Sodium Intake in Chronic Kidney Disease (STICK) (STICK)
Kidney Diseases, Renal Insufficiency, Chronic, Renal Insufficiency
About this trial
This is an interventional treatment trial for Kidney Diseases focused on measuring Chronic Kidney Disease, Sodium Reduction, eGFR 30-60ml/min/1.73m2
Eligibility Criteria
Inclusion Criteria:
- Age 40 years or older
- MDRD eGFR of 30-60ml/min/1.73m2 on ≥2 occasions ≥3 months apart
- Most recent eGFR measurement within 3 months Systolic blood pressure <160mmHg and diastolic blood pressure <95mmHg on three office blood pressure readings at time of screening and confirmed by a study ABPM before randomisation of <150/90mmHg
- No change in anti-hypertensive or diuretic medications (including dose) for 3 months before screening visit
- Consumption of moderate sodium intake at screening, defined as an estimated daily sodium intake of >2.3g/day estimated from food frequency questionnaire (FFQ) completed during the screening visit
- Self-reported willingness to modify dietary intake over sustained period, and adhere to directed recommendations over 2 years
- Signed written informed consent
Exclusion Criteria:
- Acute Kidney Injury in the preceding three months, defined as doubling of baseline serum creatinine or rapidly declining eGFR over the preceding six months, defined as a decline in eGFR of ≥10ml/min/1.73m2 in those with established CKD
- Any of the following renal conditions: glomerular disease due to post-infectious glomerulonephritis, IgA nephropathy, thin basement membrane disease, Henoch-Schonlein purpura, proliferative glomerulonephritis, membranous nephropathy (including lupus nephritis), rapidly progressive glomerulonephritis, minimal change disease, or focal segmental glomerulosclerosis
- Prior or planned renal transplantation
- Prior, current or planned renal dialysis
- Medical diagnosis known to be associated with abnormal renal sodium excretion, including Bartter syndrome, SIADH, diabetes insipidus, or serum sodium <125mmol
- Severe heart failure (defined as left ventricular ejection fraction ≤30% or NYHA Class III/IV symptoms)
- High-dose loop or thiazide diuretic therapy, exceeding a total daily dose of frusemide 80mg, bumetanide 2mg, hydrochlorothiazide 50mg, bendroflumethiazide 2.5mg, indapamide 2.5mg, metolazone 2.5mg or the use of both a loop and thiazide diuretic
- Current use of non-steroidal anti-inflammatory drugs (NSAIDs) for 3 or more days per week. Low-dose aspirin <100mg/day is not an exclusion
- Unable to follow educational advice of the research team
- Prescribed high-salt diet, low-salt diet or sodium bicarbonate
- Symptomatic postural hypotension or receiving treatment for postural hypotension
- Current or recent use (within one month) of immunosuppressive medications including tacrolimus, cyclosporine, azathioprine or mycophenolate mofetil
- Pregnancy or lactation
- Unable to comply with 24-hour urinary collections, or medical condition making collection of 24-hour urinary collection difficult (e.g. severe urinary incontinence)
- Participant unlikely to comply with study procedures or follow-up visits due to severe co-morbid illness or other factor (e.g. inability to travel for follow-up visits, drug or alcohol misuse) in opinion of research team
- Cognitive impairment defined as a known diagnosis of dementia, or inability to provide informed consent due to cognitive impairment in the opinion of the investigator
- Body Mass Index (BMI) <20kg/m2 or BMI>40kg/m2
- Participating in another clinical trial or previous allocation in this study
Sites / Locations
- HRB Clinical Research Facility Galway
Arms of the Study
Arm 1
Arm 2
Experimental
No Intervention
Sodium Reduction
Usual care
In addition to usual care, those randomised to the intervention arm will receive specific counseling on behavioural and environmental factors that promote sodium reduction after randomization and at all post-randomisation visits, targeting sodium intake of <100mmol/day (<2.3g/day).
For all participants, standard care will be provided at the nephrology clinic at GUH or by local general practitioners, and includes treatment of hypertension, underlying comorbidities and optimizing the metabolic profile. Participants randomized to usual care will also attend a dietitian-developed healthy eating guidance session but will not receive specific recommendations targeting sodium intake.