Association Between Dietary Quality and Serum Cystatin C in Kidney Transplant Recipients Based on Chinese Diet Balance Index 2016 (DBI-16)

BACKGROUND: Cystatin C (Cys) is considered to be a better marker than serum creatinine in assessing kidney function, predicting cardiovascular events, and all-cause mortality. It seems to be associated with nutritional status in the general population, but little is known about kidney transplant recipients (KTRs). This study aimed to explore the relationship between dietary balance index and serum Cys in KTRs. MATERIAL/METHODS: In a cross-sectional study, 215 KTRs completed an FFQ questionnaire and information on serum Cys. Dietary intake was assessed using the Food Frequency Questionnaire (FFQ). Dietary Balance Index 2016 (DBI-16) edition scores were calculated as an indicator of dietary quality. Data on the patient’s serum Cys were obtained through the hospital information system. RESULTS: The majority of KTRs were male (75.34%), 76.74% were aged 18–44 years, and 79.53% were abnormal serum Cys. Dairy (z=−2.161, P<0.05), meat (z=−2.578, P<0.05), and dietary diversity (z=−3.393, P<0.05) in the normal group were higher than those in the abnormal group, and the dietary quality distance (DQD) score (t=−2.264, P<0.05) was lower than that in the abnormal group. After adjusting for confounders, a low-quality diet was a risk factor for maintaining the normal level of serum Cys (OR 3.022, 95% CI 1.263–7.231, P<0.05). CONCLUSIONS: The present study suggested that KTRs with a high dietary quality might be associated with normal serum Cys levels. Dairy, meat, and varied diet seems to impact the serum Cys levels of KTRs. Dietary imbalances were prevalent among KTRs.