Influence of Grip Strength on Metacarpal Bone Mineral Density in Postmenopausal Japanese Women: A Cross-Sectional Study

Most published studies on the role of muscle strength in the maintenance of bone mineral density (BMD) focused on the relationship between specific muscle groups and adjacent bones, mostly in young and premenopausal women. This study examined the influence of grip strength on BMD of the metacarpal index in postmenopausal Japanese women. Subjects included 1168 postmenopausal women aged 40–70 years. BMD measurement was done with computed X-ray densitometry (CXD) by analyzing X-ray films of the right second metacarpal index. Grip strength was measured in both the dominant and nondominant hands using a squeeze dynamometer. Grip strength (r = 0.2474; P= 0.0001) and age (r =−0.5443; P= 0.0001) significantly correlated positively and negatively, respectively, with BMD. Physical activity (r = 0.1318; P= 0.0001) also correlated positively with BMD. Breastfeeding (r =−0.1658; P= 0.0001), however, correlated negatively with BMD. Subjects with a history of regular physical activity had higher grip strengths and BMD, than those with no physical activity. Adjustment for age, physical activity, calcium intake, BMI, breastfeeding, testing site, and menopausal type indicated a significant (P for trend = 0.0013) positive association of grip strength with BMD. Subjects with stronger grip strengths had a decreased risk for low BMD. Received: 24 February 1998 / Accepted: 7 August 1998     

Correlation of Bone Density to Strength and Physical Activity in Young Men with a Low or Moderate Level of Physical Activity

The objective of this study was to evaluate the relationship among bone mineral density (BMD), physical activity, muscle strength, and body constitution, in young men with a low or moderate level of physical exercise. Another aim was to investigate whether the head is unaffected by physical activity. The subjects consisted of 33 Caucasian healthy men, mean age 24.8 ± 2.3 years. BMDs of the total body, lumbar spine (L2-L4), femoral neck, Ward's triangle and trochanter, humerus, and head were measured using dual-energy-X-ray absorptiometry (DXA). Bivariate correlations were measured among the different BMD sites and age, weight, height, body mass index (BMI), fat mass, lean body mass, amount of physical activity (hours/week), hamstrings strength, and quadriceps strength. Significant predictors were found for all BMD sites except the head. Using all these variables, only 6% of the variation in BMD of the head could be explained, whereas 46% (total body), 31% (humerus), 17% (lumbar spine), 38% (femoral neck, Ward's), and 41% could be explained for the trochanter. Physical activity and muscle strength were found to be independent significant predictors of BMD of the total body and the sites at the proximal femur. These results suggest that at the time of peak bone mass attainment, physical activity is an important predictor of the clinically relevant proximal femur in young men with a low or moderate level of physical activity. Furthermore, since head BMD was not related to the level of physical activity, we suggest that head BMD may be used as an internal standard, to control for selection bias, in studies investigating the effect of physical activity on bone mass. Received: 5 February 1996 / Accepted: 24 September 1996     

The Effects of Lifestyle, Dietary Dairy Intake and Diabetes on Bone Density and Vertebral Deformity Prevalence: The EVOS Study

The risk of low and moderate energy fracture is related to bone mineral density (BMD). Yet it is uncertain whether the epidemiologic determinants of fracture risk are the same as for low bone density. The European Vertebral Osteoporosis Study was a population-based prevalence study of vertebral deformity in 36 age-stratified population samples aged 50–80 years. In nearly 4000 subjects (13 centers), BMD measurements were also made at the spine, femoral neck and femoral trochanter. To investigate whether effects of reported physical activity on spine deformity risk were mediated through BMD, we modeled these and other risk factor data with BMD as the dependent variate after adjusting for age, center, sex and body mass index (BMI). The significant determinants of vertebral deformity risk were also entered into logistic models of deformity risk that included BMD measurements as covariates. Both current and lifetime physical activity were positively associated with BMD. This effect was stronger with hip BMD than with spine BMD. Lifetime smoking exposure was associated with reduced BMD. Type 2 diabetes mellitus was associated with increased BMD. Weak positive associations were found between consumption of dairy products and BMD at the three measured sites and these were strengthened by an interaction with measures of physical activity in men. Physical activity in women had the largest beneficial effect in lean women and in women exposed to hormone replacement therapy. When fracture risk was modeled with BMD as a covariate, the lifestyle and dietary determinants became less strongly related to vertebral deformity risk, suggesting that BMD may have acted as an intermediary variable. However, heavy physical activity in men still increased spine deformity risk after adjusting for BMD. It is concluded that physical activity in both genders and milk consumption in young women might protect against vertebral deformities in later life through their effects on bone density. The adverse effect of smoking on BMD was confirmed. Heavy physical activity in men might increase spine deformity risk even when BMD is normal. Received: 29 June 2000 / Accepted: 5 January 2001     

