Diet quality and all-cause mortality among individuals with chronic kidney disease: a UK Biobank cohort study.

BACKGROUND

Few studies on diet and chronic kidney disease (CKD) have evaluated the role of overall dietary patterns, particularly in European populations.

OBJECTIVE

To examine the association between several diet quality indices-Alternate Mediterranean Diet (aMED), Dietary Approaches to Stop Hypertension (DASH), Alternative Healthy Eating Index-2010 (AHEI-2010), Planetary Health Diet Index (PHDI), and Dietary Inflammatory Index (DII)-and all-cause mortality among British adults with CKD.

METHODS

We analyzed data from 4102 United Kingdom Biobank participants, who were followed from February 2011 to July 2024. CKD was determined using clinical diagnoses and estimated glomerular filtration rates. Dietary indices were calculated from at least two 24-h dietary assessments, and mortality records were obtained from national death registers. Multivariable proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between dietary patterns and mortality.

RESULTS

Baseline mean age of participants was 60.6 y (women, 53.2%). Over a median follow-up of 12 y, 696 participants died (16.97%). Comparing the highest to the lowest adherence tertile of the 5 dietary patterns, the fully-adjusted HRs for all-cause mortality was 0.73 (95% CI: 0.59, 0.90) for the aMED, 0.68 (95% CI: 0.56, 0.84) for the DASH, 0.77 (0.63, 0.93) for the AHEI-2010, 0.87 (95% CI: 0.72, 1.06) for the PHDI, and 1.30 (95% CI: 1.05, 1.59) for the DII. Major dietary components driving the associations included nuts [aMED 0.84 (95% CI: 0.72, 0.99); PHDI 0.95 (95% CI: 0.91, 0.99)], legumes and nuts [DASH 0.93 (95% CI: 0.88, 0.98); AHEI-2010 0.97 (95% CI: 0.95, 1.00)], and sodium [DASH 0.92 (95% CI: 0.86, 0.99); AHEI-2010 0.96 (95% CI: 0.93, 0.99)]. Sensitivity analyses yielded consistent results.

CONCLUSIONS

In this cohort study of middle-aged and older adults with CKD, higher adherence to healthy dietary patterns, including aMED, DASH, and AHEI-2010, was associated with significantly lower all-cause mortality, whereas higher DII scores were linked to higher mortality. These findings highlight diet quality as a modifiable protective factor in individuals with CKD.