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

To determine the association of physical activities and bone mineral density of lumbar vertebrae in men.

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.

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 (P<0.05 or P<0.01), although Group A had similar body mass index as Group C, was older and had greater prevalence of smoking and hypertension than Group C (P<0.01). 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 (P>0.05). 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 (P>0.05).

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.