The effects of analytic software and scan analysis technique on the comparison of dual X-ray absorptiometry with dual photon absorptiometry of the hip in the elderly

Association of dietary fiber and risk of hip fracture in men from the Framingham Osteoporosis Study and the Concord Health and Ageing in Men Project

BACKGROUND

Data in the Offspring Framingham Osteoporosis Study (FOS) suggested that higher intake of dietary fiber was modestly protective against loss of bone mineral density at the femoral neck in men but not in women.

AIM

To examine the relationship of fiber intake with risk of hip fractures in men.

METHODS

We included 367 men from the FOS Original cohort, 1730 men from the FOS Offspring cohort, and 782 men from the Concord Health and Ageing in Men Project (CHAMP) in the analysis. Incident fractures were defined as medically confirmed first occurrence of osteoporotic fractures at the proximal femur. Fiber intake was estimated via a validated food frequency questionnaire (FFQ) or diet history. Cox proportional hazards models were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). A random-effects model was used to estimate the pooled relative risk in meta-analysis.

RESULTS

Seventy-two incident hip fractures were identified, of which 24 occurred in the FOS Original cohort [mean (SD): age 75.3 (5.1) years; follow-up time: 8.5 (6.2) years; dietary fiber: 19 (8) (g/d)], 19 in the FOS Offspring cohort [58.8 (9.8) years; 11.0 (5.9) years; 19 (8) (g/d)], and 29 in CHAMP [81.4 (4.5) years; 5.2 (1.5) years; 28 (10) (g/d)]. We did not find significant associations within each cohort between fiber intake and risk of hip fractures. The pooled HR (95% CI) was 0.80 (0.39, 1.66) comparing energy-adjusted dietary fiber at tertile 3 vs. tertile 1 (I2 = 0, p = 0.56).

CONCLUSION

These data suggested that dietary fiber was not associated with risk of incident hip fractures in men.

Role of Vitamin C in Osteoporosis Development and Treatment-A Literature Review

Osteoporosis and associated low energy fractures are a significant clinical problem, especially in the elderly population. The occurrence of a hip fracture is associated with significant mortality and a high risk of disability. For this, apart from the treatment of osteoporosis, effective prevention of both the development of the disease and related fractures is extremely important. One aspect of osteoporosis prevention is proper dietary calcium intake and normal vitamin D3 levels. However, there is some evidence for a potential role of vitamin C in osteoporosis and fracture prevention, too. This review aims to summarize the current knowledge about the role of vitamin C in osteoporosis development, prevention and treatment. The PubMed/Medline search on the role of vitamin C in bone metabolism database was performed for articles between 2000 and May 2020. Reports from in vitro and animal studies seem promising. Epidemiological studies also indicate the positive effect of high vitamin C content in the daily diet on bone mineral density. Despite promising observations, there are still few observational and intervention studies and their results do not allow for unequivocal determination of the benefits of high daily intake of vitamin C or its long-term supplementation.

Dairy Intake Is Protective against Bone Loss in Older Vitamin D Supplement Users: The Framingham Study

Background: Previous studies showed beneficial effects of specific dairy foods on bone health in middle-aged adults.Objective: We examined the association of milk, yogurt, cheese, cream, fluid dairy (milk + yogurt), and milk + yogurt + cheese intakes with bone mineral density (BMD) and 4-y percentage of change in BMD [▵%BMD; femoral neck, trochanter, and lumbar spine (LS)]. We further assessed whether these associations were modified by vitamin D supplement use in this cohort of older adults.Methods: Food-frequency questionnaire responses, baseline BMD (hip and spine, n = 862 in 1988-1989), and follow-up BMD (n = 628 in 1992-1993) were measured in the Framingham study, a prospective cohort study of older Caucasian men and women aged 67-93 y. Outcomes included baseline BMD and ▵%BMD. Dairy-food intakes (servings per week) were converted to energy-adjusted residuals, and linear regression was used, adjusting for covariates. These associations were further examined by vitamin D supplement use.Results: The mean age of the participants was 75 y. In the full sample, dairy-food items were not associated with BMD (P = 0.11-0.99) or with ▵%BMD (P = 0.29-0.96). Among vitamin D supplement users, but not among nonusers, higher milk, fluid dairy, and milk + yogurt + cheese intakes were associated with higher LS BMD (P = 0.011-0.009). Among vitamin D supplement users, but not among nonusers, higher milk + yogurt + cheese intakes were protective against trochanter BMD loss (P = 0.009).Conclusions: In this population of older adults, higher intakes of milk, fluid dairy, and milk + yogurt + cheese were associated with higher LS BMD, and a higher intake of milk + yogurt + cheese was protective against trochanter BMD loss among vitamin D supplement users but not among nonusers. These findings underscore that the benefits of dairy intake on the skeleton may be dependent on vitamin D intake.

Changes in bone mineral density may predict the risk of fracture differently in older adults according to fall history

OBJECTIVES

To determine whether the association between change in bone mass density (BMD) over 4 years and risk of hip and nonvertebral fracture differs according to an individual's history of falls.

DESIGN

Population-based cohort study.

SETTING

Framingham, Massachusetts.

PARTICIPANTS

Individuals with two measures of BMD at the femoral neck (mean age 78.8; 310 male, 492 female).

