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. 2021 Mar 30;2021(3):CD013119. doi: 10.1002/14651858.CD013119.pub2

Morales 2003a.

Study characteristics
Methods

  • Study design: parallel RCT (98 patients assessed for eligibility; 22 randomised; randomly assigned 2:1 ratio)

  • Recruitment: enrolment start and finish date not reported

  • Study duration: 5 months (2 month observational period, 3 month intervention)
Participants

  • Country: Spain

  • Setting: single‐centre; hospital outpatient clinic

  • Inclusion criteria: a chronic (disease duration > 1 year before the study) proteinuric (proteinuria with > 1 g/24 hour of protein on at least 3 consecutive determinations in the 6‐month period before the study); nephropathy of diabetic or non‐diabetic cause; presence of overweight or obesity (BMI > 27 kg/m²); SCr < 2 mg/dL

  • Number: intervention group (20); control group (10)

  • Mean age ± SD (years): intervention group (56.5 ± 15.2); control group (56.1 ± 10.1)

  • Sex (M/F): intervention group (11/9), control group (7/3)

  • Baseline characteristics

    • Nationality: not reported

    • Ethnicity: not reported

    • Mean baseline BMI (kg/m²): intervention group (33.0 ± 3.5); control group (34.3 ± 5.7)

    • Stage of CKD: stages 1 to 4

    • Mean baseline eGFR ± SD (mL/min/1.73 m²): not reported

    • Mean baseline SBP ± SD (mmHg): intervention group (140 ± 24.1); control group (135 ± 12.4)

    • Mean baseline DBP ± SD (mmHg): intervention group (79.6 ± 8.3 control group (83 ± 9.7)

    • Mean baseline energy intake ± SD (kcal/day): not reported

    • Comorbid conditions: type 2 diabetes mellitus (47%)

  • Exclusion criteria: patients with an unstable clinical condition; rapid loss of kidney function; nephrotic syndrome requiring diuretic therapy; immunosuppressive treatments; hypertension requiring more than 2 anti‐hypertensive drugs for its control
Interventions

  • Intervention type classification: lifestyle

  • Weight loss intervention/s used: dietary


Intervention group (diet group)

  • Prescribed an energy restricted diet of 500 kcal reduction with respect to their usual diet with a target of 25% to 30% fat, 55% to 60% carbohydrate

  • Protein content was adjusted to 1 to 1.2 g/kg/day. Intakes monitored with 3 day food diaries at baseline and 3 months

  • All patients were attended by the same physicians of the clinical nutrition unit. Nil further information on intervention delivery information.


Control group

  • Prescribed a protein intake of 1 to 1.2 g/kg/day, monitored with 3 day food diaries at baseline and 3 months


Co‐interventions

  • ACEi, ARB, and non‐dihydropyridine calcium channel blockers were withdrawn in patients treated with these drugs at least 6 weeks before randomisation because of their known antiproteinuric effect. Patients also were instructed to avoid NSAIDs during the study. Patients administered statins for hyperlipidaemia or antihypertensives other than ACEi, ARB, or non‐dihydropyridine calcium channel blockers (including diuretics and ’‐blockers) were instructed to continue these treatments during the study, but with no change in dose
Outcomes

  • Body weight (kg)

  • Weight loss (%)

  • BMI (kg/m²)

  • CrCl (mL/min/1.73 m²)

  • SCr (mg/dL)

  • Proteinuria (g/24 hour)

  • SBP (mmHg)

  • DBP (mmHg)

  • Total cholesterol (mmHg)

  • LDL cholesterol (mmHg)

  • HDL cholesterol (mmHg)

  • Triglycerides (mmHg)
Notes

  • Founding source: not reported

  • Trial registration: Not applicable as published before 2006

  • Possible conflicts of interest for study author: Not declared (no statement provided)
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Unclear risk Insufficient information to permit judgement
Allocation concealment (selection bias) Unclear risk Insufficient information to permit judgement
Blinding of participants and personnel (performance bias)
All outcomes High risk Same physicians saw all patients and assessed food diaries ‐ which indicated they were not blinded to the intervention group allocation
Blinding of outcome assessment (detection bias)
All outcomes High risk Outcomes assessed by physicians involved in the intervention delivery
Incomplete outcome data (attrition bias)
All outcomes Unclear risk Insufficient information to permit judgement. Attrition rate and reasons for drop‐out were not reported
Selective reporting (reporting bias) Unclear risk Some lab evaluations measures listed in the methods were not reported in the results, Intervention adherence not reported
Other bias Low risk Funding source and any possible conflicts of interest not reported. No baseline imbalance evident. Stopping antiproteinuric drugs no longer likely able to be done in a study such as this due to their established protective effects