Low-grade urinary albumin excretion in normotensive/non-diabetic obstructive sleep apnea patients

Abstract

Previous studies have indicated that high levels of urinary albumin excretion (UAE) are associated with an increased incidence of cardiovascular morbidity and mortality. This study examined the association between UAE and obstructive sleep apnea syndrome (OSAS). The study included 35 newly diagnosed OSAS patients and 11 nonapneic controls. Subjects with diabetes mellitus, hypertension, a history of renal failure, cardiac failure, coronary heart disease, collagen tissue disease, high serum creatinine, and urinary infection, and who use angiotensin-converting enzyme inhibitors and were women were excluded from the study. A single void morning urine sample at the baseline examination was used to measure UAE. There were no significant differences in the age, body mass index (BMI), and smoking habits of the OSAS patients and controls. UAE of the OSAS group was significantly higher than that of the control group (23.3 +/- 6.1 microg/min vs. 6.5 +/- 2.1 microg/min, respectively; P = 0.002). UAE was positively correlated to length of time spent at an oxygen saturation of <90% (r = 0.503, P = 0.002) and BMI (r = 0.361, P = 0.033). Regression analyses (r (2) = 0.504, P < 0.0001) showed that the length of time spent at an oxygen saturation of <90% (P < 0.0001) was risk factor for UAE, independent of age and BMI. Our study supports the notion that low-grade UAE is associated with non-hypertensive/non-diabetic OSAS, independent of age and BMI. Low-grade UAE may be a marker for subclinical vascular damage that predisposes OSAS patients to future cardiovascular disease.

Albuminuria and Renal Function in Obese Adults Evaluated for Obstructive Sleep Apnea

“…A cross-sectional study showed nondiabetic adults with untreated hypertension to have significantly greater ACR (by 57%) in the presence of OSA that correlated with AHI and 24-hour pulse pressure [20]. A case-control study showed low-grade albuminuria in nondiabetic normotensive adults with OSA that correlated with length of time at oxygen saturation <90% and BMI [21]. Our findings do not agree with these studies, which is likely due to our study design.…”

The association of obstructive sleep apnea and renal outcomes—a systematic review and meta-analysis

“…A further 19 articles were excluded following detailed review, of which 3 were review articles, which we reviewed to find potential relevant articles [ 10 , 12 , 18 ]. The remaining 16 were excluded for the following reasons: 1 focused on central apnea [ 19 ], 6 did not have a clear definition of nephropathy [ 20 – 25 ], 3 may have contained biased data (e.g., 1 related to creatinine clearance, i.e., over 200 ml/min [ 26 ], 2 had fewer than 10 subgroup participants [ 27 , 28 ]), 3 had missing data [ 6 , 7 , 29 ], and 1 focused only on the OSA population without a control group [ 30 ]. Finally, 18 studies [ 5 , 8 , 9 , 31 – 45 ] that included 7090 patients were incorporated in our meta-analysis.…”

The Triad of Sleep Apnea, Hypertension, and Chronic Kidney Disease: A Spectrum of Common Pathology

“…Many studies have shown that urinary albumin-creatinine ratio is an independent risk factor associated with the severity of OSA [54][55][56] . Faulx et al [54] have shown that the severity of OSA is significantly associated with increased urine albumin excretion.…”