Chronic kidney disease

Overview

Chronic kidney disease (CKD) is a condition in which the kidneys progressively lose function over more than 3 months. It affects approximately 15% of adults in our country; about 7-8 million people are affected. It is known as the "silent disease" because it does not cause symptoms in early stages.

It is a progressive disease; without treatment, it leads to end-stage kidney failure requiring dialysis or transplant.

Symptoms

There may be no symptoms in early stages. As it progresses:

• Fatigue, weakness
• Difficulty concentrating
• Loss of appetite
• Nausea, vomiting
• Swelling in ankles, hands, face
• Changes in urine output (increase or decrease)
• Foamy urine (proteinuria)
• Frequent urination (especially at night)
• Bloody urine
• Itching (uremic)
• Muscle cramps
• Sleep disturbances
• High blood pressure
• Shortness of breath (fluid in lungs)
• Skin color change (yellow-gray)
• Metallic taste in mouth, bad breath

Staging (Based on GFR)

• Stage 1: GFR ≥90 (kidney damage but normal function)
• Stage 2: GFR 60-89 (mild loss)
• Stage 3a: GFR 45-59 (mild-moderate loss)
• Stage 3b: GFR 30-44 (moderate-severe loss)
• Stage 4: GFR 15-29 (severe loss)
• Stage 5: GFR <15 (kidney failure — end stage)

Causes

Most common causes in our country:

• Diabetes (35-40%)
• High blood pressure (25-30%)
• Glomerulonephritis
• Polycystic kidney disease
• Recurrent urinary tract infections
• Urinary tract obstruction (stones, prostate enlargement)
• Frequent painkiller (NSAID) use
• Autoimmune diseases (lupus)
• Congenital kidney diseases
• Toxins, heavy metals

Risk Factors

• Diabetes
• High blood pressure
• Cardiovascular diseases
• Family history of kidney disease
• Over age 60
• Smoking
• Obesity
• Frequent NSAID use
• Recurrent urinary tract infections
• History of kidney stones
• Ethnicity (some populations)

Complications

• Hypertension
• Anemia
• Bone disease (renal osteodystrophy)
• Electrolyte imbalances (hyperkalemia, hypocalcemia)
• Acidosis
• Cardiovascular diseases (most common cause of death)
• Fluid overload (pulmonary edema, heart failure)
• Uremia
• Weakened immunity
• Malnutrition
• End-stage kidney failure
• Death

When to See a Doctor

• Annual check-up if you are in a risk group (diabetic, hypertensive, family history of kidney disease)
• If you have one or more symptoms
• Urinary complaints
• If you have diabetes and high blood pressure
• Unexplained weakness, edema, loss of appetite

Diagnosis and Treatment

Diagnosis:

• Blood tests:

  • Serum creatinine
  • eGFR (estimated glomerular filtration rate)
  • BUN, urea
  • Electrolytes (potassium, sodium, calcium, phosphorus)
  • Hemoglobin (anemia)
  • PTH (bone disease)
  • Vitamin D

• Urine tests:

  • Urinalysis
  • Spot urine albumin/creatinine ratio
  • 24-hour urine protein

• Imaging:

  • Kidney ultrasound
  • CT, MRI when needed

• Kidney biopsy (in some situations)

Treatment:

Treating the underlying disease is the most important step.

1. Blood pressure control:

• Target: <130/80 mmHg
• ACE inhibitors or ARBs are first choice

2. Diabetes control:

• HbA1c < 7% according to individual target
• SGLT2 inhibitors (empagliflozin, dapagliflozin) are kidney-protective
• GLP-1 agonists

3. Diet:

• Salt restriction (<5 g/day)
• Protein restriction (depending on stage)
• Potassium, phosphorus restriction (in advanced stages)
• Plenty of fluids (unless restriction is required)

4. Treating complications:

• Anemia: iron, B12, erythropoietin
• Bone disease: active vitamin D, phosphate binders
• Acidosis: bicarbonate
• High cholesterol: statin

5. In end-stage kidney failure:

• Hemodialysis (3 times a week, 4 hours)
• Peritoneal dialysis (at home, at night)
• Kidney transplantation (best option)

Prevention

Control risk factors:

• Have your blood pressure measured regularly; do not skip your medications
• Closely monitor your diabetes
• Quit smoking
• Maintain a healthy weight

Nutrition:

• Reduce salt (below 5 g per day)
• Drink plenty of water (2 L per day)
• Less processed foods
• Adequate protein (do not overdo it)
• Eat a vegetable- and fruit-rich diet

Other recommendations:

• Do not use NSAIDs (ibuprofen, naproxen) unnecessarily
• Stay away from over-the-counter "herbal" medications
• Annual kidney function test if you are at risk
• Do not ignore urinary tract infections
• Have kidney stones followed up
• Regular exercise
• Limit alcohol
• Get enough sleep