Associations of dietary fat with albuminuria and kidney dysfunction

Abstract

Background: Diet represents a potentially important target for intervention in nephropathy, yet data on this topic are scarce.

Objectives: The objective was to investigate associations between dietary fats and early kidney disease.

Design: We examined cross-sectional associations between dietary fats and the presence of high albuminuria (an established independent predictor of kidney function decline, cardiovascular disease, and mortality) or estimated glomerular filtration rate (eGFR) <60 mL ⋅ min(-1) ⋅ 1.73 m(-2) at baseline in 19,256 participants of the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study, an ongoing cohort study in US adults aged ≥45 y at time of enrollment. We used logistic regression to assess associations between quintiles of total fat and subtypes of dietary fat (saturated, monounsaturated, polyunsaturated, and trans fat) and presence of high albuminuria or eGFR <60 mL ⋅ min(-1) ⋅ 1.73 m(-2).

Results: After multivariable adjustment, only saturated fat intake was significantly associated with high albuminuria [for quintile 5 compared with quintile 1, odds ratio (OR): 1.33; 95% CI: 1.07, 1.66; P for trend = 0.04]. No significant associations between any type of fat and eGFR <60 mL · min(-1) · 1.73 m(-2) were observed. ORs between the highest quintile of saturated fat and eGFR <60 mL · min(-1) · 1.73 m(-2) varied by race with a borderline significant interaction term (ORs: 1.24 in whites compared with 0.74 in blacks; P for interaction = 0.05) in multivariable-adjusted models, but no other associations were significantly modified by race or diabetes status.

Conclusion: Higher saturated fat intake is significantly associated with the presence of high albuminuria, but neither total nor other subtypes of dietary fat are associated with high albuminuria or eGFR <60 mL · min(-1) · 1.73 m(-2).

FIGURE 1.

Exclusionary cascade for analysis subpopulation: data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study 2003–2007. FFQ, food-frequency questionnaire; ACR, albumin-to-creatinine ratio; EGFR, estimated glomerular filtration rate.