Better Predictor Of Bone Mineral Density Research Articles

Lean Mass and Disease Activity are the Best Predictors of Bone Mineral Loss in the Premenopausal Women with Rheumatoid Arthritis.

Background and Objectives:Factors determining bone mineral (BM) loss in rheumatoid arthritis (RA) are not well known. This study aimed to determine the occurrence and predictors of BM loss in the young premenopausal women with RA.Methods:Ninety-six females with RA and 90 matched controls underwent clinical, biochemical, BM density (BMD), and body composition assessments. RA disease activity was assessed using disease activity score-28 (DAS-28) and hand X-ray.Results:In the young premenopausal females with RA having median symptom and treatment duration of 30 (18–60) and 4 (2–12) months, respectively, with moderate disease activity (DAS-28, 4.88 ± 1.17), occurrence of osteoporosis and osteopenia was 7.29% and 25% at spine, 6.25% and 32.29% at hip, and 17.7% and 56.25% at wrist, respectively (significantly higher than controls). RA patients had lower BMD at total femur, lumbar spine (LS), radius total, and radius ultra-distal. Total lean mass (LM) and BM content were significantly lower in RA (P = 0.022 and <0.001, respectively). In RA, BMD at majority of sites (LS, neck of femur, greater trochanter, radius total, and radius 33%) had the strongest positive correlation with LM followed by body fat percent. RA patients with most severe disease had lowest BMD at different sites and lowest LM. Stepwise linear regression revealed LM followed by DAS-28 to be best predictors of BMD. RA patients receiving glucocorticoids did not have significantly different BMDs from patients not taking glucocorticoids.Interpretation and Conclusion:BM loss is a significant problem in the young premenopausal women with recent-onset RA. LM and disease severity were the best predictors of BMD.

Effect of Calcium Intake, Tennis Playing, and Body Composition on Bone-Mineral Density of Brazilian Male Adolescents

In this prospective, cross-sectional study male adolescent tennis players (44) and nonathletic controls (32) were evaluated to determine the effects of physical activity, dietary nutrient intakes, sexual maturation, and body composition on bone-mineral density (BMD). Dietary nutrient intakes and physical activity expenditure were estimated by 4-d diaries. Total body composition, bone-mineral content (BMC), and BMD (L1-L4, femur, and nondominant forearm) were assessed by dual-energy X-ray absorptiometry. Tennis players had significantly greater lean body mass (mean [SEM] 50.6 [1.6] kg vs. 45.1 [1.7] kg, p = .022), trochanter BMD (1.0 [0.02] g/cm2 vs. 0.9 [0.03] g/cm2, p = .032), and dominant forearm BMC (173.7 [7.4] g vs. 146.5 [9.3] g) but lower BMD in the nondominant forearm (0.7 [0.02] g/cm2 vs. 0.8 [0.03] g/cm2, p = .028). Daily average calcium intake was below the recommendation in both groups. No correlation was found between BMD and calcium intake and exercise. Lean body mass was the best predictor of BMD and BMC for both tennis players and controls (R2 = .825, .628, and .693 for L1-L4, total femur, and nondominant forearm, respectively). Based on these results the authors conclude that lean body mass is the best predictor of BMD and BMC for both tennis players and others. Tennis exerts a site-specific effect, and training should focus on ways minimize this effect. Although calcium intake showed no effect on BMD, nutrition education for young athletes should focus on promoting a balanced diet, providing energy and nutrients in adequate amounts.

Sex steroids and bone turnover markers in men with symptomatic vertebral fractures

