BMC) And Density Research Articles

Dietary non-phytate phosphorus requirement of broilers fed a conventional corn-soybean meal diet from 1 to 21 d of age

An experiment was conducted to investigate the effect of dietary non-phytate phosphorus (NPP) level on growth performance, bone characteristics and phosphorus metabolism-related gene expressions, so as to evaluate the dietary NPP requirement of broiler chicks fed a conventional corn-soybean meal diet from 1 to 21 d of age. A total of 540 day-old Arbor Acres male chicks were randomly allocated to one of nine treatments with six replicate cages of 10 birds per cage in a completely randomized design, and fed a basal corn-soybean meal diet (containing 0.08% of NPP) supplemented with 0.10, 0.15, 0.25, 0.30, 0.35, 0.40, 0.45, or 0.50% of inorganic phosphorus in the form of CaHPO4·2H2 O, respectively. Each diet contained the constant calcium content of about 1.0%. The results showed that daily weight gain, serum inorganic P, tibia bone strength, tibia ash percentage, tibia bone mineral content (BMC) and density (BMD), middle toe ash percentage, middle toe BMC and BMD were affected (P < 0.0001) by dietary NPP level, and increased linearly (P < 0.0001) and quadraticly (P < 0.004) as dietary NPP levels increased. The gene expression of type IIb sodium-phosphate cotransporter (NaPi-IIb) in the duodenum was affected (P < 0.03) and decreased linearly (P < 0.002) as dietary NPP levels increased. Dietary NPP requirements estimated based on fitted broken-line models (P < 0.0001) of the sensitive indices including daily weight gain, tibia bone strength, tibia ash percentage, tibia BMC and BMD as well as middle toe ash percentage were 0.34∼0.39%. The results from this study indicate that tibia BMC and BMD might be new, sensitive, and noninvasive criteria to evaluate the dietary NPP requirements of broilers, and the dietary NPP requirement is 0.39% for broiler chicks fed a conventional corn-soybean meal diet from 1 to 21 d of age.

Cell non-autonomous regulation of hepatic IGF-1 and neonatal growth by Kinase Suppressor of Ras 2 (KSR2).

Individuals with poor postnatal growth are at risk for cardiovascular and metabolic problems as adults. Here we show that disruption of the molecular scaffold Kinase Suppressor of Ras 2 (KSR2) causes selective inhibition of hepatic GH signaling in neonatal mice with impaired expression of IGF-1 and IGFBP3. ksr2−/− mice are normal size at birth but show a marked increase in FGF21 accompanied by reduced body mass, shortened body length, and reduced bone mineral density (BMD) and content (BMC) first evident during postnatal development. However, disrupting FGF21 in ksr2−/− mice does not normalize mass, length, or bone density and content in fgf21−/−ksr2−/− mice. Body length, BMC and BMD, but not body mass, are rescued by infection of two-day-old ksr2−/− mice with a recombinant adenovirus encoding human IGF-1. Relative to wild-type mice, GH injections reveal a significant reduction in JAK2 and STAT5 phosphorylation in liver, but not in skeletal muscle, of ksr2−/− mice. However, primary hepatocytes isolated from ksr2−/− mice show no reduction in GH-stimulated STAT5 phosphorylation. These data indicate that KSR2 functions in a cell non-autonomous fashion to regulate GH-stimulated IGF-1 expression in the liver of neonatal mice, which plays a key role in the development of body length.

