Diet and renal outcomes

Abstract

Chronic Kidney Disease (defined by decreased glomerular filtration rate and proteinuria) is associated with significant morbidity, increased cardiovascular risk and premature mortality. Advanced chronic kidney disease, including end-stage renal disease, places a significant burden on patients and healthcare systems. There is a need to identify approaches to reduce the global burden of CKD, as prevalence is rising. Dietary modification may be one such approach. Employing multiple research methodologies and statistical approaches, this PhD thesis addresses the association between diet and both surrogate and clinical renal outcomes. In particular, I focus on the following areas: (i) the association between dietary sodium intake and renal outcomes (systematic review, two prospective cohort studies and the development of a protocol for a randomised controlled trial); (ii) the association between dietary potassium intake and renal outcomes (two prospective cohort studies); (iii) the association between diet quality and renal outcomes (one prospective cohort study); (iv) the association between chronic kidney disease and functional impairment, a patient important outcome (cross-sectional study). The work presented in this thesis explores these associations in different populations (i) a high cardiovascular risk population (ONTARGET/TRANSCEND cohorts) and (ii) the general population of older adults (NIH-AARP Diet and Health Study and the CLARITY Study). The content of this thesis provides novel observational evidence on the association between diet and renal outcomes, including two of the largest prospective cohort studies reported in this area. My observational research work identified considerable uncertainty about the benefits of low sodium intake, which lead to the development of a randomised controlled trial in patients with chronic kidney disease, which will provide key data on the relationship between sodium intake and renal outcomes in patients with CKD.