Higher BMC Research Articles

Circum-menarcheal bone acquisition is stress-driven: A longitudinal study in adolescent female gymnasts and non-gymnasts

Mechanical loading through youth exercise is highly modifiable and represents a strategy to maximize peak adult bone mass, with the potential for broad implementation across the population to lower fracture risk. For girls, circum-menarcheal growth is critical, with around 50% of adult bone acquired over a 4-year period. Here, we prospectively followed 10 gymnasts and 12 age-matched non-gymnasts across approximately 4 years circum-menarche. A combination of pQCT and subject-specific finite element models were used to measure differences in bone acquisition and structure between the groups, and to determine the degree to which specific mechanical factors predict change in bone structure. At baseline, gymnasts had stronger bone, including 26% higher BMC, 51% greater compressive strength, and 21% higher trabecular density. Over the study period, both groups more than doubled their bone strength. Pre-menarcheal principal stresses predicted change in pQCT variables for non-gymnasts, but not gymnasts. The bone of non-gymnasts became more asymmetrical than the bone of gymnasts. Our results suggest that exposure to the diverse, intense mechanical signals of gymnastic loading during adolescence imparts substantial benefits to bone geometry and mechanical function. Specifically, the bone of gymnasts is better able to resist loading from multiple directions, and operates with a higher factor of safety compared to non-gymnasts.

Volleyball and Basketball Enhanced Bone Mass in Prepubescent Boys

The aim of this study was to examine the effect of volleyball and basketball practice on bone acquisition and to determine which of these 2 high-impact sports is more osteogenic in prepubertal period. We investigated 170 boys (aged 10–12 yr, Tanner stage I): 50 volleyball players (VB), 50 basketball players (BB), and 70 controls. Bone mineral content (BMC, g) and bone area (BA, cm2) were measured by dual-energy X-ray absorptiometry at different sites. We found that, both VB and BB have a higher BMC at whole body and most weight-bearing and nonweight-bearing sites than controls, except the BMC in head which was lower in VB and BB than controls. Moreover, only VB exhibited greater BMC in right and left ultra-distal radius than controls. No significant differences were observed between the 3 groups in lumbar spine, femoral neck, and left third D radius BMC. Athletes also exhibited a higher BA in whole body, limbs, lumbar spine, and femoral region than controls. In addition, they have a similar BA in head and left third D radius with controls. The VB exhibited a greater BA in most radius region than controls and a greater femoral neck BA than BB. A significant positive correlation was reported between total lean mass and both BMC and BA in whole body, lumbar spine, total hip, and right whole radius among VB and BB. In summary, we suggest that volleyball and basketball have an osteogenic effect BMC and BA in loaded sites in prepubescent boys. The increased bone mass induced by both volleyball and basketball training in the stressed sites was associated to a decreased skull BMC. Moreover, volleyball practice produces a more sensitive mechanical stress in loaded bones than basketball. This effect seems translated by femoral neck expansion.

Effects of Long-Term Surfing on Bone Health in Mature-Aged Males

Low mechanical loading aquatic activities such as swimming and scuba diving have identified decreased bone mineral density (BMD); however, the effects of long-term surfing on bone health remains uninvestigated. This was a cross-sectional observational study with two groups: surfers (n = 11) with 40 years surfing experience and age and gender-matched sedentary controls (n = 10). Data collected included physical activity questionnaires, biomarkers, BMD, bone mineral content and body composition. Surfers demonstrated a significantly (p < 0.05) higher mean BMD in the arms (+18.8%), trunk (+26.1%), ribs (+27.2%), spine (+39.5%), and lumbar spine (+22.8%). Surfers also exhibited a significantly (p < 0.05) higher BMC in the arms, trunk, ribs, spine and pelvis. Surfers also had a significantly higher (p = .046) lean muscle mass in their arms (+16.8%). Our results indicate long-term participation in surfing is beneficial to bone health and maybe an ideal physical activity for middle-aged aquatic enthusiasts.

