Association of physical activities and bone mass density of lumbar spines in men

Objective To determine the association of physical activities and bone mineral density of lumbar vertebrathe in men.Methods A total of 1169 men who sought medical attentions in the West China Hospital of Sichuan University from August,2003 to December,2005 because of ostealgia and arthralgia were given a dual-energy X-ray absorptiometry for the L2-L4 bone mineral density.The height,weight,smoking history,and diseases(eg.diabetes and hypertension) of the participants were recorded.A questionnaire survey was undertaken to assess the physical activities of the participants.The participants were classified into group A(frequent exercise),B(occasional exercise) and C(no exercise) according to the frequencies of physical activities.The bone mass densities of lumbar vertebrae of the three groups were compared.Results Group A had greater bone mineral density and mineral content in L2-L4,greater average bone mineral density,and greater all bone mineral content and T-score than group C(P0.05 or P0.01),although Group A had similar body mass index as Group C,was older and had greater prevalence of smoking and hypertension than Group C(P0.01).Group B had similar age and body mass index as Group C and greater smoking rate and prevalence of diabetes and hypertension than Group C(P0.05).But the differences of bone mineral density and mineral content of L2-L4,average bone mineral density,and all bone mineral content and T-score between Group B and C were not statistical significant(P0.05).Conclusion Physical activities can increase bone mineral density of lumbar vertebrae in men.But frequent and persistent exercises are needed to prevent decreasing mineral densities due to ageing,smoking and diseases.