Dipstick proteinuria and all-cause mortality among the general population.

ABSTRACT

BACKGROUND: Dipstick proteinuria, but not albuminuria, is used for general health screening in Japan. How the results of dipstick proteinuria tests correlate with mortality and, however, is not known. METHODS: Subjects were participants of the 2008 Tokutei-Kenshin (Specific Health Check and Guidance program) in six districts in Japan. On the basis of the national database of death certificates from 2008 to 2012, we used a personal identifier in two computer registries to identify participants who might have died. The hazard ratio (95% confidence interval, CI) was calculated by Cox-proportional hazard analysis. RESULTS: Among a total of 140,761 subjects, we identified 1641 mortalities that occurred by the end of 2012. The crude mortality rates were 1.1% for subjects who were proteinuria (-), 1.5% for those with proteinuria (+/-), 2.0% for those with proteinuria (1+), 3.5% for those with proteinuria (2+), and 3.7% for those with proteinuria (≥ 3+). After adjusting for sex, age, body mass index, estimated glomerular filtration rate, comorbid condition, past history, and lifestyle, the hazard ratio (95% CI) for dipstick proteinuria was 1.262 (1.079-1.467) for those with proteinuria (+/-), 1.437 (1.168-1.748) for those with proteinuria (1+), 2.201 (1.688-2.867) for those with proteinuria (2+), and 2.222 (1.418-3.301) for those with proteinuria (≥ 3+) compared with the reference of proteinuria (-). CONCLUSION: Dipstick proteinuria is an independent predictor of death among Japanese community-based screening participants.