Should age influence the choice of quantitative bone assessment technique in elderly women? The EPIDOS study

In a prospective cohort of 7,598 women aged 75 and over, we analyzed the effect of age on the ability of femoral neck bone mineral density (BMD) and of ultrasound (BUA and SOS) of the calcaneus to predict hip fracture. Unadjusted regression analysis showed that the risk of hip fracture was increased 1.7 times for one standard deviation increase in age (3.7 years). Overall, for a decrease of one standard deviation in quantitative bone measures, the risk was significantly increased by 2.2 times for BMD (1.9-2.5), 1.8 for BUA (1.6-2.1), and 1.9 for SOS (1.6-2.2). However the average relative risk associated with a decrease in BMD tends to diminish with advancing age, meaning that a smaller part of the risk is explained by BMD in the very elderly. This is confirmed by the areas under the ROC curves (AUC) of BMD that are significantly better before 80 years (0.75 [0.73-0.76]) than after (0.65 [0.63-0.67] in group 80-84 years and 0.65 [0.61-0.68] in group >/=85). On the other hand, as the absolute risk increases exponentially with age, the number of hip fractures attributable to a low BMD is still important in the very elderly, the risk difference between the lowest and the highest quartile of BMD is 25 hip fractures / 1,000 woman-years in the group >/=85 compared with 16 in the two other groups. Thus, after 80, quantitative assessment of bone may still be of interest for clinical decisions. Compared with quantitative ultrasound parameters, the ability of BMD to predict hip fracture was significantly superior to that of BUA and SOS only before the age of 80 (AUC of BMD 0.75 [0.73-0.76], BUA 0.67 [0.66-0.69], SOS 0.67 [0.65-0.69]). For patients older than 80, we did not observe significant differences in AUC between DXA and QUS to predict hip fracture.

HMG CoA reductase inhibitors and the skeleton: a comprehensive review

Recent studies suggest that the mevalonate pathway plays an important role in skeletal metabolism. HMG CoA reductase inhibitors ("statins"), which inhibit a key enzyme in the mevalonate pathway, are widely used for the treatment of hyperlipidemia. In vitro and animal studies demonstrate that statins stimulate the production of BMP-2, a potent regulator of osteoblast differentiation and activity, suggesting that statins may have an anabolic effect on bone. Statin use in most, but not all observational studies is associated with a reduced risk of fracture, particularly hip fracture, even after adjustment for the confounding effects of age, weight and other medication use. This beneficial effect has not been observed in clinical trials designed to assess cardiovascular endpoints. The effects of statins on bone mass and bone turnover are controversial, but increased bone mass and reduced bone turnover have been observed in controlled studies. Further studies of the skeletal effects of statins are needed, particularly their effects on surrogate markers such as bone mass, bone turnover, and microarchitecture, to determine the optimal formulation, dosing and route of administration. Clinical trials with fracture endpoints are needed before statins can be recommended as therapeutic agents for osteoporosis.

Nulliparity and fracture risk in older women: the study of osteoporotic fractures

Whether nulliparity increases fracture risk is unclear from prior studies, which are limited by small samples or lack of measured bone mineral density. No study has evaluated whether the effect of parity differs by skeletal site. We prospectively analyzed the relationship of parity to the risk of incident nontraumatic hip, spine, and wrist fractures in 9704 women aged 65 years or older participating in the Study of Osteoporotic Fractures to determine if parity reduces postmenopausal fracture risk, and if so, if this risk reduction is (1) greater at weight-bearing skeletal sites and (2) independent of bone mineral density. Parity was ascertained by self-report. Incident hip and wrist fractures were determined by physician adjudication of radiology reports (mean follow-up, 9.8 years) and spine fractures by morphometric criteria on serial radiographs. The relationship of parity to hip and wrist fracture was assessed by proportional hazards models. Spine fracture risk was evaluated by logistic regression. Compared with parous women, nulliparous women (n = 1835, 19%) had an increased risk of hip and spine, but not wrist, fractures. In multivariate models, parity remained a significant predictor only for hip fracture. Nulliparous women had a 44% increased risk of hip fractures independent of hip bone mineral density (hazards ratio, 1.44; 95% CI, 1.17-1.78). Among parous women, each additional birth reduced hip fracture risk by 9% (p = 0.03). Additionally, there were no differences in mean total hip, spine, or radial bone mineral density values between nulliparous and parous women after multivariate adjustment. In conclusion, childbearing reduces hip fracture risk by means that may be independent of hip bone mineral density.