Sex steroids play an important role in the maintenance of bone density in men and women, but the circulating, biologically active unbound fraction is influenced by the concentration of sex hormone binding globulin (SHBG). SHBG increases with advancing age in men and leads to a reduction in serum free testosterone and oestradiol, which may then affect bone turnover, bone mineral density (BMD) and the risk of fractures. We have therefore measured total and unbound sex steroids, SHBG, bone turnover markers and BMD in 57 men with symptomatic low trauma vertebral fractures and 57 age-matched male control subjects. Fasting blood and urine samples were collected from all subjects, who also underwent BMD measurement of the lumbar spine and hip. Serum testosterone, oestradiol, SHBG, bone specific alkaline phosphatase (bone ALP) and urine free deoxypyridinoline/creatinine ratio (fDPD/Cr) were measured. Free sex steroid concentrations were calculated using their ratio with SHBG and albumin and bioavailable testosterone was measured using radioimmunoassay. The two groups were then compared and regression models developed to determine the best predictors of BMD and fracture. Men with vertebral fractures had significantly lower weight and BMD at all sites than control subjects ( p < 0.0001). Serum total testosterone and oestradiol did not differ between the two groups, but calculated free androgen and free oestradiol indices were lower in the fracture group than the control subjects ( p = 0.04), due to higher SHBG (46.6 versus 36.1 nmol/L: p = 0.005). The men with vertebral fractures had significantly higher mean bone ALP (15.8 versus 11.8 μg/L: p = 0.002) and fDPD/Cr (5.5 versus 4.0 nmol/mmol: p = 0.03). Stepwise multiple regression analysis in both fracture and control groups found body weight to be the best predictor of BMD. In the fracture group weight predicted between 19.7 and 30.7% of the variance in BMD and in control subjects this was between 12.3 and 13.2%. SHBG contributed to the model for hip BMD in the fracture group alone, so that weight and SHBG together accounted for 32 to 42.9% of the variance. A model combining BMD at the spine, total femur and femoral neck with height loss best predicted fracture. In conclusion, men with symptomatic vertebral fractures have higher SHBG and lower calculated free sex steroid indices, increased bone turnover and lower BMD. Whilst body weight was the best predictor of BMD, symptomatic vertebral fracture was best predicted by BMD and height loss.

Parathyroid hormone is predictive of low bone mass in Canadian Aboriginal and White women

Canadian Aboriginal women have lower age- and weight-corrected bone mineral density (BMD) and lower vitamin D status than White women. This study was undertaken to describe the differences in biomarkers of bone metabolism and vitamin D in Aboriginal and non-Aboriginal women and to establish which biomarkers were predictive of BMD. In total, 41 rural Aboriginal, 212 urban Aboriginal and 182 urban White women were studied for BMD of the distal radius, calcaneus, lumbar spine, femoral neck, total hip and whole body using dual-energy X-ray absorptiometry. Serum biomarkers measured included calcium, phosphate, alkaline phosphatase (ALP), C-telopeptide of type 1 collagen (CTX), osteocalcin (OC), osteoprotegerin (OPG), parathyroid hormone (PTH) and 25(OH)D. Data were analyzed for differences among the three groups stratified by age (25 to 39, 40 to 59 and 60 to 75 y) using factorial ANOVA. Predictors of BMD including ethnicity, age and body weight were identified using step-wise regression. Unadjusted BMD of all sites declined with age regardless of ethnic grouping. Prediction models for 5 of 6 BMD sites included PTH accounting for age and body weight. Other predictors of BMD included OC for the radius and calcaneus; OPG for spine and total hip; and ALP for whole body and calcaneus. Serum 25(OH)D was not included in any model of BMD. After accounting for all variables in the regression equation, an average Aboriginal woman of 46 y and 79 kg was predicted to have 6% lower calcaneus BMD and 3% lower radius BMD compared to a White woman of the same age and weight. In conclusion, PTH is a better predictor of BMD than 25(OH)D in this population of Aboriginal and White women.

Body Mass Index Is Not a Good Predictor of Bone Density: Results From WHI, CHS, and EPIDOS

Body mass index (BMI) is often used to predict bone mineral density (BMD). This may be flawed. Large epidemiologic studies with BMI and BMD data were analyzed. Weight alone is a better predictor of BMD than BMI. Thus, when selecting individuals for dual-energy X-ray absorptiometry, weight should be used instead of BMI. Low body mass index (BMI) is frequently suggested as one of the factors that indicates the need for bone mineral density (BMD) screening for osteoporosis. The inclusion of the height-squared term in the denominator of this predictive factor is taken on faith or from other data, but it may not be reasonable in this case. We used data from three large epidemiologic studies to test the BMI, height, and weight as predictors of BMD: (1) the Women's Health Initiative (WHI) with 11,390 women; (2) the Cardiovascular Health Study (CHS) with 1,578 men and women; (3) and EPIDOS with 7,598 women. Dual-energy X-ray absorptiometry data on one or more BMD sites, the total hip, the femoral neck, and the lumbar spine from the three studies, as well as height and weight were examined. Correlation coefficients for BMI and weight with BMD were compared. Log transformed models were evaluated to compare the strengths of the models. The result of weight alone was a much better predictor of BMD for all sites in the three studies than BMI. Taller participants had larger BMDs than would have been predicted by BMI. In conclusion, BMIs should not be used to select individuals for BMD screening. A regression model using weight alone or weight and height is a better predictor of BMD in all three populations.

