Cross-sectional Association Between Fish Consumption and Albuminuria: The European Prospective Investigation of Cancer-Norfolk Study

Background: Studies have shown a potential beneficial role for fish and fish oil consumption in the management of diabetes and its complications. The aim of this study is to examine the association between fish consumption and albuminuria in individuals with and without diabetes. Study Design: A cross-sectional analysis conducted in the European Prospective Investigation of Cancer-Norfolk population-based cohort study. Setting & Participants: 22,384 men and women from general practices in the city of Norwich and vicinity, of whom 517 had diabetes by self-report and 21,867 did not report diabetes. Predictors: Fish consumption was measured in a validated semiquantitative food frequency questionnaire and categorized as less than 1, 1 to 2, and more than 2 portions/wk. Interaction between fish intake and diabetes status was hypothesized a priori. Outcomes & Measurements: Microalbuminuria and macroalbuminuria were defined as urinary albumin-creatinine ratio of 2.5 or greater to 24.9 and 25 mg/mmol or greater, respectively. Log-transformed albumin-creatinine ratio was used as a continuous variable. Results: Prevalences of microalbuminuria were 22.6% in participants with diabetes and 11.4% in participants without diabetes. Prevalences of macroalbuminuria were 8.3% and 0.6%, respectively. Fish consumption was associated with a lower risk of macroalbuminuria in participants with diabetes (odds ratio, 0.22, >2 versus <1 portion/wk; 95% confidence interval, 0.07 to 0.70; P for trend = 0.009) after adjustment for confounding. This association was not observed in participants with diabetes with microalbuminuria or in the nondiabetic population. There was a significant interaction between diabetes status and fish consumption of 1 to 2 portions/wk (P = 0.03) and more than 2 portions/wk (P = 0.007) for risk of macroalbuminuria. Limitations: Cross-sectional nature of study. Self-report of fish intake and diabetes status. Conclusions: Greater fish intake was associated with a lower risk of macroalbuminuria in a self-defined diabetic population. These findings merit confirmation in prospective studies and intervention trials and suggest that fish intake may be beneficial for albuminuria in people with diabetes. Am J Kidney Dis 52:876-886. (C) 2008 by the National Kidney Foundation, Inc.