as more than 10 years after baseline (HR, 1.39; 95% CI, 1.05-1.84). The older biochemical markers were not associated with fractures, but serum "free" estradiol index was independently predictive of short- and long-term fracture risk. Consistent clinical risk factors were not identified, but statistical power was limited. Identifying patients at increased long-term risk of fracture is challenging, but it is reassuring that femoral neck bone mineral density can predict osteoporotic fractures up to 20 years later.

Determinants of bone loss from the femoral neck in women of different ages

An age-stratified sample of 304 women from Rochester, Minnesota, aged 30-94 years (median 60 years) at baseline underwent measurement of femoral neck bone mineral density (BMD) over a follow-up period extending to 16 years. The average rate of change in femoral neck BMD was -1.0% per year (range -10.0% to +13.4%) and did not vary significantly with age. Because there was no marked increase in the rate of loss around the time of menopause, nor convincing evidence of there being a subset of fast losers, there was fairly good tracking of individual values over time; the correlation of baseline with femoral neck BMD values 16 years later was 0.83. Although a large number of potential determinants was assessed, the only consistent predictor of femoral neck bone loss in women of different ages was baseline femoral neck BMD (r = -0.15; p = 0.023). Otherwise, different sets of risk factors were identified for premenopausal women, women within 20 years of menopause, and women 20 years or more postmenopausal, but the predictive power of these different multivariate models was modest. Nonetheless, these data indicate that femoral neck BMD is quite predictable for extended periods of time. This is reassuring with respect to the use of statistical models that incorporate such data to estimate future fracture risk.

Secondary osteoporosis and the risk of vertebral deformities in women

Among an age-stratified sample of 942 Rochester, MN women, the overall prevalence of any vertebral deformity, as assessed by radiographic morphometry, was 21.3 per 100. The prevalence increased with age and, after adjusting for age, vertebral deformities were independently associated with height, weight, a history of distal forearm or hip fractures, and anticoagulant use. Altogether, 73% of the women with a vertebral deformity and 66% of controls had one or more of the conditions that have been linked with secondary osteoporosis, which in aggregate were associated with an age-adjusted 1.2-fold (95% CI 0.8-1.7) increase in risk that was not statistically significant. The prevalence of severe vertebral deformities was 11.7 per 100 women and the prevalence of very severe deformities was 5.7 per 100. There was a stronger relationship of age and most other risk factors with severe vertebral deformities than with isolated mild deformities, suggesting that a subset of mild deformities may not represent actual vertebral fractures. The metabolic disorders linked with secondary osteoporosis were associated with little increase in the risk of severe vertebral deformities, taken together, or of mild deformities. However, in aggregate these conditions were associated with a 2.3-fold increase (95% 1.1-4.8) in very severe vertebral deformities, which points to a role for rapid cancellous bone loss among women with the worst spinal osteoporosis.

Bone density and fracture risk in men

We evaluated different definitions of osteoporosis in a population-based sample of 348 men (age 22-90 years) compared with 351 women (age 21-93 years). Thirty-six men (10%) and 46 women (13%) had a history of osteoporotic fracture (hip, spine, or distal forearm due to moderate trauma at >/= age 35). In logistic regression analysis, osteoporotic fracture risk was associated with bone mineral density (BMD) at all sites (neck, trochanter, total hip, lumbar spine, and total wrist) in both genders (p < 0.001) except spinal BMD in men. After adjusting for age, total hip BMD was the strongest predictor of fracture risk in women (odds ratio [OR] per 1 SD decline, 2.4; 95% confidence interval [CI], 1.6-3.7), while wrist BMD was best in men (OR, 1.5; 95% CI, 1.1-2.0). Among men but not women, bone mineral apparent density (BMAD) was a better predictor of fracture than BMD (wrist BMAD OR, 1.7; 95% CI, 1.3-2.3). Hip BMD/BMAD decreased linearly from age 20 years onward in both genders, while spinal BMD/BMAD declined after age 40 in women but not in men. In both genders, total wrist BMD/BMAD decreased after age 50. By World Health Organization criteria, the age-adjusted prevalence of osteoporosis at the hip, spine, or wrist was 35% among women >/=50 years of age. A similar approach (BMD > 2.5 SD below the young male mean) produced an osteoporosis prevalence rate in men >/=50 years of age of 19%. Thus, bone density predicts fracture risk in men as it does in women, and the prevalence of osteoporosis in men, using sex-specific normal values, is substantial. These observations indicate a need for better prevention and treatment strategies for men.

