Study of low salt diet in hypertensive patients with chronic kidney disease
- Author:
Keng Hee Koh
1
Author Information
- Collective Name:Keng-Hee Koh, MRCP; Wei-Soon Lawrence Hii, MRCP; Jun Lee, MRCP; Lui-Sian Laura Ngu, MRCP; Hui-Hong Clare Tan, MRCP
- Publication Type:Journal Article
- Keywords: Low salt diet; hypertension; chronic kidney disease
- From: The Medical Journal of Malaysia 2018;73(6):376-381
- CountryMalaysia
- Language:English
- Abstract: Introduction: The efficacy of blood pressure (BP) reduction with salt restriction in CKD subjects and its sustainability is not well established. Methods: We enrolled 75 hypertensive patients with CKD into one-month salt restricting diet. 24-hour urinary sodium and potassium was measured to verify their salt intake followed by 1½ year follow-up. Results: Their creatinine clearance was 43 ± standard deviation 33ml/min/1.73m2. Urinary Na excretion (24HUNa) was 173±129mmol/day, reducing to 148±81 by 31±6 day. Mean, systolic and diastolic BP (MBP, SBP, DBP) were reduced from 102±9 to 97±11 (p<0.001), 148±10 to 139±16 (p<0.001), 78±12 to 75±12 mmHg (p=0.012) respectively. Moderate correlations were shown between reductions in 24-hour urinary Na and MBP, SBP, DBP: r=0.366, 0.260, 0.365; p=0.001, 0.025, 0.001; whereas 24-hour urinary Na-K ratio showed mild correlation. Subjects have some tendency to drift back to previous Na intake profile in follow-up and thus repetitive education is necessary. In subanalysis, 34 subjects with baseline 24HUNa >150 mmol/day, benefited significantly with MBP, SBP, DBP reduction from 102±9 to 95±9 (p=0.001), 146±10 to 135±14 mmHg (p=0.001), 80±11 to 75±11 mmHg (p=0.002) in line with 24HUNa reduction from 253±154 to 163±87mmol/day (p=0.004) and urinary protein-creation ratio reduction from geometric mean of 95 to 65 g/mol. Thirty five subjects with 24HUNa reduction of >20mmol/day have significant reduction in MBP, SBP, DBP: -8 vs -2, -15 vs -4, -5 vs -2 mmHg (p=0.027, 0.006, 0.218) and urinary protein-creatinine ratio: -82 vs 2g/mol (p=0.030) compared to the other forty subjects. Conclusion: Quantification of 24-hour urinary Na helps in predicting potential antihypertensive effect with dietary salt reduction of CKD subjects. Salt restriction reduces BP especially in patients with estimated daily sodium intake of >150mmol/day. Reduction in sodium intake beyond 20mmol/day reduced both BP and proteinuria.
- Full text:6.2018my1351.pdf
