The relationship between lower limb bone and muscle in military recruits, response to physical training, and influence of smoking status.

UNLABELLED: The relationship between bone and skeletal muscle mass may be affected by physical training. No studies have prospectively examined the bone and skeletal muscle responses to a short controlled exercise-training programme. We hypothesised that a short exercise-training period would affect muscle and bone mass together. METHODS: Femoral bone and Rectus femoris Volumes (RFVOL) were determined by magnetic resonance imaging in 215 healthy army recruits, and bone mineral density (BMD) by Dual X-Ray Absorptiometry (DXA) and repeated after 12 weeks of regulated physical training. RESULTS: Pre-training, RFVOL was smaller in smokers than non-smokers (100.9 ± 20.2 vs. 108.7 ± 24.5, p = 0.018; 96.2 ± 16.9 vs. 104.8 ± 21.3, p = 0.002 for dominant/non-dominant limbs), although increases in RFVOL with training (of 14.2 ± 14.5% and 13.2 ± 15.6%] respectively, p < 0.001) were independent of prior smoking status. Pre-training RFVOL was related to bone cortical volume (r(2) = 0.21 and 0.30, p < 0.001 for dominant and non-dominant legs), and specifically to periosteal (r(2) = 0.21 and 0.23, p < 0.001) volume. Pre-training dominant RFVOL was independently associated with Total Hip BMD (p < 0.001). Training-related increases in RFVOL and bone volumes were related. Whilst smokers demonstrated lower muscle mass than non-smokers, differences were abolished with training. Training-related increases in muscle mass were related to increases in periosteal bone volume in both dominant and non-dominant legs.

Deep peroneal nerve palsy during growth spurt: a case report.

UNLABELLED: Peripheral nerve injuries may have a number of causes, most commonly mechanical. We describe a case of a deep peroneal nerve palsy in an adolescent boy which coincided with a large growth spurt. Spontaneous recovery of full function was seen without intervention. CONCLUSION: In the absence of any other causative factors, we believe that this growth spurt resulted in temporary compression of the deep peroneal nerve at the level of the knee producing transient neurapraxia.

Lisfranc injury in the athlete: evidence supporting management from sprain to fracture dislocation.

Although Lisfranc injuries are uncommon, prompt and accurate diagnosis of such injuries in athletes is essential in preventing career-ending injury. Undisplaced injuries have an excellent result with nonoperative treatment. The presence of any displacement warrants open reduction and anatomic fixation; although current evidence mostly supports screw fixation, plate fixation may avoid joint intrusion. It is imperative to warn athletes with significantly displaced injuries that there is a risk of a poor outcome, although some recent evidence suggests that return to elite competitive sports is still likely after surgical intervention. Severe injuries may have better outcomes with limited arthrodesis.

Lisfranc injuries: an update.

Lisfranc injuries are a spectrum of injuries to the tarsometatarsal joint complex of the midfoot. These range from subtle ligamentous sprains, often seen in athletes, to fracture dislocations seen in high-energy injuries. Accurate and early diagnosis is important to optimise treatment and minimise long-term disability, but unfortunately, this is a frequently missed injury. Undisplaced injuries have excellent outcomes with non-operative treatment. Displaced injuries have worse outcomes and require anatomical reduction and internal fixation for the best outcome. Although evidence to date supports the use of screw fixation, plate fixation may avoid further articular joint damage and may have benefits. Recent evidence supports the use of limited arthrodesis in more complex injuries.

Bone structure and geometry in young men: the influence of smoking, alcohol intake and physical activity.

BACKGROUND: The development of osteoporosis is influenced by peak bone mass attained in youth - the influence of lifestyle factors upon which is poorly described, especially amongst males. We sought to address this issue in a large scale study. METHODS: Hip bone mineral density (dual X-ray absorptiometry, DXA), bone microarchitecture (calcaneal quantitative ultrasound, QUS) and femoral geometry (magnetic resonance imaging, MRI) were characterised in 723 healthy male military recruits (mean ± S.E. age 19.92 ± 0.09 years [range 16-18 years], height 177.67 ± 0.24 cm, weight 73.17 ± 0.37 kg) on entry to UK Army training. Association was sought with prior physical activity, smoking status and alcohol intake. RESULTS: DXA measures were made in 651, MRI measures in 650, and QUS measures in 572 recruits. Increasing levels of weight-bearing physical activity enhanced periostial bone apposition, increases in both total hip and femoral neck bone mineral density (BMD; p ≤ 0.0001 in both cases), and cortical [p<0.0001] and periostial bone volumes [p=0.016]. Smoking habit was associated with preserved bone geometry, but worse BMD [p=0.0001] and QUS characteristics [p ≤ 0.0005]. Moderate alcohol consumption was associated with greater BMD [p ≤ 0.015]. CONCLUSIONS: Whilst exercise (and perhaps moderate alcohol intake) is beneficial to bone morphometry, smoking is detrimental to bone mineral density in young males notable for the likely short duration of smoking to influence skeletal properties. However, differences in socio-economic status, lifestyle and related environmental factors may to some extent confound our results.

The Lichfield bone study: the skeletal response to exercise in healthy young men.

