Browsing by Subject "Absorptiometry, Photon"

Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Comparison of Body Composition Assessed by Dual-Energy X-Ray Absorptiometry and BMI in Current and Former U.S. Navy Service Members.
    (PloS one, 2015-01) Gasier, Heath G; Hughes, Linda M; Young, Colin R; Richardson, Annely M

    Background

    Little is known of the diagnostic accuracy of BMI in classifying obesity in active duty military personnel and those that previously served. Thus, the primary objectives were to determine the relationship between lean and fat mass, and body fat percentage (BF%) with BMI, and assess the agreement between BMI and BF% in defining obesity.

    Methods

    Body composition was measured by dual-energy X-ray absorptiometry in 462 males (20-91 years old) who currently or previously served in the U.S. Navy. A BMI of ≥ 30 kg/m2 and a BF% ≥ 25% were used for obesity classification.

    Results

    The mean BMI (± SD) and BF% were 28.8 ± 4.1 and 28.9 ± 6.6%, respectively, with BF% increasing with age. Lean mass, fat mass, and BF% were significantly correlated with BMI for all age groups. The exact agreement of obesity defined by BMI and BF% was fair (61%), however, 38% were misclassified by a BMI cut-off of 30 when obesity was defined by BF%.

    Conclusions

    From this data we determined that there is a good correlation between body composition and BMI, and fair agreement between BMI and BF% in classifying obesity in a group of current and former U.S. Navy service members. However, as observed in the general population, a significant proportion of individuals with excess fat are misclassified by BMI cutoffs.
  • Thumbnail Image
    ItemOpen Access
    The assessment of bone mineral content and density of the lumbar spine and proximal femur in US submariners.
    (Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA, 2014-09) Gasier, HG; Hughes, LM; Young, CR; Richardson, AM

    Unlabelled

    The submarine environment is unique in that there is limited space and no sunlight, which may negatively affect skeletal health and lead to accelerated bone loss, osteoporosis, and fractures.

    Introduction

    The primary purpose of this study was to determine whether there was an association with submarine service, specifically time spent at sea, and bone mineral content (BMC) and bone mineral density (BMD) of the lumbar spine and dual proximal femur (total hip and femoral neck) measured by DXA.

    Methods

    This is a cross-sectional study of 462 submariners 20-91 years old. Variables included in the analysis were age, height, race, alcohol intake, tobacco use, fracture history, conditions, and medications known to cause bone loss and osteoporosis and submarine service.

    Results

    Of the submarine service predictors, only serving onboard a diesel submarine was determined to be independently associated with a reduction in BMD of the total hip and femur neck, while no submarine service predictor increased the odds of having low BMD. In submariners 50+ years old, the age-adjusted prevalence of osteopenia was 15.7 % (lumbar spine) and 40.4 % (femur neck), while the prevalence of osteoporosis was 4.8 % (lumbar spine) and 4.2 % (femur neck), rates that did not differ from NHANES 2005-2008. In submariners <50 years old, 3.1 % was below the expected range for age. The proportion of submariners 50+ years old that met the FRAX criteria for pharmacological treatment was 12 %.

    Conclusions

    Intermittent periods of submergence that can range from a few days to 3+ months do not appear to compromise skeletal health differently than the general population.