What is the classification and description of Urinalysis (UA) glucose levels, including the range and interpretation of 1+ and 2+ results?

From the Guidelines

Urinalysis (UA) glucose classification is a semi-quantitative method that reports results as negative, trace, 1+, 2+, 3+, or 4+, with negative indicating no glucose detected and 1+ to 4+ representing increasing glucose levels, approximately 250 mg/dL to 2000 mg/dL or higher, respectively. The presence of glucose in urine, as indicated by these results, warrants further investigation, particularly blood glucose testing, to determine the underlying cause, as it can be a sign of uncontrolled diabetes mellitus, pregnancy, certain medications, or other conditions affecting renal glucose handling 1. The renal threshold for glucose is typically around 180-200 mg/dL, and when blood glucose levels exceed this threshold, glucose appears in the urine, overwhelming the kidneys' ability to reabsorb it 1. Key points to consider in UA glucose classification include:

• Negative: no glucose detected (normal finding)
• Trace: approximately 100 mg/dL
• 1+: about 250 mg/dL of glucose
• 2+: roughly 500 mg/dL
• 3+: approximately 1000 mg/dL
• 4+: 2000 mg/dL or higher It is essential to note that UA glucose testing should not replace blood glucose monitoring for diabetes management, as it only detects relatively high glucose levels and can be affected by urine concentration and other factors, and according to recent guidelines, urine glucose testing is not recommended for routine care of patients with diabetes mellitus 1. In the context of diabetes diagnosis, the current diagnostic criteria, as outlined in recent guidelines, include A1C, FPG, and 2-hour plasma glucose levels, with specific cut points for each test, and the diagnosis of diabetes should be made based on these criteria, rather than relying solely on UA glucose results 1.

From the Research

UA Classification Description for Glucose

• The UA classification description for glucose is based on the semi-quantitative measurement of glucosuria, which is indicated as (+), (++), (+++), and (++++) 2.
• The range for each classification is not explicitly stated in the provided studies, but it can be inferred that the classification is based on the concentration of glucose in the urine.
• A classification of 1+ may indicate a small amount of glucose in the urine, while 2+ may indicate a moderate amount, and so on.
• The study by 3 mentions that qualitative urinary glucose (UG) exhibited a sensitivity of 80.2% and a specificity of 85.6% at the optimal cutoff of glycosuria +1, suggesting that a 1+ classification may be a useful indicator of diabetes.

Urinary Glucose Measurement

• Urinary glucose can be measured using quantitative and qualitative approaches 3.
• The quantitative approach measures the concentration of glucose in the urine, while the qualitative approach indicates the presence or absence of glucose.
• The study by 3 found that quantitative UG was positively correlated with fasting plasma glucose (FPG) and 2 h plasma glucose (2 h PG), suggesting that it may be a useful indicator of diabetes.

Clinical Significance

• The presence of glucose in the urine (glucosuria) can be an indicator of diabetes mellitus 2, 3.
• The study by 2 found that referring patients with glucosuria to endocrinology or internal medicine departments can contribute to the diagnosis and treatment of diabetes mellitus.
• The study by 3 suggests that urinary glucose, either quantitatively or qualitatively measured, can be an effective approach for diabetes screening.