Proceedings of The Physiological Society

Physiology 2016 (Dublin, Ireland) (2016) Proc Physiol Soc 37, PCA200

Poster Communications

Elevated plasma concentrations of soluble (pro)renin receptor in patients with obstructive sleep apnea syndrome

K. Takahashi1, T. Nishijima2, K. Tajima1, Y. Yamashiro2, K. Hosokawa2, A. Suwabe3, S. Sakurai2

1. Department of Endocrinology & Applied Medical Science, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan. 2. Division of Behavioral Sleep Medicine, Iwate Medical University School of Medicine, Morioka, Iwate, Japan. 3. Department of Laboratory Medicine, Iwate Medical University School of Medicine, Morioka, Iwate, Japan.

(Pro)renin receptor ((P)RR) is a receptor for renin and prorenin (Ngyen et al., 2002). (P)RR is implicated in the pathophysiology of diabetes mellitus, hypertension and their complications (Nguyen 2011). Soluble (P)RR (s(P)RR) composed of extracellular domain of (P)RR is generated from (P)RR by furin, and exists in blood (Cousin et al. 2009). We have for the first time reported that plasma concentrations of s(P)RR were elevated in male patients with obstructive sleep apnea syndrome (OSAS) (Nishijima et al. 2014). The aim of the present study was to clarify the difference in plasma s(P)RR concentrations between male and female OSAS patients. Plasma s(P)RR concentrations were studied in 289 subjects (206 males and 83 females) consisting of 259 OSAS patients and 30 non-OSAS control subjects. The 259 OSAS patients were classified into mild (5 ≦ apnea hypopnea index (AHI) < 15 events/h), moderate (15 ≦ AHI < 30), and severe OSAS (AHI ≧ 30). Plasma s(P)RR levels were significantly elevated in all three OSAS groups compared to non-OSAS control subjects in the entire cohort and male subjects, whereas in female subjects, the significant elevation was found only in severe OSAS. Soluble (P)RR levels were significantly correlated with AHI in both sexes, with a higher r value found in male subjects (male r = 0.413, p < 0.0001; female r = 0.263, p < 0.05). The OSAS patients with type 2 diabetes mellitus or chronic kidney disease showed higher plasma s(P)RR levels in both sexes, particularly female OSAS patients with both these comorbidities (diabetic nephropathy). By contrast, the presence of hypertension had negligible effects on plasma s(P)RR levels in OSAS patients of both sexes. When 41 OSAS patients (26 males and 15 females) with AHI ≧ 20 were treated by continuous positive airway pressure treatment, plasma s(P)RR levels were significantly decreased. In conclusion, plasma s(P)RR levels were elevated in OSAS patients of both sexes, and a higher association with the disease severity was found in male OSAS patients.

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