A Comparison of Bone Mineral Density and Muscle Strength in Young Male Adults with Different Exercise Level

The aim of this study was to investigate any differences in bone mass at different sites between young adults subjected to a high physical activity and a group of young adults with a low level of physical activity. In addition, we compared the relationship among bone mass, muscle strength, and body constitution in these two groups. The reference group consisted of 20 men, age 24.6 ± 2.3 years, not training for more than 3 hours per week. The ice hockey players consisted of 20 players, age 23.4 ± 4.9 years, from an ice hockey team in the second highest national Swedish league, training for about 10 hours per week. The groups were matched according to age, height, and weight. Areal bone mineral density (BMD) was measured in total body, head, humerus, spine, pelvis, femur, femoral neck, Ward's triangle, trochanter, femur diaphysis, proximal tibia, and tibia diaphysis using dual energy X-ray absorptiometry. BMD was significantly higher in the total body (8.1%), humerus (11.4%), spine (12.7%), pelvis (12.4%), femoral neck (10.3%), femur (7.4%), proximal tibia (9.8%), and tibia diaphysis (7.5%) in the high activity group. Fat mass was significantly lower in the high activity group (18.7%). The high activity group also had a significantly higher lean body mass (5.4%) and a significantly higher isokinetic muscle strength of the quadriceps muscle compared with the reference group. In the reference group, there was a general strong independent relationship between muscle strength of the thigh and all BMD sites, except for the head, tibia diaphysis, and proximal tibia. Furthermore, in the same group, body mass index (BMI) independently predicted pelvis BMD. On the contrary, in the high activity group, muscle strength did not predict any BMD site at all. In the same group, body constitutional parameters (weight, height, and fat mass) independently predicted pelvis BMD, and BMI was shown to be an independent predictor of humerus BMD. The differences in BMD between the groups seem to be site-specific and may be associated with the type and magnitude of loading during off season training and preferentially during ice hockey. High physical activity seems to weaken the relationship between BMD and muscle strength. Hence, impact forces may be of greater importance in regulating bone mass than muscle strength in itself in highly trained athletes. Received: 15 October 1997 / Accepted: 1 November     

Determinants of Bone Mass and Bone Geometry in Adolescent and Young Adult Women

Bone mass and bone geometry are considered to have independent effects on bone strength. The purpose of this study was to obtain data on bone mass and geometry in young female populations and how they are influenced by body size and lifestyle factors. In a cross-sectional, observational study in six European countries, 1116 healthy Caucasian girls aged 11–15 and 526 women aged 20–23 participated. Their radius was scanned at the ultradistal site and at a site approximately 30% of the radius length from the distal end with dual energy X-ray absorptiometry (DXA). The following parameters were assessed from the scans: bone mineral content (BMC), bone mineral density (BMD), cortical wall thickness (CWT), middistal diameter (D), cortical index (CI = 2CWT/D), and the Breaking Bending Resistance Index (BBRI = (D⁴− [D-CWT]⁴)/D). Calcium intake was assessed by 3-day food records and physical activity by questionnaire. Body size parameters were measured by anthropometry. All parameters showed an increasing trend with pubertal stage and age, except for physical activity and calcium intake. BMC and BMD were relatively more dependent on body weight and age at menarche, whereas variation in D and the mechanical index BBRI was better explained by differences in height and grip strength. CI and CWT were relatively independent of variation in body size, whereas BMC and BBRI especially were explained for a substantial proportion (25–33% in the young adults) by body size parameters. Dietary intake of calcium and level of physical activity seem to contribute little to variation in bone parameters. Received: 1 October 1998 / Accepted: 26 July 1999     

