Bc418ma body composition analyzer

Standing height was measured barefoot to the nearest centimeter using a Seca 240-cm height measure (Seca GmbH & Co. KG, Hamburg, Germany) [22 ]. Hip circumference (HC) and waist circumference (WC) were measured to the nearest cm using a Seca 200-cm tape measure (seca GmbH & Co. KG, Hamburg, Germany). Waist measurement was recorded at the smallest part of the trunk on the outbreath. In cases where a natural indent could not be found, the tape was passed around the level of the umbilicus. HC was obtained at the widest part of the hips [22 ]. The measurements were later used to calculate waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR). Body weight and whole body fat mass were measured with a Tanita BC418MA body composition analyzer (Tanita Europe B.V., Amsterdam, The Netherlands) to the nearest 0.1 kg by bioelectrical impedance. Body mass index was calculated as weight in kg divided by height in m² [22 ].

The study was performed using a Tanita BC-418 MA body composition analyzer (23 (link)). The apparatus used uses a non-invasive electrical bioimpedance method. This method is based on the measurement of the total electrical resistance of the body, which is the result of resistance (passive resistance) and reactance (active resistance). This measurement is carried out using a set of surface electrodes that are connected to a computer analyzer. The process uses a current of a certain frequency and intensity. The study was conducted in the morning (8:00–12:00) to reduce the risk of physical activity affecting the instrument reading. Participants entered the study dressed in light and comfortable sportswear. The test subject’s task was to step barefoot onto the testing apparatus (sensors under the feet) and grasp special handles (sensors at the hands), during the measurement the test subject stood upright looking ahead.

Covariates were selected based on a pre-defined directed acyclic graph (online Supplemental Figure S1). Age was determined from birthdate (acquired from central registry, updated by participant) and the date when the accelerometry started (derived from the accelerometers). Information on the other covariates were obtained from the anthropometric measurements conducted by the trained nurses and the self-report questionnaire completed during the recruitment, including body mass index (BMI), body fat percentage, ethnicity, Townsend deprivation index (TDI), smoking status, menopause status, history of hysterectomy, and number of children. BMI was constructed as weight in kilograms divided by height in meters squared. The height was measured using the Seca 240 measuring rod, while the weight and the body fat percentage were assessed using the Tanita BC418MA body composition analyzer. TDI is a composite metric of material deprivation that incorporates unemployment, non-car ownership, non-home ownership, and household overcrowding, with higher values indicating lower socio-economic status [13 (link)]. TDI was assigned to each participant according to their postcode and the result of preceding national census. Details of these covariates can be found on the website of the UK Biobank.

Anthropometric measurements included height, weight (kg), body mass index (weight (kg)/(height squared (m²)), fat percentage (BC-418 MA body composition analyzer; Tanita, Tokyo, Japan) and resting blood pressure (Omron M3 or Omron M6 Comfort; Omron Corporation, Kyoto, Japan). Cardiorespiratory fitness level was assessed using the Ekblom-Bak submaximal cycle ergometer test (Monark AB, Varberg, Sweden) [21 (link)], in which the maximal oxygen uptake is estimated based on the difference in heart rate between an initial low standard workload and a subsequent higher ‘final’ workload [22 (link)]. During the cycle test, heart rate was monitored using an arm-worn Polar^® OH1 heart rate monitor (Polar Electro Oy, Kempele, Finland).

At the UK Biobank baseline interview, trained staff measured standing height using the Seca 202 device (Seca, Hamburg, Germany). BMI was calculated by dividing weight (kg) by the square of standing height (m²). The Wessex non-stretchable sprung tape measure (Wessex, UK) was used to measure waist circumference at the level of the umbilicus. The Tanita BC-418MA body composition analyzer (Tanita, Tokyo, Japan) was used to measure body fat per cent using bioelectrical impedance. DXA was used to measure fat per cent on a subset of 2457 participants included in the present study, beginning in 2014 using the GE-Lunar iDXA (GE Healthcare, Chicago, Illinois, USA).