March 19, 2010Open Access
Associations of Diet with Albuminuria and Kidney Function Decline
Key Result
The highest quartile of dietary animal fat intake was associated with a significantly increased risk of microalbuminuria (OR 1.72) compared to the lowest quartile in women with well-preserved kidney function.
Study Design
Type
Cohort (n=3,348)
Structured PICO
Does dietary intake of specific nutrients influence the risk of microalbuminuria and eGFR decline in women with well-preserved kidney function?
P
Population
3,348 female nurses with well-preserved kidney function, median age 67 years, followed for up to 14 years to assess the association of dietary nutrients with microalbuminuria and eGFR decline.
E
Exposure
Higher dietary intake of specific nutrients including animal fat, red meat, sodium, and beta-carotene (assessed via semiquantitative food frequency questionnaires over 14 years)
C
Comparator
Lowest quartile or lower intake categories of the respective nutrients
O
Outcome
Microalbuminuria presence and eGFR decline ≥ 30%surrogate
Higher intake of animal fat and red meat is associated with an increased risk of microalbuminuria, while higher sodium intake increases the risk of significant eGFR decline in women.
Main Result
Odds Ratio: 1.72 (95% CI 1.12–2.64)
Limitations
- Study population was mostly older Caucasian women, limiting generalizability to other demographics
- Specific values for systolic and diastolic blood pressure were not available
- ACR was assessed only once in 2000, making the albuminuria analyses cross-sectional
- Potential for residual confounding
- Possibility of survival bias since women who died before 2000 were not included
Abstract
BACKGROUND AND OBJECTIVES: Sparse longitudinal data exist on how diet influences microalbuminuria and estimated GFR (eGFR) decline in people with well-preserved kidney function. DESIGN, SETTINGS, PARTICIPANTS, 95% confidence interval (CI): 1.12 to 2.64) and two or more servings of red meat per week (OR: 1.51; 95% CI: 1.01 to 2.26) were directly associated with microalbuminuria. After adjustment for other nutrients individually associated with eGFR decline > or = 30%, only the highest quartile of sodium intake remained directly associated (OR: 1.52; 95% CI: 1.10 to 2.09), whereas beta-carotene appeared protective (OR: 0.62, 95% CI: 0.43 to 0.89). Results did not vary by diabetes status for microalbuminuria and eGFR outcomes or in those without hypertension at baseline for eGFR decline. No significant associations were seen for other types of protein, fat, vitamins, folate, fructose, or potassium. CONCLUSIONS: Higher dietary intake of animal fat and two or more servings per week of red meat may increase risk for microalbuminuria. Lower sodium and higher beta-carotene intake may reduce risk for eGFR decline.