Is it important to achieve physical activity recommendations at early stages of life to improve bone health?

Research in bone health during childhood is limited and important to prevent future diseases, particularly, osteoporosis. Bone parameters using DXA and pQCT in 295 Spanish children were evaluated and we found a benefit of meeting the World Health Organization physical activity recommendations in bone composition in childhood. PURPOSE: To investigate the association between physical activity (PA) and bone health in a Spanish paediatric cohort, considering the influence of meeting/not meeting the current World Health Organization (WHO) PA recommendations and to elucidate if there are differences between boys and girls. METHODS: In a cohort of children born in the region of Aragon (Spain) in 2009, followed until the age of 7 years, bone parameters were assessed using dual-energy X-ray absorptiometry (DXA) (whole body scan) and peripheral quantitative computed tomography (pQCT) (tibia scanned at the 8% (distal) and 38% (diaphyseal) of the total tibia length) in 295 7-year-old children (154 boys) in the last evaluation performed between 2016 and 2017. PA was assessed using GT3X Actigraph accelerometers. RESULTS: Boys had significantly higher areal bone mineral density (aBMD), higher total bone mineral content (BMC) at the diaphyseal site and higher trabecular BMC and vBMD, and higher total bone area at the distal site than girls (p<0.01 for all of them). Both boys and girls complying with the WHO PA recommendations had significantly higher trabecular BMC than their inactive counterparts. CONCLUSIONS: Meeting WHO PA recommendations has a beneficial effect in bone composition in childhood both in boys and in girls.

Associations between Physical Fitness, Bone Mass, and Structure in Older People.

The main aim was to analyse the associations between several physical fitness variables and bone parameters in a sample of elderly people. 129 participants (94 females and 35 males, 76.2 ± 5.4 y) from the EXERNET cohort of Zaragoza (Spain) were included in the study. Physical fitness was assessed using the Senior Fitness Test Battery. Peripheral quantitative computed tomography (pQCT) at the tibia and dual-energy X-ray absorptiometry (DXA) at the hip and lumbar spine were used to assess bone and muscle parameters. Partial correlations were used to describe the associations between fitness and bone parameters. A stepwise regression analysis was used to determine the influence of fitness variables on bone parameters. In males, significant correlations were found between lower body strength and agility with bone total mineral density (Tt.BMD) (r = 0.41 and -0.50) and cortical thickness (r = 0.40 and -0.50, respectively) and walking speed with total and cortical density (r = -0.41 and -0.40, respectively), all measured at tibia (all p < 0.05). Regarding DXA, neck areal bone mineral density (aBMD) correlated with flexibility (r = -0.37) and walking speed (r = 0.39) and Ward's triangle with walking speed (r = 0.39). Agility predicted Tt.BMD and cortical thickness (r 2 change = 24.8% and 23.0%), while walking speed predicted cortical bone mineral density (r 2 change = 19.5%) (all p < 0.05). Females showed correlations between balance and total hip aBMD (r = 0.27) and trochanter aBMD (r = 0.25). Balance predicted trochanter (r 2 change = 4.2%) and total hip aBMD (r 2 change = 4.9%) (both p < 0.05). In conclusion, bone mass in elderly males seems to be more influenced by physical fitness than in females, being agility and walking speed the variables showing greater associations. Other variables should be taken into account in females for future research.