Second Morning ACR Could Be the Alternative to First Morning ACR to Assess Albuminuria in Elderly Population

BACKGROUND: Albumin/creatinine ratio (ACR) from a first morning urine is recommended as a early indicator for diabetic nephropathy. However, it is not always feasible to collect the first morning urine for outpatients. We aimed to explore whether ACR from a second morning urine had a good consistency with that from a first morning urine to predict albuminuria in Chinese elderly citizens. METHOD: One hundred and ninety-one elderly citizens (≧60 years old) from Junliangcheng community, Dongli district, Tianjin, China were included. A first and second morning urine was collected from each participants, successfully and detected the urinary albumin and creatinine of each urine sample. Albumin to creatinine ratio from a first morning urine (ACR1) was compared with that from a second morning urine (ACR2), and the ability of ACR1 and ACR2 to predict albuminuria was assessed. RESULT: ACR1 and ACR2 were highly correlated (r = 0.901), especially in male and hypertension group (r = 0.938 and 0.904). The slope and intercept were 0.93 and 0.11 after log-transformed. And there was no statistical difference between values of ACR1 and ACR2 (P = 0.271). Overall, 26.2% participants were detected with albuminuria when judged by ACR1 and 28.3% by ACR2. A good concordance of ACR category (normal or albuminuria) was found between ACR1 and ACR2 (Kappa value = 0.815 in overall; in male and hypertension group were 0.900 and 0.850). CONCLUSION: A second morning urine ACR could be the alternative to a first morning urine ACR for albuminuria detection in elderly population.