Prolonged Progressive Calcaneal Bone Loss Despite Early Weightbearing Rehabilitation in Patients Surgically Treated for Achilles Tendinosis

We prospectively evaluated areal bone mineral density (BMD) of the calcaneus and calf-muscle strength (concentric and eccentric plantar flexion peak torque in Nm) in 10 recreational athletes (5 males and 5 females), mean age 40.9 years (range 26–55), who were selected to undergo surgical treatment for chronic Achilles tendinosis localized at the 2–6 cm level. Surgery was followed by immobilization in a plaster cast for 2 weeks, followed by flexibility training and slowly progressing strength training and weight-bearing activity. One patient was excluded after week 0 because of a new injury. Seven patients were back to their preinjury activity at the 26-week control, and eight patients at the 52-week control postoperatively. BMD in the calcaneus and calf-muscle strength on the injured and noninjured side was measured preoperatively (week 0) and postoperatively (weeks 2, 6, 16, 26, and 52). There were no significant differences in BMD between the injured and noninjured side at weeks 0, 2, and 6, but at weeks 16, 26, and 52, BMD was significantly (P < 0.05) lower (11.5%, 18.4%, and 16.4%, respectively) in the calcaneus of the injured side. Concentric and eccentric plantar flexion strength were significantly lower on the injured side preoperatively. Eccentric, but not concentric plantar flexion strength had recovered compared with the noninjured side 1 year postoperatively. Calf-muscle strength was not related to bone mass in the calcaneus. As a comparison, we used a group of 11 recreational athletes (10 males and 1 female), with a mean age of 46.1 years (range 28.9–58.5) who had been surgically treated for chronic Achilles tendinosis at the 2–6 cm level 39.5 ± 11.8 months ago. In this group, there was no significant difference in BMD of the calcaneus between the injured and noninjured side. It seems that there was a delayed and prolonged calcaneal bone loss despite early weightbearing loading in patients surgically treated for chronic Achilles tendinosis at the 2–6 cm level. Around that time, when the Achilles tendon had healed (4–6 months) and the athletes returned to their sports, the calcaneal bone had a relatively low BMD and might possibly be vulnerable to heavy loadings. There were no signs of recovery 1 year postoperatively, but in a comparison group there were no significant side-to-side differences 39.5 months postoperatively. Received: 31 December 1996 / Accepted: 21 May 1997     

Discordance Between Ultrasound of the Calcaneus and Bone Mineral Density in Black and White Women

Black women have 40% of the incidence rate for hip fracture and have a higher bone mineral density (BMD) than white women. The possibility was raised that bone quality may be disproportionately greater than the advantage in bone density in protection against osteoporotic fractures in black versus white women. Ultrasound (US) of the calcaneus is believed to measure properties of bone in addition to its density. We performed bone density measurements and US of the calcaneus in 108 black and 177 healthy white women, aged 20–70 years. The highest correlation was seen between total body bone density and speed of sound (r = 0.75). The interracial differences in BMD were all statistically significant and varied from 3.4 to 7.6%. The US measurements had lesser interracial differences than the bone density measurements, with velocity barely different between races. These findings suggest that US of the calcaneus measures properties of bone different from density. Fracture prediction data using US from prospective data in white women should not be extrapolated to black women because of the discordance between bone density and US measurements. Prospective studies are needed comparing US measurements in black women to the occurrence of osteoporotic fractures. Received: 30 May 1997 / Accepted: 8 January 1998     

