Dipstick proteinuria and risk of myocardial infarction and all-cause mortality in diabetes or pre-diabetes: a population-based cohort study

To evaluate the association between dipstick proteinuria and myocardial infarction (MI) or all-cause mortality, a cohort study was conducted among 16,573 general Chinese population with diabetes or pre-diabetes, which were defined as self-reported history of diabetes or fasting blood glucose ≥5.6 mmol/L or under blood glucose lowering therapy. Proteinuria was detected biennially during 2006-2013 by dipstick test. MI and all-cause mortality were recorded through the end of 2014. Mean age (standard deviation) of study participants was 51.16 (10.63) years, with 82.24% of male. During a median follow-up of 8.03 years, 211 MI and 403 all-cause mortality occurred. Multivariable Cox regression revealed occasional or persistent detection of trace or higher in proteinuria increased the risk of all-cause mortality, with hazard ratios (HRs) of 1.42 (95% confidence intervals [CI]: 1.10, 1.83) and 2.23 (95% CI: 1.66, 3.01), respectively, compared to sustained negative in proteinuria. A time-dependent analysis also revealed the association between degree of proteinuria and all-cause mortality, with HRs of 1.80 (95% CI: 1.31, 2.48) for trace and 3.34 (95% CI: 2.40, 4.65) for one plus or higher in proteinuria, compared to negative. The associations regarding MI lost statistical significance after multivariable adjustment. In conclusion, dipstick proteinuria was associated with an increased risk of MI and all-cause mortality among a general population with diabetes or pre-diabetes.