Total Body Bone Mineral Content Research Articles

Three-Compartment Body Composition Changes in Professional Rugby Union Players Over One Competitive Season: A Team and Individualized Approach

The purpose of this study was to investigate the longitudinal body composition of professional rugby union players over one competitive season. Given the potential for variability in changes, and as the first to do so, we conducted individual analysis in addition to analysis of group means. Thirty-five professional rugby union players from one English Premiership team (forwards: n = 20, age: 25.5 ± 4.7 yr; backs: n = 15, age: 26.1 ± 4.5 yr) received one total-body dual-energy X-ray absorptiometry scan at preseason (August), midseason (January), and endseason (May), enabling quantification of body mass, total and regional fat mass, lean mass, percentage tissue fat mass (%TFM), and bone mineral content (BMC). Individual analysis was conducted by applying least significant change (LSC), derived from our previously published precision data and in accordance with International Society for Clinical Densitometry guidelines. Mean body mass remained stable throughout the season (p > 0.05), but total fat mass and %TFM increased from pre- to endseason, and from mid- to endseason (p < 0.05). There were also statistically significant increases in total-body BMC across the season (p < 0.05). In both groups, there was a loss of lean mass between mid- and endseason (p < 0.018). Individual evaluation using LSC and Bland–Altman analysis revealed a meaningful loss of lean mass in 17 players and a gain of fat mass in 21 players from pre- to endseason. Twelve players had no change and there were no differences by playing position. There were individual gains or no net changes in BMC across the season for 10 and 24 players, respectively. This study highlights the advantages of an individualized approach to dual-energy X-ray absorptiometry body composition monitoring and this can be achieved through application of derived LSC.

Quantifying The Contributions Of Sodium And Calcium In Bone Using Serial Dxa Scans

Bone has been hypothesized to serve as a sodium reservoir to buffer acute and chronic derangements in plasma sodium concentration ([Na+]). However, the contributions of sodium in bone have yet to be quantified in imaging studies. PURPOSE: To: 1) quantify the contributions of 6g sodium chloride (NaCl) on bone mineral content (BMC) and density (BMD) using dual energy x-ray absorptiometry (DXA) scans; 2) compare the contributions of 6g NaCl vs. 6g calcium citrate (Ca3Cit2) on both BMC and BMD; and 3) assess whole body BMC changes in humans 2hrs after oral ingestion of 6g NaCl. METHODS: 1) Ten DXA scans serially performed on a spine phantom (alone) and then with 6g NaCl placed over the spine as: solid 1g tablets; crushed tablets in 1.5mL Eppendorfs (tubes); and as a solution in tubes. 2) Ten DXA scans performed on a spine phantom plus 6g Ca3Cit2 as solid 1g tablets and as crushed tablets in tubes. 3) 14 healthy humans ingested 6g NaCl, (6x1g tablets) with DXA scans taken immediately after ingestion (+tablets; just swallowed) and then repeated 2hrs following oral tablet ingestion (-tablets; due to GI absorption). RESULTS: Mean spine phantom BMC (51.38±0.26g;CV=0.51%) was significantly lower compared with spine phantom plus: NaCl tablets (55.39±0.23;p<0.0001); NaCl tubes (54.87±0.26g;p<0.0001); NaCl solution (52.49±0.28g;p<0.0001); Ca3Cit2 tablets (55.05±0.31g;p<0.0001); and Ca3Cit2 tubes (53.68±0.39g;p<0.0001). Mean spine phantom BMD (0.989±0.004g/cm2;CV=0.50%) was statistically lower when compared with phantom plus: NaCl tablets (1.063g/cm2±0.005;p<0.0001); NaCl tubes (1.056±0.005g/cm2;p<0.0001); NaCl solution (1.006±0.005g/cm2;p<0.0001); Ca3Cit2 tablets (1.058±0.006g/cm2;p<0.0001); and Ca3Cit2 tubes (1.021±0.005g/cm2;p<0.0001). Absorption of 6gm NaCl tablets into the bloodstream 2hrs after oral ingestion reduced whole body BMC by -5.5±27g. CONCLUSIONS: 6g NaCl caused significant increases in BMC and BMD in DXA scans when placed over a spine phantom in: tablet form, when crushed in tubes; and dissolved in solution. Increases in BMC and BMD were similar between 6g NaCl and 6g Ca3Cit2. Alternatively, GI absorption of 6g NaCl tablets after oral ingestion resulted in a ~6g decrease in total body BMC. Thus, changes in BMC and BMD may reflect Na+ and Ca++ mobilization in DXA scan measurements.

