Our data indicate that women who develop a vertebral fracture are at substantial risk for additional fracture within the next year.

To investigate the impact of acute salbutamol intake on performance and selected hormonal and metabolic variables during supramaximal exercise, 13 recreational male athletes performed two 30-second Wingate tests after either placebo (PLA, lactose) or salbutamol (SAL, 4 mg) oral administration, according to a double-blind and randomized protocol. Blood samples collected at rest, end of the Wingate test, recovery (5, 10, 15 min) were tested for growth hormone (GH), insulin (INS), blood glucose (GLU), and lactate determination. We found the peak and mean power performed significantly increased after SAL vs. PLA (PPSAL: 896 +/- 46; PPPLA: 819 +/- 57 W; MPSAL: 585 +/- 27; MPPLA: 534 +/- 35 W, p < 0.05), whereas no change was observed in the fatigue index. Blood glucose and INS were significantly increased by SAL at rest, at the end of the Wingate test, and during the 5 first minutes of recovery (p < 0.05). Plasma GH was significantly decreased by SAL (p < 0.05) during the recovery whereas end-exercise and recovery blood lactate tended but were not significantly increased after SAL vs. PLA. From these data, acute salbutamol intake at therapeutical dosage did appear to improve peak power and mean power during a supramaximal exercise, but the mechanisms involved need further investigation.

Increased bone formation rate pertaining to judo athletes lent protection from alterations in bone metabolic balance associated with weight cycling. This observation suggests that powerful osteogenic stimuli provided by judo's unique biomechanical environment may help prevent bone loss associated with weight loss.

The effects of a chronic salbutamol intake (SAL, 12 mg/d during 3 weeks) on changes in body composition, metabolic indices and performance during a 30-second Wingate test were determined in 8 strength-trained male athletes (T) and 7 sedentary male (UT) subjects, according to a double-blind, randomized, cross-over protocol. Blood samples were collected both at rest, at the end of the test, and during passive recovery (5 min, 10 min, 15 min) for leptin (at rest), and blood lactate measurements. No significant changes in lean body mass, fat mass, and leptin were observed with SAL treatment in either group during the trial. Peak power was significantly increased (p < 0.05) after SAL intake in all subjects (T: 11.9 %; UT: 8.3 %) with a decrease in time to peak power with SAL compared to placebo (PLA) (p < 0.05). There was no change in total work performed and in fatigue indices with SAL compared to PLA. Blood lactate was significantly increased after SAL vs. PLA during the recovery (p < 0.05) in all subjects. The data demonstrate that the chronic administration of therapeutic levels of salbutamol increases maximal anaerobic power in man, irrespective of the subjects' training status. This study also rules out any implication of an anabolic effect in this improvement in performance during supramaximal exercise. Further studies are necessary to clarify the mechanisms involved.

High calcium intake combined with physical activity during childhood have been shown to improve bone mass accrual and bone mineral density. Our aim was to study the combined effect of calcium and exercise on bone gain in children. Two milk-powder products containing either 800 mg of calcium phosphate (calcium) or not (placebo) were randomly allocated to 113 healthy premenarchal girls on a daily basis for 1 year. The group was composed of 63 exercise (7.2 +/- 4 hours of exercise/week) and 50 sedentary (1.2 +/- 0.8 hours of exercise/week) children. The final experiment had 4 groups: exercise/calcium (n = 12), exercise/placebo (n = 42), sedentary/calcium (n = 10), and sedentary/placebo (n = 21). Bone mineral density (BMD) at 6 skeletal sites and body composition were determined by DXA. Bone age was calculated and the daily spontaneous calcium intake was assessed by a frequency questionnaire. All the tests were performed at baseline and 1 year by the same observer. BMD gains were significantly greater in the exercise/calcium group than in other groups at the total body (increase of 6.3 %, p < 0.05), lumbar spine (11 %, p < 0.05), femoral neck (8.2 %, p < 0.02), and Ward's triangle (9.3 %, p < 0.01). There was no difference between the other groups. These data suggest that calcium supplementation increases the effect of physical exercise on bone mineral acquisition in the period preceding puberty, and that calcium supplementation without physical activity does not improve the BMD acquisition during this period. Physical exercise that stimulates bone accretion needs a high calcium intake to be completely effective.

