Cardiovascular implications of chronic kidney disease in older adults

Because serum creatinine is an imprecise indicator of glomerular filtration rate (GFR), estimating equations derived from the Modification of Diet in Renal Diseases study are increasingly being used to estimate GFR. The notion that GFR declines with aging is based largely on the results of cross-sectional studies that have generally not differentiated the effects of senescence from those of co-existing conditions such as hypertension. Nevertheless, GFR probably declines in many, if not all, aging individuals. The introduction of automated reporting of estimated GFR may result in an over-diagnosis of chronic kidney disease (CKD). There is a large body of evidence to suggest that a decrease in GFR and/or albuminuria is associated with an increased risk of death, particularly from cardiovascular causes, and that this risk extends to the elderly. Although the data are not consistent with regard to the level of GFR at which the increase in cardiovascular risk becomes apparent, small amounts of urine albumin excretion (levels that do not meet the definition of microalbuminuria) are associated with a higher risk of death, even among the elderly. There is currently no evidence that aggressive control of blood pressure and/or use of medications that reduce proteinuria, such as those that block the renin-angiotensin-aldosterone system, reduce the risk of cardiovascular events or death among individuals with CKD. On the other hand, secondary analyses of at least two studies have documented the benefit of lipid lowering in CKD patients. Paradoxically, a recent study has raised concern that normalizing haemoglobin may enhance the cardiovascular risk associated with CKD. To conclude, the available evidence indicates that early identification of CKD may allow physicians to aggressively modify cardiovascular risk, which, in turn, has the potential to improve patient outcomes.