The skeletal response to short-term exercise training remains poorly described. We thus studied the lower limb skeletal response of 723 Caucasian male army recruits to a 12-wk training regime. Femoral bone volume was assessed using magnetic resonance imaging, bone ultrastructure by quantitative ultrasound (QUS), and bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA) of the hip. Left hip BMD increased with training (mean ± SD: 0.85 ± 3.24, 2.93 ± 4.85, and 1.89 ± 2.85% for femoral neck, Ward's area, and total hip, respectively; all P < 0.001). Left calcaneal broadband ultrasound attenuation rose 3.57 ± 0.5% (P < 0.001), and left and right femoral cortical volume by 1.09 ± 4.05 and 0.71 ± 4.05%, respectively (P = 0.0001 and 0.003), largely through the rise in periosteal volume (0.78 ± 3.14 and 0.59 ± 2.58% for right and left, respectively, P < 0.001) with endosteal volumes unchanged. Before training, DXA and QUS measures were independent of limb dominance. However, the dominant femur had higher periosteal (25,991.49 vs. 2,5572 mm(3), P < 0.001), endosteal (6,063.33 vs. 5,983.12 mm(3), P = 0.001), and cortical volumes (19,928 vs. 19,589.56 mm(3), P = 0.001). Changes in DXA, QUS, and magnetic resonance imaging measures were independent of limb dominance. We show, for the first time, that short-term exercise training in young men is associated not only with a rise in human femoral BMD, but also in femoral bone volume, the latter largely through a periosteal response.

The association of left ventricular mass with blood pressure, cigarette smoking and alcohol consumption; data from the LARGE Heart study.

BACKGROUND: Left ventricular mass is a risk factor for cardiovascular morbidity and mortality. Although factors associated with elevated left ventricular mass have been sought and studied extensively in elderly and in diseased subjects, few studies have examined the young and healthy. The aim of this study was to examine the possible influence of lifestyle on left ventricular mass in a large group of young men. METHODS: Left ventricular mass was assessed using cardiovascular magnetic resonance in 541 healthy Caucasian male army recruits. Anthropometric, lifestyle and blood pressure data were collected. RESULTS: Mean unadjusted left ventricular mass and left ventricular mass indexed to body surface area were 163.8+/-24.9 g and 86.6+/-10.2 g m(-2) respectively. In univariate analysis, age, height, weight, alcohol consumption, systolic blood pressure, diastolic blood pressure and indices of physical activity were positively associated with unadjusted left ventricular mass (all P<0.02). By contrast, smoking was associated with lower mean left ventricular mass; never smoked 167.5+/-25.8 g vs ex-smokers 159.1+/-25.2 g vs current smokers 161.0+/-23.1 g (P=0.007). Multivariate analysis revealed weight, systolic blood pressure, smoking status and indices of physical activity to be independent predictors of left ventricular mass. CONCLUSIONS: Our data confirm an association of age, body weight, height, physical activity, diastolic and systolic blood pressure with left ventricular mass. In addition, unexpectedly, we have found smoking is associated with lower left ventricular mass in a large sample of young healthy men. Although the latter association may result from confounding effects, such an interesting observation deserves further investigation.

+9/+9 Homozygosity of the bradykinin receptor gene polymorphism is associated with reduced fat-free mass in chronic obstructive pulmonary disease.

BACKGROUND: The etiology of muscle wasting in chronic obstructive pulmonary disease (COPD) is incompletely understood. We previously showed that the D rather than the I polymorphic variant of the angiotensin-converting enzyme (ACE) gene is associated with preserved quadriceps strength in COPD. If the ACE D allele influences skeletal muscle through increased ACE-related kinin degradation [and reduced activity at the bradykinin type 2 receptor (BK(2)R)], we might expect a similar association with the +9 BK(2)R genotype in this population as well. OBJECTIVE: The objective was to test the hypothesis that the BK(2)R gene polymorphism is a determinant of fat-free mass and quadriceps strength in patients with COPD. DESIGN: In a cross-sectional design we determined BK(2)R genotype, fat-free mass, and quadriceps strength in 110 COPD patients with a mean (+/-SD) predicted forced expiratory volume in 1 s of 34.3 +/- 16.4% and in 104 healthy age-matched control subjects. RESULTS: The mean (+/-SD) fat-free mass index (in kg/m(2)) was significantly lower in 37 patients homozygous for the +9 allele than in carriers of the -9 allele (15.7 +/- 1.8 compared with 16.7 +/- 2.3; P = 0.038); the same pattern was true for quadriceps maximal voluntary force (30.8 +/- 10.4 and 36.4 +/- 12.8 kg; P = 0.02), respectively. No significant effect of BK(2)R genotype on inspiratory muscle strength or on any variable in control subjects was observed. There was no interaction between the effect of the BK(2)R and ACE genotypes on quadriceps strength. CONCLUSIONS: The genotype associated with reduced BK(2)R expression is associated with reduced fat-free mass and quadriceps strength in COPD. However, alterations in the activity at the BK(2)R do not seem to account for the previously identified association of quadriceps strength with ACE genotype.