Adiposity and bone health in Spanish adolescents. The HELENA study

While the association of lean mass (LM) with bone mass is well understood, the association of fat mass (FM) with bone mass is controversial. Our results support that adolescents with higher levels of adiposity have greater bone mass, but this association is fully explained by their higher levels of LM. We aimed (1) to study the independent association of FM and LM with bone mass and (2) to study the differences in bone mass by weight status in adolescents, after controlling for relevant confounders, such as physical activity (PA), calcium intake, and LM. Participants were 330 adolescents (167 boys, 12.5-17.5 years) from the HELENA study. The relationships of FM (DXA, n = 330; BodPod, n = 282) and LM (DXA, n = 330) with different bone variables (whole body, total hip, lumbar spine, and femoral neck) were analyzed by linear regression, and differences between weight status were analyzed by ANCOVA. Fat mass (DXA) was positively associated with bone variables in both sexes, after adjustment for height, calcium intake, and sexual maturation. Additional adjustment by PA slightly increases the associations. However, adjustment for LM inverted these associations. Similar results were obtained using BodPod instead of DXA for assessing FM. Overweight/obese adolescents had higher BMC than their non-overweight peers in most of regions studied. Additional adjustment for PA slightly increased the differences between weight status groups, while adjusting for LM inverted the associations. LM was strong and positively associated with all bone variables in both sexes. Additional adjustment for PA or FM did not change the results. Adolescents with higher levels of adiposity have greater bone mass, but this association is explained by their higher levels of LM.

Participation In A Community-based Running Program Is Associated With Higher Hip Bmc In Young Girls

Girls on the Run (GOTR) is a community-based running program that encourages social, mental, emotional and physical development in young girls through the process of training for a 5k running event. Previous reports have shown that GOTR has positive effects on self esteem and dietary behaviors; whether GOTR influences physiological outcomes is unknown. PURPOSE: To determine if participation in GOTR is associated with positive skeletal development in 8-12 year-old girls. METHODS: Girls (n=31; 9.8±1.4 yrs) were recruited from seven different GOTR Willamette Valley sites to form the intervention group. Girls who did not participate in GOTR or other organized physical activity formed the control group (n=11; 9.6±0.73 yrs). All girls completed a standard health history questionnaire at baseline. Weight, height, and time spent in moderate to vigorous physical activity (MVPA) were measured at baseline, 3, 6, and 9 months. MVPA was measured by accelerometry over a 7-day period at each time point. Bone mineral content (BMC (g/cm2); assessed using DXA) and nutrient intakes (assessed using the Youth Adolescent Food Frequency Questionnaire) were evaluated at baseline and 9-months. To determine baseline differences between groups in BMC outcomes, ANCOVA was used adjusting for age, height, weight, maturation status (years from peak ht. velocity), nutrient intakes and MVPA. The ANCOVA was repeated at 9-months adding initial BMC values to determine differences in BMC outcomes between groups at follow-up. RESULTS: At baseline GOTR participants had higher BMC at the femoral neck (FN) site compared to controls (mean + SE; 2.68 + 0.06 vs. 2.33 + 0.12; p=0.02); there were no baseline differences at any other bone site (p>0.05). At 9-months, GOTR participants had higher FN BMC (p=0.048) and higher trochanteric BMC (p=0.039) compared to controls after adjusting for growth, diet, activity and initial BMC values. There were no group differences at any other bone site (P>0.05). CONCLUSIONS: After adjusting for growth, maturation, diet, MVPA, and initial BMC values, we found that GOTR participants exhibited higher FN and trochanteric BMC compared to controls. Thus there appears to be a positive association between participation in GOTR and skeletal development at the hip in growing girls.