Incidence and risk factors for a second hip fracture in elderly women. The Study of Osteoporotic Fractures

Women with hip fracture have an increased risk of second hip fracture but other risk factors for a second hip fracture have not been established. We sought to determine the incidence and risk factors for second hip fracture, in a prospective cohort study of community-dwelling postmenopausal women over 65 years: the Study of Osteoporotic Fractures. From a cohort of 9,704 women, 632 women with a documented first hip fracture during the study were followed up until a second hip fracture or the end of follow-up. Clinical risk factors and bone mineral density were assessed at the beginning of the study. Fifty-three second hip fractures were validated by radiographs. Women with hip fracture had a 2.3% per year risk of second hip fracture. Women who walked for exercise at baseline were less likely to sustain a second hip fracture with a relative risk (RR) of 0.5 [0.3-0.9], as were those who had normal depth perception (RR=0.5 [0.3-0.9]). Women who lost weight since age 25 years had an increased risk of second incident hip fracture (RR = 2.7 [1.6-4.6]), as did those who had a low calcaneal bone mineral density (RR=1.5 [1.1-2.0] per standard deviation decrease in bone mineral density). Current use of estrogen replacement therapy at baseline was protective (RR=0.5 [0.3-0.9]) up to 2 years of follow-up. We conclude that community-dwelling women with a first hip fracture have a high risk of second hip fracture, and risk factors for this second fracture are similar to those of first hip fracture.

Quantitative ultrasound and mortality: a prospective study

Previous studies suggest that low bone mineral density (BMD) is associated with increased mortality, but the relationship between quantitative ultrasound (QUS) and mortality is unknown. We studied 5816 women over age 70 years enrolled in the Study of Osteoporotic Fractures. QUS of the calcaneus, and BMD of the calcaneus and hip, were measured at baseline, and women were contacted every 4 months to determine vital status. All reported deaths were confirmed by review of the death certificate or hospital records, and classified by ICD-9 code. During 5.0 years of follow-up, 677 women died. Women in the lowest quintile of QUS had the highest mortality during follow-up. After adjustment for age, grip strength, weight, height, health status, estrogen use, smoking, physical activity, and history of hypertension, diabetes, cardiovascular disease, cancer and stroke, each 1 SD reduction in broadband ultrasonic attenuation (BUA) was associated with a 16% increase in mortality (RH = 1.16; 95% CI: 1.07, 1.26). Mortality from cardiovascular disease, cancer and other causes were all increased among women with low QUS, but the association with cancer deaths was not statistically significant after multiple adjustments (RH = 1.09; CI: 0.93, 1.27). Low BMD was also associated with an increased risk of total and cause-specific mortality, but we found little evidence that BUA and BMD were independent predictors of mortality. Results were similar among women who did not fracture during follow-up. In this large population-based study of older women, low QUS is associated with both total and cause-specific mortality. This relationship was independent of other factors associated with mortality, such as age and health status, and suggests QUS and BMD may reflect some aspect of aging not captured by these traditional factors.

Changes in biochemical markers of bone turnover in women treated with raloxifene: influence of regression to the mean