Bone Mineral Density in the Chronic Patellofemoral Pain Syndrome

Bone mineral density (BMD) and clinical status of 40 patients with a chronic, unilateral patellofemoral pain syndrome (PFPS) were determinated. The mean duration of the disease at the time of the follow-up was 7.6 ± 1.8 (SD) years. The BMD was measured at the spine (L2–L4), and the femoral neck, trochanter area of the femur, distal femur, patella, proximal tibia, and calcaneus of both lower extremities using a dual-energy X-ray absorptiometric (DXA) scanner. The mean BMD of the affected limb (compared with the unaffected side) was significantly lower in the distal femur (−3.3%; P= 0.002), patella (−2.5%; P= 0.016), and proximal tibia (−1.9%; P= 0.008). The femoral neck, trochanter area of the femur, and calcaneus showed no significant side-to-side differences, and the spinal BMDs of men and women with the PFPS were comparable with the manufacturer's age-adjusted reference values for Western European men and women. The relative BMDs of the affected knee showed strongest correlation with the muscle strength of the same knee: the better the muscle strength compared with the healthy knee, the higher the relative BMD (r = 0.56–0.58 with P < 0.001 in each anatomic site of the knee). In the stepwise regression analysis, low body weight or low body mass index, high level of physical activity, the patient's good subjective overall assessment of his/her affected knee, and short duration of the symptoms were also independent predictors of the high relative BMD in the affected knee so that along with the muscle strength these variables could account for 51% of the variation seen in the relative BMD of the femur, 61% in the patella, and 54% in the proximal tibia. In conclusion, chronic patellofemoral pain syndrome results in a significantly decreased BMD in the knee region of the affected limb. The spine, proximal femur, and calcaneus are not affected. Recovery of normal muscle strength and knee function seems to be of great importance for good BMD. Received: 30 May 1997 / Accepted: 8 January 1998     

Reference Data and Predictive Diagnostic Models for Calcaneus Bone Mineral Density Measured with Single-Energy X-ray Absorptiometry in 7428 Chinese

Calcaneus bone mineral density (BMD) of 7428 Chinese (4126 women, 3302 men; aged 22–94 years) was measured using single-energy X-ray absorptiometry (SXA). A reference range of calcaneus BMD values for healthy Chinese men and women was established and the usefulness of this method for screening and diagnosis in osteoporosis was evaluated. The peak BMD occurred at 20–24 years old and peak BMD in women was significantly lower than in men. BMD loss in the calcaneus started at the age of 35 years for women, and at 63 years in men. BMD loss rate was 1.2%/year for women and 0.56 %/year for men after 50 years. The young normal reference for calcaneus BMD was 442.1±69.6 mg/cm² for men and 388.3±61.7 mg/cm² for women calculated from the mean BMD value of subjects whose age ranged from 20 to 49 years. The accumulated BMD loss in the calcaneus is similar to that of Ward’s triangle. Multiple linear regression showed that both age and weight were important factors. The incidence of osteoporosis in older men and women (≥60 years) is 6.6% and 32.1% respectively. We conclude that calcaneus BMD measurement is useful and sensitive for the screening and diagnosis of osteoporosis. A predictive diagnostic model for osteoporosis based on the calcaneus was constructed using multiple linear regression and the WHO criteria for diagnosing osteoporosis can be applied to calcaneus BMD. Received: 16 August 2000 / Accepted: 20 March 2001     

Muscle Strength and Physical Performance Improve Fracture Risk Prediction Beyond Garvan and FRAX: The Osteoporotic Fractures in Men (MrOS) Study