Maternal Physical Activity During Pregnancy

PURPOSE: Maternal physical activity during pregnancy influences infant’s birth weight and body composition, but its association with bone health has been poorly evaluated. This study aims at documenting in a longitudinal study the effect of objectively measured physical activity during pregnancy on infant’s bone mineral content (BMC) and density (BMD). METHODS: 7-day accelerometry recordings (Actigraph GT3X+) were performed in low-risk pregnant women at 17 and 36 weeks of gestation. BMC and BMD were evaluated by DXA in mothers and infants within 2 weeks after birth. Sociodemographics, maternal lifestyle habits, pre-pregnancy physical activity, medical history and pregnancy outcomes were collected through interview and charts’ review. Mean counts per minute (CPM) and daily time spent at moderate and vigorous physical activity (MVPA) were calculated for each period from accelerometry data. The association between physical activity data and infant’s BMC and BMD was evaluated through multiple regression models, adjusting for infant sex and length, parity, maternal pre-pregnancy BMI, gestational weight gain, multivitamin use, gestational age at delivery, infant’s age at DXA, maternal BMD and pre-pregnancy physical activity. RESULTS: : For this preliminary analysis, DXA assessment and accelerometry data for at least one visit were available for 108 pregnant women (age=29.7 ± 3.7 y; pre-pregnancy BMI=23.6 ± 4.7 kg/m2; 59.3% nulliparous) and their baby (birth weight=3451 ± 424 g; gestational age=39.7 ± 1.2 weeks; 45.4% boys). Daily time spent at MVPA at 17 weeks was negatively associated with infant’s BMC and BMD (β= -0.45 g and -0.0009 g/cm3 per 10 min of MVPA, p=0.033 and 0.026), after adjustment for confounders. Similarly, mean CPM at 17 weeks was significantly associated with infant’s BMC and BMD (β= -1.92 g and -0.004 g/cm3 per 100 CPM, p=0.010 and p=0.004). Mean CPM at 36 weeks was also associated with child’s BMC (β= -0.004 g/cm3 per 100 CPM, p=0.024). CONCLUSIONS: Higher levels of maternal physical activity measured by accelerometry during pregnancy were associated with a decrease in infant’s BMC and BMD. The impact of maternal nutrition on this association remains to be investigated. Supported by the Fondation des Étoiles, Canadian Institutes of Health Research and Fonds de Recherche du Québec-Santé.

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.

Maternal Dietary Supplementation with Oligofructose-Enriched Inulin in Gestating/Lactating Rats Preserves Maternal Bone and Improves Bone Microarchitecture in Their Offspring.

Nutrition during pregnancy and lactation could exert a key role not only on maternal bone, but also could influence the skeletal development of the offspring. This study was performed in rats to assess the relationship between maternal dietary intake of prebiotic oligofructose-enriched inulin and its role in bone turnover during gestation and lactation, as well as its effect on offspring peak bone mass/architecture during early adulthood. Rat dams were fed either with standard rodent diet (CC group), calcium-fortified diet (Ca group), or prebiotic oligofructose-enriched inulin supplemented diet (Pre group), during the second half of gestation and lactation. Bone mineral density (BMD) and content (BMC), as well as micro-structure of dams and offspring at different stages were analysed. Dams in the Pre group had significantly higher trabecular thickness (Tb.Th), trabecular bone volume fraction (BV/TV) and smaller specific bone surface (BS/BV) of the tibia in comparison with CC dams. The Pre group offspring during early adulthood had an increase of the lumbar vertebra BMD when compared with offspring of CC and Ca groups. The Pre group offspring also showed significant increase versus CC in cancellous and cortical structural parameters of the lumbar vertebra 4 such as Tb.Th, cortical BMD and decreased BS/BV. The results indicate that oligofructose-enriched inulin supplementation can be considered as a plausible nutritional option for protecting against maternal bone loss during gestation and lactation preventing bone fragility and for optimizing peak bone mass and architecture of the offspring in order to increase bone strength.

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.

WHOLE BODY AND REGIONAL BONE MINERAL CONTENT AND DENSITY IN WOMEN AGED 20-75 YEARS.

Dual-energy X-ray absorptiometry (DXA) allows measurement of whole body (WB) and regional bone mineral content (BMC) and density (BMD). To measure WB and regional bone area, BMC and BMD (arms, legs, ribs and pelvis) in women of different ages. 140 women participated (age range 20-75 yrs). Three subgroups were built: 20-44 yr (30 premenopausal women), 45-59 (80 women), and 60-75 (30 women). WB DXA was performed on a Hologic QDR 4500 A bone densitometer (Hologic Inc., Bedford MA). WB BMD T-scores were calculated by using the manufacturer-provided and the NHANES 1999-2004 reference databases, while the WB BMC Z-scores - based on the latter. Statistical analysis was performed on an IBM SPSS Statistics 19.0 for Windows platform (Chicago, IL). WB BMC and BMD Z-scores were consistently lower than the reference databases showing a difference of about 0.4 - 0.5 SD. The arms, legs and ribs lost more BMC after the age of 50-55, while the pelvis - much earlier. The total decreases in BMC were highest in the pelvis (26.36 %), followed by the arms (16.81 %) and whole body (15.91 %), while the bone area decreased mostly in the pelvis (13.23 %). The age-related declines in regional BMC, bone areas and BMD follow different patterns in appendicular and axial bones.

