TY - JOUR T1 - Impaired endothelial function in obstructive sleep apnoea: Allometric scaling can help estimate the true difference in flow-mediated response JF - Heart JO - Heart SP - 968 LP - 969 DO - 10.1136/heartjnl-2013-303772 VL - 99 IS - 13 AU - Greg Atkinson Y1 - 2013/07/01 UR - http://heart.bmj.com/content/99/13/968.2.abstract N2 - To the Editor One of the most consistent findings in research on percentage flow-mediated dilation (FMD%) is the negative correlation between baseline arterial diameter (Dbase) and FMD% itself. The study by Namtvedt et al 1 is no exception in this respect. FMD% is obviously already an attempt to ‘normalise’ the measured change in arterial diameter (in millimetre) for variability in Dbase, but seems to do this job poorly.2 ,3 In a well-designed study, Namtvedt et al 1 reported that FMD% was 3.7% lower in patients with … ER -