Self-management support for sodium restriction in patients with chronic kidney disease: randomised controlled ESMO trial

Abstract

Background: To date there are no theory-based self-management interventions to support patients with chronic kidney disease (CKD) to reduce their sodium intake. Methods: 151 patients with moderate decreased kidney function and hypertension were included in this multicentre open randomised controlled trial. The self-regulation intervention comprised education, motivational interviewing, coaching, and self-monitoring. To investigate the interventions’ effectiveness immediately after the three-month intervention and at six-month follow-up, intention to treat analysis using linear mixed modelling was conducted while adjusting for baseline values. Findings: Compared to regular care, at 3 months the intervention group showed reduced sodium excretion (adjusted difference in means -30.3 [95% confidence interval {CI} -54.7;-5.9] mmol/24h), daytime ambulant diastolic blood pressure (-3.4 [95%CI -6.3;-0.6] mmHg), diastolic office blood pressure (-5.2 [95%CI -8.4;-2.1] mmHg), protein excretion (-0.4 [95%CI -0.7;-0.1] g/24h), body weight (-1.5 [95%CI -2.7;-0.3] kg), and improved self-efficacy (0.5 [95%CI 0.1;0.9]). At 6 months, group differences in sodium excretion and ambulant blood pressure were not found anymore, but differences were detected in systolic and diastolic office blood pressure (-7.3 [95%CI -12.7;-1.9] and -3.8 [95%CI -6.9;-0.6] mmHg), protein excretion (-0.3 [95%CI -0.6;-0.1] g/24h), body weight (-1.7 [95%CI -2.9;-0.5] kg), and self-efficacy (0.5 [95%CI 0.0;0.9]). No differences in kidney function and health-related quality of life were observed. Discussion: This trial showed that the ESMO intervention modestly decreased risk factors for disease progression in patients with CKD, although several effects diminish over time. To consolidate long-term behaviour change, the intervention could be intensified (e.g. by including low-sodium cooking lessons or a maintenance phase).