Increased levels of substance P in patients taking beta‐blockers are linked with a protective effect on oropharyngeal dysphagia.

Miarons, M.; Tomsen, N.; Nascimento, W.; Espín, À.; López‐Faixó, D.; Clavé, P.; Rofes, L.

Abstract: Background: We have recently found a potential protective effect of beta‐blockers on oropharyngeal dysphagia (OD). The action mechanism by which beta‐blockers could wield this protective effect is unknown, but the neurotransmitter substance P (SP) could play a key role. The aim of this study was to analyze serum and saliva SP levels in patients taking beta‐blockers (TBB), and to explore its relationship with OD. Methods: Adult (>50 year) patients TBB were randomly recruited from the primary care setting and 1:1 matched by age, sex, and Barthel Index (BI) with patients not taking beta‐blockers (NTBB). Serum and saliva samples were taken and analyzed for their SP levels using an enzyme‐linked immunosorbent assay (ELISA). Socio‐demographic and clinical variables were collected. Dysphagia was evaluated in all patients using the clinical volume‐viscosity swallow test (V‐VST). Key Results: We studied 28 patients TBB (64.96 ± 7.31 years, 57.1% women, BI 99.6 ± 1.31, carvedilol‐equivalent dose 24.11 ± 18.12 mg) and 28 patients NTBB (65.61 ± 6.43 years, 57.1% women, BI 99.6 ± 1.31). SP serum levels were significantly higher in patients TBB (260.68 ± 144.27 vs 175.46 ± 108.36 pg/mL, P = .009) as were SP saliva levels (170.34 ± 146.48 vs 102.73 ± 52.28 pg/mL, P < .001) compared with patients NTBB. The prevalence of OD was 32.1% in patients TBB and 67.9% in patients NTBB (P = .015). Moreover, patients with OD had significantly lower SP saliva levels in comparison with patients without clinical signs of OD (98.39 ± 43.25 vs 174.69 ± 147.21 pg/mL) P < .001. Conclusions & Inferences: We have found that serum and saliva SP levels are greater in patients TBB. This increase in SP levels could be the action mechanism by which beta‐blockers protect patients from OD.

ADRENERGIC beta blockers; GASTROINTESTINAL motility disorders; DEGLUTITION disorders; SUBSTANCE P; INFLAMMATORY mediators; SERUM; SALIVA

Neurogastroenterology & Motility, 2018, Vol 30, Issue 9, p1

1350-1925

Academic Journal

10.1111/nmo.13397