Body composition reference ranges in community-dwelling adults using dual-energy X-ray absorptiometry: the Australian Body Composition (ABC) Study.

BACKGROUND: Reference ranges for lean mass (LM) and fat mass (FM) are essential in identifying soft tissue disorders; however, no such reference ranges exist for the most commonly used Hologic dual-energy X-ray absorptiometry (DXA) machine in Australia. METHODS: Cross-sectional study of community-dwelling adults (aged 18-88 years) who underwent a Hologic DXA scan at one of three commercialized densitometry centres in Australia. Age-specific and sex-specific percentile curves were generated for LM [LM, appendicular lean mass (ALM), ALM adjusted for height squared (ALM/h2 ), and ALM adjusted for body mass index (ALM/BMI)] and FM [FM, FM adjusted for height squared (FM/h2 ), appendicular fat mass, and android and gynoid fat] parameters using the LMS statistical method. Cutpoints equivalent to T-scores of -1, -2, and -2.5 standard deviations below the young mean reference group (20-29 years) were also generated for LM parameters. RESULTS: A total of 15 479 community-dwelling adults (54% men) with a median age of 33 years (interquartile range: 28, 42) were included. LM, ALM, and ALM/h2 remained stable until age 50, after which these parameters started to decline in both sexes. Compared with age 50, median percentiles of LM, ALM, and ALM/h2 declined by -5.9 kg, -3.7 kg, and -0.86 kg/m2 in men and by -2.5 kg, -1.8 kg, and -0.10 kg/m2 in women at age 70, respectively. Adjusting ALM for BMI (rather than height squared) resulted in different trends, with ALM/BMI decreasing from as early as age 20. Compared with age 20, median percentiles of ALM/BMI at age 40 declined by -0.10 kg/kg/m2 in men and by -0.06 kg/kg/m2 in women; and at age 70, ALM/BMI declined by -0.25 kg/kg/m2 in men and by -0.20 kg/kg/m2 in women. Cutpoints equivalent to T-scores of -1, -2, and -2.5 standard deviations for ALM/BMI were 1.01, 0.86, and 0.77 kg/kg/m2 in men and 0.70, 0.59, and 0.53 kg/kg/m2 in women, respectively. All FM parameters progressively increased from age 20 and continued up until age 70. CONCLUSIONS: We developed reference ranges for LM and FM parameters from Hologic DXA machines in a large cohort of Australian adults, which will assist researchers and clinicians in identifying soft tissue disorders such as obesity, sarcopenia, and cachexia.

The Effect of Sprint Interval Training on Body Composition of Postmenopausal Women.

INTRODUCTION: Menopause is accompanied by body composition changes that include a decrease in lean mass and aerobic fitness and an increase in fat mass. Sprint interval training (SIT) may be able to reverse these changes. PURPOSE: To examine the effect of an 8-wk SIT program on body composition and aerobic fitness of overweight postmenopausal women. METHODS: Forty postmenopausal women were randomized into SIT (n = 20) or control (n = 20) groups. The SIT group completed three SIT sessions a week for 8 wk with each session consisting of 20 min of alternating 8-s sprints and 12-s of light pedaling. Total mass, regional lean mass, and fat mass were assessed using dual-energy x-ray absorptiometry. Maximal oxygen uptake (V˙O2max) was predicted using a submaximal test. RESULTS: Total lean mass was significantly increased from pretest (48.1 ± 5.81 kg) to posttest (48.8 ± 5.96 kg) and fat mass was significantly reduced (pre, 29.5 ± 7.29 kg; post, 29.1 ± 7.61 kg) for the SIT group. Lean mass was mostly increased in the trunk (pre, 24.4 ± 2.79 kg; post, 24.8 ± 2.93 kg) and legs (pre, 15.6 ± 2.31 kg; post, 15.9 ± 2.34 kg). V˙O2max was significantly increased from pretest (21.7 ± 4.89 mL⋅kg⋅min) to posttest (24.4 ± 5.96 mL⋅kg⋅min) for the SIT group only. CONCLUSIONS: The SIT intervention increased total lean mass, decreased fat mass, and increased aerobic fitness of postmenopausal women after only 8 h of actual exercise over 8 wk.

Osteoporosis and low bone mineral density (osteopenia) in rural and remote Queensland.

