Chronic kidney disease

What creatinine, eGFR and urine albumin show

The kidneys filter the blood, remove metabolic waste and regulate water, electrolytes and blood pressure. Creatinine in the blood is a muscle product removed by the kidneys; its value is used to calculate eGFR, the estimated glomerular filtration rate. An eGFR below 60 ml/min for more than three months indicates reduced function. Creatinine depends on muscle mass, so it is interpreted with age and sex.

Damage also includes albuminuria, the passage of the protein albumin into the urine, measured by the albumin/creatinine ratio in a urine sample. Function may be preserved while albuminuria shows damage to the filters; staging therefore relies on both (see proteinuria and hematuria). A single abnormal value is not enough: it is confirmed by repetition after a few weeks.

Causes and risk factors

The most frequent causes are diabetes and high blood pressure (see diabetic and hypertensive nephropathy). Others are glomerulonephritis, polycystic disease, obstruction of the urinary tract, recurrent stones, recurrent infections and long-term use of some medicines, especially nonsteroidal anti-inflammatory drugs. Age, family history and heart disease increase the risk.

Why symptoms come late

The kidneys have a large functional reserve, so symptoms often appear when function has fallen considerably. There may be fatigue, swelling (edema) of the ankles and eyelids, more frequent urination at night, reduced appetite, itching, nausea and shortness of breath. Anemia, high blood pressure and mineral disorders become more common in advanced stages. For this reason people with diabetes, hypertension or a family history are checked every year even without complaints.

Treatment and the aim of slowing progression

The goal is to slow worsening and reduce cardiovascular risk, because kidney disease markedly increases the risk of heart attack and heart failure. Blood pressure (usually aimed below 130/80 mmHg, “13 over 8”, depending on the case), blood glucose, lipids and weight are controlled. Some medicines protect the kidneys, especially when there is albuminuria, but the choice and dose are made by the doctor according to function and potassium.

Avoid nonsteroidal anti-inflammatory drugs without medical advice and unverified supplements. The dose of some medicines is adjusted to eGFR. After examinations with contrast at other centers, function may be reassessed. In advanced stages, preparation for replacement of function (dialysis or transplant) is discussed; it is carried out at specialized centers outside our clinic.

Diet and daily habits to protect the kidneys

Nutrition in chronic kidney disease is individualized according to stage, tests and coexisting diseases; there is no single diet for everyone. The most consistent principle is limiting salt to about 5 g a day (roughly one level teaspoon), because sodium raises blood pressure, increases proteinuria and weakens the effect of some protective medicines. In practice this means avoiding processed foods (smoked meats, salty cheeses, ready-made soups, large amounts of salty bread and pastries) and adding spices and herbs instead of salt.

Protein should not be excessive, because a large protein load increases the work of filtration; in advanced stages the doctor or dietitian may recommend moderate intake, around 0.8 g per kilogram of body weight a day, but excessive restriction risks malnutrition, so it should not be done without guidance. Potassium and phosphorus are restricted only when tests show high levels; in that case the doctor advises on fruit, vegetables and processed products with phosphate additives. Avoid potassium salt substitutes and herbal supplements without advice, because some are nephrotoxic.

Fluids are not restricted except in advanced failure or edema; drinking enough water protects the kidneys, but drinking excessively does not “flush” them. Moderate physical activity, at least 150 minutes a week, lowers cardiovascular risk. Stopping smoking slows disease progression. Be careful with over-the-counter medicines: ibuprofen, naproxen and diclofenac can damage the kidneys, especially if you are dehydrated or taking diuretics and blood pressure medicines.

What to do on sick days and how to prepare for the visit

When you have vomiting, diarrhea or fever and cannot drink enough, you risk dehydration, which can suddenly worsen kidney function. In this situation the doctor may advise temporarily stopping some medicines (diuretics, renin-angiotensin system blockers, metformin, anti-inflammatories) until recovery; do not stop them yourself, but contact the team. Tell every doctor or radiologist before examinations with iodinated contrast, which in certain cases require preparation.

Before the visit bring earlier values of creatinine, eGFR and urine (the trend over time is what matters), home blood pressure readings and a list of medicines and supplements. Useful questions: what stage am I in and how fast is it progressing; which medicines protect me and which should I avoid; what blood pressure target do I have; what specific diet suits me; when should I begin to think about future interventions. Keep a diary of blood pressure and weight: rapid weight gain with swelling indicates fluid retention and should be reported.

Follow-up and services

Kidney function, albuminuria, electrolytes, hemoglobin and blood pressure are checked every 6 months to a year, or sooner when the doctor considers it reasonable, and more often in advanced stages or after a change of therapy. Report vomiting, prolonged diarrhea or fever, because they may require a temporary change of medicines.

Care at Tirana Polyclinic: we offer nephrology consultation, abdominal ultrasound, which assesses the size and structure of the kidneys, and interpretation of tests. Other imaging examinations are recommended at another center and the results are interpreted by the specialist.