Association Between Dietary Fiber Intake and All-Cause and Cardiovascular Mortality in Middle Aged and Elderly Adults With Chronic Kidney Disease

Yu-Jin Kwon; Hye Sun Lee; Go Eun Park; Ji-Won Lee

doi:10.3389/fnut.2022.863391

Association Between Dietary Fiber Intake and All-Cause and Cardiovascular Mortality in Middle Aged and Elderly Adults With Chronic Kidney Disease

Front Nutr. 2022 Apr 19:9:863391. doi: 10.3389/fnut.2022.863391. eCollection 2022.

Authors

Yu-Jin Kwon¹, Hye Sun Lee², Go Eun Park², Ji-Won Lee³

Affiliations

¹ Department of Family Medicine, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, South Korea.
² Biostatistics Collaboration Unit, Department of Research Affairs, Yonsei University College of Medicine, Seoul, South Korea.
³ Department of Family Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.

Abstract

Background and aims: Despite accumulating evidence on the benefits of dietary fiber in the general population, there is a lack of representative data on mortality in patients with chronic kidney disease (CKD). This study examined the role of dietary fiber intake on all-cause and cardiovascular mortality in patients with CKD using representative Korean cohort data.

Methods: The study included 3,892 participants with estimated glomerular filtration rates <60 mL/min/1.73 m² from the Korean Genome and Epidemiology Study. Mortality status was followed by data linkage with national data sources. Nutritional status was assessed using a validated food frequency questionnaire. Dietary fiber was categorized into quintiles (Q). A multivariable Cox proportional hazards regression model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cardiovascular mortality.

Results: The average daily fiber intake of patients with CKD was 5.1 g/day. During the 10.1-year follow-up period, 602 (149 cardiovascular) deaths were documented. The HR (95% CI) for all-cause mortality in the highest quintile compared with that in the lowest quintile was 0.63 (0.46-0.87) after adjusting for age, sex, BMI, smoking, alcohol intake, exercise, total calorie intake, hypertension, diabetes, and dyslipidemia (P = 0.005). The HR (95% CI) for cardiovascular mortality in the highest quintile compared with that in the lowest quintile was 0.56 (0.29-1.08) after adjusting for same confounders (P = 0.082).

Conclusion: In conclusion, we observed an inverse association between dietary fiber intake and all-cause mortality in CKD patients. Small increments in fiber intake reduced the risk of all-cause mortality by 37%. This finding highlights the need for inexpensive but important dietary modification strategies for encouraging fiber intake in the Korean CKD population.

Keywords: Korean Genome and Epidemiology Study; cardiovascular mortality; chronic kidney diseases; dietary fiber; mortality.