Abstract
STUDY OBJECTIVES: Sleep-disordered breathing (SDB) can induce hyperglycemia, hypertension, and oxidative stress, conditions that are known to cause kidney damage. Therefore, SDB may exacerbate albuminuria, which is an established marker of early-stage kidney damage in patients with type 2 diabetes mellitus (T2DM). The association between SDB and albuminuria in patients with T2DM was investigated in this study. METHODS: This cross-sectional study included 273 patients with T2DM who underwent portable sleep testing and measurement of urine albumin to creatinine ratio (UACR). The association between the severity of SDB and albuminuria was investigated. Patients were divided into three groups according to the respiratory event index (REI): the no or mild group (REI < 15 events/h), moderate (REI 15 to < 30 events/h), and severe (REI ≥ 30 events/h). Albuminuria was defined as UACR ≥ 3.4 mg/mmol creatinine. Logistic regression analysis for albuminuria included the categorical REI as the independent variable. RESULTS: The median (interquartile range) REI of all patients (age 57.9 ± 11.9 years, mean ± standard deviation, male sex 81.7%, body mass index 26.7 [24.2-29.5] kg/m(2), estimated glomerular filtration rate 82 [65-97] mL/min/1.73 m(2)) was 13.0 (7.0-24.2) events/h. The REI, as a categorical variable, was significantly associated with albuminuria after adjustment for other risk factors for albuminuria; REI 15 to < 30 events/h: odds ratio (OR) 3.35, 95% confidence interval (95% CI), 1.68-6.67, P < .001; REI ≥ 30: OR 8.52, 95% CI, 3.52-20.63, P < .001). In addition, the natural logarithm-transformed REI of all patients also correlated significantly with albuminuria. CONCLUSIONS: The severity of SDB is associated with albuminuria in patients with T2DM.