Differences in Comorbidity Burden Between those with Chronic Kidney Disease and Normal Renal Function

Introduction and Aims: Chronic kidney disease (CKD) and renal replacement therapy are both associated with significant mortality and morbidity. Co-existing comorbidity is common. The degree to which the increased morbidity and mortality is a result of the CKD, and how much a result of the co-existing comorbidity is less clear. We aimed to describe the range of comorbidity at baseline in a population cohort containing all identified within a healthcare region with CKD, those on RRT and a sample of 20,000 individuals from the same population with normal renal function. Methods: The GLOMMS-II cohort contained all individuals with a low eGFR (<60) ml/min/1.73m2 measured in our healthcare region in 2003 (in 2/3 of these with “CKD” the low eGFR was present for at least 90 days, in 1/3 with “impaired eGFR” it was not present for at least 90 days); all those with raised PCR and ACR; all those receiving RRT and a 20,000 sample of those with only normal eGFR measurements in 2003. Data-linkage to hospital episode statistics in the five years prior gave information on comorbidity in 2003. The prevalence of common comorbidities in the subgroups of the cohort is described. The odds of having each comorbidity at baseline with adjustment for age and sex are presented. Results: The prevalence of most comorbidities was higher in those with more advanced CKD (including RRT, as table). After correction for age and sex, vascular comorbidity, diabetes and haematological malignancy continued to be strongly associated with more advanced CKD. The association for other comorbidities was less marked, particularly for dementia. Impaired eGFR was also associated with many of these comorbidities Conclusions: More advanced CKD was strongly associated with vascular comorbidity and diabetes even after correction for age. This association may in part be due to the role of these comorbidities in the aetiology of CKD, as well as a consequence. In the assessment of outcomes in CKD, the effect of these comorbidities on outcome over and above that of CKD itself should be investigated further