1. Studies published as full articles in peer-reviewed journals, or as abstracts.

2. Prospective

3. Parallel or cross-over design control group

4. Studies that were greater than 3 months in length.

1. Uncontrolled or used historical controls

2. Subjects treated for less than 3 months.

3. Studies that evaluated only diet or dietary supplements on renal function or proteinuria.

4. Studies that examined the effects of fish oil or other dietary fatty acid supplements.

Recruitment:

Studies were located through three methods: A Medline search to July 1, 1999 was conducted to locate trials examining the effects of lipid-lowering therapy on the progression of renal disease. Bibliographies from these Medline articles and other recent articles were reviewed. In addition abstracts from major nephrology meetings in the previous 10 years were included that met inclusion and exclusion criteria.

Design:

1. Authors of papers identified for inclusion were contacted and asked to provide patient specific data for calculating endpoints and variances.

2. Two investigators extracted data independently and differences were resolved with conferencing.

3.  Quality index used to assess effect of study quality on results for quality assignment of individual papers: 2 points: random assignment to study group; 2 points: parallel group design; 1 point: cross-over design; 1 point: inclusion & exclusion criteria clearly delineated; 1 point: subjects masked to treatment; 1 point: investigators masked to treatment;

4. Other data collected: age, gender, cause of renal disease (diabetes, glomerulonephritis or other), change in serum cholesterol, change in blood pressure.

5. Homogeneity of treatment effects was evaluated.

Blinding Used (if applicable): not applicable

Intervention Used (if applicable): not applicable

Statistical Analysis:

Weighted means and confidence intervals were calculated for combined differences between treatment and control groups using a fixed-effects model.

The results of this meta-analysis suggest that lipid-lowering therapy in patients with renal insufficiency may help slow the rate of renal disease progression. This meta-analysis lends further support to the argument that hyperlipidemia should be treated in patients with nephrotic syndrome and/or renal insufficiency.

This meta-analysis may have important implications for therapy of patients with renal disease, because large, multicenter, randomized controlled trials to determine definitively whether lipidlowering agents slow the rate of renal disease progression may never be carried out.