Muscle strength and physical performance are associated with fracture risk in men. However, it is not known whether these measurements enhance fracture prediction beyond Garvan and FRAX tools. A total of 5665 community-dwelling men, aged ≥65 years, from the Osteoporotic Fractures in Men (MrOS) Study, who had data on muscle strength (grip strength) and physical performance (gait speed and chair stand tests), were followed from 2000 to 2019 for any fracture, major osteoporotic fracture (MOF), initial hip, and any hip fracture. The contributions to different fracture outcomes were assessed using Cox's proportional hazard models. Tool-specific analysis approaches and outcome definitions were used. The added predictive values of muscle strength and physical performance beyond Garvan and FRAX were assessed using categorical net reclassification improvement (NRI) and relative importance analyses. During a median follow-up of 13 (interquartile range 7–17) years, there were 1014 fractures, 536 MOFs, 215 initial hip, and 274 any hip fractures. Grip strength and chair stand improved prediction of any fracture (NRI for grip strength 3.9% and for chair stand 3.2%) and MOF (5.2% and 6.1%). Gait speed improved prediction of initial hip (5.7%) and any hip (7.0%) fracture. Combining grip strength and the relevant performance test further improved the models (5.7%, 8.9%, 9.4%, and 7.0% for any, MOF, initial, and any hip fractures, respectively). The improvements were predominantly driven by reclassification of those with fracture to higher risk categories. Apart from age and femoral neck bone mineral density, muscle strength and performance were ranked equal to or better than the other risk factors included in fracture models, including prior fractures, falls, smoking, alcohol, and glucocorticoid use. Muscle strength and performance measurements improved fracture risk prediction in men beyond Garvan and FRAX. They were as or more important than other established risk factors. These measures should be considered for inclusion in fracture risk assessment tools. © 2021 American Society for Bone and Mineral Research (ASBMR).     

Relationships Between Bone Mass Measurements and Lifetime Physical Activity in a Swedish Population

Lifetime occupational and leisure time activities were assessed by a questionnaire in order to evaluate their relationship to bone mass measurements and biochemical markers of bone metabolism in a population of 61 women and 61 men, randomly selected from a Swedish population register, to represent ages between 22 and 85 years. We also considered possible confounders by using questions about smoking habits, milk consumption, hormone replacement therapy (HRT), and menopausal age. Bone mineral density (BMD) and bone mineral content (bone mass, BMC) of the total body, lumbar spine, and proximal femur (neck, trochanter, Ward's triangle) were measured by dual energy X-ray absorptiometry (DXA), and BMD of the forearm with single energy X-ray absorptiometry (SXA). In addition, both DXA and SXA provided information on bone area. Quantitative ultrasound measurements (QUS) at the heel were performed to assess the speed of sound (SOS) and broadband ultrasound attenuation (BUA). Fasting blood samples were analyzed for biochemical markers of bone metabolism as well as parathyroid hormone (PTH) and total serum calcium. After adjustment for confounding factors, neither BMD nor QUS measurements were consistently related to lifetime leisure time or occupational activities; nor were there any consistent patterns relating biochemical markers of bone metabolism to bone mass measurements. However, physical activity seemed to influence bone mass, area, and width more than density. In men, high levels of leisure time activity were associated with raised values for lumbar spine area (6.2%) and width (3.3%) as well as for femoral neck area (5.5%) compared with their low activity counterpart. Men exposed to high levels of occupational activity demonstrated lower lumbar spine BMD (10.9%) and area (5.3%) than men with low activity levels. Within an unselected Swedish population, estimation of lifetime occupational and sport activities as well as bedrest, using a questionnaire, demonstrated no major effects on bone density. However, the association between high levels of lifetime activity and raised values for bone mass, area, and width indicate that geometrical changes in bone may provide better estimations of mechanically induced bone strength than bone density, at least in men. Received: 20 May 1997 / Accepted: 15 October 1997     

Radial and Metacarpal Bone Mineral Density and Calcaneal Quantitative Ultrasound Bone Mass in Normal Japanese Women