Dietary protein intake and bone mass in women

Population-based strategies to combat osteoporosis are urgently needed. The role of nutrition in such strategies has been particularly contentious. We examined the relationship among six key nutrients that are thought to affect bone metabolism and bone mineral density in the axial and appendicular skeleton using data from a population-based study in the northern United States. Data on the dietary intake of calcium, phosphorus, vitamin D, protein, fat, and total energy were obtained from a 7-day dietary record. Bone density measurements were made by dual photon absorptiometry in the lumbar spine and proximal femur, and by single photon absorptiometry in the distal and midradius. Among the 72 premenopausal women studied, there was a statistically significant positive association between protein intake and bone mineral in the distal radius and proximal femur, which was not altered by adjustment for age, weight, and physical activity. Among 218 postmenopausal women, no such relationship was found between protein intake and bone mineral, and the only significant findings in this group were negative associations between fat consumption and bone density in the lumbar spine and radius. Our results suggest that dietary protein intake may be a determinant of the peak bone mass attained by premenopausal white women. The relevance of this finding for the design of population strategies to maximize skeletal growth requires further investigation.

Predictors of hip fractures in elderly men

To assess the influence on the risk of hip fractures in men of medical conditions associated with secondary osteoporosis or with an increased likelihood of falling, we conducted a population-based nested case-control study among the 232 Rochester, Minnesota, men with an initial hip fracture due to moderate trauma in 1965-1989 and an equal number of age-matched control men from the general population. Information on selected medical and surgical conditions and certain behavioral risk factors prior to fracture (or comparable index date for controls) was obtained from inpatient and outpatient medical records in the community that averaged over 36 years in duration. After adjusting for age, obesity, and inactivity, disorders linked with secondary osteoporosis were associated with a 2-fold increase in the risk of hip fracture in men (odds ratio [OR] 2.3; 95% confidence interval [CI] 1.3-4.3), while conditions linked with an increased risk of falling were associated with almost a 7-fold increase in risk (OR 6.9; 95% CI 3.3-14.8). These factors together appeared to account for about 72% of the hip fractures in men. Increased attention must be paid to these conditions which, in aggregate, are very common in elderly men and lead to a substantial increase in the risk of hip fracture with its devastating sequelae of death, disability and cost.

Determinants of bone mineral density in older men

Osteoporosis is a significant health problem and contributor to disability and premature mortality among older men. Incidence rates for hip fracture have stabilized in women, but continue to increase in men. A major risk factor for hip fracture is bone mineral density level. The determinants of bone mineral density (BMD) are well defined in women, but not in men. The primary goal of the current research was to increase our understanding of the determinants of BMD of the proximal femur in a large community-based sample of older male volunteers. Eligibility requirements included age of 50 years or older, ambulatory, and not having undergone a bilateral hip replacement. Five hundred twenty-three men, mean mean age 66.6 years, met all eligibility requirements and participated in the Study of Osteoporotic Risk in Men or STORM. Information on demographics, medical history, anthropometry, leisure-time and occupational physical activity, muscular strength, cigarette smoking, alcohol consumption, dietary calcium intake, and medication use (thiazide diuretics and glucocorticoids) were obtained by questionnaire, interview, and examination, BMD of the proximal femur (femoral neck, greater trochanter, and Ward's triangle) was measured by dual-energy X-ray absorptiometry using the Hologic QDR-1000 and QDR-2000. The cross-sectional determinants of BMD included age, blond hair color, current body weight, thiazide diuretic use, historical physical activity, and quadriceps strength. Several variables commonly thought to be determinants of BMD were not related to BMD in this population of older men, including current cigarette smoking, alcohol consumption, current leisure-time physical activity, dietary calcium intake, vitamin D use, and caffeine intake. However, failure to find associations among BMD and some of the potential determinants may be due to lack of statistical power. Identification of the determinants of BMD could lead to the development of interventions aimed at maximizing BMD in men and could potentially decrease the risk of hip fractures.