Mineralocorticoid receptor blocker usage among sleep apnea subjects with resistant hypertension

Overweight/obesity and high blood pressure during growth period are important risk factors of cardiovascular disease later in life. Cardiovascular system, fat and muscles are among target tissues for vitamin D and low 25(OH)D levels are likely to attenuate potential benefits of its action. The study was aimed to evaluate vitamin D status and body composition in children and adolescents with primary hypertension (PH). The study population comprised 78 patients aged 15.4 ± 2.3 yrs (9–18 yrs; 15 girls) with diagnosed PH. Total 25(OH)D and parathyroid hormone (PTH) were assayed by Cobas e411 machine (Roche Diagnostics). DXA (Prodigy, GE Lunar) was used to assess total body bone mineral content (TBBMC; g), total body bone mineral density (TBBMD; g/cm2), lean body mass (LBM; g), % lean body mass (%LBM), fat mass (FM; g), % fat mass (% FM), Android %Fat, Gynoid %Fat and Trunk fat mass (Trunk FM; g). Hypertensive cases (BMI = 25.6 ± 4.2 kg/m2), compared to reference, had slightly increased TBBMD and TBBMC Z-scores (+0.40 ± 0.91 and +0.59 ± 0.96; both p < 0.001), and had markedly increased FM and FM/body weight ratio Z-scores of ±1.83 ± 1.63 (p < 0.0001) and +1.43 ± 1.05 (p < 0.0001). LBM Z-scores were slightly increased as well (+0.34 ± 1.08, p < 0.001). In contrast, markedly reduced LBM/body weight ratio Z-scores of −1.47 ± 0.90 (p < 0.0001) and disturbed relationship between FM and LBM as assessed by FM/LBM ratio Z-score of +1.53 ± 1.29 (p < 0.0001) were noted. The average serum levels of 25(OH)D of 17.8 ± 6.9 ng/mL and PTH of 34.8 ± 16.8 pg/mL were noted in PH group. 91% PH cases showed 25(OH)D levels lower than 30 ng/mL. 71% of PH subjects revealed vitamin D deficiency (25(OH)D < 20 ng/ml). 10% of PH cases showed 25(OH)D levels lower than 10 ng/mL. 25(OH)D levels negatively correlated with PTH showing r = −0.24 (p = 0.03). Absolute LBM/body weight ratio values positively correlated with 25(OH)D levels (r = 0.31; p = 0.01). In contrast, absolute FM/body weight ratio values correlated negatively with 25(OH)D levels (r = −0.32; p < 0.01). Moreover, 25(OH)D levels negatively correlated with absolute Trunk FM (r = −0.29; p < 0.05), Android %Fat (r = −0.32; p < 0.01) and with Gynoid %Fat (r = −0.28; p < 0.05). PTH and 25(OH)D concentrations did not differ when severity of hypertension, left ventricular mass and carotid intima-media thickness were controlled for. Concluding, higher muscle mass stores in body weight coincided with higher 25(OH)D levels. Higher fat mass stores coincided with lower 25(OH)D levels in PH group. Whether vitamin D insufficiency/deficiency in PH group should be considered as a cause of disease or epiphenomenon remains unknown.This article is part of a Special Issue entitled ‘16th Vitamin D Workshop’.

Long-term effects of a very-low-carbohydrate weight-loss diet and an isocaloric low-fat diet on bone health in obese adults

ObjectiveCompromised bone health is a frequently cited concern of very-low-carbohydrate (LC) diets, although limited data are available from long-term, well-controlled, randomized studies. This study compared the effects of an energy-restricted LC diet and traditional, higher-carbohydrate, low-fat (LF) diet on bone health after 12 mo. MethodsOne hundred eighteen abdominally obese adults were randomized to consume either an energy-restricted (∼6–7 MJ/d [∼1450–1650 kcal/d]), planned isocaloric LC, or LF diet for 12 mo. Body weight, total body bone mineral content and bone mineral density (BMD), and serum bone crosslaps were assessed pre- and postintervention. ResultsSixty-five participants completed the study (LC = 32, LF = 33; age: 51.3 ± 7.1 y; BMI: 33.4 ± 4.0 kg/m2). Weight loss was similar in both groups (LC: −14.5 ± 9.8 kg, LF: −11.7 ± 7.3 kg; P = 0.26). By 1 y, total body bone mineral content had not changed in either group (LC: 2.84 ± 0.47 to 2.88 ± 0.49 kg, LF: 3.00 ± 0.52 to 3.00 ± 0.51 kg; P = 0.07 time × diet effect). In both groups, total body BMD decreased (LC: 1.26 ± 0.10 to 1.22 ± 0.09 g/cm2, LF: 1.26 ± 0.09 to 1.23 ± 0.08 g/m2; P < 0.001 time) and bone serum crosslaps increased (LC: 319.3 ± 142.6 to 396.5 ± 172.0 ng/L, LF: 276.3 ± 100.6 to 365.9 ± 154.2 ng/L; P < 0.001 time) independent of diet composition (P ≥ 0.25 time × diet effect). Future studies would be strengthened by the assessment of regional BMD at clinically relevant sites (i.e., hip and spine) and multiple markers of bone turnover. ConclusionsWeight loss following a hypocaloric LC diet compared with an LF diet does not differentially affect markers of bone health over 12 mo in overweight and obese adults.

