Sleep apnea may be a novel risk factor for chronic kidney disease (CKD), a new Taiwanese study suggests.
The risk of CKD was 58% greater among sleep apnea (SA) patients compared with similar patients without the sleep disorder. The contribution of SA was equivalent to hypertension.
“Thus, SA should be added to the list of factors considered in CKD risk assessment, enhancing the ability to prevent CKD…” lead researcher Yung-Tai Chen, MD, from Taipei City Hospital in Taiwan, and colleagues concluded in Respirology.
Using Taiwan’s National Health Insurance Research Database 2000-2010, the investigators identified 8,687 patients with SA and 34,747 matched controls without SA. During a median 3.9 years, CKD developed in 157 patients with SA and 298 without SA. SA patients were 1.58 times more likely to be diagnosed with CKD. The researchers accounted for hypertension, diabetes, medications, demographic factors, and other potential confounding variables.
Dr. Chen and colleagues determined that the relative contribution of SA to CKD was 17%, similar to that of hypertension, whereas diabetes conferred a 117% greater risk of CKD. Patients who had all 3 conditions had a 479% greater risk of CKD.
The purported harmful effects of SA toward CKD risk appear independent from hypertension and diabetes. The findings support previous research showing increased CKD risk with SA. For example, a US study published in Thorax (2015;70:888-895) of mostly male veterans found 2.3 and 2.7 greater risks of CKD among those with untreated and treated obstructive SA.
Other research has found that CKD patients are at greater risk of SA. The relationship between CKD and SA might be bidirectional.
Previous research has suggested potential mechanisms, according to the investigators, including compromised renal oxygen or blood flow, activation of the renin-angiotensin system or sympathetic tone, endothelial injury, and elevated oxidative stress.
Dr. Chen and colleagues acknowledged they were unable to account for SA severity, obesity, tobacco use, and family history. As the study involved the population of Taiwan, the results may not pertain to non-Asians. Future prospective studies are needed to confirm the association.
- Chu H, Shih CJ, Ou SM, Chou KT, Lo YH, and Chen YT. Association of Sleep Apnoea With Chronic Kidney Disease in a Large Cohort from Taiwan. Respirology. doi: 10.1111/resp.12739.