Glycosuria

Glycosuria is usually diagnosed through routine urine examinations. This is because the symptoms of glycosuria are not noticeable even for years. However, if this condition is left untreated, it can lead to:

• Extreme thirst or dehydration
• Extreme hunger
• Frequent urination
• Accidental urination

If glycosuria is occurring due to type 2 diabetes, the following symptoms may be evident:

• Unexplained weight loss
• Eyesight issues
• Fatigue
• Delayed healing of cuts, sores, or other injuries
• Skin darkening, especially in the folds of the neck, armpits, and other areas

Glycosuria resulting from gestational diabetes does not clinically express any additional symptoms.

Glycosuria often occurs due to an underlying condition affecting blood sugar levels. For example, type 2 diabetes. It is the most common cause of glycosuria. The causes of glycosuria can be explained as follows:

• Diabetes: In type 2 diabetes, insulin in the body fails to transport blood sugar to different body cells effectively. This leads to increased blood sugar levels that are eliminated through urine. On the other hand, in type 1 diabetes, the production of insulin is inadequate. As a result, levels of sugar rise in the blood. This excess sugar is eliminated through urine.
• Pregnancy: Some pregnant women develop gestational diabetes. This occurs because of inadequate insulin production or resistance. Consequently, blood sugar levels rise to abnormally high amounts. 
• Renal glycosuria: This type of glycosuria is a rare phenomenon. When the kidney's tubules (renal filters) inadequately filter sugar through urine. Renal glycosuria happens because of a mutation in a specific gene. 
• Fanconi syndrome: This is an acquired or genetic condition. In this condition, the kidneys fail to absorb electrolytes and other substances due to defective nephrons. It happens when glucose and amino acids fail to absorb due to defective filtering units or nephrons. As a result, an imbalance in the levels of glucose is observed in the body. Excess glucose is eliminated through urine since the kidneys cannot reabsorb all of it. Hence, excessive glucose is excreted in the urine; a condition termed glycosuria results.

Since glycosuria does not present evident clinical symptoms, it is often diagnosed at a routine urinalysis. However, there are other tests, too.

Doctors or lab test people provide a cup for collecting urine samples. Next, a test strip is dipped in the urine cup for examination. Then, the lab technician determines the glucose level in the urine and reports the condition accordingly. In addition, doctors order a blood test to evaluate blood sugar levels.

The normal fasting blood sugar level is < 100 mg/dL, and fasting prediabetes levels are between 100-125 mg/dL. Suppose the blood sugar levels are high and diabetes hasn't been diagnosed previously. Then, doctors perform a glycated haemoglobin or HbA1C test. This blood test gives an average of blood sugar levels for the past few months.

If no symptoms are present, glycosuria is not detected unless a routine urine exam is carried out. No glycosuria treatment is needed since it is not a threat in itself. However, it is important to diagnose its cause and treat it. If diabetes is diagnosed, it should be treated accordingly. Some treatment and management options include:

• Physical exertion of at least 30 minutes every day is essential.
• A proper, diabetic-friendly diet plan that provides enough nutrients and at the same time decreases sugar or fat intake is important. This implies eating more vegetables, fruits, and whole grains.
• Take medications to help the body utilize insulin more effectively. Some examples are metformin, which allows the body to respond better to insulin, or sulfonylureas, which helps the body produce more insulin.
• Keep blood sugar levels in check to better understand how food and certain activities affect the body.

The major risk factor of glycosuria is untreated diabetes mellitus. In addition, a rise in blood sugar levels due to impaired insulin function or insulin resistance leads to glucose elimination through urine. Rarely, it may occur due to a genetic mutation that affects the renal tubules.

Some complications associated with glycosuria are as follows:

• Cardiovascular diseases such as the risk of developing heart attack and stroke
• Nerve damage
• Renal disease and failure
• Ketoacidosis
• Eye problems, and consequently, vision loss
• High blood pressure or hypertension
• Delayed wound healing

The prognosis of glycosuria is good if it is not associated with an underlying condition. However, in cases where glycosuria occurs due to an underlying medical condition, it is important to treat it. This is because untreated medical conditions, for instance, diabetes, can have debilitating effects on other organs of the body. If glycosuria is caused by diabetes, the prognosis gets better with controlled blood sugar levels. In addition, making lifestyle changes such as regular exercise and dieting further improve the condition and prevent complications.

Reviewed by Dr. Manoj Ranka, Consultant, Internal Medicine on 2-Jan-2023.