OBJECTIVE: The aim of the study was to quantify the inter-relationship between bone mineral density and physical activity, muscle strength, and body mass composition in a group of healthy 16-20-year-old women. DESIGN: A cross-sectional study. SETTING: Reykjavik area. SUBJECTS: Two-hundred and fifty-four Icelandic Caucasian women aged 16, 18 and 20 years, randomly selected from the registry of Reykjavik. MAIN OUTCOME MEASURES: Bone mineral content (BMC) and density (BMD) in lumbar spine, hip, distal forearm and total skeleton and lean mass and fat mass were measured with dual energy X-ray absorptiometry (DEXA) and compared with grip strength measured with a dynamometer and physical activity as assessed by a questionnaire. RESULTS: The lean mass had the strongest correlation with BMC and BMD, stronger than weight, height and fat mass, both in univariate analysis (r = 0.41-0.77; P<0.001) and in linear regression analysis. The total skeletal BMD was logarithmically higher by hours of exercise per week (P<0.001)). About 30% of variability in total skeletal BMD in this age group can be predicted by lean mass and physical exercise. CONCLUSIONS: Modifiable factors, such as exercise and adequate muscle seem to be significant predictors of the attainment of peak bone mass in women.
OBJECTIVE: The aim of the study was to quantify the inter-relationship between bone mineral density and physical activity, muscle strength, and body mass composition in a group of healthy 16-20-year-old women. DESIGN: A cross-sectional study. SETTING: Reykjavik area. SUBJECTS: Two-hundred and fifty-four Icelandic Caucasian women aged 16, 18 and 20 years, randomly selected from the registry of Reykjavik. MAIN OUTCOME MEASURES: Bone mineral content (BMC) and density (BMD) in lumbar spine, hip, distal forearm and total skeleton and lean mass and fat mass were measured with dual energy X-ray absorptiometry (DEXA) and compared with grip strength measured with a dynamometer and physical activity as assessed by a questionnaire. RESULTS: The lean mass had the strongest correlation with BMC and BMD, stronger than weight, height and fat mass, both in univariate analysis (r = 0.41-0.77; P<0.001) and in linear regression analysis. The total skeletal BMD was logarithmically higher by hours of exercise per week (P<0.001)). About 30% of variability in total skeletal BMD in this age group can be predicted by lean mass and physical exercise. CONCLUSIONS: Modifiable factors, such as exercise and adequate muscle seem to be significant predictors of the attainment of peak bone mass in women.
Authors: Joan M Lappe; Donald J McMahon; Ann Laughlin; Corrine Hanson; Jean Claude Desmangles; Margaret Begley; Misty Schwartz Journal: Am J Clin Nutr Date: 2017-03-15 Impact factor: 7.045