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.

ANDROGEN RECEPTOR CAG AND GGN REPEAT POLYMORPHISMS AND BONE MASS IN BOYS AND GIRLS.

the human androgen receptor (AR) gene possesses two trinucleotide polymorphic repeats, (CAG and GGN) that affect the amount of AR protein translated. In this study, we genotyped these polymorphic tracts in a representative sample of Caucasian children (Tanner ≤ 5), 152 boys (11.5 } 2.6 yrs) and 116 girls (10.1 } 3.2 yrs) from Spain and investigated their association with bone mass. the length of CAG and GGN repeats was determined by PCR and fragment analysis. Body composition was assessed by dual energy x-ray absorptiometry (DXA). Individuals were grouped as CAG short (CAGS) if harboring repeat lengths of ≤ 21 and CAG long (CAGL) if CAG > 21. Moreover, subjects were grouped as GGN short (GGNS) if harboring repeat lengths of ≤ 23 and GGN long (GGNL) if GGN > 23. in boys, significant differences in height, body mass, whole body bone mineral density (BMD) and content (BMC), upper extremities BMC, lower extremities BMC, femoral neck BMD, Ward's triangle BMC and BMD and lumbar spine BMD were observed between CAGS and CAGL groups (P < 0.05). Thus, upper extremities BMD differed between GGNS and GGNL groups. After adjusting for confounding variables, only upper extremities BMD between GGNS and GGNL groups remained significant (P < 0.05). No differences were observed in girls in any measured site in relation to either CAG or GGN polymorphisms length. our results support the hypothesis that longer alleles of the AR CAG and GGN polymorphisms are associated with increased bone mass in prepubertal boys.

Multilevel Approach of a 1-Year Program of Dietary and Exercise Interventions on Bone Mineral Content and Density in Metabolic Syndrome – the RESOLVE Randomized Controlled Trial

BackgroundWeight loss is a public health concern in obesity-related diseases such as metabolic syndrome (MetS). However, restrictive diets might induce bone loss. The nature of exercise and whether exercise with weight loss programs can protect against potential bone mass deficits remains unclear. Moreover, compliance is essential in intervention programs. Thus, we aimed to investigate the effects that modality and exercise compliance have on bone mineral content (BMC) and density (BMD).MethodsWe investigated 90 individuals with MetS who were recruited for the 1-year RESOLVE trial. Community-dwelling seniors with MetS were randomly assigned into three different modalities of exercise (intensive resistance, intensive endurance, moderate mixed) combined with a restrictive diet. They were compared to 44 healthy controls who did not undergo the intervention.ResultsThis intensive lifestyle intervention (15–20 hours of training/week + restrictive diet) resulted in weight loss, body composition changes and health improvements. Baseline BMC and BMD for total body, lumbar spine and femoral neck did not differ between MetS groups and between MetS and controls. Despite changes over time, BMC or BMD did not differ between the three modalities of exercise and when compared with the controls. However, independent of exercise modality, compliant participants increased their BMC and BMD compared with their less compliant peers. Decreases in total body lean mass and negative energy balance significantly and independently contributed to decreases in lumbar spine BMC.ConclusionAfter the one year intervention, differences relating to exercise modalities were not evident. However, compliance with an intensive exercise program resulted in a significantly higher bone mass during energy restriction than non-compliance. Exercise is therefore beneficial to bone in the context of a weight loss program.Trial RegistrationClinicalTrials.gov NCT00917917

Effect of whole-body vibration training on bone mass in adolescents with and without Down syndrome: a randomized controlled trial.