Isokinetic Strength And Lower Limb Bone Mass Of Soccer Players And Non-athletes 11-15 Years

Bone resistance can be enhanced as a response to high impact loads associated from regular sport training, and by high levels of tension in specific bone areas as a result of muscular contractions. There is, in general, a lack of information on the relationship between muscle strength and bone mass in youth populations. PURPOSE: To analyse the relationship between isokinetic peak torque (PT) of the quadriceps (Q) and harmstrings (H) muscles and bone mineral density and content (BMD, BMC) of the lower limb of youth male soccer players and age-matched controls non involved in sport (11-15 years). METHODS: 58 young males were divided in 2 groups according: soccer players (SP; n=39) and nonathletic controls (C; n=19). The former were regularly involved in soccer for at least 3 years (3-5 sessions a week, more than 300 minutes a week), while the latter participated only in the compulsory physical education classes at school (2 weekly sessions of 45-90 minutes each) and did not participate in any kind of regular or organized sport activity for at least 3 years. Isokinetic dynamometry at an angular velocity of 90°.s-1 was used to determine the maximum voluntary concentric torque of the Q and H muscles of the dominant and non-dominant limb. BMC and BMD were quantified with dual energy X-ray absorptiometry. Habitual physical activity was monitored with accelerometers during waking hours for 8 consecutive days. Maturity status was assessed by stage of pubic hair according the Tanner method. Statistical procedures included ANCOVA and multiple regression models. RESULTS: SP showed higher mean PT of the Q and H and higher BMC and BMD of lower limb than C (154.7±27.7 vs 108.7±23.5 Nm; 78.0±21.3 vs 45.6±11.5 Nm; 470.5±85.4 vs 288.8±66.0 g; 1.29±0.12 vs 0.96±0.10 g/cm2; respectively). No significant differences were found between dominant and non-dominant limb strength, BMC and BMD in both groups (p>0.05). After adjusting for maturity status, leg extension PT and soccer practice were positively associated with lower limb BMC [b= 2.54, p<0.001; b= 63.24, p=0.001, respectively; R2 =84.5%] and BMD [b= 0.03, p<0.001; b= 0.18, p<0.001, respectively; R2 =81.4%]. CONCLUSIONS: Muscle strength of knee extensors of boys is associated with lower limb BMD and BMC. Regular training for soccer contributes to the enhancement of lower limb BMD and BMC.

Higher BMC and areal BMD in children and grandchildren of individuals with hip or knee replacement

The relationship between aBMD and osteoarthritis (OA) remains unclear. We compared aBMD, BMC and bone size among children and grandchildren of Hutterites with hip or knee replacement ( n = 23 each) to children and grandchildren of age- and sex-matched controls (178 children and 267 grandchildren). There were no differences in anthropometric measures or activity levels between case and control probands, but femoral neck (FN) and spine (LS) aBMD and Z-scores were greater in cases than controls (0.89 vs. 0.80 g/cm 2; 1.15 vs. 1.03 g/cm 2; 1.5 vs. 0.8; 2.4 vs. 1.2: all p < 0.05). Hip, FN and LS aBMD (1.05 vs. 0.97, 0.92 vs. 0.84, 1.15 vs. 1.03 g/cm 2), BMC (34.1 vs. 32.0, 4.58 vs. 4.27, 69.5 vs. 62.4 g) and Z-scores (1.0 vs. 0.4; 0.9 vs. 0.2; 1.3 vs. 0.2) were greater in daughters of cases than controls (hip BMC p = 0.06, others p < 0.05); there were no differences between sons. Grandchildren (aged 8–39 years) were categorized as growing (premenarcheal or male < 14 years) or not growing (≥ 2 years post-menarcheal or males ≥ 18 years): 33 were not classified. Post-menarcheal, but not premenarcheal, granddaughters of cases had greater hip, FN and LS aBMD Z-scores (0.7 vs. −0.1; 0.6 vs. −0.1; 0.8 vs. −0.3); greater hip and spine aBMD (1.03 vs. 0.95, 1.10 vs. 0.98 g/cm 2); greater femoral neck and spine BMC (4.77 vs. 4.21, 66.7 vs. 55.4 g); and greater spine bone area (60.7 vs. 56.6 cm 2) compared to granddaughters of controls (all, p < 0.05), which remained significant when height, weight, and age were included as covariates. Growing grandsons of cases were taller and heavier than control grandsons, and a greater hip aBMD among grandsons of cases (0.88 vs. 0.76 g/cm 2) was the only bone difference that remained significant after taking into account body size differences. Grandsons who were not growing had greater spine bone area (1.19 vs. 1.08 cm 2) if their grandparent had OA compared to grandsons whose grandparents did not have OA. We speculate that there is a genetic basis for OA that leads to early differences in growth patterns among boys and greater peak bone mass and aBMD among girls.

