Nasal continuous positive airway pressure improved circadian pattern of blood pressure and glycemic control in a diabetic hemodialysis patient with obstructive sleep apnea syndrome

The prevalence of sleep apnea syndrome (SAS) in hemodialysis patients is extremely high as compared to the general population, and it has recently been suggested that SAS is a risk factor for cardiovascular complication. We report a case of obstructive SAS, who presented nighttime hypertension in a diabetic hemodialysis patient. A 33-year-old woman undergoing hemodialysis for three years due to diabetic end stage renal disease was admitted to our hospital for nighttime esquinancea, insomnia and severe hypertension. Ambulatory blood pressure monitoring showed reverse-dipper status. We administered antihypertensive drugs and tried to control her dry weight to reduce volume overload, but failed to improve clinical symptoms and hypertension. Polysomnography was performed and she was diagnosed as having obstructive SAS with an apnea-hypopnea index (AHI) of 30.1. After nasal continuous positive airway pressure (CPAP) treatment, symptoms were improved and AHI was reduced to 14.7. Daytime and nighttime blood pressure decreased and the circadian pattern was restored to dipper pattern. Moreover, plasma glucose at the start of dialysis session and HbA1c level were reduced after CPAP treatment. We speculate that increased activity of the sympathetic nervous system along with SAS might have played an important role in hypertension presenting reverse-dipper status and insulin resistance. The restoration of a circadian blood pressure pattern and improvement in insulin sensitivity induced by nasal CPAP treatment may lead to an improvement in the prognosis of hemodialysis patients.