Dietary Guideline Adherence Index and Kidney Measures in the Framingham Heart Study

Background: No observational studies have directly considered dietary guidelines when examining the prospective association between dietary intake and kidney measures.

Study design: Prospective cohort study.

Setting & participants: We examined participants who attended examinations 7 (1998-2001) and 8 (2005-2008) in the Framingham Offspring Cohort.

Predictors: Individual components of Dietary Guidelines for Americans Adherence Index (DGAI) that reflect adherence to key dietary recommendations based on the 2005 guideline.

Outcomes & measures: The primary outcome was incident low estimated glomerular filtration rate (eGFR) at follow-up after exclusion of prevalent low eGFR at baseline. Low eGFR was defined as serum creatinine-based eGFR<60mL/min/1.73m².

Results: Among 1,822 participants (mean age, 59.4 years; 54.6% women), 181 incident cases of low eGFR were identified. After adjustment for potential confounders, compared to optimal adherence to meat and legume recommendations, low adherence was associated with higher odds of incident low eGFR (P for trend = 0.01); ORs in the lowest and intermediate adherence categories were 2.98 (95% CI, 1.13-7.92) and 1.65 (95% CI, 1.02-2.66), respectively. Low adherence to dairy product recommendations was also associated with higher odds of incident low eGFR compared to optimal adherence (P for trend = 0.03); ORs in the lowest and intermediate adherence categories were 1.98 (95% CI, 1.03-3.82) and 1.59 (95% CI, 0.81-3.11), respectively. In addition, low adherence to meat and legume recommendations was associated with rapid eGFR decline (P for trend = 0.01), and low adherence to dairy product recommendations was associated with rapid eGFR decline (P for trend = 0.01) and incident albuminuria (P for trend = 0.03).

Limitations: The DGAI was developed based on the 2005 Dietary Guidelines for Americans.

Conclusions: Better adherence to dietary recommendations for both meat and legumes and dairy products was associated with lower risk for developing adverse kidney measures.