Dietary patterns related to fat and bone mass in preschoolers

We aimed to determine dietary patterns (DP) related to both fat (FM) and bone mass (BMC) in preschoolers. FM and BMC were measured by DXA (Hologic QDR4500) at age 4 y (n = 326). Four 3‐d diet records collected from age 3 to 4 y were used to estimate intake (servings/d) of 34 food groups (NDS v 2005). We used reduced rank regression to extract DP to explain a maximum variation in FM and BMC simultaneously. The 1st DP (DP1) was associated with both higher FM and higher BMC, explaining 14% (FM) and 13% (BMC) of variation. DP2 was associated with lower FM and higher BMC, explaining an additional 4% of variation in each. DP1 was characterized by high intake of non‐whole grain, fried food, lunch meat, egg, dessert and discretionary fat. DP2 was characterized by high intake of whole grain, vegetables, lunch meat, beans, soy and savory snacks. DP1 (r = 0.6) and DP2 (r = 0.4) scores were related to kcal intake (p &lt; 0.01). In ANCOVA models adjusting for activity, age, sex, BMI, and ht, DP1 scores, but not kcal intake, were associated with FM and BMC (p ≤ 0.01). Using the residuals of the relation between kcal and DP1 scores in place of DP1 scores, both the residuals and kcal were associated with FM (p &lt; 0.05); and residuals but not kcal were associated with BMC (p &lt; 0.01). DP2 scores and residuals persisted in adjusted models for FM. A diet proportionately high in fat, with a high absolute amount of protein, is related to both high adiposity and high BMC in preschoolers. NIH R21DK077100

The relationship between muscle size and bone geometry during growth and in response to exercise

As muscles become larger and stronger during growth and in response to increased loading, bones should adapt by adding mass, size, and strength. In this unilateral model, we tested the hypothesis that (1) the relationship between muscle size and bone mass and geometry (nonplaying arm) would not change during different stages of puberty and (2) exercise would not alter the relationship between muscle and bone, that is, additional loading would result in a similar unit increment in both muscle and bone mass, bone size, and bending strength during growth. We studied 47 competitive female tennis players aged 8–17 years. Total, cortical, and medullary cross-sectional areas, muscle area, and the polar second moment of area ( I p) were calculated in the playing and nonplaying arms using magnetic resonance imaging (MRI); BMC was assessed by DXA. Growth effects: In the nonplaying arm in pre-, peri- and post-pubertal players, muscle area was linearly associated BMC, total and cortical area, and I p ( r = 0.56–0.81, P < 0.09 to < 0.001), independent of age. No detectable differences were found between pubertal groups for the slope of the relationship between muscle and bone traits. Post-pubertal players, however, had a higher BMC and cortical area relative to muscle area (i.e., higher intercept) than pre- and peri-pubertal players ( P < 0.05 to < 0.01), independent of age; pre- and peri-pubertal players had a greater medullary area relative to muscle area than post-pubertal players ( P < 0.05 to < 0.01). Exercise effects: Comparison of the side-to-side differences revealed that muscle and bone traits were 6–13% greater in the playing arm in pre-pubertal players, and did not increase with advancing maturation. In all players, the percent (and absolute) side-to-side differences in muscle area were positively correlated with the percent (and absolute) differences in BMC, total and cortical area, and I p ( r = 0.36–0.40, P < 0.05 to < 0.001). However, the side-to-side differences in muscle area only accounted for 11.8–15.9% of the variance of the differences in bone mass, bone size, and bending strength. This suggests that other factors associated with loading distinct from muscle size itself contributed to the bones adaptive response during growth. Therefore, the unifying hypothesis that larger muscles induced by exercise led to a proportional increase in bone mass, bone size, and bending strength appears to be simplistic and denies the influence of other factors in the development of bone mass and bone shape.

