Serum osmolality measured in fingertip capillary blood is comparable to serum osmolality measured in venous blood

Applied Physiology, Nutrition, and Metabolism, Ahead of Print. Blood osmolality is considered the gold standard hydration assessment, but has limited application for technical and invasive reasons. Paired antecubital-venous blood and fingertip-capillary blood were collected pre- and 30  min post-drinking 600 mL water in 55 male/female participants. No bias (0.2 mOsmo/kg, limits of agreement = −2.5 to 2.8 mOsmo/kg) was found between sampling methods, with high linear correlation (Spearman’s r = 0.95, P <  0.001). Capillary blood sampling offers an accurate less-invasive method for determining serum osmolality than venous blood sampling.

Source: Applied Physiology, Nutrition, and Metabolism - August 8, 2023 Category: Physiology Authors: K. Bergin-Taylor M.P. Funnell R.A. Ferguson S.A. Mears L.J. James Source Type: research