Dietary patterns and risk of incident chronic kidney disease: a prospective cohort study

Diet likely plays a crucial role in the aetiology of chronic kidney disease (CKD), a growing global health problem. We prospectively examined sex-specific associations between different dietary patterns and CKD. Among 27,126 adults (66.5% females) followed from 1997 to 2016, baseline dietary intake was assessed using a semi-quantitative food frequency questionnaire. We estimated the Dietary Approaches to Stop Hypertension (DASH) and the Nordic Nutrition Recommendations (NNR) scores, and derived three dietary patterns via reduced rank regression using protein, phosphorus, potassium, and sodium as mediators: DP1 (high levels of all nutrients), DP2 (high potassium and phosphorus, low sodium), and DP3 (low potassium and sodium, high phosphorus). Sex-stratified multivariable Cox models were used to evaluate linear, non-linear, and categorical associations with CKD incidence, with categorical exposure defined by tertiles of adherence (low, medium, high). During a 17.9-year mean follow-up, we identified 687 incident cases of CKD. In males, DP1 showed a U-shaped association with CKD risk (HR_low/medium = 1.41; 95%CI: 1.06, 1.89, HR_high/medium = 1.39; 95%CI:1.05, 1.85). DP3 was associated with higher CKD risk in females (HR_linear = 1.12; 95%CI: 1.01, 1.25). The NNR was associated with lower CKD risk in both females (HR_linear = 0.90, 95% CI: 0.81-1.00; HR_medium/low = 0.77, 95% CI: 0.61-0.99) and males (HR_linear = 0.86; 95%CI: 0.77, 0.97), while the DASH was associated with lower CKD risk in females only (HR_linear = 0.86; 95%CI: 0.78, 0.96, HR_high/low = 0.70; 95%CI: 0.54, 0.91). Higher adherence to the NNR reduced CKD risk in both sexes, whereas sex-specific associations were observed between the DASH diet, CKD-oriented dietary patterns, and CKD risk.