Dual-energy X-ray absorptiometry at the lumbar spine in German men and women: a cross-sectional study

A cross-sectional, population-based study of 238 randomly selected females and 224 males with German ethnic background (aged 20-80 years) was carried out to establish lumbar spine bone mineral density (BMD) values, using dual X-ray absorptiometry (DXA), for a German population. Comparison was made to the reference range provided by the manufacturer of the DXA equipment. No sex difference in peak spine BMD was found in our study (1.091 +/- 0.114 g/cm2 for males versus 1.070 +/- 0.113 g/cm2 for females, n.s.). Different patterns of bone loss could be detected in both sexes. In premenopausal women there was no significant correlation between age and BMD (y = 1.044 + 0.00047x, r = 0.03, P = 0.73) whereas reduction of female BMD at the spine was demonstrated in postmenopausal women (y = 1.189-0.0041x, r = -0.28, P = 0.01), underscoring the important role of the menopause for later manifestation of spinal osteoporosis in women. In contrast, in males we found no significant change of BMD with aging (y = 1.071-0.0007x, r = -0.08, P = 0.25). Employing commonly used exclusion criteria, BMD values of the study subjects were found mostly within the normal range of BMD. The major finding of our study was good concordance between female data of our study population and the reference data provided by the manufacturer. Clinically significant discrepancies between our data and the Hologic reference range for males could be detected. Our data on males (30-39 years of age) were up to 7% lower than those provided by the manufacturer, probably due to differences in sampling procedures.

Comparison of respondents and nonrespondents in an osteoporosis study

We attempted to enroll an age-stratified random sample of Rochester, Minnesota women > or = 30 years of age in a population-based prospective study of the determinants of bone loss. Using the resources of the Rochester Epidemiology Project, 541 women were contacted and 305 agreed to participate. Of 236 nonrespondents, 38 were ineligible and 198 refused to participate resulting in a 61% response rate for eligible subjects. We reviewed community medical records for respondents and nonrespondents (including ineligibles) to determine whether the two groups differed with regard to variables that might be important in osteoporosis research. There was little difference between respondents and nonrespondents for a history of cigarette smoking, hyperthyroidism, thyroidectomy, or age-related fractures. Respondents survived better, were less likely to be obese or have renal failure, and more likely to have had an oophorectomy and consume alcohol (P < 0.01). These data suggest that nonrespondents were less healthy than respondents.

Historical assessment of risk factors in screening for osteopenia in a normal Caucasian population

BACKGROUND

Bone mineral density (BMD) can predict fracture, however, the common use of historical risk factors to predict low BMD is unproven.

AIMS

To identify significant historical risk factors for osteopenia. To establish predicting equations for BMD and test their ability to identify those who should be referred for BMD scanning.

METHODS

Three hundred and twenty female and 131 male volunteers underwent questionnaire assessment of risk factors and BMD by dual photon absorptiometer at hip and spine. Significant risk factors (P < 0.05) were used to construct a linear regression model to predict BMD. This was cross validated on a second sample of 107 females and 131 males selected from the electoral roll analysing the ability to detect those subjects with BMD in the lower third of the age matched normal range.

RESULTS

In women lower BMD at the spine was associated with increased age, decreased weight, smoking, and delayed menarche. Lower femoral BMD was associated with increased age, decreased weight, family history, inactivity, and smoking. In men lower BMD at the lumbar spine was associated with lower weight, and inactivity. Lower BMD at the femur was associated with increased age, decreased weight, family history, and low calcium intake. When cross validated on the second sample, the models produced sensitivity of 86-89% and sensitivity of 25-46%. Referring those with these risk factors could save 10-23% on scanning. Measuring BMD at the site in question remains the only accurate way of assessing an individual's risk of osteopenia.

