lbuminuria is known to be associated with an increased risk of death, independent of renal function levels, but studies have not previously shown whether this association is similar for adults of all ages.
Dr Ann O'Hare and colleagues from the University of Washington examined the association between ACR and all-cause mortality among 94,934 people with diabetes. Patients enrolled in the study had an average age of 67 years.
Dr O'Hare and colleagues stratified the patients in their study according to their kidney function using eGFR.
They found that, in patients aged 75 years or older, ACR was independently associated with an increased risk of death at all levels of eGFR.
In younger age groups, this association was present at higher levels of eGFR, but, at lower eGFR levels, the association was less marked.
The researchers found that more than half of all patients aged 75 years or older met the necessary criteria to be diagnosed as having chronic kidney disease. In many cases, this was on the basis of an isolated and moderate reduction in eGFR.
However, because patients' ACR was independently associated with mortality at all levels of eGFR, the researchers suggested that ACR could be used to identify at-risk elderly patients.
'In the clinical setting, the ACR may be particularly helpful for risk stratification in elderly patients who meet the current eGFR criteria for chronic kidney disease,' the researchers said.
'At older ages, an ACR of less than 30mg/g may serve to identify a large subgroup of patients with moderate reductions in eGFR who are at relatively lower risk for death.'