The purpose of this study was to examine the effect of lifetime physical activity of farmers on skeletal status. Seventy-one healthy, postmenopausal women (mean age 52.3 ± 5.9 years, range 42–61 years) who worked professionally on farms were compared with 78 matched controls (mean age 51.8 ± 5.5 years, range 42–61 years). Broadband ultrasound attenuation (BUA) and speed of sound (SOS) at the os calcis were measured using an ultrasound transmission imaging system. Bone mineral density (BMD) of the lumbar spine and femoral neck were measured by dual-energy X-ray absorptiometry (DXA). Differences in BUA, SOS, and BMD between farmers and controls were expressed relative to standard deviation (SD) of the farmers. Farmers had significantly higher density values than controls (difference = 1.3 SD in the spine and 1.5 SD in the femoral neck, P < 0.0001 for both comparisons). Ultrasound values were significantly higher in the farmers compared with the controls in calcaneus (difference = 1.1 SD for BUA and 0.7 SD for SOS, P < 0.0001 for both comparisons). The difference of spine BMD, femoral neck BMD, BUA, and SOS between farmers and controls, as judged by comparison of the slopes of the regression lines, was unchanged with age and years since menopause. These results suggest that lifetime physical activity has a positive effect on bone status of postmenopausal farmers. Received: 19 March 1998 / Accepted: 7 August 1998     

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. Received: 16 March 2001 / Accepted: 19 February 2002     

Bone Mineral Density Is a Predictor of Survival

The purpose of this study was to examine the relationship between bone mineral density (BMD) and survival in both sexes and to compare BMD with other established risk factors such as blood pressure and cholesterol. A population-based prospective study of 1924 individuals (850 men, 1074 women) was performed in G?teborg from 1980 to 1983. Measurements of BMD were obtained in 1468 (76%) of the participants (653 men, 815 women). This selection of individuals generated 10,965 person years, and death was registered for 289 men and 197 women in the 7-year period (2661 days) after bone mineral measurement. Later information on date of death was obtained from the official population register. This information covers 7 years from the time of survey of the last examined participant (in Dec. 1983). At the beginning of the study, BMD was measured in the calcaneus by dual photon absorptiometry (DPA), and blood pressure, serum cholesterol, serum triglycerides, and body mass index (BMI) were also recorded. The study was coordinated with the National Register of Causes of Death and the National Cancer Register. A modified version of the Cox proportional hazards model was used to calculate and determine the age-adjusted relations between nontrauma mortality and BMD. When the various quartiles of BMD were compared prospectively from 70, 75, and 79 years of age with survival figures during the 2661-day follow-up period, the first and the second quartiles with the lowest BMD at entry showed the lowest survival rate in both men (P= 0.01) and women (P= 0.01). A decrease of 1 SD of BMD in a univariate analysis was associated with a 1.39-fold increase in mortality in both men (95% confidence interval 1.25–1.56, P < 0.001) and women (95% confidence interval 1.22–1.58, P < 0.001), and a multivariate analysis demonstrated a relative risk of 1.23 (95% confidence interval 1.10–1.41, P < 0.001) in men and 1.19 (95% confidence interval 1.02 to 1.39, P= 0.019) in women. All relations were adjusted for sex, age, and follow-up. This study indicates that BMD is a predictor of survival, especially for subjects over 70. Bone mineral density was found to be a better predictor of death than blood pressure and cholesterol. This study indicates that, after adjustments have been made for diseases, low bone mass is an independent predictor of mortality and might be a marker of general health or functional aging. Its measurement might therefore be a valuable tool in general health investigations. Received: 26 December 1996 / Accepted: 27 January 1998     

Influence of Physical Activity on Ultrasound and Dual-Energy X-ray Absorptiometry Bone Measurements in Peripubertal Girls: A Cross-Sectional Study

