Population data provide evidence against the presence of a set point for hemoglobin levels or tissue oxygen delivery

Though set points have long been regarded as integral components of homeostatic physiology evidence is accumulating casting doubt on the existence of such set points for some parameters. In this work we show that examination of the population correlations between haemoglobin and erythropoietin indicates that haemoglobin is yet another parameter, the regulation of which, is unlikely to be ordered about a set point level. This finding is relevant to understanding haemoglobin physiology but also has relevance to the understanding of homeostatic regulation in general. AbstractHemoglobin levels are believed to be regulated as per a set point model of regulation. This model of regulation, by which specific levels of a parameter are targeted and defended by physiological systems, implies a particular population correlation between the parameter and its controlling hormone. Empirical population correlations of other parameters and their controlling hormones, have denied the presence of such set point ‐based regulation. To assess if hemoglobin is regulated according to a set point model we performed a systematic search of PubMed/MEDLINE and Web of Science identifying relevant reports published up to November 2018. Population hemoglobin/erythropoietin level correlations were retrieved, and thes e empirically derived correlations were compared with the positive correlation implied by a set point model of regulation. Authors of papers containing potentially suitable data were contacte...

Source: Physiological Reports - June 25, 2019 Category: Physiology Authors: Stephen P. Fitzgerald, Niels Grote Beverborg, Yves Beguin, Ferruh Artunc, Henrik Falhammar, Nigel G. Bean Tags: Original Research Source Type: research