MEASUREMENTS

Cox proportional hazards models were used to estimate hazard ratios (HRs) for the association between percentage change in BMD (per sex-specific standard deviation) and risk of incident hip and nonvertebral fracture. Models were stratified based on history of falls (≥1 falls in the past year) and recurrent falls (≥2 falls) ascertained at the time of the second BMD test. Interactions were tested by including the term "fall history * change in BMD" in the models.

RESULTS

Mean change in BMD was -0.6%/year; 27.8% of participants reported falls, and 10.8% reported recurrent falls. Seventy-six incident hip and 175 incident nonvertebral fractures occurred over a median follow-up of 9.0 years. There was no difference in the association between change in BMD and hip fracture according to history of falls (P for interaction = .57). The HR associated with change in BMD and nonvertebral fracture was 1.31 (95% confidence interval (CI) = 1.10-1.56) in participants without a history of falls and 0.95 (95% CI 0.70-1.28) in those with a fall (interaction P = .07). Results for recurrent fallers were similar.

CONCLUSION

The effect of BMD loss on risk of nonvertebral fracture may be greater in persons without a history of falls. It is possible that change in BMD contributes less to fracture risk when a strong risk factor for fracture, such as falls, is present.

Milk and yogurt consumption are linked with higher bone mineral density but not with hip fracture: the Framingham Offspring Study

Dairy foods are a complex source of essential nutrients. In this study, fluid dairy intake, specifically milk, and yogurt intakes were associated with hip but not spine bone mineral density (BMD), while cream may adversely influence BMD, suggesting that not all dairy products are equally beneficial for the skeleton.

PURPOSE

This study seeks to examine associations of milk, yogurt, cheese, cream, most dairy (total dairy without cream), and fluid dairy (milk + yogurt) with BMD at femoral neck (FN), trochanter (TR), and spine, and with incident hip fracture over 12-year follow-up in the Framingham Offspring Study.

METHODS

Three thousand two hundred twelve participants completed a food frequency questionnaire (1991–1995 or 1995–1998) and were followed for hip fracture until 2007 [corrected]. Two thousand five hundred and six participants had DXA BMD (1996-2001). Linear regression was used to estimate adjusted mean BMD while Cox-proportional hazards regression was used to estimate adjusted hazard ratios (HR) for hip fracture risk. Final models simultaneously included dairy foods adjusting for each other.

RESULTS

Mean baseline age was 55 (±1.6) years, range 26-85. Most dairy intake was positively associated with hip and spine BMD. Intake of fluid dairy and milk was related with hip but not spine BMD. Yogurt intake was associated with TR-BMD alone. Cheese and cream intakes were not associated with BMD. In final models, yogurt intake remained positively associated with TR-BMD, while cream tended to be negatively associated with FN-BMD. Yogurt intake showed a weak protective trend for hip fracture [HR(95%CI), ≤4 serv/week, 0.46 (0.21-1.03) vs. >4 serv/week, 0.43 (0.06-3.27)]. No other dairy groups showed a significant association (HRs range, 0.53-1.47) with limited power (n, fractures = 43).

CONCLUSION

Milk and yogurt intakes were associated with hip but not spine BMD, while cream may adversely influence BMD. Thus, not all dairy products are equally beneficial for the skeleton. Suggestive fracture results for milk and yogurt intakes need further confirmation.

Repeat bone mineral density screening and prediction of hip and major osteoporotic fracture

IMPORTANCE

Screening for osteoporosis with bone mineral density (BMD) is recommended for older adults. It is unclear whether repeating a BMD screening test improves fracture risk assessment.

OBJECTIVES

To determine whether changes in BMD after 4 years provide additional information on fracture risk beyond baseline BMD and to quantify the change in fracture risk classification after a second BMD measure.

DESIGN, SETTING, AND PARTICIPANTS

Population-based cohort study involving 310 men and 492 women from the Framingham Osteoporosis Study with 2 measures of femoral neck BMD taken from 1987 through 1999.

MAIN OUTCOMES AND MEASURES

Risk of hip or major osteoporotic fracture through 2009 or 12 years following the second BMD measure.

RESULTS

Mean age was 74.8 years. The mean (SD) BMD change was -0.6% per year (1.8%). Throughout a median follow-up of 9.6 years, 76 participants experienced an incident hip fracture and 113 participants experienced a major osteoporotic fracture. Annual percent BMD change per SD decrease was associated with risk of hip fracture (hazard ratio [HR], 1.43 [95% CI, 1.16 to 1.78]) and major osteoporotic fracture (HR, 1.21 [95% CI, 1.01 to 1.45]) after adjusting for baseline BMD. At 10 years' follow-up, 1 SD decrease in annual percent BMD change compared with the mean BMD change was associated with 3.9 excess hip fractures per 100 persons. In receiver operating characteristic (ROC) curve analyses, the addition of BMD change to a model with baseline BMD did not meaningfully improve performance. The area under the curve (AUC) was 0.71 (95% CI, 0.65 to 0.78) for the baseline BMD model compared with 0.68 (95% CI, 0.62 to 0.75) for the BMD percent change model. Moreover, the addition of BMD change to a model with baseline BMD did not meaningfully improve performance (AUC, 0.72 [95% CI, 0.66 to 0.79]). Using the net reclassification index, a second BMD measure increased the proportion of participants reclassified as high risk of hip fracture by 3.9% (95% CI, -2.2% to 9.9%), whereas it decreased the proportion classified as low risk by -2.2% (95% CI, -4.5% to 0.1%).