The aim of this cross-sectional study was to investigate whether two types of physical exercise affect the growing skeleton differently. We used calcaneal quantitative ultrasound measurements (QUS) and dual-energy X-ray absorptiometry (DXA) for measurement of bone mineral density (BMD), and to test how QUS values reflect the axial DXA values in these various study groups. A total of 184 peripubertal Caucasian girls aged 11–17 years (65 gymnasts, 63 runners, and 56 nonathletic controls) were studied. Weight, height, stage of puberty, years of training, and the amount of leisure-time physical activity were recorded. Broadband ultrasound attenuation (BUA) and sound of speed (SOS) through the calcaneus were measured. The BMD of the femoral neck and the lumbar spine were measured by DXA. The differences in mean values of bone measurements among each exercise group were more evident in pubertal than prepubertal girls. The mean BUA and SOS values of the pubertal gymnasts were 13.7% (77.8 dB/MHz versus 68.4 dB/MHz, P < 0.05) and 2.2% (1607.7 m/s versus 1572.4 m/s, P < 0.001) higher than of the controls, respectively. The mean BMD of the femoral neck in the pubertal gymnasts and runners was 20% (0.989 g/cm² versus 0.824 g/cm², P < 0.001) and 9.0% (0.901 g/cm² versus 0.824 g/cm², P < 0.05) higher than in the controls, respectively. The amount of physical activity correlated weakly but statistically significantly with all measured BMD and ultrasonographic values in the pubertal group (r = 0.19–0.35). The correlation between ultrasonographic parameters and BMD were weak, but significant among pubertal runners (r = 0.47–0.55) and controls (r = 0.39–0.42), whereas the DXA values of the femoral neck and the ultrasonographic parameters of the calcaneus did not correlate among highly physically active gymnasts. By stepwise regression analysis, physical activity accounted for much more of the variation in the DXA values than the ultrasonographic values. We conclude that the beneficial influence of exercise on bone status as measured by ultrasound and DXA was evident in these peripubertal girls. In highly active gymnasts the increase of the calcaneal ultrasonographic values did not reflect statistically significantly the BMD values of the femoral neck. Received: 28 June 1999 / Accepted: 2 November 1999     

Calcaneus Bone Mineral Density Using Single X-ray Absorptiometry in Japanese Women

Calcaneus bone mineral density (BMD) of 738 Japanese women (605 healthy and 133 with osteoporosis) was measured using single X-ray absorptiometry (SXA). A reference range of calcaneus BMD values for healthy Japanese women was established and the usefulness of this method for screening and diagnosis of osteoporosis was evaluated. There was no significant age change of calcaneus BMD prior to menopause, though values decreased significantly thereafter. BMD loss ratio was 1.7%/year in the 10 years after menopause. The reference range of calcaneus BMD was 410 ± 43 mg/cm², calculated from the mean BMD value of subjects whose ages ranged from 25 to 50 years old. The fracture threshold for the spine was established as 294 mg/cm², which corresponded to −2.67 SD from the average BMD of the young healthy women, and the odds ratio for spine fracture in the subjects with BMD lower than this threshold was 3.52 [95% CI (confidence interval) 1.34–9.26]. The spine fracture group showed statistically lower calcaneus BMD than the nonfracture group when subjects with adjusted age and body size were analyzed. There were no significant differences in the ROC analysis for spine fracture between calcaneus BMD and spine BMD. Therefore, calcaneus BMD is not readily affected by degenerative change or soft tissue, and the annual decrement rate (1.7%/year) can be detected easily and with low precision error (0.8%). These indices may prove useful for the screening and diagnosis of osteoporosis. Received: 16 September 1998 / Accepted: 28 January 1999     

Age-Related cortical bone loss at the metacarpal

In order to evaluate in vivo the entity of endosteal and periosteal changes with age in the two sexes, and their relative contribution to age-related cortical bone loss, we undertook a cross-sectional study on a population of normal Caucasian subjects. The group included 189 women and 107 men who were studied by photodensitometry and radiogrammetry of the second metacarpal bone, derived from the same standard hand X-ray. Of the subjects, 134 were 65 years of age or older (75 women and 59 men). Metacarpal bone mineral density (BMD) correlated with age in both sexes, with an annual bone loss rate of 0.5% in women and 0.15% in men. In the over 65 group, correlation was significant only in women, who underwent an acceleration in the rate of bone loss (1% per year). Marrow cavity width (M), cortical index at the second metacarpal shaft (MI) and external width (W) all correlated with age in both sexes, although generally better in the female than in the male sex. M almost doubled from the fourth to the ninth decade in women and increased 50% in men. In the same age interval, MI showed an annual decrease of 0.49% in females and 0.33% in males. In the over 65 group, cortical thinning rate was significant in women (0.39% per annum) but not in men (0.14% per annum), whereas correlation of W was not significant in either sex. Finally, MI correlated with BMD in the whole study population and in the over 65, with a female prevalence in correlation strength maintained throughout life. The following conclusions can be derived for metacarpal aging: (1) an acceleration in cortical bone loss occurs in females after age 65; (2) age-related growth in periosteal diameter, although significant in the whole population, is negligible in the elderly of both sexes; (3) age-related cortical bone loss is generally more dependent on cortical thinning in women than in men. Received: 1 November 1995 / Accepted: 23 May 1996     