High fat diet enriched with saturated, but not monounsaturated fatty acids adversely affects femur, and both diets increase calcium absorption in older female mice

Diet induced obesity has been shown to reduce bone mineral density (BMD) and Ca absorption. However, previous experiments have not examined the effect of high fat diet (HFD) in the absence of obesity or addressed the type of dietary fatty acids. The primary objective of this study was to determine the effects of different types of high fat feeding, without obesity, on fractional calcium absorption (FCA) and bone health. It was hypothesized that dietary fat would increase FCA and reduce BMD. Mature 8-month-old female C57BL/6J mice were fed one of three diets: a HFD (45% fat) enriched either with monounsaturated fatty acids (MUFAs) or with saturated fatty acids (SFAs), and a normal fat diet (NFD; 10% fat). Food consumption was controlled to achieve a similar body weight gain in all groups. After 8wk, total body bone mineral content and BMD as well as femur total and cortical volumetric BMD were lower in SFA compared with NFD groups (P<.05). In contrast, femoral trabecular bone was not affected by the SFAs, whereas MUFAs increased trabecular volume fraction and thickness. The rise over time in FCA was greater in mice fed HFD than NFD and final FCA was higher with HFD (P<.05). Intestinal calbindin-D9k gene and hepatic cytochrome P450 2r1 protein levels were higher with the MUFA than the NFD diet (P<.05). In conclusion, HFDs elevated FCA overtime; however, an adverse effect of HFD on bone was only observed in the SFA group, while MUFAs show neutral or beneficial effects.

Associations between hypothalamic–pituitary–adrenal axis function and peak bone mass at 20 years of age in a birth cohort

In older adults, high-normal circulating cortisol levels are associated with lower bone mass, but relationships between hypothalamic–pituitary–adrenal axis function and peak bone mass in young adults have not been examined. We studied 411 male and 390 female participants in the Western Australia Pregnancy Cohort (Raine) Study. At 18years of age, participants underwent a Trier Social Stress Test (TSST) with measurement of plasma and salivary cortisol at baseline and at multiple time points after stress. Cortisol responses were classified as anticipatory responder (significant fall in cortisol during the test), reactive responder (significant increase) or non-responder. At 20years, total body bone mineral content (BMC) and density (BMD) were measured by DXA. In males, after adjustment for weight, height (for BMC and bone area only), alcohol and smoking, there was a significant inverse relationship between both plasma and salivary cortisol measured at baseline in the TSST and each of BMC and BMD, such that each additional 10% of salivary cortisol was associated with reductions of 6.9g (95% CI −11.7, −2.2) in BMC, and 1.8mg/cm2 (95% CI −3.3, −0.4) in BMD. Males classified as anticipatory responders in the TSST had 3.2% lower BMC (adjusted mean±SE: 3131±28 vs. 3233±18g, P=0.006) and 2.5% lower BMD (1108±9 vs. 1136±6mg/cm2, P=0.022) than reactive responders. In females, there were no significant relationships between baseline cortisol or TSST responses and BMC or BMD in covariate-adjusted analyses. We conclude that in young males (but not females), higher circulating cortisol at the baseline of the stress test and an anticipatory responder pattern on the TSST are associated with lower total body bone mass.