Measures with extreme magnitude are most likely to be the result of measurement variability. Repeated measurements genuinely lessen such variability, leading to a phenomenon known as regression to the mean (RTM), which may affect biochemical markers of bone turnover. We therefore studied four markers of bone turnover in the Multiple Outcomes of Raloxifene Evaluation (MORE) trial--serum procollagen type I C-propeptide (PICP), osteocalcin (OC), bone-specific alkaline phosphatase (BAP) and urinary type I collagen breakdown product (CTX)--among the 1704 women treated with raloxifene who had marker measurements and were at least 70% adherent, and among 915 control group patients. We examined the existence of RTM, and applied a method of adjustment for RTM of both baseline and follow-up results. We found that women who had the most extreme values tended to go in the opposite direction with the subsequent measurement, i.e., exhibited a pattern of RTM. For example, among women whose urinary CTX decreased at least 60% in the first 6 months, 61% had an increase in the next 6 months; and among those who had an increase in the first 6 months, 81% had a decrease in the next 6 months. We found a similar pattern for each of the four markers. When adjusting for RTM we obtained estimated true values of both baseline values and change in markers. These estimated true values were substantially different from the observed value when the latter was further from the mean. For example, for a 10% increase in urinary CTX in the first 6 months, after accounting for RTM we estimate that there was in fact a 3% decrease (80% confidence interval: -38% to 53%). We conclude that the few initial extreme marker responses observed in women treated with raloxifene represent RTM, and that one practical consequence is that patients with an increase in markers during the first 6 months should be continued on raloxifene therapy, because the values usually decrease later on.

Timing of estrogen replacement therapy for optimal osteoporosis prevention

To determine whether estrogen initiated at age 60 yr or later reduces rates of bone loss and fracture incidence, we performed a prospective cohort study of 6910 nonosteoporotic women, 65 yr of age or older. Estrogen use, medical history, lifestyle, and anthropometric data were obtained by questionnaire, interview and examination. We identified five patterns of estrogen use: never users (67%); past early users (started under age 60 yr with no current use; 23%); past late users (started at age 60 or later with no current use; 2%); current early users (started under age 60 yr with use both at baseline and 6 yr later; 6.7%); and current late users (started at age 60 or later with use at baseline and 6 yr later; 1.5%). Bone mineral density was measured at the total hip twice, an average of 3.5 yr apart, and at the calcaneus, an average of 5.7 yr apart. Incident nonspine fractures were validated by radiographic report. Bone mineral density was significantly higher among current users, compared with never and past users. The annual rate of hip bone loss was significantly lower in current early users (-0.22%/yr) and current late users (-0.35%/yr) in comparison with never users (-0.6%/yr), past early users (-0.6%/yr), and past late users (-0.72%/yr). During an average of 11.0 yr of follow-up, 1953 nonspine fractures were confirmed. The multiple-adjusted relative risk of nonspine fracture was 0.63 (95% confidence interval 0.51-0.78) among current early users and 0.75 (0.50-1.12) among current late users, compared with never users. Early initiation and long-term continuation of estrogen is associated with a reduction in the risk of nonspine fractures, and initiation at or after age 60 yr with long-term continuation may also be associated with a reduced fracture risk.

Type 2 diabetes in older well-functioning people: who is undiagnosed? Data from the Health, Aging, and Body Composition study

OBJECTIVE

To assess, in an older population, the prevalence of diagnosed and undiagnosed diabetes, the number needed to screen (NNTS) to identify one individual with undiagnosed diabetes, and factors associated with undiagnosed diabetes.

RESEARCH DESIGN AND METHODS

Socioeconomic and health-related factors were assessed at the baseline examination of the Health, Aging, and Body Composition (Health ABC) Study, a cohort of 3,075 well-functioning people aged 70-79 years living in Memphis, Tennessee and Pittsburgh, Pennsylvania (42% blacks and 48% men). Diabetes was defined according to the 1985 World Health Organization criteria (fasting glucose > or =7.8 mmol/l or 2-h glucose > or =11.1 mmol/l) and the 1997 American Diabetes Association criteria (fasting glucose > or =7.0 mmol/l).

RESULTS

The prevalence of diagnosed and undiagnosed diabetes was 15.6 and 8.0%, respectively, among all participants (NNTS 10.6), 13.9 and 9.1% among white men (NNTS 9.5), 7.8 and 7.4% among white women (NNTS 12.4), 22.7 and 9.1% among black men (NNTS 8.5), and 21.6 and 6.2% among black women (NNTS 12.6). In multivariate analyses, compared with individuals without diabetes, individuals with undiagnosed diabetes were more likely to be men and were more likely to have a history of hypertension, higher BMI, and larger waist circumference. NNTS was lowest in men (9.1), individuals with hypertension (8.7), individuals in the highest BMI quartile (6.9), and individuals in the largest waist circumference quartile (6.8).

