Kidney function declines faster with high sleep apnea risk



PHILADELPHIA – Patients with type 2 diabetes, chronic kidney disease, and a high risk of obstructive sleep apnea have more rapid loss of kidney function than do similar patients with a low risk of sleep apnea, findings from a retrospective cohort study suggest.

Of 56 patients with diabetic nephropathy who underwent screening for obstructive sleep apnea, 34 (61%) were at high risk. Compared with 22 patients with a low risk score, the high-risk patients had a significantly greater loss of estimated glomerular filtration rate over time (median loss of -3.4 vs. 1.5 ml/min/1.73 m2 per year for the high- vs. low-risk patients, respectively), Dr. Roberto Pisoni reported in a poster at the annual meeting of the American Society of Nephrology.

This finding was despite comparable blood pressure for the high- and low-risk groups (systolic: 141.7 and 143.7 mm Hg; diastolic: 72.0 and 72.4 mm Hg, respectively), proteinuria upon admission to a chronic kidney disease clinic (urinary protein/creatinine ratio, 1.9 and 1.6 g/g, respectively), and time spent in clinic (1.9 vs. 2.1 years, respectively), said Dr. Pisoni of the Medical University of South Carolina, Charleston.

Patients in the high- and low-risk groups also had similar baseline gender, body mass index, use of renin-angiotensin-aldosterone system blockers, eGFR, and co-morbidities, he noted.

Data used for this study were from the University of Alabama at Birmingham Chronic Kidney Disease Database. Patients had completed the Berlin questionnaire to assess for sleep apnea during a 9-month study period.

Obstructive sleep apnea is common in patients with type 2 diabetes and is also associated with glomerular hyperfiltration and proteinuria in patients with normal renal function, which raised the question of whether it might be related to chronic kidney disease progression, Dr. Pisoni explained. He noted that the association between obstructive sleep apnea and diabetic nephropathy has not been fully investigated.

The study demonstrated that the “simple approach” of assessing obstructive sleep apnea risk identifies patients who are also at increased risk of CKD progression, he said, adding that the findings require replication in a prospective cohort.

Dr. Pisoni reported having no disclosures.

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