CONCLUSIONS AND RELEVANCE

In untreated men and women of mean age 75 years, a second BMD measure after 4 years did not meaningfully improve the prediction of hip or major osteoporotic fracture. Repeating a BMD measure within 4 years to improve fracture risk stratification may not be necessary in adults this age untreated for osteoporosis.

Equivalence and precision of knee cartilage morphometry between different segmentation teams, cartilage regions, and MR acquisitions

OBJECTIVE

To compare precision and evaluate equivalence of femorotibial cartilage volume (VC) and mean cartilage thickness over total area of bone (ThCtAB.Me) from independent segmentation teams using identical Magnetic Resonance (MR) images from three series: sagittal 3D Dual Echo in the Steady State (DESS), coronal multi-planar reformat (DESS-MPR) of DESS and coronal 3D Fast Low Angle SHot (FLASH).

DESIGN

Nineteen subjects underwent test-retest MR imaging at 3 T. Four teams segmented the cartilage using prospectively defined plate regions and rules. Mixed models analysis of the pooled data were used to evaluate the effect of acquisition, team and plate on precision and Pearson correlations and mixed models were used to evaluate equivalence.

RESULTS

Segmentation team differences dominated measurement variability in most cartilage regions for all image series. Precision of VC and ThCtAB.Me differed significantly by team and cartilage plate, but not between FLASH and DESS. Mean values of VC and ThCtAB.Me differed by team (P < 0.05) for DESS, FLASH and DESS-MPR. FLASH VC was 4-6% larger than DESS in the medial tibia and lateral central femur, and FLASH ThCtAB.Me was 5-6% larger in the medial tibia, but 4-8% smaller in the medial central femur. Correlations between DESS and FLASH for VC and ThCtAB.Me were high (r = 0.90-0.97), except for DESS vs FLASH medial central femur ThCtAB.Me (r = 0.81-0.83).

CONCLUSIONS

Cartilage morphology metrics from different image contrasts had similar precision, were generally equivalent, and may be combined for cross-sectional analyses if potential systematic offsets are accounted for. Data from different teams should not be pooled unless equivalence is demonstrated for cartilage metrics of interest.

Plasma phosphatidylcholine concentrations of polyunsaturated fatty acids are differentially associated with hip bone mineral density and hip fracture in older adults: the Framingham Osteoporosis Study

Polyunsaturated fatty acids (PUFAs) may influence bone health. The objective of this work was to examine associations between plasma phosphatidylcholine (PC) PUFA concentrations and hip measures: (1) femoral neck bone mineral density (FN-BMD) (n = 765); (2) 4-year change in FN-BMD (n = 556); and (3) hip fracture risk (n = 765) over 17-year follow-up among older adults in the Framingham Osteoporosis Study. BMD measures were regressed on quintile of plasma PC PUFAs (docosahexaenoic acid [DHA], linoleic acid [LA], and arachidonic acid [AA]), adjusted for covariates. Hazard ratios (HR) and 95% confidence interval (CI) for hip fracture were estimated by quintile of plasma PC PUFAs, adjusted for covariates. Higher concentrations of PC DHA were associated with loss of FN-BMD over 4 years in women (p-trend = 0.04), but was protective in men in the uppermost quintile compared to men grouped in the lower four quintiles, in post hoc analysis (p = 0.01). PC LA concentrations were inversely associated with baseline FN-BMD in women (p-trend = 0.02), and increased hip fracture risk in women and men (p-trend = 0.05), but body mass index (BMI) adjustment attenuated these associations (p-trend = 0.12 and p-trend = 0.14, respectively). A trend toward a protective association was observed between PC AA and baseline FN-BMD in men (p-trend = 0.06). Women and men with the highest PC AA concentrations had 51% lower hip fracture risk than those with the lowest (HR = 0.49, 95% CI = 0.24-1.00). Opposing effects of PC DHA on FN-BMD loss observed in women and men need further clarification. Bone loss associated with PC LA may be confounded by BMI. High PC AA concentrations may be associated with reduced hip fracture risk.

Protective effects of fish intake and interactive effects of long-chain polyunsaturated fatty acid intakes on hip bone mineral density in older adults: the Framingham Osteoporosis Study

BACKGROUND

Polyunsaturated fatty acids and fish may influence bone health.

OBJECTIVE

We aimed to examine associations between dietary polyunsaturated fatty acid and fish intakes and hip bone mineral density (BMD) at baseline (1988-1989; n = 854) and changes 4 y later in adults (n = 623) with a mean age of 75 y in the Framingham Osteoporosis Study.

DESIGN

BMD measures were regressed on energy-adjusted quartiles of fatty acid intakes [n-3 (omega-3): α-linolenic acid, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and EPA+ DHA; n-6 (omega-6): linoleic acid (LA) and arachidonic acid (AA); and n-6:n-3 ratio] and on categorized fish intakes, with adjustment for covariates. Effect modification by EPA+DHA intake was tested for n-6 exposures.