CONCLUSIONS

In approximately one-third of all older people with diabetes, the condition remains undiagnosed. Screening for diabetes may be more efficient among men and individuals with hypertension, high BMI, and large waist circumference.

Measuring fitness in healthy older adults: the Health ABC Long Distance Corridor Walk

OBJECTIVES

The Health ABC Long Distance Corridor Walk (LDCW) was designed to extend the testing range of self-paced walking tests of fitness for older adults by including a warm-up and timing performance over 400 meters. This study compares performance on the LDCW and 6-minute walk to determine whether the LDCW encourages greater participant effort.

DESIGN

Subjects were administered the LDCW and 6-minute walk during a single visit. Test order alternated between subjects, and a 15-minute rest was given between tests.

SETTING

The Baltimore Veterans Affairs Medical Center.

PARTICIPANTS

Twenty volunteers age 70 to 78.

MEASUREMENTS

The LDCW, consisting of a 2-minute warm-up walk followed by a 400-meter walk and a 6-minute walk test were administered using a 20-meter long course in an unobstructed hallway. Heart rate (HR) and blood pressure (BP) were recorded at rest and before and after all walks.

RESULTS

All 20 subjects walked a faster pace over 400 meters than for 6 minutes, in which the mean distance covered was 402 meters. From paired t-tests, walking speed was faster (mean difference = 0.23 m/sec; P < .001), and ending HR (mean difference = 7.6 bpm; P < .001) and systolic BP (mean difference = 8.3 mmHg; P = .024) were greater for the 400-meter walk than for the 6-minute walk. Results were independent of test order and subject fitness level.

CONCLUSIONS

Providing a warm-up walk and using a target distance instead of time encouraged subjects to work closer to their maximum capacity. This low-cost alternative to treadmill testing can be used in research and clinical settings to assess fitness and help identify early functional decline in older adults.

Association between endogenous hormones and sex hormone-binding globulin and bone turnover in older women: study of osteoporotic fractures

Estrogen therapy decreases bone remodeling, but the association between endogenous estradiol (E2), estrone (E1), testosterone (T), and bone turnover in older women is not clear. To test the association of serum E2, E1, free T, and sex hormone-binding globulin (SHBG) with bone turnover, we analyzed cross-sectional relationships among E2, E1, T, SHBG, and biochemical markers of bone turnover serum osteocalcin [OC], serum bone-specific alkaline phosphatase [bAP], and serum breakdown products of C telopeptide of type I collagen [CTx] in 704 women enrolled in the Study of Osteoporotic Fractures. Women with lower estradiol levels tended to have higher levels of bone turnover, but the association was weak (R(2) = 0.01 for the association E2-OC, p = 0.03; and R(2) = 0.024 for E2-CTx, p = 0.001). Relationships between SHBG and turnover were also weak (R(2) for the association SHBG-OC was 0.07, p < 0.001, and 0.03 for SHBG-sCTx, p = 0.03), or not significant (R(2) < 0.01 for the association SHBG-bAP). Associations of E1 and T with these markers were of the same magnitude. These results were not modified after adjustment for age, weight, and smoking status. We conclude that older women with low endogenous hormones have somewhat higher bone turnover, but these associations are weak. Bone turnover is determined mainly by factors other than endogenous concentrations of sex hormones.