Whole-body vibration training (WBV) attracts great interest as osteoporosis prevention strategy. Twenty-six adolescents with and without Down syndrome (DS) (13 DS; 12-18 years) performed 20 weeks of WBV. The results indicate that WBV seems to provoke a lesser response in adolescents with DS than in those without DS. This study aims to observe the differences between adolescents with and without DS in the effects of 20 weeks of WBV training, on bone mineral content (BMC) and density (BMD). Twenty-six adolescents (13 DS; 12-18 years) were measured with dual-energy X-ray absorptiometry before and after the intervention (3/week, 10 repetitions (30-60 s) and 1-min rest, frequency 25-30 Hz and peak-to-peak displacement of 2 mm (peak acceleration 2.5-3.6 g)). Both, an intention-to-treat (ITT) analysis designed to assess the effects on bone mass and a per-protocol analysis, designed to compare poor and high compliers, were performed. The ITT analysis revealed significant increases in all BMC and BMD parameters (dz = 0.66 to 1.64; all p < 0.05) in the non-DS group, whilst DS group improved whole-body, subtotal (whole-body less head), upper limbs (ULIMBS), pelvis, lower limbs (LLIMBS) and spine BMC (dz = 0.75 to 1.76; all p < 0.05) and subtotal, pelvis, LLIMBS and spine BMD (dz = 0.73 to 1.28; all p < 0.05). Significantly greater increases were evident in the absolute and percent changes of the non-DS group over DS group (d = 0.88 to 3.85; all p < 0.05). ULIMBS BMD showed a tendency towards an interaction (f = 0.41 and p = 0.086) with higher increase for non-DS group. When a per-protocol analysis was considered, high-complier adolescents had 8.1 versus 5.3 % of gains in the spine BMC over poor-complier adolescents (d = 0.93; p < 0.05). Twenty weeks of WBV training may improve BMC and BMD in clinically relevant skeletal sites in both groups. Nevertheless, this type of training seems to provoke a lesser response in adolescents with DS than in those without DS.

Dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and micro-computed tomography techniques are discordant for bone density and geometry measurements in the guinea pig.

This study aims to examine agreement among bone mineral content (BMC) and density (BMD) estimates obtained using dual-energy X-ray absorptiometry (DXA), peripheral quantitative computed tomography (pQCT), and micro-computed tomography (μCT) against high-resolution μCT and bone ash of the guinea pig femur. Middle-aged (n=40, 86weeks) male guinea pigs underwent in vivo followed by ex vivo DXA (Hologic QDR 4500A) scanning for intact and excised femur BMC and areal density. To assess bone architecture and strength, excised femurs were scanned on pQCT (Stratec XCT 2000L) as well as on two μCT scanners (LaTheta LCT-200; Skyscan 1174), followed by three-point bending test. Reproducibility was determined using triplicate scans; and agreement assessed using Bland-Altman plots with reference methods being high-resolution μCT (Skyscan) for BMD and bone ashing for BMC. All techniques showed satisfactory ex vivo precision (CV 0.05-4.3%). However, bias compared to the reference method was highest (207.5%) in trabecular bone volume fraction (BV/TV) measured by LaTheta, and unacceptable in most total femur and cortical bone measurements. Volumetric BMD (vBMD) and BV/TV derived by LaTheta and pQCT at the distal metaphysis were biased from the Skyscan by an average of 49.3 and 207.5%, respectively. Variability of vBMD, BV/TV and cross-sectional area at the diaphysis ranged from -5.5 to 30.8%. LaTheta best quantified total femur BMC with an upper bias of 3.3%. The observed differences among imaging techniques can be attributable to inherent dissimilarity in construction design, calibration, segmentation and scanning resolution used. These bone imaging tools are precise but are not comparable, at least when assessing guinea pig bones.

Dual-Energy X - Rayabsorptiometry (Dxa) Assessment of Body Composition and Body Fat Distribution in Cushing’s Women

