Trace proteinuria by dipstick screening is associated with metabolic syndrome, hypertension, and diabetes

The purpose of this study is to determine the association of dipstick-determined trace proteinuria with metabolic syndrome (MetS) and its components in each age, gender, and eGFR category among a large general population.

A total of 270,190 people (102,223 men and 167,967 women) aged 40–74 years were included. Subjects were categorized as having negative, trace, and positive proteinuria by the dipstick method.

The prevalence of MetS increased with increasing levels of proteinuria in any estimated glomerular filtration rate (eGFR) category (odds ratios for MetS relative to negative proteinuria: 1.22, 1.23, and 1.25 for trace proteinuria, and 2.19, 1.81, and 1.80 for positive proteinuria among subjects with eGFR of ≥ 90, 60–89, and 45–59 ml/min/1.73 m², respectively). These associations were statistically significant in each age and sex category. Among MetS components, the prevalence of hypertension and diabetes increased with increasing levels of proteinuria (odds ratios for hypertension: 1.23 and 1.87, and odds ratios for diabetes: 1.28 and 2.18 for trace and positive proteinuria, respectively), which were similarly observed in any eGFR category. There were little or no differences in the prevalence of abdominal obesity and dyslipidemia (reduced HDL-cholesterol and/or elevated triglycerides) between the levels of proteinuria.

Subjects with dipstick-determined trace proteinuria showed intermediate risk of having MetS, hypertension, and diabetes between negative and positive proteinuria in any eGFR category in a large general population. Thus, MetS components should be checked for subjects with trace proteinuria even in those with normal eGFR for the early prevention of cardiovascular diseases.