Influence of smoking on the antiosteoporotic efficacy of raloxifene

The efficacy of estrogen therapy may be modified in women who smoke because of increased catabolism of estrogen and the interaction of tobacco products with the estradiol receptor. We examined whether the efficacy of raloxifene differed in smoking vs. nonsmoking women. We compared change in bone mineral density and biochemical markers of bone turnover, and incidence of new vertebral fracture in postmenopausal women of the Multiple Outcomes on Raloxifene Efficacy trial, who were randomized to either raloxifene (60 or 120 mg/d) or placebo. In the 17% of women who were current smokers, we found, compared with nonsmokers, lowered baseline trochanter bone mineral density (0.540 vs. 0.557 g/cm(2); P < 0.001) and serum osteocalcin (24.8 vs. 26.6 ng/liter; P < 0.001). Baseline urinary type I collagen breakdown products was increased among smokers (291.8 vs. 276.9 micromol/liter; P = 0.04). Body mass index was also lower in smokers (24.3 vs. 25.4; P < 0.001). After 6 months of treatment, there was no significant difference in reduction of bone turnover between smokers and nonsmokers. After 4 yr of treatment, the smoking-treatment interaction was not significant between smokers and nonsmokers for the percent increase in femoral neck bone mineral density (P = 0.25), trochanter bone mineral density (P = 0.24), and spine bone mineral density (P = 0.37). The smoking-treatment interaction for reduction in vertebral fracture risk was not significant either [odds ratio for fracture, 0.67 (0.45-0.98) for smokers and 0.56 (0.47-0.68) for nonsmokers; P = 0.44]. These results were not modified after stratification by tertiles of body mass index or when comparing heavy smokers vs. light smokers. We conclude that smoking does not influence the antiosteoporotic effect of raloxifene. This may represent an advantage over estrogen replacement therapy.

Airflow limitation is underrecognized in well-functioning older people

OBJECTIVES

Dyspnea is a common symptom in older people. A reduced forced expiratory volume in 1 second (FEV1) is associated with a higher mortality rate from cardiovascular and respiratory disease, and increased admissions to hospitals. Underrecognized or undertreated airflow limitation may exacerbate the problem. The purpose of this study was to assess the prevalence and treatment of airflow limitation in a cohort of well-functioning older people.

DESIGN

Cross-sectional study.

SETTING

Baseline of a clinical-epidemiological study of incident functional limitation.

PARTICIPANTS

Participants attended the baseline examination of the Health, Aging, and Body Composition study, a prospective cohort study of 3,075 well-functioning subjects age 70 to 79.

MEASUREMENTS

Demographic and clinical data were collected by interview. Spirometry was performed unless contraindicated and repeated until three acceptable sets of flow-volume loops were obtained. Patients on bronchodilator medications had spirometry performed posttherapy. Blinded readers assessed the flow-volume loops, and inadequate tests were omitted from analysis. Airflow limitation was defined as a reduced forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) as determined by age-, sex-, and race-normalized values. Severity of airflow limitation was defined by American Thoracic Society criteria.

RESULTS

Two thousand four hundred eighty-five subjects (80.8%) had assessable spirometry and data on treatment and diagnosis (1,265 men, 1,220 women). The mean age was 73.6 years. Two hundred sixty-two subjects (10.5%) had airflow limitation; 43 (16.4%) of these never smoked. Only 37.4% of participants with airflow limitation and 55.6% of participants with severe airflow limitation reported a diagnosis of lung disease. Only 20.5% of subjects with at least moderate airflow limitation had used a bronchodilator in the previous 2 weeks.

CONCLUSION

Despite their good functional status, airflow limitation was present, and underrecognized, in a considerable proportion of our older population. The low bronchodilator use suggests a significant reservoir of untreated disease. Physicians caring for older people need to be more vigilant for both the presence, and the need for treatment, of airflow limitation.

Race and sex effects on the association between muscle strength, soft tissue, and bone mineral density in healthy elders: the Health, Aging, and Body Composition Study

Two factors generally reported to influence bone density are body composition and muscle strength. However, it is unclear if these relationships are consistent across race and sex, especially in older persons. If differences do exist by race and/or sex, then strategies to maintain bone mass or minimize bone loss in older adults may need to be modified accordingly. Therefore, we examined the independent effects of bone mineral-free lean mass (LM), fat mass (FM), and muscle strength on regional and whole body bone mineral density (BMD) in a cohort of 2,619 well-functioning older adults participating in the Health, Aging, and Body Composition (Health ABC) Study with complete measures. Participants included 738 white women, 599 black women, 827 white men, and 455 black men aged 70-79 years. BMD (g/cm2) of the femoral neck, whole body, upper and lower limb, and whole body and upper limb bone mineral-free LM and FM was assessed by dual-energy X-ray absorptiometry (DXA). Handgrip strength and knee extensor torque were determined by dynamometry. In analyses stratified by race and sex and adjusted for a number of confounders, LM was a significant (p < 0.001) determinant of BMD, except in white women for the lower limb and whole body. In women, FM also was an independent contributor to BMD at the femoral neck, and both FM and muscle strength contributed to limb BMD. The following were the respective beta-weights (regression coefficients for standardized data, Std beta) and percent difference in BMD per unit (7.5 kg) LM: femoral neck, 0.202-0.386 and 4.7-5.9%; lower limb, 0.209-0.357 and 2.9-3.5%; whole body, 0.239-0.484 and 3.0-4.7%; and upper limb (unit = 0.5 kg), 0.231-0.407 and 3.1-3.4%. Adjusting for bone size (bone mineral apparent density [BMAD]) or body size BMD/height) diminished the importance of LM, and the contributory effect of FM became more pronounced. These results indicate that LM and FM were associated with bone mineral depending on the bone site and bone index used. Where differences did occur, they were primarily by sex not race. To preserve BMD, maintaining or increasing LM in the elderly would appear to be an appropriate strategy, regardless of race or sex.