AbstractIntroduction. Body composition and body fat distribution show difference in women with Cushing's syndrome (CS) compared to healthy control women (C) with almost equal body mass index (BMI) (28.89±3.53kg/m2vs. 29.39±4.04kg/m2) and they were compared with DXA.Methods. Total and regional fat mass (FM), FM%, tissue mass (TM), TM%, android FM (A), gynoid FM (G), lean body mass (LBM), bone mineral density (BMD) and content (BMC) were determined as well as their relationships in 10 CS and 10 C women.Results. Regional FM, FM%, TM and TM% values were not different between CS and C except for arm TM % (45.06±3.1% vs. 40.23±6.29%) (p&lt;0.043). Arms+legs/trunk TM and FM ratio were significantly lower in CS compared to C (p&lt;0.0001). Arms/A (1.1±0.12), legs/A (3±0.41) and legs/trunk TM ratios (0.52±0.07) were significantly lower in CS compared to C (1.3±0.13) (p&lt;0.002), (4.29 ±0.67) (p&lt;0.0001) and (0.69±0.09) (p&lt;0.0001). Legs/A (2.57±0.73), legs/trunk (0.48±0.13) and arms+legs/trunk FM ratio (0.66±0.14) in CS were significantly lower compared to C [(4.2±1.16; 0.71±0.12 (p&lt;0.001) and 0.89±0.14 (p&lt;0.002)]. A/GTM (0.67±0.1) and A/G FM ratio (0.72± 0.2) in CS were significantly higher compared to C (0.48±0.05) (p&lt;0.0001) and (0.46±0.09) (p&lt;0.001). Legs LBM in CS 10.8±1.95kg was lower compared to C 12.7±2.1 kg (p&lt;0.046). Only spine BMD value in CS (0.89±0.09 kg/cm2) was lower compared to C (0.94±0.12 kg/cm2) (p&lt;0.017).Conclusion. Central to peripheral regional TM, FM and LBM ratios differentiated significantly and precisely patients with CS and C and confirmed extreme central obesity in CS.

Does Exercise Have an Additional Effect To Strontium Ranelate On Bone Status?

Physical exercise is known to exert beneficial effects on bone status. Strontium Ranelate (SR) has been shown to have anti-osteoporotic properties. PURPOSE: We conducted a study testing impact activity, using strontium ranelate alone, or impact activity (E) + strontium ranelate in female rats either ovariectomized (OVX) or not (SHAM). METHOD: 96 female Wistar rats, 5 weeks old at baseline were used. Animals in the E groups were subjected to 10 impacts per day from 45 cm, 5 days a week over 8 weeks. Strontium ranelate group animals received 625 mg/kg of SR per gavage in 0.5 % carboxymethylcellulose (vehicle) daily for 8 weeks. Sham (SHAM) group animals were used as a control. Bone mineral density (BMD) and content (BMC) (whole body and left femur) were measured by DXA at weeks 0, 4 and 8. Morphological properties of trabecular and cortical bone from femur, tibia and L2 to L4 vertebrae were analyzed by μCT (Skyscan, 1072). Osteocyte apoptosis was studied by cleaved caspase-3 immunostaining and expressed as a percentage of total cells. RESULTS: μCT (Skyscan) analysis showed a deleterious effect of OVX, and a beneficial effect of Strontium Ranelate and of impact activity on Bone Volume (BV)/TV, Trabecular Number (Tb.N), Trabecular Thickness (Tb.Th), Trabecular Separation (Tb.Sp) and SMI. Strontium Ranelate and impact activity demonstrated a significant additive effect for these parameters. This was confirmed at all sites (femur, tibia and L2-L4 vertebrae). Cortical thickness was increased in Strontium ranelate groups; cortical porosity (Ct.Po) and Pore Number (Po.N) were improved at femur and tibia in the strontium ranelate groups, and significantly more in the impact activity + strontium ranelate groups. OVX groups had a significant excess of osteocyte apoptosis versus SHAM. Impact activity did not significantly reduce osteocyte apoptosis in SHAM and OVX groups while strontium ranelate significantly reduced osteocyte apoptosis in all groups. There was no significantly cumulative effect of impact activity when combined with strontium ranelate on this parameter. CONCLUSION: This data constitutes the first description of an additive effect of strontium ranelate + impact activity on bone status, and of a beneficial effect of Strontium ranelate on osteocyte apoptosis.

Influences of physical fitness on bone mass in women with fibromyalgia.

The aim of this study was to provide information about the relationship of bone mineral content (BMC) and density (BMD) with some physical-fitness-related variables in a sample of women with fibromyalgia (FM) and age-matched women without FM. Twenty-eight women clinically diagnosed with FM (age 51.1 ± 8.4 yr, M ± SD) and 22 age-matched controls participated in the study. Whole-body BMC and BMD, lean mass, handgrip strength, quadriceps strength, and cardiovascular fitness were measured in all participants. The association between physical-fitness variables and bone-related variables was tested by linear regression controlling for body weight as a possible confounder. There were no differences in BMC or BMD between groups. Women with FM had lower values of handgrip strength, quadriceps strength, and VO2peak than the control group. Handgrip strength and aerobic capacity were associated with BMC and BMD and quadriceps strength was associated with BMD in women with FM; however, only VO2peak was associated with BMC in the group of women without FM. Bone mass of women with FM may be more susceptible to changes in physical fitness than that of the women without fibromyalgia.

