Ge lunar prodigy

Body composition DXA was performed using GE Lunar Prodigy dual-energy X-ray absorptiometry (DXA) scanner (GE Healthcare, Madison, WI, USA) by a certified technician. The software used for the total and regional body composition estimation was Encore (GE Healthcare) version 15. Each region was automatically analysed and then supervised by a Nuclear Medicine Physician. The following variables were registered: fat mass (Kg), fat free mass (Kg), appendicular skeletal muscle mass (Kg), appendicular skeletal muscle mass index (Kg/m²).

Body composition was assessed immediately following each RMR measurement via Dual-Energy X-Ray Densitometry (DXA; GE Lunar Prodigy, GE Healthcare Asia-Pacific). Each DXA scan provided an assessment of fat mass, lean mass and bone mineral content (BMC). Fat-free mass (FFM) was calculated as lean mass plus BMC. Radiation safety approval was provided by the Radiation Safety Committee at the John James Hospital, Canberra. Athletes provided a urine sample at first void for assessment of hydration status via urine-specific gravity from digital hand-held refractometer (ATAGO, USA). Energy intake and consumption of macronutrients were recorded for the three days immediately prior to each RMR measurement, and later analysed for total energy and macronutrient intake by an accredited practising dietician using FoodWorks Professional v7.0.3016 (Xyris Software Pty Ltd, Australia). Athletes were not instructed to adhere to certain dietary guidelines or practices in order to assess natural behaviours in an applied setting.

The BMD (g/cm²) of the lumbar spine was measured based on DXA images (GE Lunar Prodigy, GE Healthcare, Madison, WI, USA) using Encore software version 11.0 (GE Healthcare, Chicago, IL, USA), according to the manufacturer’s guidelines. The precision error in BMD of the lumbar spine was 1.7%. Lumbar spines with compression fractures or severe sclerotic changes were excluded during the image acquisition process.
The TBS of the lumbar spine was assessed by TBS iNsight Software, version 2.0.0.1 (Med-Imaps, Pessac, France) using the lumbar spine DXA file.

The primary outcome was change in fat mass index (FMI) from age 18 to 22 years (∆FMI). The secondary outcome was change in fat mass from age 18 to 22 years (∆FM). We also explored change in body mass index (BMI) from age 18 to 22 years (∆BMI) as an outcome. During clinic visits at age 18 and 22 years, participants underwent a whole-body DXA scan (GE Lunar Prodigy, USA). Detailed study procedures have been described elsewhere [29 (link)]. Scan images were analyzed using the in-built GE Lunar enCore software. Fat mass (kg) was derived from the image analysis. FMI was calculated by dividing fat mass (kg) by height squared (height²).

As described above, determination of the number of subjects to be enrolled in the present study was based on a combination of data from other published studies in our laboratory and a pilot study specific to the subject population and exercise protocol (McFarlin et al., 2006 (link), 2013 (link); Strohacker et al., 2012 (link); Carpenter et al., 2013 (link)). Over a period of 2 years, we enrolled subjects until we reached our target of over 100 total subjects completing the entire study protocol. College-aged men and women who were of average physical activity status and who were not actively exercising were recruited. Subjects were screened for inclusion/exclusion criteria using a written medical history form, a whole body DXA scan for body composition (GE Lunar Prodigy; USA), and a graded exercise test on a treadmill. Detailed subject characteristics are presented in Table 1.