Glucose Tolerance Test + Urine (GTT)

Glucose Tolerance Test (GTT) – Comprehensive Screening for Glucose Levels in Plasma and Urine

The Glucose Tolerance Test (GTT) with Urine Screening from Lab Tests Dubai is a comprehensive metabolic evaluationthat assesses how your body processes glucose after a controlled sugar load. This advanced test measures plasma glucose at fasting, 1-hour, and 2-hour intervals—the gold standard for diagnosing diabetes and prediabetes—and includes optional urine glucose testing to detect glucosuria, a sign of persistent hyperglycemia.

Using enzymatic spectrophotometry for plasma and dipstick/chemical analysis for urine, this dual-sample test delivers highly accurate results within just 1 day, making it essential for:

• Diagnosing type 2 diabetes and prediabetes
• Screening for gestational diabetes (GDM)
• Evaluating insulin resistance and metabolic syndrome
• Monitoring patients with renal glycosuria or kidney disease

Available with home blood and urine collection, Lab Tests Dubai makes metabolic testing accurate, convenient, and patient-friendly—ideal for pregnant women, diabetics, and high-risk individuals.

Why You Need This Test

If you’re at risk for diabetes or insulin resistance, this test could prevent long-term complications.

You need the GTT with Urine Screening if:

• You’re pregnant and due for gestational diabetes screening (24–28 weeks)
• You have PCOS, obesity, or a family history of diabetes
• You’ve had abnormal fasting glucose or HbA1c
• You experience symptoms of blood sugar imbalance (fatigue, thirst, frequent urination)
• You notice sweet-smelling urine or ants around urine (possible glucosuria)
• You’re being evaluated for renal glycosuria or kidney dysfunction

While plasma glucose is diagnostic, urine glucose can indicate:

• Kidney threshold issues
• Poor diabetes control

This test gives you both diagnostic precision and real-world insight.

Symptoms That Indicate This Test

Consider the GTT with Urine Screening if you experience:

• For Diabetes & Prediabetes:

• Excessive thirst or frequent urination

• Unexplained fatigue or low energy

• Increased hunger despite eating

• Blurred vision

• Slow-healing wounds or frequent infections

• For Glucosuria (Sugar in Urine):

• Sweet or fruity-smelling urine

• Presence of ants or insects near urine

• Nocturia (nighttime urination)

• Unexplained dehydration

• For Gestational Diabetes:

• No symptoms (often asymptomatic)

• High fasting glucose in prenatal labs

• Large baby (macrosomia) on ultrasound

These signs may point to impaired glucose tolerance—and this test provides definitive diagnosis.

Natural Production: How Glucose Metabolism Works

After eating, carbohydrates are broken down into glucose, which enters the bloodstream.

In response, the pancreas releases insulin, which helps cells absorb glucose for:

• Immediate energy
• Storage as glycogen (liver/muscles)
• Conversion to fat (if excess)

But in insulin resistance or pancreatic dysfunction:

• Cells don’t respond well to insulin
• Glucose stays elevated longer

The GTT measures:

• Fasting glucose → Baseline insulin sensitivity
• 1-hour & 2-hour glucose → Peak and recovery response
• Urine glucose → Confirms persistent hyperglycemia

Abnormal levels indicate prediabetes, diabetes, or renal issues.

What Happens If Untreated? Risks of Ignoring Glucose Intolerance

Ignoring abnormal GTT results can lead to:

• Type 2 Diabetes – progression from prediabetes

• Gestational Diabetes Complications –

• Large baby → C-section risk

• Preterm birth

• Neonatal hypoglycemia

• Higher risk of type 2 diabetes later

  • Cardiovascular Disease – from chronic high glucose
  • Kidney Damage (Nephropathy) – glucose damages glomeruli
  • Nerve & Vision Damage – over time

Early detection via GTT allows for:

• Diet and lifestyle changes
• Metformin (if needed)
• Insulin therapy in GDM

One test can protect both mother and baby.

How to Prepare for the Test

To ensure accurate results:

• Fast for 8–12 hours (water allowed) – no food or drink except water
• Avoid alcohol and caffeine 24 hours before
• No smoking or strenuous exercise before the test
• Continue medications unless instructed otherwise – inform your doctor
• Rest during the test – avoid walking or stress

Procedure

1. Fasting blood draw (Plasma Glucose)
2. First-morning urine sample (for baseline)
3. Drink 75g glucose solution (sweet, syrupy drink)
4. Wait exactly 1 hour, then 2 hours – no eating, drinking, or smoking
5. Second and third blood draws at 1-hour and 2-hour marks
6. Urine samples collected at each interval (optional)

Our trained team ensures a smooth experience—available at clinics or via home collection with on-site testing.

Test Overview: Enzymatic & Dipstick Methodology

• Plasma Glucose: Enzymatic Spectrophotometry (Glucose Oxidase)

• Urine Glucose: Dipstick / Chemical Test (Glucose Oxidase)

  | Turnaround Time (TAT) | 1 Day | | Category | Diabetes & Metabolic Health | | Purpose | Diagnose diabetes, prediabetes, gestational diabetes, detect glucosuria | | Testing Location | Lab Tests Dubai – Accredited Labs & Home Collection Across UAE |

Interpretation (WHO Criteria – 75g OGTT)

Results are reported with clinical notes and reference ranges.