The effects of swimming training on bone tissue in adolescence.

The aim was to analyze bone mineral content (BMC) and density (BMD) in regular swimming trained adolescents and the interaction that weigh-bearing sports may have on these values. Bone mass was evaluated by dual energy x-ray absorptiometry (DXA) and quantitative ultrasound (QUS) in 77 swimmers (34 females/43 males) and 52 normoactive controls (CG; 23 females/29 males) from 11 to 18 years. Swimmers who had performed or were performing other sports (OSP; 11 females/20 males) were compared with pure swimmers (PSW; 23 females/23 males). Both groups were compared with CG. Bone values were compared using analyses of covariance adjusting for height, calcium intake, subtotal lean (whole body lean minus head), and pubertal status. Male PSW showed lower BMD and BMC at several sites than male CG. However, for male OSP, only lumbar spine BMC was lower in OSP than male CG. Male PSW showed lower BMD and BMC when compared with male OSP. Female PSW showed higher arm BMD and lower leg BMC than female CG, while female OSP only presented lower leg BMC than female CG. Contrary to males, female-PSW presented higher BMD and BMC than female OSP. No differences in QUS values were found between swimmers and CG. To summarize, although more information is needed for females, it seems that for males, swimming is associated with lower BMC and BMD.

Fetal and neonatal exposure to the endocrine disruptor, methoxychlor, reduces lean body mass and bone mineral density and increases cortical porosity.

Endogenous estrogen has beneficial effects on mature bone and negatively affects the developing skeleton, whereas the effect of environmental estrogens is not known. Methoxychlor (MXC) is a synthetic estrogen known as a persistent organochlorine and used as a pesticide. Methoxychlor and its metabolites display estrogenic, anti-estrogenic and anti-androgenic activity and may therefore influence bone. Fifty-eight male fetal and neonatal rats were exposed to either: a negative control (DMSO), 0.020, 100 mg/kg MXC, or 1 mg/kg β-estradiol-3-benzoate (EB; positive control). Rats were treated daily for 11 days, from embryonic day 19 to postnatal day (PND) 7 or for 4 days during the postnatal period (PND 0-7). All rats were analyzed at PND-84. Total body, femur, spine, and tibia areal bone mineral density (BMD) and content (BMC), lean body mass (LBM) and fat were measured by dual energy X-ray absorptiometry. Bone geometry and volumetric (v) BMD were measured using micro-computed tomography and biomechanical properties using three-point bending were assessed. Rats exposed to EB or MXC (at either the high and/or low dose), independent of exposure interval showed lower body weight, LBM, tibia and femur BMD and length, and total body BMD and BMC than DMSO control group (p ≤ 0.05). Methoxychlor and EB exposure increased cortical porosity compared to DMSO controls. Trabecular vBMD, number and separation, and cortical polar moment of inertia and cross-sectional area were lower due to EB exposure compared to control (p < 0.05). Early MXC exposure compromises cortical porosity and bone size at maturity, and could ultimately increase the risk of fracture with aging.

Long-term vitamin D3 supplementation does not prevent colonic inflammation or modulate bone health in IL-10 knockout mice at young adulthood.

Inflammatory bowel disease (IBD) is an idiopathic disease that can impair bone metabolism. Low vitamin D status has been implicated in its progress. This study used interleukin (IL)-10 knockout (KO) mice, that develop an intestinal inflammation when housed in a non-sterile environment, to determine if supplementation with vitamin D3 throughout life could mitigate inflammation and attenuate the lower bone mineral content (BMC) and density (BMD), and bone strength. Female IL-10 KO mice were randomized 25 or 5000 IU vitamin D3/kg diet throughout pregnancy and lactation. At weaning, offspring received the same or opposite diet as their mother until age three months. Body weight growth was similar among groups within a sex. At three months of age, there were no differences in inflammation and gene expression in the colon of offspring. Male offspring exposed to continuous 25 IU vitamin D3/kg diet had lower (p < 0.001) colonic VDR expression and those exposed only to low vitamin D3 until weaning had higher serum IL-6. There were no differences in femur or vertebral BMC, BMD or bone strength. In summary, long-term exposure to vitamin D3 did not attenuate intestinal inflammation or preserve bone mineral or bone strength. Thus, supplementation with vitamin D3 does not exert anti-inflammatory effects in this mouse model that mimics human inflammatory bowel disease.