An optimal dietary non-phytate phosphorus level of broilers fed a conventional corn–soybean meal diet from 4 to 6 weeks of age

It is imperative to evaluate precise nutrient requirements of animals in order to optimize productivity and minimize feed cost and nutrient excretions. The current non-phytate phosphorus (NPP) recommendation for broilers is based on the papers published 30 years ago. However, today’s commercial birds are quite different from those before 30 years. Therefore, the present experiment was conducted with growing male broiler chickens to evaluate an optimal dietary NPP level of broiler chickens fed a conventional corn–soybean meal diet from 4 to 6 weeks of age. The 1-day-old chicks were fed corn–soybean meal diet containing 0.39% NPP from 1 to 3 weeks of age. At 22 days of age, 360 birds were selected and randomly allotted by BW to one of 10 dietary treatments with six replicate cages of six birds per cage for each treatment. Birds were fed the P-unsupplemented corn–soybean meal basal diet and the basal diet supplemented with inorganic P as CaHPO4·H2O ranging from 0.00% to 0.45% with 0.05% increment from 4 to 6 weeks of age. The dietary NPP levels were 0.09%, 0.14%, 0.20%, 0.24%, 0.30%, 0.34%, 0.38%, 0.45%, 0.49% and 0.54%, respectively, and the dietary Ca level was fixed at 0.90% for all treatments. The results showed that average daily gain, serum inorganic P concentration, tibia bone strength, tibia ash percentage and P percentage, tibia bone mineral content (BMC) and density (BMD), middle toe ash percentage and P percentage, middle toe BMC, total body BMC and BMD were affected (P<0.0001) by dietary NPP level, and increased linearly (P<0.0001) and quadratically (P<0.003) as dietary NPP levels increased. Optimal dietary NPP levels estimated based on fitted broken-line models (P<0.0001) of the above indices are 0.21%, 0.29%, 0.29%, 0.29%, 0.29%, 0.31%, 0.29%, 0.30%, 0.27%, 0.29% and 0.28%, respectively. It is suggested that the total body BMC and BMD, and middle toe ash P and BMC might be new, sensitive and non-invasive criteria to evaluate the dietary NPP requirements of broilers. The optimal dietary NPP level would be 0.31% for broiler chickens fed a conventional corn–soybean meal diet from 4 to 6 weeks of age.

Magnesium and Space Flight.

Magnesium is an essential nutrient for muscle, cardiovascular, and bone health on Earth, and during space flight. We sought to evaluate magnesium status in 43 astronauts (34 male, 9 female; 47 ± 5 years old, mean ± SD) before, during, and after 4–6-month space missions. We also studied individuals participating in a ground analog of space flight (head-down-tilt bed rest; n = 27 (17 male, 10 female), 35 ± 7 years old). We evaluated serum concentration and 24-h urinary excretion of magnesium, along with estimates of tissue magnesium status from sublingual cells. Serum magnesium increased late in flight, while urinary magnesium excretion was higher over the course of 180-day space missions. Urinary magnesium increased during flight but decreased significantly at landing. Neither serum nor urinary magnesium changed during bed rest. For flight and bed rest, significant correlations existed between the area under the curve of serum and urinary magnesium and the change in total body bone mineral content. Tissue magnesium concentration was unchanged after flight and bed rest. Increased excretion of magnesium is likely partially from bone and partially from diet, but importantly, it does not come at the expense of muscle tissue stores. While further study is needed to better understand the implications of these findings for longer space exploration missions, magnesium homeostasis and tissue status seem well maintained during 4–6-month space missions.

Football training in men with prostate cancer undergoing androgen deprivation therapy: activity profile and short-term skeletal and postural balance adaptations.

To investigate the activity profile of football training and its short-term effects on bone mass, bone turnover markers (BTMs) and postural balance in men with prostate cancer (PCa) undergoing androgen deprivation therapy (ADT). This was a randomised 12-week study in which men with PCa undergoing ADT were assigned to a football intervention group [FTG, n = 29, 67 ± 7 (±SD) years] training 2‒3 times per week for 45‒60 min or to a control group (n = 28, 66 ± 5 years). The activity profile was measured using a 5-Hz GPS. The outcomes were total body and leg bone mineral content (BMC) and density, BTMs and postural balance. In the last part of the 12 weeks, FTG performed 194 ± 41 accelerations and 296 ± 65 decelerations at >0.6 m/s/s and covered a distance of 905 ± 297 m at speeds >6 km/h and 2646 ± 705 m per training session. Analysis of baseline-to-12-week change scores showed between-group differences in favour of FTG in total body BMC [26.4 g, 95 % confidence interval (CI): 5.8-46.9 g, p = 0.013], leg BMC (13.8 g, 95 % CI: 7.0‒20.5 g, p < 0.001) and markers of bone formation: P1NP (36.6 µg/L, 95 % CI: 10.4‒62.8 µg/L, p = 0.008) and osteocalcin (8.6 µg/L, 95 % CI: 3.3‒13.8 µg/L, p < 0.01). The number of decelerations correlated to the increase in leg BMC (r = 0.65, p = 0.012). No between-group differences were observed for the remaining outcomes. Football training involves numerous runs, accelerations and decelerations, which may be linked to marked increases in bone formation markers and preserved bone mass in middle-aged and elderly men with PCa undergoing ADT. ClinicalTrials.gov: NCT01711892.

