Guoxin Zhang,1,* Liqin Yang,2,* Fang Zhao,1 Xiaoyun Zhao1 

1Respiratory and Critical Care Medicine Department, Tianjin Chest Hospital, Tianjin, People’s Republic of China; 2Institute of Mental Health, Tianjin Anding Hospital, Mental Health Center of Tianjin Medical University, Tianjin, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Xiaoyun Zhao, Respiratory and Critical Care Medicine Department, Tianjin Chest Hospital, Tianjin, 300222, People’s Republic of China, Tel +86 8818 2075, Email zxydoctor@163.com

Objective: To explore the characteristics of elderly patients with central sleep apnea (CSA).
Methods: This retrospective study divided 123 patients with CSA into elderly and non-elderly groups, and compared them in terms of demographic characteristics (age, BMI, etc), underlying diseases (hypertension, coronary heart disease, and cardiac arrhythmias, etc). and polysomnography parameters. Multiple linear regression analysis was conducted to investigate the potential risk factors of central apnea index (CAI).
Results: Compared with the non-elderly group, patients in the elderly group had lower body mass index, a higher proportion of comorbidities of coronary heart disease, arrhythmias, and diabetes, lower apnea-hypopnea index (AHI), obstructive apnea index (OAI) and oxygen desaturation index (ODI). CAI of the elderly group showed a trend higher than that of the non-elderly group with no statistical difference. However, the ratio of CAI to AHI in the elderly group was significantly higher (0.264 vs 0.154, P=0.003). True CSA was less prevalent than companion CSA in both groups. The results of multiple regression analysis indicated CAI was independently associated with age (β=0.256, P=0.005), OAI (β=− 0.543, P< 0.001), MAI (β=− 0.267, P=0.005), ODI (β=0.538, P< 0.001), heart failure (β=0.300, P< 0.001).
Conclusion: CSA typically coexists with other types of sleep apnea. Elderly CSA patients have characteristics such as a lower BMI, and a milder decrease in blood oxygen saturation, along with higher prevalence of arrhythmia and coronary heart disease. Age may be a potential risk factor for CSA.

Keywords: elderly people, sleep apnea, heart failure, oxygen desaturation index