Anthropometric,Bone Age,and Bone Mineral Density Changes after a Family-Based Treatment for Obese Children

Our objective was to identify anthropometric, bone age, and bone mineral density (BMD) changes after a family-based treatment program for obese children. We conducted a longitudinal prospective study of 50 obese children (body mass index percentage [BMI%] ≥120%) aged 9.12 ± 1.72 years (range 6–13) at baseline. A family-based treatment program, based on inadequate feeding style with progressive modification, aerobic physical exercise increase, active parental involvement, and the use of behavioural strategies (contracting, self-monitoring, social reinforcement), was developed during a 12-month period. Anthropometric data, lumbar spine (L2-L4) BMD by dual-energy X-ray absorptiometry, bone age (BA), bone age to chronological age ratio (BA/CA), and predicted adult height (PAH) were determined at baseline and 12 months. The statistical method used was analysis of variance and the paired Student t-test. Mean BMI standard deviation score (SDS) loss was –0.61 ± 0.76 and BMI% loss was –5.17 ± 9.73%. Height SDS significantly decreased, BA/CA ratio also decreased significantly, and PAH change was not significant. Lumbar spine BMD SDS and BMD% did not significantly change. A family-based treatment program was effective in obese children by reducing by 5% the BMI in 1 year and increasing the activity level. Treatment reduced growth velocity and delayed bone maturation rate without affecting PAH, reflecting a situation of previous early maturation. The treatment did not modify gaining bone mass.     

Heritability of Spinal Trabecular Volumetric Bone Mineral Density Measured by QCT in the Diabetes Heart Study

The heritability of trabecular volumetric bone mineral density (BMD) determined by quantitative computed tomography (QCT) has not yet been reported. The purpose of this study was to investigate the heritability of BMD as determined by QCT and DXA in 124 women and 120 men (age 39–83 years, BMI 17–75, 84% type 2 diabetics) from 101 families (232 sibling pairs) in the Diabetes Heart Study. Volumetric BMD had a heritability (h²) estimate of 0.73 (SE = 0.15, P < 0.0001) at the lumbar spine and 0.71 (SE = 0.15, P < 0.0001) at the thoracic spine. Areal BMD heritability estimates were 0.56 for PA spine, 0.43 for total hip, 0.43 for femoral neck, 0.45 for distal radius, 0.42 for mid-radius, and 0.52 for whole body (all P < 0.01). After accounting for familial correlation using generalized estimating equations, volumetric BMD was inversely associated with age (r = –0.52, P < 0.0001) and duration of diabetes (r = –0.24, P < 0.01) and positively associated with body weight (r = 0.25, P < 0.01). In multivariate analysis, adjustment for age, sex, and race lowered the h² estimates for volumetric BMD at the lumbar (h² = 0.41, P < 0.01) and thoracic (h² = 0.48, P < 0.001) spine, increased the h² estimate for areal BMD at the mid radius (h² = 0.58, P < 0.0001), and had little effect on the h² estimate for areal BMD at other sites (h² = 0.41–0.55, all P < 0.01). Additional adjustment for BMI, duration of diabetes, and physical activity had little effect on the h² estimates for volumetric BMD or areal BMD except at the hip where they were lowered (h² = 0.31–0.33, all P < 0.05). These data suggest that, like areal BMD, volumetric BMD is highly heritable and may be used in designing linkage studies to locate genes governing bone metabolism.     