RESULTS

High intakes (≥3 servings/wk) of fish relative to lower intakes were associated with maintenance of femoral neck BMD (FN-BMD) in men (dark fish + tuna, dark fish, and tuna) and in women (dark fish) (P < 0.05). Significant interactions between AA and EPA+DHA intakes were observed cross-sectionally in women and longitudinally in men. In women with EPA+DHA intakes at or above the median, those with the highest AA intakes had a higher mean baseline FN-BMD than did those with the lowest intakes (quartile 4 compared with quartile 1: P = 0.03, P for trend = 0.02). In men with the lowest EPA+DHA intakes (quartile 1), those with the highest intakes of AA (quartile 4) lost more FN-BMD than did men with the lowest intakes of AA (quartile 1; P = 0.04). LA intake tended to be associated with FN-BMD loss in women (P for trend < 0.06).

CONCLUSIONS

Fish consumption may protect against bone loss. The protective effects of a high AA intake may be dependent on the amount of EPA+DHA intake.

Dietary acid load is not associated with lower bone mineral density except in older men

High dietary acid load may be detrimental to bone mineral density (BMD), although sufficient calcium intake might neutralize this effect. In observational studies, the association between BMD and dietary acid load, estimated by net endogenous acid production (NEAP) and potential renal acid load (PRAL), has been inconsistent, and the potential modifying effect of calcium intake has not been assessed. We therefore examined the cross-sectional associations of estimated NEAP and PRAL with BMD in the Framingham Osteoporosis Study. We hypothesized that higher estimated NEAP and PRAL would be associated with lower BMD, but only among those with total calcium intake < 800 mg/d. BMD of the femoral neck and lumbar spine was measured, and estimated NEAP and PRAL were calculated via FFQ among 1069 Framingham Original (1988-1989, 1992-1993; 62% women, mean age 76 y) and 2919 Offspring (1996-2001; 56% women, mean age 60 y) cohort participants. Cohort- and sex-specific ANCOVA was used to calculate multivariable-adjusted mean BMD for estimated NEAP and PRAL quartiles. Assuming no uncontrolled confounding, estimated NEAP, but not PRAL, was inversely associated with femoral neck BMD (P-trend = 0.04) in Original cohort men, whereas neither was associated with lumbar spine BMD. Estimated NEAP and PRAL were not associated with BMD at any site among Original cohort women or Offspring cohort men and women. There were no significant interactions between either estimated NEAP or PRAL and total calcium intake. These results suggest that, with a possible exception of older men, dietary acid load does not have a measureable negative effect on bone health, regardless of total calcium intake.

Cross-calibration and comparison of variability in 2 bone densitometers in a research setting: the framingham experience

New technology introduced over time results in changes in densitometers during longitudinal studies of bone mineral density (BMD). This requires that a cross-calibration process be completed to translate measurements from the old densitometer to the new one. Previously described cross-calibration methods for research settings have collected single measures on each densitometer and used linear regression to estimate cross-calibration corrections. Thus, these methods may produce corrections that have limited precision and underestimate the variability in converted BMD values. Furthermore, most of the previous studies have included small samples recruited from specialized populations. Increasing the sample size, obtaining multiple measures on each machine, and using linear mixed models to account for between- and within-subject variability may improve cross-calibration estimates. The purpose of this study was to conduct an in vivo cross-calibration of a Lunar DPX-L (Lunar Corporation, Madison, WI) with a Lunar Prodigy densitometer (GE Medical Systems Lunar, Madison, WI) using a sample of 249 healthy volunteers who were scanned twice on each densitometer, without repositioning, at both the femur and spine. Scans were analyzed using both automated and manual placement of regions of interest. Wilcoxon rank-sum tests and Bland-Altman plots were used to examine possible differences between repeat scans within and across densitometers. We used linear mixed models to determine the cross-calibration equations for the femoral neck, trochanter, total hip, and lumbar spine (L2-L4) regions. Results using automated and manual placement of the regions of interest did not differ significantly. The DPX-L densitometer exhibited larger median absolute differences in the BMD values by repeat scans of femoral neck (0.016 vs 0.012, p=0.1) and trochanter (0.011 vs. 0.009, p=0.06) compared with the Prodigy densitometer. The Bland-Altman plots revealed no statistically significant linear relationship between the differences in paired measures between machines and mean BMD. In our large sample of healthy volunteers, we did detect systematic differences between the DPX-L and Prodigy densitometers. Our proposed cross-calibration method, which includes acquiring multiple measures and using linear mixed models, provides researchers with a more realistic estimate of the variance of cross-calibrated BMD measures, potentially reducing the chance of making a type I error in longitudinal studies of changes in BMD.

Application of the National Osteoporosis Foundation Guidelines to postmenopausal women and men: the Framingham Osteoporosis Study

We applied the 2008 National Osteoporosis Foundation (NOF) Guidelines to Framingham Osteoporosis Study participants and found nearly one half of Caucasian postmenopausal women and one sixth of men aged 50 years and older would be recommended for osteoporosis treatment. Given the high proportion of persons recommended for treatment, NOF Guidelines may need to be re-evaluated with respect to budget impact.