Bone mass and breast cancer risk in older women: differences by stage at diagnosis

BACKGROUND

Older women with low bone mineral density (BMD) have a decreased incidence of breast cancer. It is not known whether this association is confined to early-stage, slow-growing tumors.

METHODS

We prospectively studied 8905 women who were 65 years of age or older during the period from 1986 through 1988 and had no history of breast cancer. At study entry, we used single-photon absorptiometry to measure each woman's BMD at three skeletal sites: the wrist, forearm, and heel. The women were followed for a mean of 6.5 years for the occurrence of breast cancer. All statistical tests were two-sided.

RESULTS

During 57 516 person-years of follow-up, 315 women developed primary invasive or in situ breast cancer. Multivariate analyses that adjusted for age, obesity, and other covariates revealed that the risk of breast cancer for women in the highest quartile of BMD for all three skeletal sites was 2.7 (95% confidence interval [CI] = 1.4 to 5.3) times greater than that for women in the lowest quartile at all three skeletal sites. The magnitude of increased risk associated with high BMD differed by the stage of disease at diagnosis and was greater for more advanced tumors (relative risk [RR] for TNM [i.e., tumor-lymph node-metastasis] stage II or higher tumors = 5.6; 95% CI = 1.2 to 27.4) than for early-stage disease (RR for in situ/TNM stage I tumors = 2.2; 95% CI = 1.0 to 4.8).

CONCLUSIONS

Elderly women with high BMD have an increased risk of breast cancer, especially advanced cancer, compared with women with low BMD. These findings suggest an association between osteoporosis and invasive breast cancer, two of the most prevalent conditions affecting an older woman's health.

Risk for fracture in women with low serum levels of thyroid-stimulating hormone

BACKGROUND

Biochemical evidence of hyperthyroidism may be associated with low bone mass, particularly in older postmenopausal women, but no prospective studies of thyroid function and subsequent fracture risk have been done.

OBJECTIVE

To examine the association between low levels of thyroid-stimulating hormone (TSH) and fracture in older women.

DESIGN

Prospective cohort study with case-cohort sampling.

SETTING

Four clinical centers in the United States.

PATIENTS

686 women older than 65 years of age from a cohort of 9704 women recruited from population-based listings between 1986 and 1988.

MEASUREMENTS

Baseline assessment of calcaneal bone mass, spine radiography, and history of thyroid disease. Spine radiography was repeated after a mean follow-up of 3.7 years; nonspine fractures were centrally adjudicated. Thyroid-stimulating hormone was measured in sera obtained at baseline from 148 women with new hip fractures, 149 women with new vertebral fractures, and a subsample of 398 women randomly selected from the cohort.

RESULTS

After adjustment for age, history of previous hyperthyroidism, self-rated health, and use of estrogen and thyroid hormone, women with a low TSH level (0.1 mU/L) had a threefold increased risk for hip fracture (relative hazard, 3.6 [95% CI, 1.0 to 12.9]) and a fourfold increased risk for vertebral fracture (odds ratio, 4.5 [CI, 1.3 to 15.6]) compared with women who had normal TSH levels (0.5 to 5.5 mU/L). After adjustment for TSH level, a history of hyperthyroidism was associated with a twofold increase in hip fracture (relative hazard, 2.2 [CI, 1.0 to 4.4]), but use of thyroid hormone itself was not associated with increased risk for hip fracture (relative hazard, 0.5 [CI, 0.2 to 1.3]).