Visceral fat and body composition changes in a female population after RYGBP: a two-year follow-up by DXA.

Our aim was to monitor the impact of Roux-en-Y gastric bypass (RYGBP) on body composition over a 24-month period by dual-energy X-ray absorptiometry (DXA). Forty-one women (40.6 ± 10.0 years old; 42.6 ± 6.6 kg/m(2)) entering a bariatric surgery programme were submitted to whole-body DXA (Lunar iDXA) before treatment and after 3, 6, 12 and 24 months. Fat mass (FM), non-bone lean mass (LM), bone mineral content (BMC) and density (BMD) were measured at whole body and regionally. Android visceral adipose tissue (VAT) was estimated by a recently validated software. Twenty-nine patients (44.3 ± 11.8 years old; BMI, 45.4 ± 8.9 kg/m(2)) concluded the study. Following surgery, the progressive decrease of BMI was associated with reduced whole-body and regional FM. LM showed a moderate decrease at 3 months and stabilized thereafter. A progressive decrease of total FM/LM and android FM/LM ratios were observed in the 3- to 6-month (-19.1 ± 8.4 % and -26.5 ± 10.9 %, respectively; p < 0.0001) and 6- to 12-month periods (-23.5 ± 16.8 % and -29.4 ± 23.9 %, respectively; p < 0.0001). VAT was the parameter showing the largest decrease (-65.6 ± 17.5 % at 12 months; p < 0.0001). Two years after the surgery, a slight but significant decrease of total and regional LM was observed, without any significant change in BMI. Body composition significantly changes after RYGBP with a metabolically healthier redistribution of total and regional FM and a positive balance of FM/LM variation. DXA should be considered as a valid supplementary tool for the clinical assessment and follow-up in patients undergoing bariatric surgery.

Lean mass is the strongest predictor of bone mineral content in type-2 diabetes and normal individuals: an eastern India perspective.

BackgroundImpact of body fat distribution on bone mineral content (BMC) and density (BMD) at different sites has not been studied in type-2 diabetes (T2DM). This study aimed to compare BMC and BMD in normal (BMI < 25 kg/m2) and increased BMI (BMI ≥ 25 kg/m2) T2DM patients with age and BMI matched normal controls, and evaluate the impact of lean mass and body fat distribution parameters on them.MethodsSeventy-six T2DM patients and 56 normal controls underwent anthropometric assessment, blood sampling and estimation of BMC, BMD, body fat and lean mass distribution by dual energy X-ray absorptiometry (DXA).ResultsIncreased BMI individuals (n = 63) had significantly higher BMD, BMC, fat mass and significantly lower 25-hydroxy-vitamin-D (25OHD), as compared to normal BMI individuals (n = 69). Lean mass had stronger positive correlation with BMC and BMD, compared to fat mass. BMI, sagittal abdominal diameter (SAD) and Android/Gynoid (A/G) ratio had positive correlation with BMC and BMD. Percent body fat had negative correlation with BMC and BMD. T2DM patients had higher central obesity (A/G ratio). WC was the best predictor of A/G ratio. Regression analysis revealed lean mass to be the strongest predictor of BMC after adjusting for age, sex, BMI and 25OHD, in normal individuals and patients with diabetes, followed by fat mass. BMD right femur, BMC, lean mass and A/G ratios were significantly higher in males (n = 74). Fat mass and percent body fat were significantly higher in females (n = 58). Fat mass was the best predictor of BMC in males where as lean mass was the best predictor of BMC in females.ConclusionIncreased BMI and T2DM are associated with increased BMC and BMD at different sites, with lean mass having the strongest impact on BMC in normal individuals and patients with diabetes. Males have higher BMC and BMD as compared to females, likely due to a greater lean mass, A/G ratio, along with lesser fat mass and percent body fat.