A Prospective Study of Bone Mineral Density Change in Taiwan

In 1989, a cross-sectional study was carried out in Lin-Kou Township, Taiwan, to determine the distribution of bone mineral density (BMD) in the lumbar spine of Chinese people. Lumbar spine BMD was measured using dual-photon absorptiometry in 404 healthy volunteers (266 women and 138 men, aged 15 to 83 years). In 1994–1995, 318 of the same volunteers were reexamined for the present study. Except for there being fewer males and smokers present, there were no significant differences between the second survey respondents and nonrespondents. Spine BMD decreased at over 1% per year in Chinese women over age 50, which was somewhat higher than reported for caucasian women. Since there was a loss of BMD in Chinese women after their 20s, a case can be made for starting preventive activities for female adolescents. There were no differences in the mean BMD change rates among the different age groups of Chinese men. Baseline BMD, menopause, and weight change were associated with the lumbar spine BMD change rates in Chinese women. Body mass index was the only variable significantly associated with BMD change in Chinese men. The rate of BMD change was not associated with diet. Received: 18 February 1997 / Accepted: 5 June 1997     

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     

Low Bone Mineral Density in Rotating-Shift Workers

Shift workers have been reported to have an increased bone resorption. However, no existing evidence indicates lower bone mineral density (BMD) in this group. The objective of this study was to test the hypothesis that a rotating-shift work schedule is associated with low BMD and osteoporosis. We evaluated 70 postmenopausal nurses from the Naval Hospital in Concepcion, Chile. The participants were categorized according to the type of work schedule: 39 had a rotating shift and 31 were daytime workers. Medical history, a health examination, a questionnaire on health-related behaviors and biochemical determinations, and BMD examination were obtained for all participants. When comparing the 2 groups, the rotating-shift workers had lower BMD in the lumbar spine (L1–L4: 0.957 ± 0.15 vs 1.104 ± 0.13; p < 0.05) and lower bone density in both femoral neck bones (right: 0.936 ± 0.17 vs 1.06 ± 0.12; p < 0.05 and left: 0.956 ± 0.19 vs 1.05 ± 0.12; p < 0.05). Additionally, the T-scores for 10 (25.6%) of the rotating-shift workers indicated osteoporosis at lumbar spine (T-score > ?2.5). No evidence of osteoporosis was found for daytime workers. When comparing the 2 groups, the rotating-shift workers had a higher prevalence of osteopenia (T-score = ?1.0 to ?2.5) than the daytime workers: 46.2% vs 35.5%, respectively. We found significant evidence that rotating-shift workers have lower BMD in the trabecular and cortical bones, thus suggesting that this type of work may be a risk factor for osteoporosis. Because this is the first time that this osteoporosis risk factor has been reported, the association needs to be replicated and confirmed in other settings.     

Bone Mineral Density in French Canadian Women

This cross-sectional study investigated bone mineral density (BMD) at the lumbar spine (L2–4) and femoral neck in French Canadian women residing in the Quebec city area. Data collection was initiated in 1988 and completed in 1994. A total of 747 French Canadian Caucasian women (16–79 years of age) with no metabolic bone disease were evaluated. BMD measurements were obtained using dual-photon absorptiometry (DPA) or dual-energy X-ray absorptiometry (DXA). Anthropometric measures such as weight, height and body mass index (BMI) were recorded. Medical files provided information on demographic characteristics, hormonal profile and lifestyle habits. Results show a curvilinear trend of BMD with aging. Furthermore, the peak BMD at the lumbar spine (L2–4) was reached at 29 years followed by a stable phase until 35 years, after which BMD started to decrease. The pattern of bone evolution at the femoral neck was different, peak BMD being achieved earlier, at 21 years, while after age 26 years a significant decrease was already observed. Women older than 60 years showed the lowest BMD. Regression analysis showed that age, weight and height are determinants of BMD at the lumbar spine and explained 33.9% of inter-individual variation. At the femoral neck, 29.1% of variation was explained by age and height only. In conclusion, our data suggest that French Canadian women have a different pattern of bone loss at the femoral neck compared with the lumbar spine, according to their mean BMD values. Received: 21 July 1997 / Accepted: 15 October 1997     

