Continuous Positive Airway Pressure Effect on Albuminuria Progression in Patients with Obstructive Sleep Apnea and Diabetic Kidney Disease: A Randomized Clinical Trial.

Rationale: Obstructive sleep apnea (OSA) is associated with impaired glycemic control and a higher risk of vascular complications, such as diabetic kidney disease (DKD). However, the effect of apnea-hypopnea suppression on DKD progression is unclear. Objectives: To assess the effect of continuous positive airway pressure (CPAP) on the urinary albumin-to-creatinine ratio (UACR) in patients with DKD and OSA. Methods: In a 52-week, multicentric, open-label, parallel, and randomized clinical trial, 185 patients with OSA and DKD were randomized to CPAP and usual care (n = 93) or usual care alone (n = 92). Measurements and Main Results: UACR, estimated glomerular filtration rate, serum concentrations of creatinine and glycated hemoglobin, insulin resistance, lipid concentrations, sleepiness, and quality of life. A 52-week change in UACR from baseline did not differ significantly between the CPAP group and the usual-care group. However, in per-protocol analyses that included 125 participants who met prespecified criteria for adherence, CPAP treatment was associated with a great reduction in UACR (mean difference, -10.56% [95% confidence interval, -19.06 to -2.06]; P = 0.015). CPAP effect on UACR was higher in nonsleepy patients with more severe OSA, worse renal function, and a more recent diagnosis of DKD. CPAP treatment also improved glycemic control and insulin resistance, as well as sleepiness and health-related quality of life. Conclusions: In patients with OSA and DKD, the prescription of CPAP did not result in a statistically significant reduction in albuminuria. However, good adherence to CPAP treatment in addition to usual care may result in long-term albuminuria reduction compared with usual care alone. Clinical trial registered with www.clinicaltrials.gov (NCT02816762).

Obstructive sleep apnea is associated with impaired renal function in patients with diabetic kidney disease.

Obstructive sleep apnea (OSA) is a recognized risk factor for the development of diabetic kidney disease (DKD). Our objectives were to compare the urinary albumin-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) of patients with DKD according to OSA severity, and to evaluate the contribution of sleep parameters to their renal function. In a multicenter, observational, cross-sectional study, 214 patients with DKD were recruited. After a sleep study, UACR and eGFR were measured, as well as serum creatinine, fasting glucose, glycated hemoglobin, insulin resistance, lipid profile and C-reactive protein. UACR was higher in severe OSA patients (920 ± 1053 mg/g) than in moderate (195 ± 232 mg/g, p < 0.001) or mild OSA/non-OSA subjects (119 ± 186 mg/g, p < 0.001). At the same time, eGFR showed an OSA severity-dependent reduction (48 ± 23 vs. 59 ± 21 vs. 73 ± 19 ml/min per 1.73 m2, respectively; p < 0.001). Apnea-hypopnea index (AHI and desaturation index (ODI) were identified as independent predictors for UACR and eGFR, respectively. Therefore, in patients with DKD under optimized treatment, severe OSA is associated with a higher UACR and a lower eGFR, reflecting an additional contribution to the impairment of their renal function, although no causality can be inferred.

[Diagnostic value of respiratory polygraphy in patients with low probability of obstructive sleep apnea syndrome]. / Valor diagnóstico de la poligrafía respiratoria en pacientes con baja probabilidad de síndrome de apneas e hipopneas durante el sueño.

INTRODUCTION AND OBJECTIVE: Polysomnography (PSG) is the gold standard technic for the diagnosis of obstructive sleep apnea syndrome (OSAS). It is an expensive, complex and not always available technic, meaning that respiratory polygraphy (RP) has become usual. Although RP is not validated in low probability patients, Spanish guidelines recommend conservative treatment in patients with negative RP. We intended to study the prevalence and severity of OSAS through PSG in a sample of patients with low probability and negative RP. MATERIAL AND METHODS: Retrospective, observational, descriptive and analytic study of low probability OSAS patients with negative RP in whom a PSG was performed. Anthropometric, clinical and sleep data were collected. RESULTS: Eighty-two patients were included. After PSG, a greater number of hypopneas (137.8±70.1 vs. 51.2±38.4 [P<.05]) and apnea hypopnea index (27.8±15.6 vs. 11.7±7.1 [P<.05]) was observed, as well as an increment in OSAS prevalence of 17%, which was 35% in severe OSAS. In mild OSAS, there was a decrement of 41%. CONCLUSION: According with the results of this study, RP significantly underestimates the prevalence and severity of OSAS in low probability patients. While it is necessary to adequately stratify the OSAS probability in order to correctly indicate diagnosis tests, we recommend performing a PSG in low probability patients with negative RP.