Lean mass predicts the size-dependent and size-adjusted BMD better than fat mass in premenopausal females: a cross-sectional analysis

Introduction: In the human body, the influence of lean and fat masses on the bone tissue is unclear. This study was conducted to examine the association of different body compartments in order to find out the major determinant of bone mass. We used both size-dependent and size adjusted bone mass measures in the analysis Methods: A group of 128 healthy premenopausal females, aged 25-50 years was selected randomly from the local community, stratified according to their BMI. Lean mass (LM), fat mass (FM), total body bone mineral density (TBBMD) and total body bone mineral content (TBBMC) were measured using a DXA scan. TBBMD was divided by the standing height to estimate height-adjusted total body BMD (TBBMD-ht). Furthermore, TBBMD was divided by the bone area and height to estimate bone mineral apparent density (BMAD). Results: Both FM and LM showed significant and positive correlations with TBBMC and corresponding r values were 0.33 and 0.73, respectively (P Conclusions: Among these premenopausal women LM predicted bone mass stronger than FM. Magnitude and directions of the correlations between bone mass and LM were different when BMC was adjusted for bone size and height of subjects. These results support the idea that lean mass has dual effects on bone tissue where it influences both linear measurements and mineral content to different extents. Journal of the Ceylon College of Physicians, 2014,45, 22-27

Osteoporotic risk and physeal closure in prepubertal ovariohysterectomized cats

We aimed to examine the early effects of prepubertal ovariohysterectomy (P-OHE) on bone loss and proximal physeal closure in cats. Fourteen kittens randomly underwent P-OHE or sham operations (S-OP) at three months (mo) of age and were allocated to group I and group II. Each mo between four and nine mo of age, dual-energy X-ray absorptiometry (DEXA) scans were performed to determine the total body bone mineral density (BMD) and bone mineral content (BMC). Proximal radial physeal closure and radial length were determined by radiography. Bone-specific alkaline phosphatase (BAP), carboxy-terminal collagen teleopeptide (CTX), 17-β estradiol, progesterone, calcium (Ca) and phosphorus (P) were measured in the serum samples. No significant differences were observed between the groups in terms of BMD, BMC, BAP, BAP/CTX, P, progesterone and body weight (BW) (between 4 and 9mo) and for Ca (between 5 and 9mo) and for CTX levels (between 4 and 8mo). The 17-β estradiol was significantly higher at 6, 8 and 9mo of age in the S-OP group due to puberty (P=0.02, P=0.03 and P=0.02 respectively). Although there was a significant difference (P=0.0002) between the P-OHE and S-OP groups in terms of the proximal radial physeal closure times (7.43±0.20mo and 6.14±0.14mo, respectively), no significant difference was observed for the mean radius length (10.59±0.10cm and 10.06±0.27cm, respectively) at the last evaluation time. In conclusion, prepubertal ovariohysterectomized cats do not have any osteoporotic risks until nine mo of age and exhibit a delayed physeal closure time without a change in radius length.

Effects of a Specialist-Led, School Physical Education Program on Bone Mass, Structure, and Strength in Primary School Children: A 4-Year Cluster Randomized Controlled Trial.

This 4-year cluster randomized controlled trial of 365 boys and 362 girls (mean age 8.1 ± 0.3 years) from grade 2 in 29 primary schools investigated the effects of a specialist-taught physical education (PE) program on bone strength and body composition. All children received 150 min/week of common practice (CP) PE from general classroom teachers but in 13 schools 100 min/week of CP PE was replaced by specialized-led PE (SPE) by teachers who emphasized more vigorous exercise/games combined with static and dynamic postural activities involving muscle strength. Outcome measures assessed in grades 2, 4, and 6 included: total body bone mineral content (BMC), lean mass (LM), and fat mass (FM) by DXA, and radius and tibia (4% and 66% sites) bone structure, volumetric density and strength, and muscle cross-sectional area (CSA) by pQCT. After 4-years, gains in total body BMC, FM, and muscle CSA were similar between the groups in both sexes, but girls in the SPE group experienced a greater gain in total body LM (mean 1.0 kg; 95% CI, 0.2 to 1.9 kg). Compared to CP, girls in the SPE group also had greater gains in cortical area (CoA) and cortical thickness (CoTh) at the mid-tibia (CoA, 5.0% [95% CI, 0.2% to 1.9%]; CoTh, 7.5% [95% CI, 2.4% to 12.6%]) and mid-radius (CoA, 9.3% [95% CI, 3.5% to 15.1%]; CoTh, 14.4% [95% CI, 6.1% to 22.7%]), whereas SPE boys had a 5.2% (95% CI, 0.4% to 10.0%) greater gain in mid-tibia CoTh. These benefits were due to reduced endocortical expansion. There were no significant benefits of SPE on total bone area, cortical density or bone strength at the mid-shaft sites, nor any appreciable effects at the distal skeletal sites. This study indicates that a specialist-led school-based PE program improves cortical bone structure, due to reduced endocortical expansion. This finding challenges the notion that periosteal apposition is the predominant response of bone to loading during the prepubertal and early-pubertal period.

