A comparison of the effect of two types of vibration exercise on the endocrine and musculoskeletal system.

BACKGROUND: Whole body vibration (WBV) is a novel training intervention but a comparison of different methods of WBV has rarely been performed. AIM: To compare the short and medium term effects of two regimens of WBV on endocrine status, muscle function and markers of bone turnover. PATIENTS AND METHODS: Over a period of 16 weeks, 10 men with a median age of 33 yrs (range, 29,49), were randomised to stand on the Galileo platform (GP) or Juvent1000 platform (JP) 3 times/wk. The total study duration was 16 weeks with measurements performed in a 4 week period of run-in, 8 weeks of WBV and a 4 week period of washout. These measurements included an assessment of anthropometry, body composition, muscle function and biochemical markers of endocrine status and bone turnover. To assess immediate effects of WBV, measurements were also performed at 60 mins before and 5, 30 and 60 mins after WBV. To assess immediate effects of WBV, measurements were also performed at 60 mins before and 5, 30 and 60 mins after WBV. RESULTS: GP at 22 Hz was associated with an immediate increase in serum GH, rising from 0.07 µg/l (0.04,0.69) to 0.52 µg/l (0.06,2.4) (p=0.06), 0.63 µg/l (0.1,1.18) (p=0.03), 0.21 µg/l (0.07,0.65) (p=0.2) at 5 mins, 20 mins and 60 mins after WBV, respectively. An immediate effect was also observed in median serum cortisol which reduced from 316 nmol/l (247,442) before WBV to 173 nmol/l (123,245) (p=0.01),165 nmol/l (139,276) (p=0.02) and 198 nmol/l (106,294) (p=0.04) at 5 mins, 20 mins and 60 mins after WBV, respectively. Median serum CTX reduced significantly after 8 weeks of WBV training in the GP group from 0.42 ng/ml (0.29,0.90) pre-WBV to 0.29 ng/ml (0.18,0.44) at the end of WBV training (p=0.03). Over the 8 weeks, there was a reduction in median serum cortisol in the GP group from 333 nmol/l (242,445) (pre-WBV) to 270 nmol/l (115,323) (WBV) (p=0.04). None of the changes observed in the JP group reached statistical significance. Neither group showed any significant effect on muscle function, IGF-1, testosterone, leptin, CRP, creatine kinase, insulin or other markers of bone turnover. CONCLUSION: WBV can stimulate GH secretion, reduce circulating cortisol and reduce bone resorption. These effects are independent of clear changes in muscle function and depend on the type of WBV that is administered.

Skeletal morbidity in children receiving chemotherapy for acute lymphoblastic leukaemia.

BACKGROUND: Children receiving chemotherapy for acute lymphoblastic leukaemia (ALL) may be susceptible to skeletal morbidity. AIM: To determine the incidence and risk factors for skeletal morbidity in ALL children. PATIENTS AND METHODS: The medical records of all (n=186, boys=110) children presenting to a single centre with ALL between 1997 and 2007 and treated on UKALL97, UKALL97/01 or UKALL2003 were studied. Skeletal morbidity included musculoskeletal pain, fractures and osteonecrosis (ON). Musculoskeletal pain was classified as any event of limb pain, muscle pain, joint symptoms or back pain that required radiological examination. Fractures and ON were confirmed by x-rays and MRI, respectively. RESULTS: Skeletal morbidity, presenting as musculoskeletal pain, fractures or ON were reported in 88 (47%) children of whom 56 (63%) were boys. Of 88 children, 49 (55%), 27 (30%) and 18 (20%) had musculoskeletal pain, fracture(s) or ON, respectively. 6 (7%) had fractures and ON. The median (10th, 90th centiles) age at diagnosis of ALL in those children without skeletal morbidity was 3.9 (1.4-12) years which was lower than in those with skeletal morbidity at 8.2 (2.2-14.3) years (p<0.00001, 95% CI 1.7 to 4.4). Children with ALL diagnosed over 8 years of age were at increased risk of developing fracture(s) (p=0.01, OR=2.9, 95% CI 1.3 to 6.5) whereas the risk of ON was higher in those who were diagnosed after 9 years of age (p<0.0001, OR=15, 95% CI 4.1 to 54.4). There was no sex difference in the incidence of skeletal complications. Children who received Dexamethasone had a higher incidence of skeletal morbidity than those who were treated with Prednisolone (p=0.027, OR=2.6, 95% CI 1.1 to 5.9). CONCLUSION: The occurrence of skeletal morbidity in ALL children may be influenced by age and the type of glucocorticoids. These findings may facilitate the development of effective bone protective intervention.

Secondary osteoporosis.

Secondary osteoporosis is more difficult to define in children than in adults but clearer definitions have recently been provided by the International Society for Clinical Densitometry. Whereas in adults, osteoporosis is defined on the basis of reduced bone density on scanning, in children the definition requires additional clinical parameters to be fulfilled. Secondary osteoporosis may arise either as a result of the effects of underlying disease or as a result of the treatment of such diseases (e.g. with glucocorticoids). The normal balance of bone formation and removal, both by bone modelling and remodelling, is disturbed in such a way as to alter the normal accumulation of bone that occurs during childhood. A multitude of intrinsic and extrinsic factors contributes to these processes. The underlying principles of treatment of secondary osteoporosis is, where possible, to remove the underlying cause. Where this is not possible, minimising the effects of treatment with drugs that adversely effect bone may be sufficient to eliminate any deterioration in bone quality. If this is not possible, the use of bone sparing drugs such as the bisphosphonates may be necessary whilst ensuring that attention is paid to optimising calcium and vitamin D intake and encouraging exercise and mobility.