Risk Factors or Causes of Chronic Kidney Disease

Chronic kidney disease could result from chronic exposure to risk factors such as,

  1. Poorly controlled hypertension
  2. Poorly managed diabetes
  3. Hyperlipidemia or dyslipidemia
  4. Severe heart failure
  5. Poorly managed arrhythmias
  6. Health conditions involving chronic inflammation of the kidneys & associated structures, such as, lupus and glomerulonephritis
  7. Overuse or abuse of NSAID drugs like naproxen, aspirin, indomethacin, ibuprofen, and diclofenac
  8. Hereditary conditions of the kidney affecting the kidney structure, such as, polycystic kidney disease
  9. Health conditions involving obstruction to urine flow, such as, renal stones, prostate hypertrophy in men, and cancerous mass in the kidneys.

 

How does poorly controlled hypertension contribute to chronic kidney disease?

  1. Glomerulus is the filtering unit of the nephron and filters the blood, while the blood flows through the capillary network in the glomerulus.
  2. Individuals with poorly controlled hypertension have elevated pressures in the afferent and efferent arterioles supplying blood to and draining out of glomerulus.
  3. As a response to continued chronic exposure to elevated pressures in the blood vessels (afferent and efferent arterioles), the walls of the vessels harden & thicken, which compromises the lumen of the vessels.
  4. Compromised lumen has lesser space to accommodate blood flow and consequently, leads to reduced blood flow in the affected blood vessels and glomerulus. Reduced blood flow through the filtering units, glomeruli, result in compromised GFR.
  5. Reduced blood flow through the glomeruli contributes to lower oxygen supply and reduced nutrient delivery to the tissues in the kidney. Chronic exposure of renal tissues to reduced oxygen supply can lead to increased fibrous tissue deposition in the kidney, progressive renal tissue death & necrosis, which can compromise the renal function.
  6. Also, thickened walls of blood vessels can make diffusion of oxygen and other essential nutrients from the blood to the renal tissues difficult. This can also contribute to progressive tissue death & necrosis of renal tissue, which can compromise the renal function.
  7. Continued exposure of renal tissue to risk for reduced blood flow, reduced GFR, compromised oxygen & nutrient delivery, and consequent renal tissue death & necrosis, over a period of time, lead to findings of CKD.

How does poorly managed diabetes contribute to chronic kidney disease?

  1. Poorly managed diabetic individuals can often present with high blood sugars. Elevated sugars in these patients combine with certain proteins and lipids in the blood forming substances or molecules that can increase risk for inflammation.
  2. These pro-inflammatory molecules can affect the renal blood vessels and cause inflammation of the renal blood vessels (afferent and efferent arterioles supplying blood to and draining out of glomerulus respectively).
  3. Chronic inflammation and consequent damage to the renal blood vessels result in thickening and hardening of the involved blood vessels.
  4. Also, high blood glucose in these individuals can also contribute to oxidation of lipids or fats in the blood, which can increasingly deposit in the inflamed portions of the renal blood vessels, forming an atherosclerotic plaque.
  5. Hardening of renal blood vessels with increased plaque deposition can result in compromised lumen of blood vessels with lesser space to accommodate the needed blood flow.
  6. This can lead to reduced blood flow in the affected blood vessels and glomerulus. Reduced blood flow through the filtering units, glomeruli, result in compromised GFR.
  7. Reduced blood flow through the glomeruli contributes to lower oxygen supply and reduced nutrient delivery to the tissues in the kidney. Chronic exposure of renal tissues to reduced oxygen supply can lead to increased fibrous tissue deposition in the kidney, progressive renal tissue death & necrosis, which can compromise the renal function.
  8. Also, thickened walls of blood vessels can make diffusion of oxygen and other essential nutrients from the blood to the renal tissues difficult. This can also contribute to progressive tissue death & necrosis of renal tissue, which can compromise the renal function.
  9. Continued exposure of renal tissue to risk for reduced blood flow, reduced GFR, compromised oxygen & nutrient delivery, and consequent renal tissue death & necrosis, over a period of time, lead to findings of CKD.