OBJECTIVE: To report that prevalence rates of osteoporosis and osteopenia differ according to different levels of remoteness in Queensland, Australia. DESIGN: Retrospective analysis of bone mineral density scans undertaken between April 2015 and April 2016. SETTING: Mobile laboratory housing a dual energy X-ray absorptiometry in rural and remote Queensland. PARTICIPANTS: Four-thousand-four-hundred-and-twenty-seven referred individuals 70 years of age or older. MAIN OUTCOME MEASURES: Bone mineral density (g cm-2 ) at two sites was used to measure the level of bone health as per the World Health Organization criteria for osteoporosis. RESULTS: A slightly higher percentage of women was screened and the percentage screened in both men and women decreased as levels of remoteness increased. Women in outer regional areas had significantly higher odds of having osteopenia over normal bone mineral density, compared to women in an urban setting. CONCLUSION: As the level of remoteness increased, there was a decrease in the percentage of men and women being screened to determine their risk of osteoporosis. Furthermore, the current data suggest that women in more remote areas have significantly lower bone density, compared to an urban female population. Finally, men and women have similar levels of osteopenia across Queensland, Australia.

Assessment of segmental arm soft tissue composition in breast cancer-related lymphedema: a pilot study using dual energy X-ray absorptiometry and bioimpedance spectroscopy.

BACKGROUND: Changes in arm soft tissue composition, especially increased adipose tissue, has been found in advanced, non-pitting breast cancer-related lymphedema (BCRL). The aim of this study was to examine whether these changes were localized to any particular region of the arm and whether they occurred in lymphedema which still pitted to pressure. Secondary aims were to explore relationships between arm segment volumes, bioimpedance spectroscopy (BIS) measurements of extracellular fluid (ECF), and dual-energy X-ray absorptiometry (DXA) measurements of tissue composition. METHODS AND RESULTS: Nine women with unilateral BCRL participated. The dominant arm was affected in 4 women, and all presented with lymphedema that pitted to pressure. Arm volume was calculated from circumferences by the truncated cone method, ECF was determined with BIS and fat and lean tissue content measured by DXA. BIS and DXA measurements for women with lymphedema were made of the whole arm and also of four 10 cm-segments measured from the ulnar styloid at the wrist. Whole arm DXA data were compared to those of 45 women of similar age and body mass index without lymphedema. All women with lymphedema had a significantly larger absolute fat mass in their affected arm compared to their unaffected arm, (median difference between arms 146.9 g). The forearm segment 10 - 20 cm proximal to the wrist had the highest median inter-limb fat difference of all four arm segments. CONCLUSIONS: The soft tissue composition changes associated with BCRL may occur in the presence of pitting and predominantly affect the proximal forearm.

Weight loss strategies for obese adults: personalized weight management program vs. standard care.

OBJECTIVE: The objective of this study was to evaluate the effect of a 32-week personalized Polar weight management program (PWMP) compared with standard care (SC) on body weight, body composition, waist circumference, and cardiorespiratory fitness in overweight or obese adults. RESEARCH METHODS AND PROCEDURES: Overweight or obese (29 +/- 2 kg/m(2)) men and women (n = 74) 38 +/- 5 years of age were randomly assigned into either PWMP (men = 20, women = 21) or SC (men = 15, women = 18). Both groups managed their own diet and exercise program after receiving the same standardized nutrition and physical activity advice. PWMP also received a weight management system with literature to enable the design of a personalized diet and exercise weight loss program. Body weight and body composition, waist circumference, and cardiorespiratory fitness were measured at weeks 0, 16, and 32. RESULTS: Eighty percent of participants completed the 32-week intervention, with a greater proportion of the dropouts being women (PWMP: 2 men vs. 7 women; SC: 2 men vs. 4 women). At 32 weeks, PWMP completers had significantly (p < 0.001) greater losses in body weight [6.2 +/- 3.4 vs. 2.6 +/- 3.6 (standard deviation) kg], fat mass (5.9 +/- 3.4 vs. 2.2 +/- 3.6 kg), and waist circumference (4.4 +/- 4.5 vs. 1.0 +/- 3.6 cm). Weight loss and fat loss were explained by the exercise energy expenditure completed and not by weekly exercise duration. DISCUSSION: More effective weight loss was achieved after treatment with the PWMP compared with SC. The results suggest that the PWMP enables effective weight loss through tools that support self-monitoring without the requirement of more costly approaches to program supervision.