Comparison of the Lunar Prodigy and iDXA Dual-Energy X-ray Absorptiometers for Assessing Total and Regional Body Composition

The objective of the study was to assess the agreement of the Lunar Prodigy with the newer Lunar iDXA dual-energy X-ray absorptiometer for determining total body and regional (arms, legs, trunk) bone mineral density (BMD), bone mineral content (BMC), fat mass (FM), lean tissue mass (LTM), total body mass, and percent fat. Ninety-two healthy adult males (n = 36) and females (n = 56) were scanned consecutively on the iDXA and the Prodigy dual-energy X-ray absorptiometers. For iDXA, relative to Prodigy, paired t tests indicated significantly lower estimates for total body and regional BMD and BMC (p < 0.001). Measures of total body and trunk FM, LTM, and percent fat did not differ between the instruments. In regional analyses, estimates of FM and percent fat were greater, and that of LTM was lower, in the arms (p < 0.001). In contrast, iDXA estimates of LTM were higher in the legs (p < 0.001). All body composition measures were significantly correlated (p < 0.001). Bland-Altman analyses indicated that significant bias existed between iDXA and Prodigy for total body and regional BMD estimates (p < 0.001) such that iDXA underestimated BMD to a greater extent in persons with higher values. In addition, iDXA overestimation bias existed for FM in total body, arms, and legs, and the overestimation was primarily observed in participants with greater body fat (p < 0.001). When combining or comparing data from iDXA with those from Prodigy, investigators should be aware that certain total body and regional estimates are significantly different. The greatest percent differences were observed for arm BMD, FM, and percent fat.

Body Size, Bone Mineral Density, and Body Composition in Obese Women After Laparoscopic Sleeve Gastrectomy: A 1-Year Longitudinal Study.

Changes in body weight, waist and hip circumferences, body composition, and skeletal status in women after bariatric surgery were evaluated. Thirty-six women [mean age 41.2 ± (SD) 9.5 years, weight 115.7±18.0 kg, and BMI 42.1±5.3 kg/m(2)] underwent laparoscopic sleeve gastrectomy. Bone mineral density (BMD) at lumbar spine, femoral neck, total hip, and total body, and body composition were evaluated at baseline and 3, 6, and 12 months after surgery.Weight, BMI, waist and hip circumferences decreased significantly. Total body bone mineral content (TBBMC) increased by 2.5±3.5%, and fat, lean body mass, total mass and fat-% decreased significantly by 38.9±12.0%, 15.4±5.9%, 26.5±8.1%, and 17.6±8.9%, respectively. Slight decreases in total body (0.6±2.2%) and spine (1.2±7.1%) BMD were not significant, whereas total hip and femoral neck BMD decreased significantly by 5.3±8.2%, and 6.2±7.0% (p<0.001). Change (Δ) in TBBMC correlated only with Δ in weight (r=0.38, p<0.05) whereas Δ in all other body composition parameters correlated significantly with Δ in body weight and circumferences (r=0.46-0.98). The Δ in BMD (except total body BMD) correlated significantly with Δ in body composition parameters (r=0.34-0.59). Baseline fat and lean content besides changes in body fat and lean mass accounted for bone changes. In conclusion, bone loss after bariatric surgery is related to post-operative changes in body composition, as well as to weight loss and decrease in waist and hip circumferences.