CONCLUSIONS

Women older than 65 years of age who have low serum TSH levels, indicating physiologic hyperthyroidism, are at increased risk for new hip and vertebral fractures. Use of thyroid hormone itself does not increase risk for fracture if TSH levels are normal.

Bone mineral density and endogenous hormones and risk of breast cancer in postmenopausal women (United States)

OBJECTIVE

This case-cohort study was designed to examine whether total hip bone mineral density (BMD) is independently associated with breast cancer over and above its association with other determinants, including levels of total and bioavailable estradiol and testosterone and sex-hormone binding globulin.

METHODS

Our study population was selected from a cohort of 8,203 postmenopausal women who were screened for the Fracture Intervention Trial in 1992, at which time BMD was assessed, and blood samples were obtained. A total of 109 women developed breast cancer during four years of follow-up; 173 other randomly selected women from the larger cohort were also selected. Cox proportional hazards with robust variance adjustment was used for these analyses.

RESULTS

Relative to women in the lower fourth of the BMD distribution, the risk associated with being in the upper fourth was 2.6 (95% confidence interval (CI) 1.1-5.8). After adjusting for serum hormone levels, the corresponding relative risk was 2.5 (95% CI 0.9-5.2). With body mass index and number of years since menopause added to the multivariate analysis, the relative risk decreased to 1.4 (95% CI 0.5-4.0).

CONCLUSIONS

BMD may not influence breast cancer risk independent of its relationship with endogenous hormones and measured covariates.

Fracture risk reduction with alendronate in women with osteoporosis: the Fracture Intervention Trial. FIT Research Group

We examined the effect of alendronate treatment for 3-4 yr on risk of new fracture among 3658 women with osteoporosis enrolled in the Fracture Intervention Trial. This cohort included women with existing vertebral fracture and those with osteoporosis as defined by T score of less than -2.5 at the femoral neck but without vertebral fracture. All analyses were prespecified in the data analysis plan. The magnitudes of reduction of fracture incidence with alendronate were similar in both groups. The two groups were, therefore, pooled to obtain a more precise estimate of the effect of alendronate on relative risk of fracture (relative risk, 95% confidence interval): hip (0.47, 0.26-0.79), radiographic vertebral (0.52, 0.42-0.66), clinical vertebral (0.55, 0.36-0.82), and all clinical fractures (0.70, 0.59-0.82). Reductions in risk of clinical fracture were statistically significant by 12 months into the trial. We conclude that reductions in fracture risk during treatment with alendronate are consistent in women with existing vertebral fractures and those without such fractures but with bone mineral density in the osteoporotic range. Furthermore, reduction in risk is evident early in the course of treatment. This pooled analysis provides a more precise estimate of the antifracture efficacy of alendronate in women with osteoporosis than that in prior reports.

Upper gastrointestinal tract safety profile of alendronate: the fracture intervention trial

OBJECTIVES

To determine whether alendronate sodium treatment is associated with upper gastrointestinal (GI) tract adverse experiences (AEs)-particularly those of the stomach, duodenum, or esophagus-in the Fracture Intervention Trial, and to assess the relationship between alendronate use and upper GI tract events among women at increased risk for these outcomes.

DESIGN

Randomized, double-blind, placebo-controlled trial with a mean follow-up of 3.8 years. Women were initially randomized to receive alendronate sodium, 5 mg/d, or placebo. After 2 years, the alendronate sodium dose was increased to 10 mg/d.

PARTICIPANTS

A total of 6459 women aged 54 to 81 years recruited from 11 US clinical centers. All participants had low hip bone mineral density. Women with major upper GI tract disease (recent ulcers, upper GI tract bleeding, or use of daily medication for dyspepsia) were excluded. Regular nonsteroidal anti-inflammatory drug users were not excluded.