Long-term fracture prediction by bone mineral assessed at different skeletal sites

Bone mineral density (BMD) was measured at the lumbar spine and cervical and intertrochanteric regions of the proximal femur by dual-photon absorptiometry and bone mineral content was assessed at the distal and midradius by single-photon absorptiometry in an age-stratified random sample of 304 Rochester, Minnesota women aged 30-94 years. Over follow-up extending to 10 years (median 8.3 years), 93 women experienced 163 new fractures. After adjusting for age, these bone mineral measurements predicted the likelihood of any incident fracture due to moderate trauma, with relative hazards varying from 1.4 to 1.6 per SD decrease in baseline bone mineral. A 1 SD decrease in lumbar spine BMD increased the risk of a new vertebral fracture comparably to a 17 year increase in age; a 1 SD decrease in femoral BMD was comparable to a 13-14 year increase in age on the risk of a hip fracture. We conclude that bone mineral measurements made at a variety of skeletal sites can predict the occurrence for at least 8-10 years of moderate trauma fractures of the sort that might be related to osteoporosis.

Osteoporosis risk factors, gynaecological history and fractures in perimenopausal women--the results of the baseline postal enquiry of the Kuopio Osteoporosis Risk Factor and Prevention Study

The Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE) Study examines the risk factors of osteoporosis, the relationship of risk factors to bone density and fractures, as well as the possibility to prevent bone loss by administering certain hormones. The baseline postal enquiry in 1989 was sent to all the 14,220 women aged 47-56 years residing in the Kuopio Province, Finland. The questionnaire included questions about their gynaecological history, physical exercise and smoking habits, calcium intake, body weight and height, history of bone fractures, health disorders, their current and previous use of drugs, as well as their willingness to participate in bone densitometry and in a clinical hormone trial. The response rate was 92.8%. In all, 56% reported some previous use of female hormones. Strong contraindications for oestrogen replacement therapy were found in 9.3% of the women. Almost half of the respondents reported lack of regular physical exercise, 11.9% were smokers, and 17.0% reported a calcium intake from milk products of less than 500 mg daily. The incidence of fractures increased steadily with age. The incidence of premenopausal fractures within the last 10 years was 7.65 per 1000 person/years and that of postmenopausal fractures was 17.40 per 1000 person/years (P = 0.000). The effect of menopause on fracture incidence was stronger than the effect of a 5-year age increase. Of the respondents, 84.4% were willing to participate in bone densitometry and 68.3% for long-term prevention of osteoporosis with oestrogen.

Dietary calcium and hip fracture risk: the NHANES I Epidemiologic Follow-Up Study

The effect of dietary calcium on hip fracture risk was examined prospectively using the NHANES I Epidemiologic Follow-Up Study cohort, which is derived from a nationally representative sample of the United States population. A cohort of 4342 white men and postmenopausal women ages 50-74 years at baseline (1971-1975) were observed through 1987 for up to 16 years of follow-up. Quantitative estimates of calcium intake were obtained at baseline from a 24-h recall, while weekly frequency of dairy food consumption was obtained from a qualitative food frequency. By 1987, 44 men and 122 women had experienced a hip fracture according to hospital records or death certificates. In the total sample of women the risk of hip fracture was only slightly lower for the highest quartile compared with the lowest. However, although not statistically significant, the age-adjusted risk of hip fracture was approximately 50% lower in the highest quartile of calcium intake compared with the lowest quartile in the subgroup of women who were at least 6 years postmenopausal and not taking postmenopausal hormone. The low relative risk observed among men, although interesting, must be interpreted cautiously due to small sample size. Adjusting for other risk factors did not appreciably change the results for either sex. The pattern of relative risks for calcium quartiles and by selected cutpoints was not consistent with a dose-response effect of calcium. Our results suggest that calcium may lower hip fracture risk in late menopausal women.

Influence of breastfeeding and other reproductive factors on bone mass later in life

The influence of reproductive factors on bone mass at six skeletal sites was assessed in an age-stratified random sample of white women residing in Rochester, Minnesota. After age-adjustment, whether or not women had ever breastfed, total duration of breastfeeding and duration of breastfeeding per child were not associated with reduced bone mineral, but breastfeeding for more than 8 months was associated with greater bone mineral at some sites. There were no consistent effects on bone mineral, after adjusting for age, of gravidity or parity, age at menarche, age at first delivery, use of oral contraceptives or estrogen replacement therapy, various sex hormones, nor any of the other reproductive factors assessed. There was a strong protective effect of obesity, which was also correlated with a number of the reproductive variables. While animal studies suggest that pregnancy and lactation may be associated with calcium loss from the skeleton, these data indicate that such factors have little long-term impact on bone mass in humans and little potential for identifying women at high risk of osteoporosis later in life.