INTRODUCTION

Little is known about the public health impact of the NOF Guidelines. Therefore, we determined the proportion of US Caucasians recommended for treatment of osteoporosis according to NOF Guidelines (2003 and 2008).

METHODS

One thousand nine hundred and forty-six postmenopausal women and 1,681 men aged > or =50 years from the Framingham Study with information on bone mineral density (1987-2001) were included. Information on clinical predictors was used to estimate the 10-year probability of hip and major osteoporotic fracture by FRAX (version 3.0).

RESULTS

Overall proportion of women meeting treatment criterion was less when the 2008 NOF Guidelines were applied (41.1%) compared with 2003 Guidelines (47.8%). The proportion of women aged <65 years meeting treatment criterion was much less when applying 2008 Guidelines (23.1% in 2003, 8.3% in 2008), whereas the proportion of women aged >75 years increased slightly (78.3% in 2003, 86.0% in 2008). Seventeen percent of men aged > or =50 years met treatment criterion (2.5% aged 50-64 years, 49.8% aged >75 years).

CONCLUSIONS

Nearly one half of Caucasian postmenopausal women and one sixth of men aged 50 years and older would be recommended for osteoporosis treatment according to 2008 NOF Guidelines. Given the high proportion of persons recommended for treatment, NOF Guidelines may need to be re-evaluated with respect to budget impact.

Inverse association of carotenoid intakes with 4-y change in bone mineral density in elderly men and women: the Framingham Osteoporosis Study

BACKGROUND

In vitro and in vivo studies suggest that carotenoids may inhibit bone resorption and stimulate proliferation and differentiation of osteoblasts. Few studies have examined the association between carotenoid intake (other than beta-carotene) and bone mineral density (BMD).

OBJECTIVE

We evaluated associations between total and individual carotenoid intake (alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, and lutein+zeaxanthin) with BMD at the hip, spine, and radial shaft and the 4-y change in BMD.

DESIGN

Both cross-sectional and longitudinal analyses were conducted in 334 men and 540 women (mean +/- SD age: 75 +/- 5 y) in the Framingham Osteoporosis Study. Energy-adjusted carotenoid intakes were estimated from the Willett food-frequency questionnaire. Mean BMD and mean 4-y BMD changes were estimated, for men and women separately, by quartile of carotenoid intake with adjustment for age, BMI, height, physical activity index, smoking (never compared with ever smokers), multivitamin use, season of BMD measurement (for cross-sectional analyses on BMD only), estrogen use (in women), and intakes of total energy, calcium, vitamin D, caffeine, and alcohol.

RESULTS

Few cross-sectional associations were observed with carotenoid intake. Associations between lycopene intake and 4-y change in lumbar spine BMD were significant for women (P for trend = 0.03), as were intakes of total carotenoids, beta-carotene, lycopene and lutein+zeaxanthin with 4-y change in trochanter BMD in men (P for trend = 0.0005, 0.02, 0.009, and 0.008, respectively).

CONCLUSIONS

Carotenoids showed protective associations against 4-y loss in trochanter BMD in men and in lumbar spine in women. No significant associations were observed at other bone sites. Although not consistent across all BMD sites examined, these results support a protective role of carotenoids for BMD in older men and women.

High vitamin C intake is associated with lower 4-year bone loss in elderly men

Vitamin C is essential for collagen formation and normal bone development. We evaluated associations of total, supplemental, and dietary vitamin C intake with bone mineral density (BMD) at the hip [femoral neck, trochanter], spine, and radial shaft and 4-y BMD change in elderly participants from the Framingham Osteoporosis Study. Energy-adjusted vitamin C intakes were estimated from the Willett FFQ in 1988-89. Mean BMD and 4-y BMD change was estimated, for men and women, by tertile/category of vitamin C intake, adjusting for covariates. We tested for interaction with smoking, calcium, and vitamin E intake. Among 334 men and 540 women, the mean age was 75 y and mean vitamin D intake was 8.25 mug/d (women) and 8.05 mug/d (men). We observed negative associations between total and supplemental vitamin C intake and trochanter-BMD among current male smokers (P-trend = 0.01). Among male nonsmokers, total vitamin C intake was positively associated with femoral neck BMD (P-trend = 0.04). Higher total vitamin C intake was associated with less femoral neck and trochanter-BMD loss in men with low calcium (all P-trend </= 0.03) or vitamin E intakes (all P-trend = 0.03). Higher dietary vitamin C intake tended to be associated with lower femoral neck-BMD loss (P-trend = 0.09). These associations were attenuated but retained borderline significance (P-trend < 0.1) after adjusting for potassium intake (a marker of fruit and vegetable intake), suggesting that vitamin C effects may not be separated from other protective factors in fruit and vegetables. Null associations were observed among women. These results suggest a possible protective role of vitamin C for bone health in older men.

Plasma B vitamins, homocysteine, and their relation with bone loss and hip fracture in elderly men and women

CONTEXT

Elevated homocysteine is a strong risk factor for osteoporotic fractures among elders, yet it may be a marker for low B-vitamin status.

OBJECTIVE

Our objective was to examine the associations of plasma concentrations of folate, vitamin B12, vitamin B6, and homocysteine with bone loss and hip fracture risk in elderly men and women.