Spine Trabecular Bone Score (TBS) Cross-Calibration for GE Prodigy and iDXA Scanners

Total body fat, lean, and bone mineral content (BMC) in addition to regional fat and lean mass values for arms, legs, and trunk were compared across a pencil-beam (Lunar DPXL) and 2 fan-beam (GE Lunar Prodigy and GE Lunar iDXA) dual-energy X-ray absorptiometry (DXA) systems.Subjects were a multiethnic sample of 99 healthy adult males (47%) and females (mean ± SD: age, 46.3 ± 16.9 yr; weight, 73.4 ± 16.6 kg; height, 167.6 ± 9.7 cm; body mass index, 26.0 ± 5.2 kg/m2) who had whole-body scans performed within a 3-h period on the 3 systems. Repeated measures ANOVA was used to test the null hypothesis that the mean values for the 3 systems were equal. Translation equations between the methods were derived using regression techniques.Bone mineral content (BMC): For both genders, total BMC by iDXA was lower (p ≤ 0.004) than the other systems. Lean: for males, iDXA was lower (p ≤ 0.03) than the other systems for total, trunk, and arms. For females, DPXL estimated higher (p < 0.001) lean mass compared with the other systems for total, trunk, and arms, but iDXA estimated greater legs lean mass. For both genders, all DPXL mean values were greater than Prodigy mean values (p < 0.001).Fat: in females, all the 3 systems were different from each other for total, trunk, and legs (p ≤ 0.04). For arms, DPXL and iDXA were higher than Prodigy (p < 0.0004). For males, DPXL was less (p < 0.001) for total body, trunk, and legs compared with the other 2 systems and greater than Prodigy only for arms (p < 0.0007). These data were used to derive translation equations between systems. For several measurements, the differences between systems were related to gender.For estimation of BMC and body composition, there was high agreement between all DXA systems (R2 = 0.85–0.99). Even so, cross-calibration equations should be used to examine data across systems to avoid erroneous conclusions.

The associations of exposure to combined hormonal contraceptive use on bone mineral content and areal bone mineral density accrual from adolescence to young adulthood: A longitudinal study

BackgroundThe association of long term combined hormone based contraceptives (CHC) use on bone mineral content (BMC) and areal bone mineral density (aBMD) development remains controversial, as it appears that the relationship may be age-dependent. The purpose of this study was to investigate the long-term associations of CHC exposure on the accrual of bone parameters from adolescence into young-adulthood. Methods110 women (67 exposed to CHC) were drawn from the Pediatric Bone Mineral Accrual Study (PBMAS). Serial measures of total body (TB), lumbar spine (LS) and femoral neck (FN) BMC and aBMD were assessed by DXA (a total of 950 scans) and aligned by biological age (BA, years from peak height velocity [PHV]). Multilevel random effects models were constructed to assess the time dependent associations between annual CHC exposure and the development of bone parameters. ResultsAfter BA, height, lean tissue mass, fat mass, calcium and vitamin D intake, and physical activity were controlled, it was observed that those individuals exposed to CHC 6-years post PHV developed significantly less (−0.00986±0.00422g/cm2) TB aBMD than their non CHC exposed peers. Additionally, there were significant BA by CHC exposure interactions, where CHC exposure 6-years or more post PHV resulted in developing less TB BMC (−4.94±2.41g), LS BMC (−0.29±0.11g) and LS aBMD (−0.00307±0.00109g/cm2). One year after the attainment of PHV, CHC users were predicted to have 1.2% more TB BMC, 3.8% more LS BMC and 1.7% more LS aBMD than non-users. At 9-years post PHV the predicted differences showed that CHC users had 0.9% less TB BMC and 2.7% less LS BMC and 1.6% less LS BMD than those not exposed to CHC. ConclusionsCHC may not hinder the development of BMC or aBMD during adolescence; however, exposure 6-years or more after PHV may be detrimental.

Associations between Bone Mineral Characteristics and Serum Levels of Ghrelin and Peptide YY in Overweight Adolescent Boys

Background/Aims: The role of ghrelin and peptide YY (PYY) in bone mineralization is not fully known. The aim of this study was to determine whether acylated and des-acyl ghrelin and PYY in addition to leptin are related to bone mineral density (BMD) in adolescent overweight boys (OWB) and normal-weight boys (NWB). Participants and Methods: Fifty- five OWB (BMI >85th percentile) and 154 NWB (BMI <85th percentile) aged 12-16 years participated in this study. Fasting serum acylated and des-acyl ghrelin, PYY, leptin, testosterone levels, total body (TB) and lumbar spine (LS) bone mineral content (BMC), and BMD were measured. TB BMC for height and TB and LS bone mineral apparent density (BMAD) were calculated. Results: No differences were seen in acylated and des-acyl ghrelin or PYY levels, while the leptin levels were significantly higher in the OWB compared to the NWB. In the OWB, TB BMAD was positively correlated with acylated ghrelin and leptin, and TB BMC for height was positively correlated with PYY. In the OWB, the variability of TB BMD was determined by TB fat-free mass and des-acyl ghrelin, whereas the variability of TB BMAD was determined by leptin. Conclusions: Des-acyl ghrelin and PYY are involved in the bone mineralization process in puberty, and the impact can vary between normal and overweight subjects.