Association of red blood cell 5-methyltetrahydrfoate folate with bone mineral density in postmenopausal Iranian women

Recent studies have suggested that hyperhomocysteinemia and low plasma folate are associated with fracture and also bone mineral density (BMD) and that they may contribute to the pathogenicity of osteoporosis in postmenopausal women. However, as plasma total homocysteine (tHcy) and plasma folate can be regarded as short-term markers when compared to a long-term variable such as BMD, in this study we tested the hypothesis that low red blood cell 5-methyltetrahydrofolate (RBC 5-MTHFR) as a long-term marker of the folate status may be a better predictor of BMD than plasma 5-MTHF, and its deficiency may contribute to the pathogenicity of osteoporosis in postmenopausal Iranian women. The BMD at the femoral neck and lumbar spine (measured by dual-energy X-ray absorptiometry, DXA) together with anthropometric and biochemical components of the homocysteine re-methylation pathway including plasma tHcy, 5-MTHF and vitamin B12, RBC 5-MTHF and creatinine were determined in 366 postmenopausal women. RBC 5-MTHF was more highly correlated with BMD at the lumbar spine (r=0.21, P=0.001) and femoral neck (r=0.19, P=0.004) than was plasma 5-MTHF (lumbar spine; r=0.14, P=0.03 and femoral neck; r=0.17, P=0.006). Stepwise multiple linear regression analyses revealed that RBC 5-MTHF was one of the predictors of BMD explaining 4.3 and 4.0% variance of BMD at the lumbar spine and femoral neck, respectively, whereas plasma 5-MTHF was excluded in the model and not determined to be a predictor of BMD at both the lumbar spine and femoral neck when adjusted for age, BMI, years since menopause and RBC 5-MTHF. This study suggests that RBC 5-MTHF is a better predictor of BMD than plasma 5-MTHFR when compared to a long-term marker such as BMD, and its deficiency is associated with low BMD that may contribute to the pathogenicity of osteoporosis in postmenopausal women.

Bone mineral density and osteoporosis among a predominantly Caucasian elderly population in the city of São Paulo, Brazil

This cross-sectional study covered 301 individuals over 70 years of age--207 women (W) and 94 men (M)--living in the city of São Paulo, Brazil. Our aims were to evaluate the prevalence of low bone mineral density (BMD) in this population and the possible factors that influence BMD. The subjects were submitted to a bone densitometry scan (DXA) to evaluate the BMD at lumbar spine (LS), femoral neck (FN), trochanter (T), total femur (TF) and total body composition. At the time, the participants filled in a questionnaire about lifestyle habits, diet and medical history, as well as having blood samples taken to check hormone and biochemical levels. Anthropometric parameters were measured. Osteopenia and osteoporosis were defined in accordance with the criteria suggested by the World Health Organization. In the different sites studied, the prevalence of osteopenia and osteoporosis varied, in men ranging 33.3-57.4% and 6.4-16.1%, respectively, and in women ranging 36.6-56.5% and 22.2-33.2%, respectively. Weight was the variable that most strongly correlated with BMD at the proximal femur in both sexes (men, r =0.44-0.52; women, r =0.48-0.52) and with BMD at LS in women (r =0.44). Height was the parameter that best correlated with BMD at LS in men (r =0.34). In men follicle-stimulating hormone, growth hormone and glycemia correlated with BMD at T and TF, while plasma albumin only correlated with BMD at T. In women glycemia correlated with BMD at LS, and follicle-stimulating hormone correlated with BMD at FN, T and TF. In conclusion, we found a high prevalence of osteopenia and osteoporosis in this population, with weight being the best predictor of BMD. The prevalence of osteoporosis and osteopenia at FN was as high in men as that observed in women.

Predicting low bone density in children and young adults with quadriplegic cerebral palsy.

