Association Cystatin C and Risk of Stroke in Elderly Patients With Obstructive Sleep Apnea: A Prospective Cohort Study

Xiaofeng Su; Yinghui Gao; Weihao Xu; JianHua Li; Kaibing Chen; Yan Gao; JingJing Guo; LiBo Zhao; Huanhuan Wang; Xiaoshun Qian; Junling Lin; Jiming Han; Lin Liu

doi:10.3389/fnins.2021.762552

Association Cystatin C and Risk of Stroke in Elderly Patients With Obstructive Sleep Apnea: A Prospective Cohort Study

Front Neurosci. 2021 Dec 15:15:762552. doi: 10.3389/fnins.2021.762552. eCollection 2021.

Authors

Xiaofeng Su^{1

2}, Yinghui Gao³, Weihao Xu⁴, JianHua Li⁴, Kaibing Chen⁵, Yan Gao⁶, JingJing Guo⁷, LiBo Zhao¹, Huanhuan Wang², Xiaoshun Qian¹, Junling Lin⁸, Jiming Han², Lin Liu¹

Affiliations

¹ Department of Pulmonary and Critical Care Medicine of the Second Medical Center and National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China.
² Medical College, Yan'an University, Yan'an, China.
³ PKU-UPenn Sleep Center, Peking University International Hospital, Beijing, China.
⁴ Cardiology Department of the Second Medical Center and National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China.
⁵ Sleep Center, The Affiliated Hospital of Gansu University of Chinese Medicine, Lanzhou, China.
⁶ Department of General Practice, 960th Hospital of PLA, Jinan, China.
⁷ Sleep Medicine Center, Department of Respiratory and Critical Care Medicine, Peking University People's Hospital, Beijing, China.
⁸ Department of Pulmonary and Critical Care Medicine, Beijing Chaoyang Hospital Affiliated to Capital Medical University, Beijing, China.

Abstract

Background: Few prospective cohort studies have assessed the relationship between Cystatin C (Cys-C) and risk of stroke in elderly patients with obstructive sleep apnea (OSA). The study sought to examine the association between baseline serum Cys-C and long-term risk of stroke among elderly OSA patients. Methods: A total of 932 patients with OSA, no history of stroke, ≥60 years of age, and complete serum Cys-C records were included in this study. All patients had completed polysomnography (PSG). OSA was defined as an apnea-hypopnea index (AHI) of ≥5 events per hour. Participants were categorized into four groups according to baseline serum Cys-C concentration, split into quartiles. Multivariate Cox regression were used to evaluate the association between Cys-C and the incidence of new-onset stroke. Results: Stroke occurred in 61 patients during the median 42-month follow-up period. The cumulative incidence rate of stroke was 6.5%, which included 54 patients with ischemic stroke and 7 patients with hemorrhagic stroke. The cumulative incidence of stroke was higher among patients with baseline serum Cys-C concentration of ≥1.15 mg/L when compared with other groups (P _Log-rank < 0.001). After adjusting for potential confounding factors in the Cox regression model, patients with a serum Cys-C concentration of ≥1.15 mg/L had a 2.16-fold higher risk of developing stroke compared with patients with serum Cys-C ≤ 0.81 mg/L (HR, 2.16, 95%CI, 1.09-6.60; P = 0.017). Additionally, there was a higher risk in those of age ≥70 years (HR, 3.23, 95%CI, 1.05-9.24; P = 0.010). The receiver-operating characteristic curves showed that the capability of Cys-C to identify elderly patients with OSA who had a long-time risk of stroke was moderate (AUC = 0.731, 95% CI: 0.683-0.779, P = 0.001). Conclusion: Increased Cys-C concentration was identified as a risk factor in the incidence of stroke in elderly patients with OSA, independent of gender, BMI, hypertension and other risk factors. Additionally, it conferred a higher risk in patients of age ≥70 years.

Keywords: Cystatin C; cohort study; elderly; obstructive sleep apnea; stroke.