How does hyperlipidemia contribute to chronic kidney disease?

  1. Hyperlipidemia is a condition when the blood has cholesterol and fats in excess.
  2. Individuals in hyperlipidemic state can be at increased risk for chronic kidney disease, as the excess fats and cholesterol start to increasingly deposit on the inner lining of the renal blood vessels, forming an atherosclerotic plaque.
  3. Increased plaque deposition in the renal blood vessels can result in compromised lumen of the involved blood vessels with lesser space to accommodate the needed blood flow.
  4. This can lead to reduced blood flow through the glomerulus and reduced filtering activity in the glomerulus, resulting in compromised GFR.
  5. Reduced blood flow through the glomeruli contributes to lower oxygen supply and reduced nutrient delivery to the tissues in the kidney. Chronic exposure of renal tissues to reduced oxygen supply can lead to increased fibrous tissue deposition in the kidney, progressive renal tissue death & necrosis, which can compromise the renal function.
  6. Continued exposure of renal tissue to risk for reduced blood flow, reduced GFR, compromised oxygen & nutrient delivery, and consequent renal tissue death & necrosis, over a period of time, lead to findings of CKD.

How does heart failure contribute to chronic kidney disease?

  1. Glomerulus is the filtering unit of the nephron. Afferent and efferent arterioles supply blood to and drain out of glomerulus respectively. Blood is filtered while it flows through the capillary network in the glomerulus.
  2. Individuals with heart failure can present with poor pumping ability of the heart muscle, which results in reduced blood volume pumped out of the heart into circulation.
  3. This results in reduced volume of blood flowing through the afferent arterioles into the glomerulus.
  4. Reduced blood flow into the glomerulus result in lesser volume of blood filtered through the glomerulus, thus compromising the GFR.
  5. Reduced blood flow through the glomeruli contributes to lower oxygen supply and reduced nutrient delivery to the tissues in the kidney. Chronic exposure of renal tissues to reduced oxygen supply can lead to progressive tissue death & necrosis, which can compromise the renal function.
  6. Continued exposure of renal tissue to risk for reduced blood flow, reduced GFR, compromised oxygen & nutrient delivery, and consequent renal tissue death & necrosis, over a period of time, lead to findings of CKD.

How does poorly managed arrhythmias contribute to chronic kidney disease?

  1. Glomerulus is the filtering unit of the nephron. Afferent and efferent arterioles supply blood to and drain out of glomerulus respectively. Blood is filtered while it flows through the capillary network in the glomerulus.
  2. Individuals with poorly managed arrhythmias can present with irregular and inefficient pumping action of the heart. This can contribute to an overall reduced blood volume pumped out of the heart into circulation.
  3. This can result in reduced volume of blood flowing through the afferent arterioles into the glomerulus.
  4. Reduced blood flow into the glomerulus results in lesser volume of blood filtered through the glomerulus, thus compromising the GFR.
  5. Reduced blood flow through the glomeruli contributes to lower oxygen supply and reduced nutrient delivery to the tissues in the kidney. Chronic exposure of renal tissues to reduced oxygen and nutrient supply can lead to progressive tissue death & necrosis, which can compromise the renal function.
  6. Continued exposure of renal tissue to risk for reduced blood flow, reduced GFR, compromised oxygen & nutrient delivery, and consequent renal tissue death & necrosis, over a period of time, lead to findings of CKD.

 

How does chronic inflammatory state contribute to chronic kidney disease?

  1. Chronic inflammatory state could be secondary to infections, such as, recurrent UTI or hepatitis. Chronic inflammatory state could also be common in individuals with history of on and off activation of autoimmune disorders, such as, lupus or rheumatoid arthritis.
  2. Individuals with recurrent infections or autoimmune disorders can develop antibodies, which upon combining with antigens in the blood, form antigen-antibody complexes.
  3. These antigen-antibody complexes could deposit along the lining of glomerulus, which is the filtering unit of the kidney.
  4. Excessive deposition of these complexes along the glomerulus can result in chronic inflammation and damage to the glomerulus.
  5. Chronic inflammation and injury to the glomeruli contribute to compromised filtering ability of the glomerulus and reduced GFR.
  6. Chronic inflammation and injury to the glomeruli could also result in increased fibrous tissue deposition in the kidney, compromised oxygen & nutrient delivery, progressive renal tissue death & necrosis. This can compromise the overall renal function and over a period of time, lead to findings of CKD.

