• Clinical science

Chronic kidney disease

Abstract

Chronic kidney disease (CKD) is defined as an abnormality of the kidney structure or function for ≥ 3 months. The most common causes of CKD in the United States are diabetes mellitus, hypertension, and glomerulonephritis. Since the kidneys have exceptional compensatory mechanisms, most patients remain asymptomatic and are unaware of their condition until their kidney function is significantly impaired. Patients typically present with symptoms of fluid overload (e.g., peripheral edema) and uremia. Laboratory evaluation shows hyperkalemia, hyperphosphatemia, and hypocalcemia, as well as metabolic acidosis. Management focuses mainly on treating the underlying disease and preventing possible complications, e.g., treating hypertension, avoiding nephrotoxic substances, and maintaining adequate hydration. If chronic kidney disease progresses to end-stage renal disease (ESRD), renal replacement therapy (dialysis) or a kidney transplant is necessary.

Definition

  • Chronic kidney disease is defined as an abnormality of the kidney structure or function for ≥ 3 months.
  • Associated with an irreversible reduction of the excretory (glomerular, tubular) and the endocrine functions of the kidney
Diagnostic criteria (≥ 3 months)
Abnormalities of the kidney structure

Abnormalities of the urine sediment

Moderate – severe albuminuria

Pathologic abnormalities

History of kidney transplantation

Abnormalities detected on imaging

OR
Abnormalities of the kidney function GFR < 60 mL/min/1.73 m2

References:[1]

Epidemiology

  • About 10% of adults in the US suffer from chronic kidney disease.
  • African Americans are at increased risk of developing chronic kidney disease.

References:[2][3]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

Causes of CKD in the US
Diabetic nephropathy Most common cause, accounts for 44% of cases in the US
Hypertensive nephropathy 28%
Glomerulonephritis 8%
Polycystic kidney disease/hereditary 2%
Urological disease 0.5%
Other causes: amyloidosis, toxins, chronic inflammation

References:[3][4][5]

Clinical features

Patients develop secondary hyperparathyroidism and subsequent renal osteodystrophy due to hyperphosphatemia, hypocalcemia, and the insufficient production of vitamin D!

References:[6][7][8][9][10][11][12][13]

Stages

Classification based on glomerular filtration rate

Stage Glomerular filtration rate (GFR) (mL/min/1.73 m2) Description
1 > 90 Normal or high
2 60 to 89 Mildly decreased
3 30 to 59 Moderately decreased
4 15 to 29 Severely decreased
5 < 15 Kidney failure

Classification based on albuminuria

Stage Urinary albumin excretion (mg/day) Description
A1 < 30 Normal
A2 30 to 300 Microalbuminuria
A3 > 300 Macroalbuminuria

Diagnostics

In chronic renal disease, close surveillance of serum potassium values as well as calcium and phosphate values is essential!References:[13][14][15][16]

Treatment

References:[13][14][17][18][19][20][16][21][21]