Bone Mineral Density in Flatwater Sprint Kayakers

To elucidate the possible skeletal benefits of the muscular contractions and the nonweight-bearing loading pattern associated with kayaking, we investigated the bone mineral density (BMD, g/cm²) of 10 elite kayakers, six males and four females, with a median age of 19 years. Each subject was compared with the mean value of two matched controls. BMD of the total body, head, ribs, humerus, legs, proximal femur (neck, wards, trochanter), spine, lumbar spine, and bone mineral content (BMC, g), of the arms was obtained using a dual energy X-ray absorptiometer (DXA). Body composition was also assessed. The kayakers had a significantly (P < 0.05–0.01) greater BMD in most upper body sites: left and right humerus (10.4% and 11.7%), respectively, ribs (6.4%), spine (10.9%), and a greater BMC of the left and right arm (15.7% and 10.6%, respectively). No significant differences in the BMD of the total body, head, or any of the lower body sites were found, except for the pelvis, which was significantly greater in kayakers (5.1%). The controls had a significantly lesser lean body mass (10.4%) and greater percentage of body fat (19.5%) than the kayakers. Bivariate correlation analysis in the controls demonstrated significant and strong relationships between BMD in upper body sites and lean body mass, weight, and fat; the effects of training seem to outweigh most such relationships in kayakers. In conclusion, it seems that the loading pattern and muscular contractions associated with kayaking may result in site-specific adaptations of the skeleton. Received: 21 April 1998 / Accepted: 1 October 1998     

Bone Mineral Density and Sports Participation

The objective of our study was to identify differences in bone mineral density (BMD) according to different sports among adolescents, as well as to identify assessments of relevant mediators. The sample consisted of 429 adolescents with a mean age of 13.3 ± 1.7 yr. The sports modalities that we evaluated were judo, karate, kung fu, swimming, basketball, and soccer. Nonsports group was composed of 111 adolescents. Bone density was assessed using dual-energy X-ray absorptiometry. Regarding BMD values, female engaged in karate had higher BMD values than girls from the no sports group (p = 0.01). Boys engaged in soccer and karate presented the highest BMD values than all the other groups (p = 0.01). The most relevant mediators were the body mass index and lean soft tissue for boys and girls. Different sports presented different results regarding BMD gains, which were influenced by body mass index and whole-body lean soft tissue.     

A Correlation Exists Between Subchondral Bone Mineral Density of the Distal Radius and Systemic Bone Mineral Density

Background  

Intraarticular distal radius fractures are common and risk articular congruity owing to disruption of the subchondral bone. Studies regarding microstructure and mechanical properties of the distal radius, however, focus only on the cortical and trabecular bones in the metaphysis and not on the subchondral bone.     

The Association of Pelvic Bone Mineral Density and With Proximal Femoral and Spine Bone Mineral Density in Post-menopausal Women

Pelvic fragility fractures result in significant morbidity and their incidence has increased over the past 30 years. One of the main risk factors in skeletal fragility is bone mineral density (BMD). Most of the current literature has focused on understanding spine and hip BMD. We aimed to measure the BMD of pelvis in a cohort of post-menopausal women and compare it to BMD at other skeletal sites. A questionnaire regarding risk factors for osteoporosis was completed by each participant. DXA scan of the pelvis was performed using research software. Three areas of the pelvis corresponding to common fractures were defined on pelvic DXA: R1 = symphysis public, R2 = inferior public rami, R3 = superior public rami. Pelvic BMD was calculated as the average BMD of R1-3. BMD at each location was reported as mean and standard deviation (SD). ANOVA was used to compare BMD between R1-R3 and pelvis, femoral neck, total hip, and spine. Pearson correlation was used to correlate pelvic BMD to BMD of proximal femur and spine. BMD was compared in four participant groups: 1- osteoporosis in spine and hip, 2- osteoporosis in spine only, 3-osteoporosis in hip only, and 4- no osteoporosis in spine and hip. The effect of diabetes and obesity on BMD at various skeletal sites was analyzed. Among the one hundred postmenopausal women enrolled in the study, age was: 64 ± 8, 31% were obese (BMI ≥ 30), and 8% had a diagnosis of type 2 diabetes. Pelvic area R3 had significantly higher BMD than R1 or R2 (p < 0.001). Pelvic BMD (0.50 ± 0.16) was significantly lower than total hip (0.70 ± 0.20) and spine BMD (0.97 ± 0.19) (p < 0.001). Pelvic BMD correlated with BMD at other skeletal locations, with the highest correlation with total hip (total hip: R2: 0.70, femoral neck R2: 0.50, spine R2: 0.65). Pelvic BMD was significantly lower in patients with osteoporosis of both hip and spine compared to the group without osteoporosis at both locations (p = 0.02). Obesity and type 2 diabetes were both associated with significantly higher BMD at pelvis, spine, and total hip. Pelvic BMD is lower than at other skeletal sites and is highly correlated with total hip area bone density. Obesity and type 2 diabetes are associated with higher pelvic BMD. To establish guidelines for the treatment pelvic BMD, studies defining the association of pelvic BMD with pelvic fracture risk are needed.     

