Bone mineral density, muscle strength and physical activity. A population-based study of 332 subjects aged 15-42 years.
The aim of this population-based study was to find out whether differences in levels of physical activity have an influence on bone mass quantity and whether quadriceps muscle strength is a reliable determinant of bone mass. Included were 175 men and 157 women, aged 15-42 years. Bone mineral density (BMD) was measured at various sites by dual X-ray absorptiometry (DXA) and single photon absorptiometry (SPA). Muscle strength was assessed using an isokinetic muscle force meter. A questionnaire was used to estimate the level of physical activity. We found a positive correlation between physical activity and BMD for boys at the distal forearm and for girls at the trochanter (age group 15-16 years). Active men (age group 21-42 years) had up to 9% higher BMD levels at the hip than those who were less active. Quadriceps muscle torque was not an independent predictor of BMD. Our data suggest that a higher level of physical activity-within the limits of a "normal life style"-may have a positive effect on BMD in the proximal femur of young adults, which in turn may lessen the subsequent risk of fracture.
Düppe
H
H
Department of Orthopedics, Malmö University Hospital, Sweden.
Gärdsell
P
P
Johnell
O
O
Nilsson
B E
BE
Ringsberg
K
K
D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D015519:Bone Density; D003430:Cross-Sectional Studies; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D010809:Physical Fitness; D011237:Predictive Value of Tests; D012727:Sex Characteristics; D017678:Sex Distribution; D011795:Surveys and Questionnaires; D013548:Sweden