Many children and young adults with cerebral palsy (CP) have diminished bone mineral density (BMD) and a propensity to fracture with minimal trauma. The aim of this study was to identify variables which are routinely assessed as part of standard clinical care and that might be used to identify those individuals with CP who are most likely to have low BMD. One hundred and seven participants (ages 2 years 1 month to 21 years 1 month; mean age 10 years 11 months, SD 4 years 2 months) with moderate to severe spastic CP were assessed in detail. This included gathering clinical data, taking anthropometric measures of growth and nutrition, as well as dual energy X-ray absorptiometry measures of BMD. Seventeen participants were ambulatory with assistance (Gross Motor Function Classification System [GMFCS] level III), and 90 were capable of little or no ambulation even with assistance (26 GMFCS level IV and 64 GMFCS level V). Weight z score proved to be the best predictor of BMD z score. Declining BMD z scores also correlated with increasing age and greater severity of involvement. It can be predicted, with reasonable reliability, that a 10-year-old non-ambulatory child with quadriplegic CP and a 'typical' weight z score of -2 will have a BMD z score that is at best -2. Prior fractures, use of anticonvulsants, and feeding difficulties further reduce predicted BMD.

Body composition, bone mineral density, and circulating leptin levels in postmenopausal Turkish women.

We analyzed the relationship between serum leptin levels and bone mineral density (BMD) values as well as the relationship between serum leptin levels and whole body composition, whether or not they were associated. In addition, we also investigated whether lean mass or fat mass is a better predictor of BMD in postmenopausal Turkish women. One hundred consecutive postmenopausal women with a mean age of 55.1 +/- 6.3 years who visited our outpatient clinic for the evaluation of osteoporosis were recruited. Skin fold thickness at four sites and waist:hip ratio were measured. Body mass index (BMI) was calculated in kg/m(2). Serum concentrations of leptin, insulin, and estradiol were evaluated. Bone formation and resorption markers were also determined. The BMD values were measured by dual energy X-ray absorptiometry (DEXA) at the lumbar spine and femoral neck. Whole body composition (lean mass, fat mass, and percentage of fat), total bone mineral content (BMC) in g, and total BMD were also measured by DEXA. Serum leptin levels did not correlate with BMD values at all skeleton sites measured. Leptin correlated positively with fat mass, percentage of fat, and BMI (r = 0.738 and P = 0.00, r = 0.536 and P = 0.00, r = 0.356 and P = 0.00, respectively). Lean mass correlated with BMD at all sites measured (r = 0.339 and P = 0.00, r = 0.312 and P = 0.01, r = 0.523 and P = 0.00, r = 0.636 and P = 0.00). Lean mass correlated with BMI (r = 0.636, P = 0.00) but not with serum leptin (r = -0.021, P = 0.881), and it was an independent determinant of BMD at all skeleton sites measured. Our study showed that lean mass is a better predictor than fat mass of bone mineral density and that serum leptin levels are not associated with BMD.

AGE IMPACTS THE RELATIONSHIP OF SOFT TISSUE MASS TO BONE MINERAL DENSITY

1084 The relative influence of fat and lean tissue mass (LTM) on bone mineral density (BMD) is controversial. Part of the problem may lie in the use of total body BMD were approximately 12% is head BMD. The purpose of this study was to examine the association between BMD and soft tissue mass while accounting for the possible influence of factors such as head BMD, age, and athletic. A cohort of 1020 females, 274 of whom were collegiate athletes, all had total body BMD measurements on the Lunar DPX (version 3.61), from which values for lean and fat tissue mass were obtained along with total, arm, leg, and head BMD. The subjects ranged in age from 6 to 84 years. As expected, athletes had significantly higher BMD compared to age-matched nonathletes at all sites except for the head. Stepwise multiple regression was used to determine the best predictors of total and regional BMD. When all ages were included in the analysis, total LTM was the best predictor of both total body BMD and trunk + limb BMD (total body BMD not including head) while arm and leg LTM were the best predictors of arm and leg BMD with R ranging from .68 to .75. Exclusion of the athletes from the analyses yielded similar results. However, when only those participants older than 45 were analyzed, total fat mass was the best predictor of BMD for all sites including trunk + limb (R = .43 to .44). In conclusion, lean tissue mass appears to exert the most influence on BMD in younger females. However, in older females, total fat mass is a better predictor of BMD, possibly because of a greater peripheral synthesis of estrogen.

