A cross-sectional study of radial and tibial ultrasonography between different ethnic and physically active groups

Research has attempted to quantify the effect physical activity has on bone health measured by ultrasonography as well as clarify the differences in bone health between ethnic groups. An original thesis was produced as part of a greater research project investigating ultrasonography and muscle strength in different ethnic groups. Quantitative ultrasound (Sunlight MiniOmni®) of the distal radius and mid-shaft tibia was measured in 132 male students aged 18-25 (69.22±11.04kg, 1.74±0.08m) as well as quadricep strength and anthropometrics. An aim of the study was to determine if frequency and type of physical activity affect radial and tibial ultrasound (SOS). Using the Stanford Patient Research Questionnaire, 66 multi-ethnic British males (21.04±1.57 yrs; 73.97±7.6 kg; 1.80±0.06m) were stratified for frequency of total physical activity and strength activity. Radial and tibial ultrasound were not significantly different between any of activity groups (p>.05), attributed to lack of difference in fat free mass. A second aim was to determine a main effect or interaction between exercise and ethnicity. Significant ethnic differences were found between Caucasian British (n=48; 21.45±1.32yrs; 72.56±6.7kg; 1.79±0.07m) and Malay Malaysian (n=66; 20.17±0.59yrs; 64.47±12.01kg; 1.68±0.06m) men for adjusted radius SOS (3984.745 and 4077.982, respectively) (p<.005) and tibia SOS (3885.47 and 3956.27, respectively) (p<.01). Ethnic group determined radial (6.3%) and tibia (5.7%) ultrasound. Body mass is strongest determinant of radial ultrasound (7.3%). No other variables impact tibia SOS (p<.05). An interaction effect existed between ethnicity and exercise for radius SOS (p=.005). Greater competition and training as a district athlete largely reduced radial SOS in Malaysians but not British, suggesting a negative association between volume of training and bone health for Malaysians only. Factors associated with bone mass changeable under exercise were different between Malaysians but not British groups, suggesting activity levels between controls and athletes were not consistent, misinterpreting an interaction effect. Ethnic differences in radial and tibial ultrasound varied. No group had consistently higher SOS for both sites, the size of the difference was not consistent and different external factors affected the difference. Better quantification of physical activity with a focus on physiological adaptation of factors associated with osteogenesis, along with more control of groups is required.