Kidneys and bones seem like two unrelated and entirely different organs having a different set of functions. Yes, it is agreed that kidneys help in the elimination of toxins from the body while the bones help in movements and support the body’s framework. So, how do kidneys affect the bones?
However, in spite of having dissimilar functions, the health of kidneys and bones are interlinked. The disorders affecting the kidneys may affect the bones causing conditions like osteoporosis.
Hence, women need to understand the implications of kidney disorders on bone health so that they can take precautions to protect the bone tissues.
How do kidneys affect the bones?
Chronic kidney disorders occur when there is damage to the kidneys resulting in the loss of renal functions. Due to this, the balance of minerals in the body is affected.
The loss of proper functioning of the kidneys can cause an imbalance in the levels of calcium and phosphorus in the blood thereby triggering bone diseases. [1]
What are chronic kidney diseases?
Chronic kidney diseases refer to a form of kidney damage that occurs gradually over several years, often due to high blood pressure or diabetes. Once damaged, the kidneys lose their ability to filter blood and eliminate toxic metabolites efficiently.
This results in the build-up of waste products in the body due to which the functions of other organs are affected. The accumulation of harmful chemicals and toxins in the blood could also cause damage to the bone and joint tissues thereby causing bone disorders.
The role of minerals and hormones in kidney functions and bone health
Minerals and hormones are important for maintaining the strength of the bones. If the minerals and hormones are not in balance, the bones can become porous and weak resulting in malformations.
Healthy bones rebuild continuously with the help of nutrients and hormones such as:
- Calcium
- Phosphorus
- The active form of vitamin D called calcitriol
- Parathyroid hormone
The kidneys play a key role in maintaining optimum bone mass by balancing the levels of phosphorus and calcium in the blood.
Healthy kidneys also activate a form of vitamin D consumed through dietary sources by turning it into its active form called calcitriol. Calcitriol helps the kidneys to maintain normal calcium levels in the blood and promotes the formation of new bone cells. [2] [3]
The kidneys also support the removal of excess phosphorus from the body via urine thus maintaining the balance of phosphorus and calcium in the blood. The increased phosphorus levels due to kidney disorders may lead to pulling out of calcium from the bones making them weak. [4]
The parathyroid glands in the neck secrete a parathyroid hormone that helps in controlling calcium levels in the blood. Kidney disorders could affect the functions of the parathyroid gland.
It may result in excess secretion of parathyroid hormone due to which the movement of calcium from the bones to the blood is increased. As a result, the bones begin to lose calcium thereby increasing the risk of osteopenia and osteoporosis. [5]
This is how a kidney disorder could affect bone health by creating an imbalance in the levels of hormones and minerals.
Why should women with kidney disorders take precautions to maintain bone health?
The complications caused due to kidney disorders tend to develop gradually. The loss of bone mineral density linked to chronic kidney diseases takes several years to be evident.
Also, women are known to be at a higher risk of osteoporosis after menopausal age. The comorbidity due to the existing kidney disorders could speed up the bone loss in menopausal women putting them at a much higher risk of osteoporosis and fractures.
At the same time, the symptoms of osteoporosis may not appear until the bone changes have become substantially worse. Hence, women need to be more cautious about their bone health, especially if they are suffering from a kidney disorder.
They should perform tests to assess their calcium and vitamin D levels and check their bone mineral density at regular intervals. This would help in the early diagnosis of osteoporosis allowing them to adopt appropriate measures to prevent fractures.
Bone Disorders In Young Girls with Kidney Disorders
It is not just the older women who need to be alert about the risk of poor bone health. Even young girls diagnosed with a kidney disorder are likely to suffer from bone diseases. [6]
The malfunctions of the kidneys can affect the development of the bones in your girl. At a younger age, the bones are still growing and developing.
The imbalance in the level of calcium and phosphorous due to a kidney disorder would hamper the bone formation processes. This can slow down bone growth resulting in short stature and deformities. [7]
The lack of adequate levels of calcium may also prevent the proper development of the bones in the legs making them bending inward or outward. This condition is called renal rickets indicating the role of the kidneys in the development of the deformity. [8] [9]
Treatment of bone disorders caused due to chronic kidney diseases
- Increasing the intake of foods rich in calcium and vitamin D is highly recommended to promote bone mineral density. [10]
- Reducing the intake of foods containing phosphorus is important for preventing bone loss. Processed and packaged foods usually contain high levels of phosphorus. Some other foods known to contain a high amount of phosphorus include beer, cheese, dried beans, nuts, peas, and peanut butter.
Women with a kidney disorder should avoid the consumption of these foods in order to regulate phosphorus levels in the blood and reduce calcium loss.
- Treating bone disorders linked to kidney malfunctions also includes preventing damage to the bones by controlling the secretion of the parathyroid hormone.
- Women may be advised to use medications that regulate and support kidney functions.
- In severe cases, women might need to undergo dialysis to eliminate harmful toxins and maintain a normal level of hormones and minerals in the blood. Dialysis involves the filtering of waste products and extra fluids from the body by artificial means. [11]
Conclusion
Women diagnosed with kidney disorders should be aware of how the malfunctioning of this organ could affect their bones.
They should increase their intake of calcium and vitamin D and receive treatment for restoring kidney functions. This would minimize the impact of a kidney disorder on their bone health.
References:
- https://www.kidney.org/transplantation/transaction/TC/winter13/Osteo
- https://www.ncbi.nlm.nih.gov/books/NBK526025/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3944129/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5347182/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4991918/
- https://link.springer.com/article/10.1007/s00467-007-0671-3
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3103992/
- https://www.niddk.nih.gov/health-information/kidney-disease/children/caring-child-kidney-disease/growth-failure-chronic-kidney-disease
- https://jasn.asnjournals.org/content/18/1/223
- https://www.webmd.com/osteoporosis/guide/vitamin-d-for-osteoporosis
- https://cjasn.asnjournals.org/content/13/6/962
