Go Fish: Omega-3 Fatty Acid Supplementation in Diabetes-Related Kidney Disease

Diabetes is the most common cause of end-stage kidney disease in the United States. Half of
patients with diabetes develop kidney disease. The benefits of omega-3 fatty acids have
been shown in animal models of kidney injury. Mechanistic studies of omega-3 fatty acid
supplements support biological plausibility: omega-3 supplements have been shown to improve
vascular reactivity, lower oxidative stress, reduce inflammation, and have beneficial
effects on the metabolism of eicosanoids favoring synthesis of vasodilatory prostaglandins
and thromboxanes. However, in spite of overwhelming evidence for a potential benefit of
dietary omega-3 fatty acids at preventing or slowing progression of kidney disease for
adults with NIDDM, clinical trials providing evidence to support recommendations of
supplementation are lacking.

The current recommendation for omega-3 intake for adults, one gram/day of DHA+EPA, is based
on evidence for cardiovascular disease risk (CVD) reduction. Whether omega-3 fatty acid
prevents or slows progression of diabetic kidney disease, whether the current recommended
dose is adequate to modify disease, or whether a higher dose should be recommended, needs to
be determined.

In this setting, we propose to conduct a randomized placebo-controlled cross-over clinical
trial to determine the effects of a daily dose of omega-3 fatty acid supplementation (4.0
g/day) compared with placebo on urine protein excretion and biomarkers of kidney injury and
function in adults with diabetes and proteinuria.