High Intensity Resistance Training: Effects on Bone in Older Men and Women

There is evidence that high intensity resistance training promotes bone maintenance in older women, however, the effect of high intensity free weight training has not been investigated in older men or women. Furthermore, little is known about the chronic effect of weight training on serum insulin growth factor-I (IGF-I) in this population. We compared the effects of a moderate intensity seated resistance-training program with a high intensity standing free weight exercise program on bone mass and serum levels of IGF-I and IGFBP3 in healthy older men and women. Twenty-eight men (54.6 ± 3.2 years) and 26 nonestrogen-replaced women (52.8 ± 3.3 years) served as their own controls for 12 weeks, then were randomly assigned to a moderate or high intensity training group and trained three times/week for 24 weeks. Prior to and after the control period and at the end of training, bone mass and body composition were assessed by dual energy X-ray absorptiometry (DXA), muscle strength by isokinetic dynamometry, muscular power by Wingate Anaerobic Power Test, and IGF-I by radioimmunoassay (RIA). A repeated measures analysis of covariance (ANCOVA) revealed that high intensity training resulted in a gain in spine BMD in men (1.9%), P < 0.05, but not in women, whereas moderate intensity training produced no changes in either gender at this site. Increases were observed at the greater trochanter, P < 0.03, in men regardless of training intensity, but not in women at any hip site. However, when compared with zero, both men and women in the high intensity group demonstrated significant increases in trochanteric BMD (1.3% and 2.0%, respectively) and a decrease in femoral BMD (−1.8%). Neither circulating serum IGF-I nor IGFBP3 were altered by either training regimen, but both training programs resulted in improvements in total body strength (37.62%) and lean mass (males 4.1%, females 3.1%). We conclude that although resistance training of moderate to high intensity produced similar muscle changes in older adults, a higher magnitude is necessary to stimulate osteogenesis at the spine. However, at the spine, intensity was not sufficient to offset low levels of estrogen in early postmenopausal women. Furthermore, bone changes were not accompanied by changes in circulating serum levels of IGF-I or IGFBP3. Received: 21 July 1999 / Accepted: 11 January 2000     

Risk factors for falls in a longitudinal population-based cohort study of Japanese men and women: The ROAD Study

The objective of this study was to clarify the associations of physical performance and bone and joint diseases with single and multiple falls in Japanese men and women using a population-based longitudinal cohort study known as Research on Osteoarthritis/osteoporosis Against Disability (ROAD). A total of 452 men and 896 women were analyzed in the present study (mean age, 63.9 years). A questionnaire was used to assess the number of falls during the 3-year follow-up. Grip strength, 6-m walking time, and chair stand time were measured at baseline. Knee osteoarthritis (OA) and lumbar spondylosis were defined as Kellgren Lawrence = 2, 3 or 4. Vertebral fracture (VFx) was assessed with the Japanese Society of Bone and Mineral Research criteria. Osteoporosis was defined by bone mineral density using dual energy X-ray absorptiometry based on World Health Organization criteria. Knee and lower back pain were estimated by an interview. During a 3-year follow-up, 79 (17.4%) men and 216 (24.1%) women reported at least one fall, and 54 (11.9%) men and 111 (12.4%) women reported multiple falls. Knee pain was a risk factor for multiple falls in women, but not in men. VFx tended to be associated with multiple falls in women, but not in men. A longer 6-m walking time was a risk factor for multiple falls in women, whereas a longer chair stand time was a risk factor for multiple falls in men. We found gender differences in risk factors for falls.