Suppression of the osteogenic response in the aging skeleton

The ability of physical stimuli demonstrated as potently osteogenic in the young adult skeleton were evaluated for their capacity to stimulate new bone formation in the aging skeleton. Using the externally loadable, functionally isolated turkey ulna preparation, the ulnae of 1-year-old (n = 5), and 3-year-old (n = 3) turkeys were subjected to 300 cycles per day of a load regimen generating a high but physiologic level of normal strain (3,000 microstrain). Following 8 weeks of loading, areal properties and histomorphometry were performed on both the experimental and intact control ulnae. Bone cross-sectional areas in the 1-year-old animal increased by 30.2% (+/- 7.8%) as compared with the intact contralateral control ulnae, whereas the areal properties of the older skeleton remained essentially unchanged (-3.3 +/- 7.5%). Renewed bone formation in the experimental ulnae of the 1-year-old animals was characterized by the activation of periosteal bone apposition (4.0 +/- 0.4 microns/day). In comparison, periosteal bone formation in the 3-year-old males was activated in only 1 animal, and this at a significantly attenuated level (less than 0.8 micron/day). The histomorphometric evaluation of intracortical bone remodeling revealed no significant differences between the control and experimental ulnae in either age group. However, osteon mean wall thickness and bone formation sigma were significantly increased in the 3-year-old males (P less than 0.05). In conclusion, these data suggest that a physical signal that is clearly osteogenic in the young adult skeleton is hardly acknowledged in older bone tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Is caffeine consumption a risk factor for osteoporosis?

High caffeine consumption has been proposed as a risk factor for osteoporotic fracture, but the evidence associating high caffeine intake with low bone density is inconsistent. We therefore examined the influence of caffeine consumption on bone mineral at six skeletal sites in an age-stratified random sample of white women residing in Rochester, Minnesota. After age adjustment, there was no association between overall caffeine consumption and bone mineral at five of the six sites. In the femoral shaft, however, there was a statistically significant interaction between age and caffeine consumption so that high caffeine intake was associated with slight reductions in bone mineral among elderly subjects but with modestly increased bone mineral at younger ages. When caffeine intake was categorized by source, no consistent influence of coffee, tea, or other caffeinated beverage consumption could be detected on bone mineral. Caffeine intake was, however, positively associated with cigarette smoking and alcohol consumption. After adjusting for age, caffeine consumption was not correlated with biochemical indices of bone turnover, circulating concentrations of estradiol and estrone, or other dietary and musculoskeletal variables. These data suggest that caffeine intake in the range consumed by a representative sample of white women is not an important risk factor for osteoporosis. Among elderly women, however, in whom calcium balance performance is impaired, high caffeine intake may predispose to cortical bone loss from the proximal femur.

Prevalence of fractures among 10,000 women from the 1900 to 1940 birth cohorts resident in Gothenburg

The prevalence of fractures in women aged 45-86 years resident in the city of Gothenburg, Sweden, was investigated by means of a postal questionnaire. A sample of 10,000 women from seven birth cohorts (1900-1940) was obtained at random from the population register. The response rate was 70.1% in the 1900-1920 and 81.0% in the 1930 and 1940 birth cohorts. When the prevalence of fractures sustained between 25 and 46 years of age was analyzed a higher figure emerged for women from the 1930 and 1940 birth cohorts than for those from the 1900-1920 cohorts, indicating an increasing incidence of fractures over time. There was a significant independent correlation between early menopausal age and a high rate of fractures. Menopausal age decreased with increasing tobacco consumption. There was also a significant independent correlation between tobacco-smoking and a high fracture rate. The prevalence of tobacco-smoking increased from 30.0 to 38.1% between the 1930 and 1940 birth cohorts, which may further increase the fracture risk in future years. Despite increasing vitality and longevity among the elderly in Gothenburg, there are indications that the number of fractures will increase in the future.