Abstract: FR-PO540

Effect of Renal Function and Obstructive Sleep Apnoea on Nocturnal Blood Pressure in Patients with CKD Stage 3-4

Session Information

Category: Hypertension

  • 1106 Hypertension: Clinical and Translational - Secondary Causes

Authors

  • Hornstrup, Bodil Gade, University Clinic of Nephrology and Hypertension, Holstebro, Denmark
  • Gjørup, Pia Holland, Department of Medicin, Holstebro, Denmark
  • Wessels, Jost, Department of Medicin, Holstebro, Denmark
  • Lauridsen, Thomas G., Department of Medicin, Holstebro, Denmark
  • Pedersen, Erling B, Aarhus University, Aarhus, Denmark
  • Bech, Jesper N., University Clinic of Nephrology and Hypertension, Holstebro, Denmark
Background

Many patients with chronic kidney disease (CKD) suffer from high nocturnal blood pressure (BP) and lack of nocturnal BP decrease. These are known to be associated with poorer outcome related to cardiovascular morbidity and mortality. Reasons for high nocturnal BP in patients with CKD are not known. In this case control study, we studied the effect of obstructive sleep apnoea (OSA) and renal function on nocturnal BP in CKD 3-4 subjects.

Methods

Seventy patients with CKD 3-4 (eGFR 15-59 mL/min) from the Renal Outpatients Clinic, Holstebro Hospital were compared with 56 healthy age-matched controls. 24 h ambulatory BP monitoring, blood samples (creatinine) and cardio respiratory monitoring (Apnoea Hypopnea Index, AHI) were performed in all participants.

Results

Non-dipping was seen in 44% (n=31) of CKD3-4 cases and 18% (n=10) of healthy controls (p=0.002). Moderate to severe OSA (AHI>15) was diagnosed in 26% (n=18) of CKD 3-4 cases and 2% (n=2) of controls (p<0.001). Regression analysis showed an association between BMI and nocturnal BP decrease in CKD (p = 0.001), but not in controls; eGFR or OSA were not associated with nocturnal BP.
Compared to dipping CKD3-4 cases, non-dipping CKD3-4 cases had higher BMI (32 vs. 29 kg/m2, p= 0.024) and HbA1c (52 vs. 43 mmol/mol, p=0.03), longer duration of antihypertensive treatment (10 vs. 6 years, p= 0.02), received more antihypertensive drugs (3 vs. 2, p<0.007), and more had history of AMI (29 vs. 5%, p=0.009).

Conclusion

Non-dipping and moderate to severe OSA were more frequently seen in CKD 3-4 than in healthy controls. In contrast to BMI, neither eGFR nor OSA were associated to nocturnal BP decrease in either group. Non-dipping CKD 3-4 had more obesity, diabetes and ischemic heart disease than dipping CKD. In addition, non-dipping in this CKD 3-4 population was associated with a longer duration and more complex hypertension treatment.

Funding

  • Private Foundation Support