Effects Of 6-month Soccer And Traditional Physical Activity Programs On Body Composition, Cardiometabolic, Inflammatory And Oxidative Markers In Obese Boys

BACKGROUND: Physical activity (PA) is important in obesity prevention; however, the effectiveness of different PA modalities remains to be determined among children. PURPOSE: To compare the effects of a 6-month soccer program and a traditional PA program on changes in body composition, cardiometabolic risk factors (CMRF), inflammatory and oxidative stress markers, cardiorespiratory fitness (CRF) and perceived psychological status of obese children. METHODS: Eighty eight boys (8-12 yrs; BMI >2 standard deviations of WHO reference values) participated in one of three groups: soccer (SG), traditional activity (AG) and control (CG). SG and AG programs involved 3 sessions per week for 60-90 min at an average intensity of 70-80% of maximal heart rate (HRmax). CG participated in activities of normal daily living. All boys participated in school physical education, two sessions per week 45-90-min. Measurements were taken at baseline and after 6 months, and included body size and composition (total body bone mineral content and density, percentage body fat, lean mass using DXA), CMRF (blood pressure, fasting blood glucose, high-density lipoprotein-cholesterol, total cholesterol, triglycerides, fasting insulin), inflammatory and oxidative stress markers (adiponectin, leptin, resistin, C-reactive protein), CRF and perceived psychological status (self-esteem, body image, attraction to PA, quality of life). PA and dietary intake were assessed before and immediately following the intervention. RESULTS: The three groups had similar characteristics at baseline. After 6 months both intervention groups had significantly lower fat percentage (SG:-6.9% vs CG:8.3%, p=0.03; AG:-12.0% vs CG:8.3%, p=0.006), waist circumference (SG:-5.3% vs CG:-0.2%, p=0.002; AG:-5.0% vs CG:-0.2%, p=0.006) and total cholesterol (SG:-7.5% vs CG:3.9%, p=0.036), and higher self-esteem esteem (SG:8.2% vs CG:-12.0%, p=0.001; AG:9.7% vs CG:-10.8%, p=0.007), perceived physical competence (SG:7.9% vs CG:-4.9%, p=0.010; AG:7.4% vs CG:-4.9%, p=0.025) and attraction to PA (SG:8.2% vs CG:-1.0%, p=0.014; AG:6.4% vs CG:-1.0%, p=0.049) compared with CG. CONCLUSIONS: PA interventions over 6 months positively influenced several indicators of health status among obese boys. The results also suggested that soccer has the potential as an effective tool for the prevention and reduction of childhood obesity and associated consequences.

Fat and Lean Mass Predict Total Body Bone Mineral Content during Energy Restriction with Exercise

Fat and Lean Mass Predict Total Body Bone Mineral Content during Energy Restriction with Exercise

Obesity-related changes in bone structural and material properties in hyperphagic OLETF rats and protection by voluntary wheel running

PurposeTo examine how the development of obesity and the associated insulin resistance affect bone structural and material properties, and bone formation and resorption markers in the Otsuka Long-Evans Tokushima Fatty (OLETF) rat model. MethodsThis was a 36-week study of sedentary, hyperphagic, male OLETF rats (OLETF-SED), exercise-treated OLETF rats (OLETF-EX) and sedentary non-hyperphagic controls (LETO-SED) with data collection at 13, 20, and 40weeks of age (n=5–8 animals per group per timepoint). ResultsBody mass and fat (%) were significantly greater in OLETF-SED versus controls. OLETF-SED were insulin resistant at 13 and 20weeks, with overt diabetes by 40weeks. At 13weeks, OLETF-SED had lower total body BMC and BMD and serum P1NP compared with LETO-SED. Differences in total body BMC and BMD between OLETF-SED and LETO-SED persisted at 20weeks, with reductions in total and cortical BMD of the tibia. OLETF-SED also had lesser femur diameter, cross-sectional area, polar moment of area, and torque at fracture than LETO-SED. By 40weeks, OLETF-SED had elevated bone resorption and reduced intrinsic bone strength. OLETF-EX did not show the excessive weight gain, obesity, insulin resistance or diabetes observed in OLETF-SED. OLETF-EX had greater BMD than OLETF-SED, and structural and material properties of the femur were significantly increased in OLETF-EX relative to OLETF-SED and LETO-SED. ConclusionsThe negative skeletal effects of excessive adiposity and insulin resistance were evident early in the progressive obesity with lasting negative impacts on intrinsic and extrinsic bone strength. Exercise protected against obesity-associated skeletal changes with marked benefits on the biomechanical properties of bone.