MEASUREMENTS

Self-reported upper GI tract AEs were ascertained by interview every 3 months. Serious upper GI tract AEs were confirmed and classified by review of hospital records and endoscopy reports, if available. Upper GI tract AEs were further analyzed in 2 specified groups-gastroduodenal and esophageal-to examine events that might be related to upper GI tract mucosal irritation. Gastric and duodenal perforations, ulcers, and bleeding events were combined for analysis of these clinically important outcomes.

RESULTS

The overall incidence of upper GI tract events was similar in the alendronate and placebo groups (47.5% vs. 46.2%; relative risk [RR], 1.02; 95% confidence interval [CI], 0.95-1.10). The incidence of gastroduodenal perforations, ulcers, and bleeding events was 1.6% in the alendronate group and 1.9% in the placebo group (RR, 0.86; 95% CI, 0.59-1.24). The incidence of nonspecific upper GI tract conditions, such as abdominal pain, dyspepsia, nausea, and vomiting, was also similar in the 2 groups. Esophageal events occurred in 10.0% and 9.4% of patients in the alendronate and placebo groups, respectively (RR, 1.06; 95% CI, 0.91-1.24). Esophagitis not reported as reflux was more common in the alendronate group (0.7%) than in the placebo group (0.4%), but not significantly so (RR, 1.71; 95% CI, 0.90-3.39). Alendronate use was not associated with a significant increase in upper GI tract events among women at increased risk for these events (those aged > or =75 years with previous upper GI tract disease or using nonsteroidal anti-inflammatory drugs).

CONCLUSION

In these older women, upper GI tract complaints, particularly dyspepsia and abdominal pain, were common, but alendronate treatment was not associated with an increased incidence of upper GI tract events, even in high-risk subgroups.

Clinical use of biochemical markers of bone remodeling: current status and future directions

Biochemical markers of bone turnover provide a means of evaluating skeletal dynamics that complements static measurements of bone mineral density (BMD). This review evaluates the use of commercially available bone turnover markers as aids in diagnosis and monitoring response to treatment in patients with osteoporosis. High within-person variability complicates but does not preclude their use. Elevated bone resorption markers appear to be associated with increased fracture risk in elderly women, but there is less evidence of a relationship between bone formation markers and fracture risk. The critical question of predicting fracture efficacy with treatment has not been answered. Changes in bone markers as currently determined do not predict BMD response to either bisphosphonates or hormone replacement therapy. Single measurements of markers do not predict BMD cross-sectionally (except possibly in the very elderly), or change in BMD in individual patients, either treated or untreated. On the other hand, research applications of bone turnover markers are of value in investigating the pathogenesis and treatment of bone diseases. Markers have potential in the clinical management of osteoporosis, but their use in this regard is not established. Additional studies with fracture endpoints and information on negative and positive predictive value are needed to evaluate fully the utility of bone turnover markers in individual patients.

Biochemical markers of bone turnover and prediction of hip bone loss in older women: the study of osteoporotic fractures

To examine the ability of commercially available biochemical markers of bone formation and resorption to predict hip bone loss, we prospectively obtained serum and timed 2-h urine specimens from 295 women age 67 years or older who were not receiving estrogen replacement therapy. Serum was assayed for two markers of bone formation: osteocalcin (OC) and bone-specific alkaline phosphatase (BALP). Urine specimens were assayed for four markers of bone resorption: N-telopeptides (NTX), free pyridinolines (Pyr), free deoxypyridinoline (Dpyr), and C-telopeptides (CTX). Measurements of hip bone mineral density were made at the time the samples were collected and then repeated an average of 3.8 years later. Higher levels of all four resorption markers were, on average, significantly associated with faster rates of bone loss at the total hip, but not at the femoral neck. Women with OC levels above the median had a significantly faster rate of bone loss than women with levels below the median, but there was no significant association between levels of BALP and hip bone loss. The sensitivity and specificity of higher marker levels for predicting rapid hip bone loss was limited, and there was considerable overlap in bone loss rates between women with high and low marker levels. We conclude that higher levels of urine NTX, CTX, Pyr, Dpyr, and serum OC are associated with faster bone loss at the hip in this population of elderly women not receiving estrogen replacement therapy, but these biochemical markers have limited value for predicting rapid hip bone loss in individuals.