Midregional Pro-Adrenomedullin as a Predictor for Therapeutic Response to Midodrine Hydrochloride in Children With Postural Orthostatic Tachycardia Syndrome

Neuropeptides and peptide hormones in syncope and orthostatic intolerance

“…In this regard, changes in circulatory catecholamines have tended to be of greatest interest given the apparent association of VVS with anxiety or stress states [8][9][10][11][12][13][14]. However, the potential role of NPs has also attracted attention; specifically, BNP [8], vasopressin (VP) [8,15,16], atrial natriuretic peptide (ANP) [8,17], adrenomedullin (ADM) [17][18][19], galanin (GAL) [19,20], and endothelin-1 (ET-1) [17,[21][22][23]. A summary of the primary physiologic effects of these NPs is shown in Table 2.…”

“…Zhang et al [18] examined the predictive value of the MR-proADM in assessing the therapeutic efficacy of midodrine hydrochloride for children with POTS. The authors reported higher levels of MR-proADM in otherwise healthy children with a clinical diagnosis of POTS compared with normal controls.…”

“…In an editorial [10] accompanying the article by Zhang et al [18], concerns were raised regarding the study design, the midodrine dose employed, and the physiological mechanism for the apparent efficacy of midodrine in patients with elevated ADM. Excluding concerns related to the utility of midodrine in POTS patients, the possibility that vasoactive peptides, particularly ADM, contribute to the pathophysiology of POTS is intriguing.…”

“…Excluding concerns related to the utility of midodrine in POTS patients, the possibility that vasoactive peptides, particularly ADM, contribute to the pathophysiology of POTS is intriguing. Even if NPs are epiphenomena in POTS, the study from Zhang et al [18] raises the prospect of utilizing vasoactive peptide concentrations as useful quantitative markers of POTS severity, and potentially as a means other than symptom status that can be tracked in individual patients as treatments are introduced.…”

Peptides in Postural Orthostatic Tachycardia Syndrome

“…Consequently, efforts designed to gain more sophisticated understanding of this mysterious affliction are welcome. In this issue of the Journal, Zhang et al (21) investigated levels of circulating MR-proADM as a surrogate for ADM in children carrying a diagnosis of POTS. The authors report higher levels of MR-proADM in otherwise healthy children with a clinical diagnosis of POTS compared with normal controls.…”