Age related changes in body composition and bone mass in healthy men

OLIVERI B; MASTAGLIA SR; FERNANDEZ C; DEFERRARI JM; SEIJO M; BAGUR A

Nashville,USA

Congreso; 27th Meeting American Society Bone and Mineral Research; 2005

ASBMR

Age-Related Regional Changes in Body Composition and Bone Mass in Healthy Men B. Oliveri, S. R. Mastaglia*, C. Fernández*, J. M. Deferrari*, M. Seijo*, A. Bagur*. Sección Osteopatías Médicas, Hospital de Clínicas, Universidad de Buenos Aires, Buenos Aires, Argentina. Presentation Number: M072 DXA methodology allows performing a precise assessment of bone mineral density (BMD) and the three compartments of body composition (BC): bone mineral content (BMC), fat and lean mass. These parameters are measured in a total body (TB) scan, and body subregions can be distinguished. This evaluation may have implications in clinical practice. Normal reference values are necessary to correctly evaluate changes in different diseases. The purposes of this study were to 1- Establish BMD reference values in healthy men at different decades of life (from the age of 20 to 79 years) 2- Analyze BMD and BC changes throughout the decades of life 3- Evaluate changes in the different subregions. The study population comprised 103 normal Caucasian male volunteers aged 20 to 79 years with a body mass index (BMI) between 20-30 g/m2. BMD and BC (BMC, fat, %fat and lean mass ) of TB and subregions (legs, arms, trunk, total spine and pelvis) were determined by DXA (LUNAR-DPX-L ). The changes from 20-29 to 70-79 years were analyzed by ANOVA . Comparative data from 20-29 years and 70-79 years are shown. From 20-29 to 70-79 years there was a small decline of @ 4% in TB BMD and subregions (arms, legs, trunk) (NS) and only pelvis and total spine BMD showed a significant diminution (10% and 6%; p<0.002 and p<0.006 respectively). TB BMC showed a 15% diminution (p<0.02), with all subregion BMCs decreasing significantly from 13 to 23% (p<0.05). TB lean mass also showed an 8% decline ( 56.5 vs 51.5 kg) (0.1<p>0.05) with only lean mass of the legs exhibiting a significant diminution (-15%) ( p< 0.001). A progressive increase in BMI (24± 2.1 to 27± 2.0 g/cm2) (p<0.02), percentage of fat (18.8± 5.6 % to 29.5± 4.9%) (p<0.001) and total fat mass (14.3± 5.7 to 21.6± 3.8) ( p < 0.003), mainly due to a 5 kg (+73%)( p< 0.0001) increase in trunk fat mass, was observed throughout the decades of life.To conclude: 1-Reference values for TB and BMD of subregions and BC in healthy men were obtained for each decade of life. 2-Non significant changes in TB BMD, with a diminution in TB BMC, were observed with aging. 3- TB lean mass tended to decrease with aging, while BMI, TB fat mass and its percentage were found to increase. 3- Analysis of subregional BMD showed a diminution in total spine and pelvis and in all BMC subregions.4.Evaluation of BC subregions showed a central increase in fat mass (predominantly trunk) with peripheral lean mass (predominantly legs) tending to decrease. These changes in BC may have implications in the risk of cardiovascular and metabolic syndromes.