Relaxin in Obstructive Sleep Apnea: Relationship with Blood Pressure and Inflammatory Mediators.
Respiration
; 91(1): 56-62, 2016.
Article
em En
| MEDLINE
| ID: mdl-26731435
ABSTRACT
BACKGROUND:
Obstructive sleep apnea (OSA) is associated with nocturnal intermittent hypoxia, which may be responsible for increased circulating levels of vascular endothelial growth factor (VEGF) and inflammatory mediators, such as metalloproteinases (MMPs), and which contributes to the pathogenesis of systemic hypertension. Why some OSA patients remain normotensive is poorly understood. Relaxin-2, a pregnancy hormone, may sometimes circulate in men and could increase in hypoxic conditions. It exerts a vasodilatory activity and can modulate the release of molecules, such as MMPs and VEGF.OBJECTIVES:
The objective of this study was to explore if circulating relaxin-2 in male OSA subjects may be related to OSA severity, to circulating levels of MMPs, of their inhibitors (tissue inhibitors of metalloproteinases; TIMPs), and of VEGF, and if it may protect from hypertension. PATIENTS ANDMETHODS:
Fifty untreated male subjects with suspected OSA were recruited. After nocturnal polysomnography, a morning venous blood sample was withdrawn. Then, 24-hour ambulatory blood pressure (BP) monitoring was performed.RESULTS:
The respiratory disturbance index in the sample was 30.4 [interquartile range (IQR) 15.6-55.2]. Relaxin-2 was detectable in 20 subjects. These subjects did not differ in OSA severity or diurnal and nocturnal BP from subjects with undetectable relaxin-2, but they showed lower TIMP-1 (126.8 ± 29.1 vs. 156.9 ± 41.7 pg/ml, respectively; p = 0.007) and a marginally higher MMP-9/TIMP-1 molar ratio [0.58 (IQR 0.23-1.35) vs. 0.25 (IQR 0.15-0.56); p = 0.052].CONCLUSIONS:
Relaxin-2 in male subjects was not related to OSA severity, but it was associated with lower TIMP-1. As it was often undetectable, even when BP values were normal, it is unlikely that it plays a role as a major factor protecting from hypertension in OSA.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Relaxina
/
Mediadores da Inflamação
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Inibidores Teciduais de Metaloproteinases
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Apneia Obstrutiva do Sono
/
Metaloproteinases da Matriz
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Fator A de Crescimento do Endotélio Vascular
/
Hipertensão
/
Hipóxia
Tipo de estudo:
Etiology_studies
Limite:
Adult
/
Humans
/
Male
/
Middle aged
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article