Raloxifene, estrogen, and alendronate affect the processes of fracture repair differently in ovariectomized rats.

We investigated the effects of inhibitors of bone resorption (estrogen, raloxifene, and alendronate) on the processes of fracture repair in ovariectomized (OVX) rats. One hundred forty female Sprague-Dawley rats at 3 months of age were either OVX or sham-operated and divided into five groups: sham control, OVX control, estrogen (17alpha-ethynyl estradiol [EE2], 0.1 mg/kg), raloxifene (Rlx, 1.0 mg/kg), and alendronate (Aln, 0.01 mg/kg) groups. Treatment began immediately after the surgery. Four weeks postovariectomy, prefracture controls were killed and bilateral osteotomies were performed on the femoral midshafts and fixed with intramedullary wires. Treatment was continued and fracture calluses were excised at 6 weeks and 16 weeks postfracture for evaluation by X-ray radiography, quantitative computed tomography (QCT,) biomechanical testing, and histomorphometry. At 6 weeks postfracture, Aln and OVX had larger calluses than other groups. Sham and OVX had higher ultimate load than EE2 and Rlx, with Aln not different from either control. Aln calluses also contained more mineral (bone mineral content [BMC]) than all other groups. By 16 weeks postfracture, OVX calluses were smaller than at 6 weeks and the dimensions for Aln had not changed. Aln had higher BMC and ultimate load than OVX, EE2, and Rlx. EE2 and Rlx had similar biomechanical properties, which were similar to sham. Interestingly, OVX and Aln animals were heavier than other groups at all time points; therefore, ultimate load was normalized by body weight to show no significant differences in strength of the whole callus between groups at either 6 weeks or 16 weeks postfracture. However, Aln strongly suppressed remodeling of the callus, resulting in the highest content of woven bone, persistent visibility of the original fracture line, and lowest content of lamellar bone, compared with other groups. Therefore, the larger Aln callus appeared to be a remarkable, morphological adaptation to secure the fracture with inferior material. In conclusion, OVX-stimulated bone turnover resulted in the fastest progression of fracture repair that was most delayed with Aln treatment, consistent with marked suppression of bone resorption and formation activity. Estrogen and Rlx had similar effects that were generally similar to sham, indicating that mild suppression of bone turnover with these agents has insignificant effects on the progression of fracture repair.

Bone mineralisation in ex-preterm infants aged 8 years.

In preterm infants, in whom perinatal mineralisation deficits are common, there is little information on long-term bone mineralisation. Using a Hologic QDR 1000 dual energy X-ray absorptiometer, bone mineral content and density (BMC and BMD) were measured in lumbar, spine, forearm and hip in 46 ex- preterm infants <32 weeks gestation together with controls at 8 years of age. Height and weight were recorded, as was history of bone fracture. Preterm infants were shorter by 4.9 cm (95% CI, 2.4 7.3) and lighter by 2.6 kg (95% CI, 0.7 4.4). BMC for all sites measured was significantly lower in the preterm group, but did not remain so when adjusted for height and weight. BMD was significantly reduced in the hip of the preterm group. Prolonged ventilation was associated with the lowest BMC and duration of preterm formula feeding correlated with higher BMC. Accidental fractures were less common in the preterm group. Ex preterm infants have significant reduction in bone mineral mass commensurate with their reduced growth and reduced bone mineral density in their hips.

Effect of loading on bone regenerated at implant dehiscence sites in humans.