DESIGN

This was a longitudinal follow-up study of the Framingham Osteoporosis Study.

SETTING

Community dwelling residents of Framingham, MA, were included in the study.

PARTICIPANTS

A total of 1002 men and women (mean age 75 yr) was included in the study.

MAIN OUTCOME MEASURES

Baseline (1987-1989) blood samples were used to categorize participants into plasma B-vitamin (normal, low, deficient) and homocysteine (normal, high) groups. Femoral neck bone mineral density (BMD) measured at baseline and 4-yr follow-up was used to calculate annual percent BMD change. Incident hip fracture was assessed from baseline through 2003.

RESULTS

Multivariable-adjusted mean bone loss was inversely associated with vitamin B6 (P for trend 0.01). Vitamins B12 and B6 were inversely associated with hip fracture risk (all P for trend < 0.05), yet associations were somewhat attenuated and not significant after controlling for baseline BMD, serum vitamin D, and homocysteine. Participants with high homocysteine (>14 micromol/liter) had approximately 70% higher hip fracture risk after adjusting for folate and vitamin B6, but this association was attenuated after controlling for vitamin B12 (hazard ratio = 1.49; 95% confidence interval 0.91, 2.46).

CONCLUSIONS

Low B-vitamin concentration may be a risk factor for decreased bone health, yet does not fully explain the relation between elevated homocysteine and hip fracture. Thus, homocysteine is not merely a marker for low B-vitamin status.

Age, gender, and body mass effects on quantitative trait loci for bone mineral density: the Framingham Study

A genome-wide scan was performed in participants from the Framingham Osteoporosis Study (1557 members of 330 mostly Caucasian pedigrees), with 401 microsatellite markers spaced on average at 10 cM. Bone mineral density (BMD) was measured at the femoral neck, trochanter, Ward's area, and lumbar spine with DXA. Our recent study (J Bone Mines Res 17 (2002), 1718) reported a number of regions with suggestive linkage to possible quantitative trait loci (QTL). The current study estimates the heterogeneity of linkage in these regions in subsamples of our pedigrees, stratified on the known biological contributors to bone mass of sex, age, and body mass index (BMI). The pedigree sample was stratified into three sets of subgroups by sex [males (age range 35- 96 years), females (29-91 years)], by age [60 or younger (29-60 years) and older than 60 (61-96 years)], and by BMI [stratified into low or high BMI, by median cut-off 27.7 in males (BMI range 17-53) and 25.8 in females (14-54)]. Heritability estimates of BMD (adjusted for age, anthropometry, nutrition, physical activity, and, in females, estrogen use) in subsamples ranged from 0.47 to 0.69. Two-point and multipoint variance component linkage analyses of BMD (using SOLAR) in subsamples supported findings of previously reported suggestive linkage results in the total sample on 8q24.13 and 14q31 (LODs>2.0). However, heterogeneity of linkage was observed on 6p21.2 and 21qter, where findings in the total sample were not supported by subsamples. On the other hand, subsample-specific maxima were found, on 4q34.1 (males), 9q22-9q31 (younger), 16p13.2 (high BMI), and 17p13.3 (older), which were not reflected by the total sample results. In conclusion, heterogeneity of QTL effects was revealed in pedigree members stratified by sex, age, and BMI; in some instances new loci were identified in subgroups. These findings may suggest that effects of genes on the determination of BMD differ between men and women, younger and older, and lean and obese adults. Evaluation of family members stratified in homogeneous groups may be warranted in genetic studies of bone mass.

Genome screen for quantitative trait loci contributing to normal variation in bone mineral density: the Framingham Study

A genome-wide scan was performed in a randomly ascertained set of 330 extended families from the population-based Framingham Study to identify chromosomal regions possibly linked to bone mineral density (BMD). A set of 401 microsatellite markers was typed at a 10-centimorgan (cM) average density throughout the genome. BMD was measured at the femoral neck, trochanter, Ward's area, and lumbar spine in 1557 participants of both Framingham cohorts. BMDs were adjusted for age, body mass index (BMI), height, alcohol, caffeine, calcium and vitamin D intakes, smoking, physical activity, and estrogen use in women within each sex and cohort. Strong heritabilities (values between 0.543 and 0.633) were found for the adjusted BMD at all sites. Two-point and multipoint quantitative linkage analyses were performed for each BMD site using the maximum likelihood variance components method. By two-point screening, loci of suggestive linkage were identified on chromosomes 6 and 21, with the maximum log10 of the odds ratio (LOD) scores of 2.34 for the trochanter at D21S1446 and 2.93 for the femoral neck at D6S2427. Lumbar spine BMD had maxima at D6S2427 (LOD = 1.88) and at D12S395 (LOD = 2.08). Multipoint linkage analysis revealed suggestive linkage of trochanteric BMD at a broad (approximately 20 cM) interval on chromosome 21q, with the peak linkage close to D21S1446 (LOD = 3.14). LOD scores were 2.13 at 8q24 with Ward's BMD and 1.92 at 14q21.3 with lumbar spine BMD. This largest genome screen to date for genes underlying normal variation in BMD, adjusted for a large number of covariates, will help to identify new positional candidate genes, otherwise unrecognized.

