Differential Associations Between Two Markers of Probable Sarcopenia and Continuous Orthostatic Hemodynamics in The Irish Longitudinal Study on Ageing

Abstract

Background: Sarcopenia and orthostatic hypotension are growing age-related health burdens associated with adverse outcomes including falls. Despite a possible pathophysiological link, the association between the two disorders is not well elucidated. We sought to investigate this relationship in The Irish Longitudinal Study on Ageing (TILDA). Methods: Data from 2,858 participants at wave 3 of TILDA were analyzed. Probable sarcopenia was defined as per the European Working Group on Sarcopenia in Older People revised definition cut-offs (hand grip strength (HGS) < 27kg in men, <16kg in women and/or five-chair stand test (5CST) time >15s). Participants underwent an active stand orthostatic test with continuous blood pressure (BP) monitoring. Multi-level mixed effects models, controlling for possible confounders, were used to assess the effect of probable sarcopenia by HGS and 5CST criteria on the change in BP after standing. Results: HGS- and 5CST-defined probable sarcopenia were independently associated with an attenuated BP recovery at 10-20s post-stand (systolic BP: β -0.54, P<0.001; β -0.25, P<0.001). On average, those meeting HGS probable sarcopenia criteria had a significantly lower BP at 20, 30 and 40s (differences in systolic BP: -5.01mmHg, -3.68mmHg, -2.32mmHg, P<0.05 for all). Those meeting 5CST probable sarcopenia criteria had a significant difference in systolic BP at 20s (-1.94mmHg, P=0.002) but not at 30 or 40s. Conclusions: Probable sarcopenia had a significant association with delayed orthostatic blood pressure recovery, with HGS-defined probable sarcopenia having a stronger association than 5CST-defined probable sarcopenia. Results support a modest but significant pathophysiological link between probable sarcopenia and orthostatic hypotension.