The Effect of Dietary Phosphorus Restriction on Urine Protein Excretion in Patients With Proteinuria: A Randomized Controlled Trial

Dietary Magnesium Intake and Proteinuria: Is There a Relationship?

The possible relationship between dietary magnesium status and proteinuria has been suggested by a number of previous studies. However, human studies on this association are limited. Therefore, the present study aimed to investigate the independent relationship between dietary magnesium intake and urinary protein excretion. The present study was a post hoc analysis of the previous randomized clinical trial that evaluated the effect of dietary phosphorus restriction on proteinuria. The baseline data of 90 participants with proteinuria and chronic kidney disease was used to measure the association between dietary magnesium intake and proteinuria. Participants were asked to record their 24-h food intake for three days a week in a questionnaire. Urinary protein to creatinine ratio (UPCR) in a random urine sample was measured to be a marker for proteinuria. Out of 90 patients included in the study, 47 were men and 43 were women. The mean ± standard deviation of age and body mass index were 59.05 ± 14.16 years and 29.02 ± 5.54 kg/m2, respectively. The patients' average daily dietary intake of energy and magnesium were 2183 kcal and 169.44 mg, respectively. A significant inverse correlation was found between the dietary intake of magnesium and UPCR (r =  - 0.219, p = 0.042). This association remained significant even after adjusting for confounding variables (β =  - 0.222, p = 0.028). The findings of the present study showed a significant inverse relationship between the magnesium intake and proteinuria. Although, the design of the current research was cross-sectional, it has provided a basis for conducting future longitudinal studies and trials to better elucidate such a relationship.

Lifestyle Interventions, Kidney Disease Progression, and Quality of Life: A Systematic Review and Meta-analysis

Rationale & Objective

Poor dietary patterns and low physical activity levels are important lifestyle-related factors that contribute to negative health outcomes in individuals with chronic kidney disease (CKD). Previous systematic reviews have not explicitly focused on these lifestyle factors, nor undertaken meta-analyses of any effects. We aimed to evaluate the effect of lifestyle interventions (such as diet, exercise, and other lifestyle-related interventions) on the risk factors for and progression of CKD and the quality of life.

Study Design

Systematic review and meta-analysis.

Setting & Study Populations

Individuals aged 16 years or older with CKD stages 1 to 5 not requiring kidney replacement therapy.

Selection Criteria for Studies

Randomized controlled trials of interventions.

Data Extraction

Kidney function, albuminuria, creatinine, systolic blood pressure, diastolic blood pressure, body weight, glucose control, and quality of life.

Analytical Approach

A random-effects meta-analysis with evidence certainty assessed using GRADE.

Results

Seventy-eight records describing 68 studies were included. Twenty-four studies (35%) were dietary interventions, 23 (34%) exercise, 9 (13%) behavioral, 1 (2%) hydration, and 11 (16%) multiple component. Lifestyle interventions resulted in significant improvements in creatinine (weighted mean difference [WMD], -0.43 mg/dL; 95% CI, -0.74 to -0.11; P = 0.008); 24-hour albuminuria (WMD, -53 mg/24 h; 95% CI, -56 to -50; P < 0.001); systolic blood pressure (WMD, -4.5 mm Hg; 95% CI, -6.7 to -2.4; P < 0.001); diastolic blood pressure (WMD, -2.2 mm Hg; 95% CI, -3.7 to -0.8; P = 0.003); and body weight (WMD, -1.1 kg; 95% CI, -2.0 to -0.1; P = 0.025). Lifestyle interventions did not result in significant changes in the estimated glomerular filtration rate (0.9 mL/min/1.73 m²; 95% CI, -0.6 to 2.3; P = 0.251). However, narrative synthesis indicated that lifestyle intervention resulted in improvements in the quality of life.

Limitations

Certainty of the evidence was rated very low for most outcomes, primarily owing to the risk of bias and inconsistency. No meta-analysis was possible for quality-of-life outcomes because of variations in measurement tools.

Conclusions

Lifestyle interventions seem to positively affect some risk factors for progression of CKD and quality of life.