A better diet quality is associated with a reduced likelihood of CKD in older adults

Studies of diet in relation to chronic kidney disease (CKD) have focused on individual nutrients. The relationship between overall patterns of food intake and renal function has not been well explored. We aimed to investigate the associations between diet quality with the prevalence, incidence and progression of CKD in a cohort of older adults.

1952 participants aged ≥50 years at baseline were examined between 1992-1994 and 2002-2004. Dietary data were collected using a semi-quantitative food frequency questionnaire. A modified version of the Healthy Eating Index for Australians was developed to determine total diet scores (TDS). Baseline biochemistry including serum creatinine was measured. CKD was defined as MDRD estimated glomerular filtration rate (eGFR) <60 mL min⁻¹·1.73 m⁻². Participants in the highest quartile of mean TDS compared to those in the first quartile (reference), had a 41% reduced likelihood of having eGFR <60 mL min⁻¹·1.73 m⁻², [multivariable-adjusted odds ratio, OR, 0.59 (95% confidence intervals, CI, 0.41-0.85), P-trend = 0.005]. Each unit increase in TDS was associated with a 15% decrease in the odds of having prevalent CKD, multivariable-adjusted OR 0.85 (95% CI 0.74-0.97). A non-significant, inverse association between TDS and CKD incidence was observed (P-trend = 0.10).

Older adults with better diet quality had a reduced likelihood of having eGFR <60 mL min⁻¹·1.73 m⁻². Adherence to dietary guidelines were not prospectively associated with CKD incidence or progression. Further studies with adequate power are warranted to assess the longitudinal association between diet quality and CKD.