The relations between physical ability and bone mass in women aged over 65 years

In this cross-sectional study of 55 women (mean age 73.54 +/- 5.87), the magnitude of the relation between different indices of physical ability and confounding factors to bone density were determined. Physical fitness was assessed by direct measurement of maximal oxygen consumption (VO2 max), isokinetic muscle strength, and quadriceps and psoas muscle surfaces and densities using computed tomography. Anthropometry, chronological and gynecological ages, and dietary calcium intake were also recorded. The bone mineral density (BMD) was evaluated at the axial level (lumbar spine and proximal femur) and at the peripheral level (radius and tibia, cancellous and cortical compartments). Parameters related to physical ability proved to be the best predictors of BMD in radial and tibial cancellous compartments, spine, femoral neck, and trochanter, accounting for 15-27.5% of the total variance. The VO2 max was a major determinant of the femoral mineral density and one of the predictors of radial and tibial cancellous compartments. Psoas parameters were strongly related to spine mineral density and also constituted a predictor of radius (cancellous) and tibia mineral densities. The arm muscle strength could predict, though weakly, the BMD of axial skeleton, whereas thigh muscle strength only predicted the BMD of inferior limbs. No correlation was observed between current dietary calcium intake and BMD. Age-postmenopause and fertile life remained predictive of BMD at mostly cancellous sites, whereas anthropometry exerted important effects on radial and tibial cortices. The study suggests distinct sets of relations between physical ability and the BMD variables. Subjects with greater and denser psoas muscles had greater spine BMD, and those with higher VO2 max had greater proximal femur BMD.

Relationship of regional body composition to bone mineral density in college females

The purpose of this study was to examine relationships between regional body composition and bone mineral density (BMD) in college females. Subjects were 12 nonathletic females (< 3 h.wk-1 of exercise) and 46 female varsity athletes: basketball (N = 14), volleyball (N = 13), gymnastics (N = 13), and tennis (N = 6). Dual energy x-ray absorptiometry was used to determine BMD and body composition. The mean (+/- SD) age, height, weight, and menarche for the subjects were 19.9 +/- 2.1 yr, 167.9 +/- 9.4 cm, 62.1 +/- 9.0 kg, and 13.6 +/- 1.7 yr, respectively. Mean lumbar (1.327 g.cm-2), femoral neck (1.172 g.cm-2), and total body (1.200 g.cm-2) BMD of the athletes were significantly greater than nonathletes (P < 0.05) but did not differ among the teams. Significant correlations were found between regional leg BMD and leg lean tissue mass (LTM) (r = 0.59, P < 0.001) and between arm LTM and arm and lumbar BMD (r = 0.47 and 0.56, respectively). Significant correlations were also found between leg fat mass and leg BMD (r = 0.40). However, only regional LTM was a significant predictor of BMD using stepwise multiple regression. In summary, regional LTM appears to be a better predictor of BMD than regional fat mass.

Contributions of chronological age, age at menarche and menopause and of anthropometric parameters to axial and peripheral bone densities.

Bone mineral density (BMD) was measured in 128 normal postmenopausal women at different skeletal sites: lumbar spine and proximal femur, using dual-energy X-ray absorptiometry (DXA), and the cancellous and cortical envelopes of the distal third of radius and tibia, using precise low-dose quantitative computed tomography (QCT). Multivariate analysis included chronological age, ages related to menstrual history (menopause and menarche) and anthropometric factors, e.g. height and weight, as independent predictive variables. Weight is a much-studied predictor of bone density. At sites of high bone turnover, i.e. cancellous envelope, the effect of weight appeared overshadowed by estrogen-related parameters: age-past-menopause was the first predictor of BMD in the cancellous compartment of radius and in Ward's triangle, and the number of reproductive years was the strongest predictor of BMD in the cancellous compartment of tibia and in the spine (L2-4). This suggests that in addition to menopause, the length of menstrual life should be considered as an explanation for the variations in current bone mass in postmenopausal women. At the cortical level of radius, the effect of chronological age was predominant. At the cortical level of tibia, height and weight were the best predictors of BMD. We conclude that the influence of parameters related to menstrual history is predominant in sites with mainly cancellous tissue and that anthropometric factors constitute the best predictors of BMD in the cortical sites of weight-bearing bones.