Few investigations have studied the long-term fate of bone formed following the technique of guided tissue regeneration. The aim of the present study was to evaluate bone fill around implant fixtures with dehiscence defects and to study its response to loading. Ten patients were treated with overdentures supported by 2 fixtures ad modum Brånemark. A third 7 mm x 3.75 mm diameter fixture was placed for the purposes of the study in the most anterior part of the mandible with a dehiscence defect of 4 to 5 mm on the buccal aspect (and 3 to 4 threads exposed) which was covered with a Gore-Tex membrane and buried beneath the mucosa. Fixtures were exposed after 5 months (stage 2), ball abutments connected and loaded through an overdenture for 1 year. Nine fixtures were functioning well after 1 year of loading, 6 of which were retrieved with a trephine for histological examination and compared with 6 unloaded fixtures retrieved in our previously reported study. The bone area filling the thread profiles (BA%) and the bone to metal contact (BMC%) were measured in the 3 most apical and 3 most coronal thread profiles on the buccal and lingual surfaces. Statistically significant higher BMC% (P < 0.01) were observed in loaded fixtures in the apical regions (buccal: loaded 51%, unloaded 25%; lingual: loaded 49%, unloaded 24%). Differences approached significance for the regeneration site (loaded 22%, unloaded 6%) but were no different for the coronal lingual region (loaded 28%, unloaded 20%). There were no differences for BA%. This study confirms that there is an increase in bone to metal contact with time and following fixture loading and that this may also occur with bone regenerated under Gore-Tex membranes.

110 WHOLE BODY BONE MINERAL CONTENT (BMC) AND CALCIUM INTAKE IN HEALTHY CHILDREN

To evaluate the relation between calcium intake and bone mineralisation whole body BMC was determined twice (Hologic 1000/W DXA scanner) with one year interval in healthy children aged 5-19 y (F 201, M 142). Calcium intake was measured with a Food Frequency Questionnaire and pubertal stages were assessed ad modum Tanner at the first scan. The association between calcium intake and BMC at the first examination, controlled for bone area, height, weight and age was estimated using multiple regression. Annual bone calcium accretion expressed as mg calcium per day was calculated as the difference between the two DXA scans (data not shown). The ratio between bone calcium accretion rate (mg/d) and calcium intake (mg/d) was calculated. There was a modest but significant effect of calcium intake on BMC. A 100% increase in calcium intake was associated with a 0.8% higher BMC in girls (p=0.04) and a 1.1% higher BMC in boys (p=0.04). Table Conclusion: The results suggest a significant effect of calcium on BMC. The bone calcium retention in relation to calcium intake was highest in mid-puberty indicating a better utilization of calcium in this age group.

Bone mineral density of the calcaneus in 70??? to 81-yr-old male athletes and a population sample

Bone mineral content (BMC/W) and density (BMD) were studied in 70- to 81-yr-old active male endurance-trained (long-distance runners, cross-country skiers, N = 67), strength-trained (throwers, weight-lifters, N = 14), and speed-trained (sprinters, jumpers, N = 16) athletes. A population sample of similar age (N = 42) served as a control group. The measurements were performed at the calcaneus by single-energy photon absorption. The endurance-trained athletes had higher bone width and depth, and the strength and speed-trained athletes higher bone depth than the control subjects. The three groups of athletes showed 19-28% higher BMC (g.cm-1) and BMC/W (g.cm-2) than the control group (P less than 0.01-0.001). When the results were corrected for bone depth by assessing BMD (g.cm-3), the mean differences between the athletes and controls were 11-16% (P less than 0.05-0.01, not significant for the strength group). The highest BMD values were associated with moderate training for running and cross-country skiing. BMD did not correlate with serum total testosterone, but there was a negative correlation between BMD and sex hormone binding globulin and a positive correlation between BMD and the free androgen index in the endurance group. The results indicate that athletes having a long-term training history and being still active at over 70 yr of age preserve superior trabecular bone mass compared with the average male population of the same age.