Hi everyone, Today, we will be discussing the impact of abnormal kidney development on chronic kidney disease.
The kidneys are vital organs that regulate fluid, electrolyte, and acid-base balance in our body.
It is in the kidneys that blood is filtered of all waste and this waste is excreted as urine.
The kidney contains millions of these tiny structures. What are these structures? This is the nephron and the nephron is the functional unit of the kidney where the
kidney performs its functions of blood filtration.
The focus of this video will be on one specific part of the nephron: the glomerulus. The glomerulus is a network of small blood vessels where filtration of the blood occurs.
Abnormal development, as we will learn later on, of the nephron can lead to kidney disease.
Let's discuss a bit of background on chronic kidney disease next.
As mentioned previously, the main functions of the kidneys are to filter water from your blood, produce urine, and maintain blood pressure.
In chronic kidney disease(CKD), our kidneys are damaged and are unable to filter blood the way they are supposed to. This results in the accumulation of waste in our body.
It is referred to as chronic kidney disease because this damage can occur slowly over a long period of time, typically persisting for more than 3 months.
Some of the symptoms of advanced CKD can include chest pain, swelling, nausea, cramps, etc. In extreme cases, the disease can worsen and possibly lead to kidney failure.
CKD is diagnosed through analysis of blood and urine tests.
It is possible to not present any symptoms associated with CKD, as your kidneys can be doing just enough to keep you feeling healthy despite the damage.
For this reason, the best way to know whether you have kidney disease is by getting blood and urine tests done.
This graphic from the National Kidney Foundation depicts the various stages of CKD.
If results show that you have a glomerular filtration rate (GFR) of less than 60 or high levels of substances such as protein in your blood, you are diagnosed with CKD.
A GFR below 15 indicates kidney failure.
Now let’s discuss the causes of Chronic Kidney disease. Hypertension, or high blood pressure, can be a cause for kidney disease as the pressure damages small blood vessels in your kidneys.
Another high risk group for developing CKD is individuals with diabetes, as excessive glucose can damage the filters in the kidneys.
However, other causes such as glomerulosclerosis, which involves scarring of the glomerulus, can also influence the onset of this disease.
There are some genetic risk factors as well. CKD has a relatively high heritability of 30-75% meaning that a large amount of the differences seen in those with kidney disease
versus without, can be attributed to genes. Sickle cell trait, another genetic condition, has also been associated with higher risks of kidney disease.
There are still many other factors which can affect CKD progression. These include heart disease, stroke, family history, obesity, tobacco use, and age.
The one cause of particular interest to us is abnormal kidney development.
Treatment options for CKD target the cause of the kidney damage and aim to slow its progression into kidney failure.
In less severe cases, lifestyle changes are recommended to maintain the best health. Some examples of this include diet and exercise changes.
Medications that deal with some of the problems associated with CKD can also be used to slow its progression. In CKD patients with hypertension, medication to manage high blood pressure is common.
In the event of kidney failure, a patient would need either dialysis treatment (which helps remove waste from the blood using a machine) or an organ transplant.
Now that we've covered the basics of CKD, let's discuss the basics of abnormal kidney development.
Several issues can arise during kidney development ranging from very severe to subtle structural changes of the kidney.
In about one of 500 births, some abnormality occurs in the development of the kidneys or urinary tract. Structural changes in kidney development can be broken down in macro and micro anatomical changes.
Some examples of macro anatomical kidney structural changes include: Duplicated Ureters - Where instead of one tube draining the kidney into the bladder, there are now two.
Renal Agenesis - Which is where you are either born with only one functional kidney or zero.
Multicystic kidney - which is where multiple cysts form on kidney due to nephrons filling with urine.
Macro changes can be spotted at birth using ultrasound. Doctors can treat these abnormalities if caught early and reduce the risk of disease.
The national kidney foundation state that babies with urinary tract abnormalities detected by prenatal ultrasound often do very well.
There is also a second class of anatomical changes which are harder to spot. Micro anatomical changes are difficult to notice in their early stages. Some examples of micro anatomical kidney structural changes include:
Nephron endowment - The number of functional nephrons an individual has at birth.
Another example is glomerulosclerosis - hardening of the glomerulus which can cause a loss of protein into the urine. Another example is abnormal glomerulogenesis – which is the abnormal formation of the glomeruli.
Over time the effects of the micro anatomical abnormalities compound and become more pronounced. Chronic kidney disease is a long-term disease characterized by the lack of kidney function.
You can begin to see the picture of how these small changes compound over the years contributing more and more to decreased kidney function and eventually, CKD.
Several different factors have been shown to contribute to abnormal kidney development. During fetal development, negative events can have an impact on kidney development.
For instance, low birthweight and prematurity have been associated with low nephron count, and increase in risk of hypertension and kidney disease later in life.
Notably, the health and diet of the mother during pregnancy can contribute to abnormal kidney development.
A second potential factor that leads to abnormal kidney development is genetics. During the development of the kidneys, interactions between specific types of cells leads to the formation of nephrons.
Genetic mutations can affect these interactions and result in lower nephron counts. A third factor in kidney development is postnatal nutrition, or simply put, the nutrition of the
child following birth. Studies have shown that overeating or diets with excessive protein for children can lead to CKD later in life.
Now that we've discussed the background of both topics. Let’s connect them using a fictional story.
Here is Betty. Growing up Betty had no macro anatomical kidney changes. During the routine ultrasound exam before birth, Betty’s organs seemed perfectly fine.
What could not be observed in the ultrasounds however is the decreased nephron count and the presence of scarred glomeruli. These abnormalities were the result of genetic factors.
As Betty grew up, she was unaware of the micro changes to her kidney. Her diet was high in salt and sugar which is an added risk factor for chronic kidney disease.
The symptoms of CKD were not yet present as the effects of the decreased nephron count are still compounding with age. The functional parts of her kidney are under more
stress as compared to someone with a perfectly normal kidney at her age.
Betty was still unaware of her kidney changes growing up due to the slow onset of chronic kidney disease. Up until adulthood, Betty rarely got her blood and urine tests done.
One day, during a visit to the doctors complaining of a nausea and swelling, Betty gets a blood test after the suggestion from her doctor. The tests revealed that she has stage 2 chronic kidney disease.
Betty’s doctor recommends lifestyle changes to put less strain on her kidney. He also recommends a diet that will drastically slow the progression of chronic kidney disease.
What lessons can we take away from Betty's situation. Had Betty got blood and urine tests done on an annual basis, the doctor could have recommended these lifestyle changes before
the drop in kidney function. Early intervention can significantly slow the progression of chronic kidney disease.
As for how frequently you should be getting these tests done, consult your family physician.
The second lesson we can learn is that of maintaining a balanced diet. Diets high in salt and sugar can lead to hypertension and diabetes which are risk factors for chronic kidney disease.
Maintaining a healthy balanced diet is beneficial to all organ systems, not just the kidneys.
And that concludes our talk, thanks for watching.