Effect of dietary protein on bone loss in elderly men and women: the Framingham Osteoporosis Study

Few studies have evaluated protein intake and bone loss in elders. Excess protein may be associated with negative calcium balance, whereas low protein intake has been associated with fracture. We examined the relation between baseline dietary protein and subsequent 4-year change in bone mineral density (BMD) for 391 women and 224 men from the population-based Framingham Osteoporosis Study. BMD (g/cm2) was assessed in 1988-1989 and in 1992-1993 at the femur, spine, and radius. Usual dietary protein intake was determined using a semiquantitative food frequency questionnaire (FFQ) and expressed as percent of energy from protein intake. BMD loss over 4 years was regressed on percent protein intake, simultaneously adjusting for other baseline factors: age, weight, height, weight change, total energy intake, smoking, alcohol intake, caffeine, physical activity, calcium intake, and, for women, current estrogen use. Effects of animal protein on bone loss also were examined. Mean age at baseline (+/-SD) of 615 participants was 75 years (+/-4.4; range, 68-91 years). Mean protein intake was 68 g/day (+/-24.0; range, 14-175 g/day), and mean percent of energy from protein was 16% (+/-3.4; range, 7-30%). Proportional protein intakes were similar for men and women. Lower protein intake was significantly related to bone loss at femoral and spine sites (p < or = 0.04) with effects similar to 10 lb of weight. Persons in the lowest quartile of protein intake showed the greatest bone loss. Similar to the overall protein effect, lower percent animal protein also was significantly related to bone loss at femoral and spine BMD sites (all p < 0.01) but not the radial shaft (p = 0.23). Even after controlling for known confounders including weight loss, women and men with relatively lower protein intake had increased bone loss, suggesting that protein intake is important in maintaining bone or minimizing bone loss in elderly persons. Further, higher intake of animal protein does not appear to affect the skeleton adversely in this elderly population.

Dietary vitamin K intakes are associated with hip fracture but not with bone mineral density in elderly men and women

BACKGROUND

Vitamin K has been associated with bone mineral density (BMD) and risk of hip fracture. The apolipoprotein (apo) E4 allele (APOE*E4) has been associated with bone fracture through a putative effect on vitamin K transport in blood.

OBJECTIVE

The objective was to determine the associations between vitamin K intake, apo E genotype, BMD, and hip fracture in a population-based cohort of elderly men and women.

DESIGN

Dietary vitamin K intake was assessed with a food-frequency questionnaire in 335 men and 553 women (average age: 75.2 y) participating in the Framingham Heart Study in 1988-1989. Incidence of hip fractures was recorded from 1988 to 1995. BMD at the hip, spine, and arm was assessed on 2 separate occasions (1988-1989 and 1992-1993). Comparisons between apo E genotype and BMD were made relative to E4 allele status (at least 1 epsilon4 allele compared with no epsilon4 allele).

RESULTS

Individuals in the highest quartile of vitamin K intake (median: 254 microg/d) had a significantly lower fully adjusted relative risk (0.35; 95% CI: 0. 13, 0.94) of hip fracture than did those in the lowest quartile of intake (median: 56 microg/d). There were no associations between vitamin K intake and BMD in either men or women. No association was found between the E4 allele and BMD, and there were no significant interactions between the E4 allele and phylloquinone intake and BMD or hip fracture.

CONCLUSIONS

Low vitamin K intakes were associated with an increased incidence of hip fractures in this cohort of elderly men and women. Neither low vitamin K intake nor E4 allele status was associated with low BMD.

Risk factors for longitudinal bone loss in elderly men and women: the Framingham Osteoporosis Study

Few studies have evaluated risk factors for bone loss in elderly women and men. Thus, we examined risk factors for 4-year longitudinal change in bone mineral density (BMD) at the hip, radius, and spine in elders. Eight hundred elderly women and men from the population-based Framingham Osteoporosis Study had BMD assessed in 1988-1989 and again in 1992-1993. BMD was measured at femoral neck, trochanter, Ward's area, radial shaft, ultradistal radius, and lumbar spine using Lunar densitometers. We examined the relation of the following factors at baseline to percent BMD loss: age, weight, change in weight, height, smoking, caffeine, alcohol use, physical activity, serum 25-OH vitamin D, calcium intake, and current estrogen replacement in women. Multivariate regression analyses were conducted with simultaneous adjustment for all variables. Mean age at baseline was 74 years +/-4.5 years (range, 67-90 years). Average 4-year BMD loss for women (range, 3.4-4.8%) was greater than the loss for men (range, 0.2-3.6%) at all sites; however, BMD fell with age in both elderly women and elderly men. For women, lower baseline weight, weight loss in interim, and greater alcohol use were associated with BMD loss. Women who gained weight during the interim gained BMD or had little change in BMD. For women, current estrogen users had less bone loss than nonusers; at the femoral neck, nonusers lost up to 2.7% more BMD. For men, lower baseline weight and weight loss also were associated with BMD loss. Men who smoked cigarettes at baseline lost more BMD at the trochanter site. Surprisingly, bone loss was not affected by caffeine, physical activity, serum 25-OH vitamin D, or calcium intake. Risk factors consistently associated with bone loss in elders include female sex, thinness, and weight loss, while weight gain appears to protect against bone loss for both men and women. This population-based study suggests that current estrogen use may help to maintain bone in women, whereas current smoking was associated with bone loss in men. Even in the elderly years, potentially modifiable risk factors, such as weight, estrogen use, and cigarette smoking are important components of bone health.