In this study, ALN 70 mg OW produced a 50% greater reduction in bone resorption as measured by urine NTx and significantly greater increases in lumbar spine and hip BMD than did RIS 5 mg daily. The treatments had similar safety profiles and were generally well-tolerated. Additional studies are needed comparing OW ALN with OW RIS, which became available after the commencement of the present study.

Objective: Despite a preliminary understanding of leptin -skeletal interactions, data in humans are inconsistent and the exact roles of leptin on bone metabolism have not yet been defined. The aim of this study was to examine the possible role of leptin in the regulation of bone metabolism in healthy, physically trained adults. Methods and Design: Body composition and bone mass (dual-energy X-ray absorptiometry), anthropometry, serum leptin, insulin, cortisol, osteocalcin, C-terminal telopeptide of type I collagen (CTx) and total plasma proteins were measured in judoists at normal body weight, after weight reduction and after weight regain. Physical training, weight cycling history, menstrual status and nutritional intake using a 7-day food record were assessed. Results: Precompetitive weight loss averaged 4^0.3% of bodyweight and resulted in a significant decrease in leptin levels of 64% (P , 0.001) and of 31% for insulin (P , 0.0001). CTx and cortisol concentrations rose by 33% (P , 0.0001) and 81% (P , 0.05) respectively. Osteocalcin and total plasma protein remained unaffected by weight loss. A 4^0.5% weight regain induced a 276% increase in leptin levels (P , 0.001) and an 18% increase in insulin (P , 0.001). CTx and cortisol decreased by 23% (P , 0.0001) and 27% (P , 0.05) respectively. Changes in leptin were significantly correlated with changes in bone resorption marker in response to both weight loss (r ¼ 0.56, P , 0.01) and regain (r ¼ 0.44, P , 0.05). Conclusions: These findings suggest that leptin is involved in the regulation of bone metabolism in healthy adults and might play a potential role in the prevention of osteoporosis.European Journal of Endocrinology 154 389-395

Microcomputed tomography (microCT) produces three-dimensional (3D) images of trabecular bone. We compared conventional microCT (CmicroCT) with a polychromatic x-ray cone beam to synchrotron radiation (SR) microCT with a monochromatic parallel beam for assessing trabecular bone microarchitecture of 14 subchondral femoral head specimens from patients with osteoarthritis (n=10) or osteoporosis (n=4). SRmicroCT images with a voxel size of 10.13 microm were reconstructed from 900 2D radiographic projections (angular step, 0.2 degrees). CmicroCT images with a voxel size of 10.77 microm were reconstructed from 205, 413, and 825 projections obtained using angular steps of 0.9 degrees, 0.45 degrees, and 0.23 degrees, respectively. A single threshold was used to binarize the images. We computed bone volume/ tissue volume (BV/TV), bone surface/bone volume (BS/BV), trabecular number (Tb.N), trabecular thickness (Tb.Th and Tb.Th*), trabecular spacing (Tb.Sp), degree of anisotropy (DA), and Euler density. With the 0.9 degrees angular step, all CmicroCT values were significantly different from SRmicroCT values. With the 0.23 degrees and 0.45 degrees rotation steps, BV/TV, Tb.Th, and BS/BV by CmicroCT differed significantly from the values by SRmicroCT. The error due to slice matching (visual site matching +/- 10 slices) was within 1% for most parameters. Compared to SRmicroCT, BV/TV, Tb.Sp, and Tb.Th by CmicroCT were underestimated, whereas Tb.N and Tb. Th* were overestimated. A Bland and Altman plot showed no bias for Tb.N or DA. Bias was -0.8 +/- 1.0%, +5.0 +/- 1.1 microm, -5.9 +/- 6.3 microm, and -5.7 +/- 29.1 microm for BV/TV, Tb.Th*, Tb.Th, and Tb.Sp, respectively, and the differences did not vary over the range of values. Although systematic differences were noted between SRmicroCT and CmicroCT values, correlations between the techniques were high and the differences would probably not change the discrimination between study groups. CmicroCT provides a reliable 3D assessment of human defatted bone when working at the 0.23 degrees or 0.45 degrees rotation step; the 0.9 degrees rotation step may be insufficiently accurate for morphological bone analysis.