Determinants of Bone Mineral Density in Older Men

Although osteoporosis in men is increasingly recognized as an important health issue and bone mass appears to be a major determinant of fracture, there remain few data concerning the determinants of bone mass in men. To determine the correlates of bone density in men, we studied a large group of older subjects recruited from three rural communities in the northwestern United States. Three hundred and fifty-five men over the age of 60 years (mean 71.5 ± 7.4 years) without known disorders of mineral metabolism were recruited by community advertising. Bone mineral density was measured at the lumbar spine, proximal femur and radius by dual-energy X-ray absorptiometry, and factors potentially related to skeletal status were assessed by direct measurements or questionnaire. In univariate analyses weight (positively) and age (negatively) were associated with bone density. After adjustment for these two factors, alcohol intake, osteoarthritis and thiazide use were associated with higher bone density, while previous fractures, gastrectomy, peptic ulcer disease, rheumatoid arthritis, glucocorticoid use, hypertension, previous hyperthyroidism, height loss since age 20 years, chronic lung disease and smoking were related to lower density. In multivariate models, only weight and a history of cancer were related to higher bone mass, and age, previous fracture, rheumatoid arthritis, gastrectomy and hypertension were associated with lower density. These data contribute to the emerging field of osteoporosis in men, and may help in the clinical identification of men at higher risk of osteopenia. Received: 27 September 1999 / Accepted: 20 March 2000     

Bone Mineral Density Around the Knee Joint: Correlation With Central Bone Mineral Density and Associated Factors

Introduction: The aims of this study were to (1) assess the bone mineral density (BMD) around the knee joint, (2) determine the correlation between central and knee BMDs, and (3) investigate the factors associated with BMD around the knee joint in patients with knee osteoarthritis (OA). Methodology: This cross-sectional study included 122 patients who underwent total knee arthroplasty. Central and knee dual-energy X-ray absorptiometry was performed preoperatively. BMD at 6 regions of interest (ROIs) around the knee joint were measured, and their correlations with central BMD were determined using Spearman's correlation analysis. Lower limb alignment, severity of OA, body mass index (BMI), preoperative functional and pain scores were assessed to elucidate the factors associated with knee BMD using linear regression analysis. Results: Around the knee joint, BMD was the lowest at the distal femoral metaphysis and lateral tibial condyle. Knee BMD was significantly correlated with central BMD. However, the correlation coefficients varied by the ROI. Additionally, multivariate analysis revealed different associations with respect to the regions around the knee joint. Varus alignment of the lower limb was associated with increased BMD of the medial condyles and decreased BMD of lateral condyles. High grade OA was a protective factor; it was associated with increased BMD at the lateral condyles of the femur and tibia. Higher BMI was an independent protective factor in all ROIs around the knee joint except the lateral femoral condyles. Lower functional level was not associated with decreased BMD, whereas a higher pain score was significantly associated with lower BMD at the proximal tibial metaphysis. Conclusions: Knee BMD was significantly correlated with central BMD. However, the correlations varied with the regions around the knee joint probably due to their independent association with the alignment of the lower limb, severity of OA, BMI, and preoperative pain level.