Potassium, magnesium, and fruit and vegetable intakes are associated with greater bone mineral density in elderly men and women

BACKGROUND

Osteoporosis and related fractures will be growing public health problems as the population ages. It is therefore of great importance to identify modifiable risk factors.

OBJECTIVE

We investigated associations between dietary components contributing to an alkaline environment (dietary potassium, magnesium, and fruit and vegetables) and bone mineral density (BMD) in elderly subjects.

DESIGN

Dietary intake measures were associated with both cross-sectional (baseline) and 4-y longitudinal change in BMD among surviving members of the original cohort of the Framingham Heart Study. Dietary and supplement intakes were assessed by food-frequency questionnaire, and BMD was measured at 3 hip sites and 1 forearm site.

RESULTS

Greater potassium intake was significantly associated with greater BMD at all 4 sites for men and at 3 sites for women (P < 0.05). Magnesium intake was associated with greater BMD at one hip site for both men and women and in the forearm for men. Fruit and vegetable intake was associated with BMD at 3 sites for men and 2 for women. Greater intakes of potassium and magnesium were also each associated with less decline in BMD at 2 hip sites, and greater fruit and vegetable intake was associated with less decline at 1 hip site, in men. There were no significant associations between baseline diet and subsequent bone loss in women.

CONCLUSION

These results support the hypothesis that alkaline-producing dietary components, specifically, potassium, magnesium, and fruit and vegetables, contribute to maintenance of BMD.

Alendronate for the prevention and treatment of glucocorticoid-induced osteoporosis. Glucocorticoid-Induced Osteoporosis Intervention Study Group

BACKGROUND

Osteoporosis is a common complication of long-term glucocorticoid therapy for which there is no well-proved preventive or restorative treatment.

METHODS

We carried out two 48-week, randomized, placebo-controlled studies of two doses of alendronate in 477 men and women, 17 to 83 years of age, who were receiving glucocorticoid therapy. The primary end point was the difference in the mean percent change in lumbar-spine bone density from base line to week 48 between the groups. Secondary outcomes included changes in bone density of the hip, biochemical markers of bone turnover, and the incidence of new vertebral fractures.

RESULTS

The mean (+/-SE) bone density of the lumbar spine increased by 2.1+/-0.3 percent and 2.9+/-0.3 percent, respectively, in the groups that received 5 and 10 mg of alendronate per day (P<0.001) and decreased by 0.4+/-0.3 percent in the placebo group. The femoral-neck bone density increased by 1.2+/-0.4 percent and 1.0+/-0.4 percent in the respective alendronate groups (P<0.01) and decreased by 1.2+/-0.4 percent in the placebo group (P<0.01). The bone density of the trochanter and total body also increased significantly in the patients treated with alendronate. There were proportionally fewer new vertebral fractures in the alendronate groups (overall incidence, 2.3 percent) than in the placebo group (3.7 percent) (relative risk, 0.6; 95 percent confidence interval, 0.1 to 4.4). Markers of bone turnover decreased significantly in the alendronate groups (P<0.001). There were no differences in serious adverse effects among the three groups, but there was a small increase in nonserious upper gastrointestinal effects in the group receiving 10 mg of alendronate.

CONCLUSIONS

Alendronate increases bone density in patients receiving glucocorticoid therapy.

Effect of hand dominance on bone mass measurement in sedentary individuals

The aim of this study was to determine in healthy sedentary subjects the effect of hand dominance on side-to-side difference in bone area and bone mass for upper and lower extremities. Dual-energy X-ray absorptiometry (DXA) measurements of both forearms and hips were performed on 193 right-handed and 20 left-handed subjects as determined by self-report. Scan acquisition and scan analyses were performed by one investigator, but all scan pairs were independently assessed for symmetry of positioning and movement artifacts by three investigators. Results show that DXA measurements between sides may be highly correlated regardless of the symmetry of the scan pair. However, asymmetric DXA scan pairs may have more than twice the side-to-side difference found in symmetric DXA scan pairs at the hip. Side-to-side differences between subregions were greater than the differences between measurements at the total radius, ulna, or hip. For symmetric pairs of DXA scans, the dominant forearm has significantly higher bone area and bone mineral content (BMC). Bone mineral density (BMD) was significantly higher only in the ulna of the dominant forearm. However, the nondominant forearm has higher values than dominant forearm in at least one DXA measurement in >24% of the subjects. There were no significant differences in any DXA measurements between hips, and higher DXA measurements did not occur significantly more frequently at the hip corresponding to the dominant hand. We conclude that healthy sedentary subjects tend to have proportionally higher bone area and BMC in the dominant forearm that results in similar BMD between dominant and nondominant forearms. This relationship does not appear to be applicable to measurements at the hip. In addition, there is a significant proportion of subjects with higher bone area and BMC in the nondominant extremities. Thus, in sedentary subjects, the consistency in the use of same extremity and the consistency in scan acquisition techniques and scan analyses is of greater importance than the selection of an extremity based on hand dominance in DXA studies.