How does overuse or abuse of NSAIDs contribute to chronic kidney disease?

  1. Glomerulus is the filtering unit of the nephron. Afferent and efferent arterioles supply blood to and drain out of glomerulus respectively. Blood is filtered while it flows through the capillary network in the glomerulus.
  2. Prostaglandins are substances present in the blood which help with healthy dilation of the afferent arterioles supplying blood into the glomerulus. This healthy dilation of afferent arterioles contribute to adequate blood supply into the glomerulus, decent filtration activity, and maintenance of healthy GFR.
  3. NSAID drugs like naproxen, aspirin, indomethacin, ibuprofen, and diclofenac inhibit synthesis of prostaglandins. So, individuals with history of overuse or abuse of NSAID drugs can present with less prostaglandin activity.
  4. This can result in collapse of the afferent arterioles supplying blood into the glomerulus. Reduced blood flow into the glomerulus results in lesser volume of blood filtered through the glomerulus, thus compromising the GFR.
  5. Reduced blood flow through the glomeruli contributes to lower oxygen supply and reduced nutrient delivery to the tissues in the kidney. Chronic exposure of renal tissues to reduced oxygen and nutrient supply can lead to progressive tissue death & necrosis, which can compromise the renal function.
  6. Continued exposure of renal tissue to risk for reduced blood flow, reduced GFR, compromised oxygen & nutrient delivery, and consequent renal tissue death & necrosis, over a period of time, lead to findings of CKD.

How does polycystic kidney disease contribute to chronic kidney disease?

  1. Polycystic kidney disease is a genetic condition, where individuals develop large cyst like outpouchings from the renal tubules.
  2. These large cyst like outpouchings can compress the afferent and efferent arterioles in the kidney, thus compromising the blood flow through these vessels supplying blood to and draining out of the glomerulus.
  3. Reduced blood flow through the glomerulus result in lesser volume of blood filtered through the glomerulus, thus compromising the GFR.
  4. Reduced blood flow through the glomeruli contributes to lower oxygen supply and reduced nutrient delivery to the tissues in the kidney. Chronic exposure of renal tissues to reduced oxygen & nutrient supply can lead to progressive tissue death & necrosis, which can compromise the renal function.
  5. Continued exposure of renal tissue to risk for reduced blood flow, reduced GFR, compromised oxygen & nutrient delivery, and consequent renal tissue death & necrosis, over a period of time, lead to findings of CKD.

How does obstruction to urine flow contribute to chronic kidney disease?

  1. Common cause for urinary obstruction, especially in males, is an enlargement of prostate gland. Enlarged prostate gland, depending on the degree of enlargement, could varyingly compress the urethra and block the flow of urine out of the urinary bladder.
  2. Obstruction to urine flow could also be secondary to factors like tumors or renal stones.
  3. Irrespective to the factor causing the urinary obstruction, any block to urine flow down stream could result in a back pressure. This back pressure can compromise the filtration pressure in the glomerulus, which is a force driving the glomerular filtration activity and GFR.
  4. Compromised filtration pressure in the glomerulus can result in reduced blood flow through the glomerulus, reduced glomerular filtration activity, and consequently, reduced GFR.
  5. Reduced blood flow through the glomeruli contributes to lower oxygen supply and reduced nutrient delivery to the tissues in the kidney. Chronic exposure of renal tissues to reduced oxygen & nutrient supply can lead to progressive tissue death & necrosis, which can compromise the renal function.
  6. Continued exposure of renal tissue to risk for reduced blood flow, reduced GFR, compromised oxygen & nutrient delivery, and consequent renal tissue death & necrosis, over a period of time, lead to findings of CKD.