Volume and Nutritional Status Evaluated by Bioimpedance Affected by Body Positions

OBJECTIVE: Body composition analysis is useful technique for assessing hydration, nutritional status and predicting clinical outcomes. Bioimpedance analysis (BIA) is a cheap and noninvasive tool for monitoring body composition but needs some improvements regarding measurement methods. We aimed to fi nd out if body position has an effect on the BIA results. MATERIAL and METHODS: Personal characteristics including age, gender, height, weight and blood pressure were recorded. Hydration and nutritional status measured by body composition monitor in supine and standing positions consequently for each individual. RESULTS: Two hundred and one populations from various region in Turkey, 61% (n: 123) male, mean age was 46.3±12 years (18-76) of age, participated in this crossectional study. From supine to standing positions overhydration and extracellular water (ECW) were increased from 0.04±1.08 and 17.69±2.92 to 0.46±1.05 L and 17.84±2.90 L while intracellular water (ICW) decreased from 22.55±4.35 to 22.04±4.28 L signifi cantly. Systolic and diastolic blood pressures were 131.3±18.1 and 75.1±12 decreased to 127.0±16.0 and 72.2±9.0 mmHg in supine to standing positions (p> 0.05). CONCLUSION: Supine and standing positions could affect the volume parameters of BIA due to shift of ECW and ICW by gravity but nutritional parameters also changes signifi cantly. Protocols should be re evaluated in order to get more accurate results in bioimpedance measurements.