Nocturnal Blood Pressure - Central and Peripheral 24-h Blood Pressure in Chronic Kidney Disease.

150 patients with chronic kidney disease (CKD III-IV) and 75 healthy subject is examined with both central and peripheral 24 hours blood pressure monitoring, 1 night home polygraphy to determine whether the subject has obstructive sleep apnea, and if so the degree (AHI), blood- and urine samples to determine levels of u-AQP2 og u-ENaCɣ, PRC, p-AngII, p-Aldosterone, p-Avp og p-Endothelin.

Primary outcomes

• decrease in peripheral systolic blood pressure at night [< 24 hours]: The difference in the decrease in systolic blood pressure at night by peripheral 24-h BP between patients with chronic kidney disease and healthy subjects.

Secondary outcomes

• decrease in central systolic blood pressure at night [< 24 hours]: The difference in the decrease in systolic BP at night by central 24-h BP between patients with chronic kidney disease and healthy subjects.
• difference in peripheral and central systolic and diastolic blood pressure throughout the day, during the daytime and during nighttime [< 24 hours]: The difference in systolic blood pressure and diastolic blood pressure throughout the day, during the daytime and during nighttime between measurements with peripheral 24-hour monitoring and central 24 hour monitoring in both patients with chronic kidney disease and healthy subjects.
• The correlation between the decrease in nighttime blood pressure on the one hand and severity of OSA, severity of kidney disease and blood pressure during the daytime on the other. [< 24 hours]
• U-AQP2 (urine aquaporin 2) og u-ENaCɣ (urine epithelial sodium channel) [24 hours]: 24 hour urine sample.
• PRC (plasma renin concentration), p-AngII (angiotensin II), p-Aldosterone. P-Avp (vasopressin), p-Endothelin. [< 1 hour]

Sex: All, ages: 18 Years to 80 Years, accepts healthy volunteers

Patients, group 1:

Inclusion Criteria:

* eGFR 15-59 mL/min/1.73 m2 (estimated GFR)
* 18-80 years
* males and females

Exclusion Criteria:

* lack of desire to participate
* treatment for OSA
* malignant disease
* Abuse of drugs or alcohol
* pregnant and lactating
* incompensated heart failure
* atrial fibrillation
* liver disease (ALAT> 200)
* Severe chronic obstructive lung disease (forced expiratory volume in 1 second <50% predicted)

Healthy Subjects:

inclusion criteria

* Healthy volunteers men and women
* age 40 - 80 years
* BMI within the normal range, ie. between 18.5 to 25.0 kg/m2

exclusion Criteria

* Arterial hypertension, ie. ambulatory blood pressure> 130 mmHg systolic and / or 80 mmHg diastolic.
* a history or clinical signs of cardial, pulmonary, hepato, renal, endocrine, cerebral or neoplastic disorders
* Alcohol abuse, ie. > 14 drinks / week for women and> 21/uge for men
* Substance abuse
* Daily medicine intake/ treatment apart from oral contraceptives
* Smoking
* Pregnancy or breastfeeding
* Lack of desire to participate
* Clinically significant, discrepant results of blood or urine sample at inclusion study (ie B-hemoglobin and B-White blood cell count, p-Sodium, p-Potassium, p-creatinine, p-ALAT, p-bilirubin , p-alkaline phosphatase, p-cholesterol, p-albumin or b-glucose and urine for hematuria, albuminuria or glucosuria)
* Clinically significant differences in the electrocardiogram
* Blood Donation for the past month preceding the day on the first attempt sequence.

• Results publication: Hornstrup BG, Gjoerup PH, Wessels J, Lauridsen TG, Pedersen EB, Bech JN. Nocturnal blood pressure decrease in patients with chronic kidney disease and in healthy controls - significance of obstructive sleep apnea and renal function. Int J Nephrol Renovasc Dis. 2018 Nov 8;11:279-290. doi: 10.2147/IJNRD.S176606. eCollection 2018. PMID 30510439