SCREENING-TESTS FOR MICROALBUMINURIA IN NONDIABETIC ELDERLY SUBJECTS AND THEIR RELATION TO BLOOD-PRESSURE

1. Microalbumuria in non-diabetic elderly subjects is predictive of va scular disease and mortality, and related to levels of blood pressure. 2. This study was designed to examine whether more restricted periods of urine collection retained the relation to the prevailing level of blood pressure and successfully identified subjects with microalbuminu ra. 3. Fifty elderly subjects (aged over 60 years) made two consecutiv e 24-h urine collections for measurement of urinary albumin excretion, divided between daytime and night-time periods, Thirty-three subjects also provided a random 'spot' urine sample, Clinic and 24-h ambulator y blood pressure were also recorded.4. Median 24-h urinary albumin exc retion was 15.75 mg; 17 subjects had microalbuminuria. The median 24-h albumin-creatinine ratio was 1.91 mg/ mmol, A threshold albumin-creat inine ratio of greater than or equal to 3.0 mg/ mmol in a random urine sample predicted microalbuminuria with 92% sensitivity and 90% specif icity, Alternatively, threshold values of 2.5 mg/mmol for men and 4.5 mg/mmol for women in an overnight urine collection predicted microalbu minuria with 88% sensitivity and 100% specificity. 5. The closest rela tion between albumin-creatinine ratio and blood pressure was that betw een spot albumin-creatinine ratio and clinic systolic blood pressure ( r = 0.64, P < 0.001), Albumin-creatinine ratio was generally related t o clinic systolic blood pressure, diastolic blood pressure and ambulat ory systolic blood pressure, Microalbuminuric subjects had significant ly higher levels of clinic and ambulatory systolic blood pressure than non-microalbuminuric subjects. 6. Microalbuminuria in the elderly is most closely related to clinic systolic blood pressure. Screening for microalbuminuria in the elderly can usefully be performed by the measu rement of albumin-creatinine ratio in a random urine sample, with a th reshold of greater than or equal to 3.0 mg/mmol.