An often-overlooked problem: kidney disease in people with cerebral palsy and other neurodevelopmental disabilities

People with neurodevelopmental disabilities (disabilities associated with the brain, spinal cord and nerves) such as cerebral palsy, autism spectrum disorders and intellectual disabilities (disabilities that affect learning and communication) often have many unmet and complex medical needs, which can increase the risk of developing other health conditions like chronic kidney disease (CKD). In fact, studies show that people with neurodevelopmental disabilities have higher rates of CKD than the general population.

According to Daniel Whitney, who studies diseases and conditions that affect bones, joints, muscles and other connective tissues in children with cerebral palsy, there are a variety of reasons people with neurodevelopmental disabilities have complex medical needs, including: 

• pre-term birth (babies born prematurely are at a greater risk of having cerebral palsy than babies not born prematurely)
• insufficient growth of organs
• motor dysfunction
• low physical activity 
• mental health disorders 
• social stigma 

"Pre-term birth can impact the final development of certain types of kidney cells and reduce the number of functioning kidney cells," said Daniel, an adjunct professor at the University of Michigan with a PhD in applied physiology. "This can place a burden and stress on the available kidney cells, leading to early kidney function decline."

In addition, exercise, which can help prevent conditions like diabetes and heart disease – two major causes of kidney disease – is not always easy for people with neurodevelopmental disabilities. "For people with neuromuscular issues [issues that affect the nerves and muscles], like cerebral palsy, there is motor dysfunction [issues with moving] making activity challenging and exhausting," Daniel said. "For people with neurodevelopmental disabilities but without neuromuscular issues, reasons for low physical activity can be related to limited options for participation in life activities, limited options for adapted sports/exercise/activities when growing up and thus missing out on opportunities to develop active habits and interests, and stigma that may prohibit the desire to want to engage in the surrounding environment." 

Daniel also cited the many medicines people with cerebral palsy and neurodevelopmental disabilities often take as a reason for the higher rate of CKD in this population versus the general population. "Certain medications may be toxic to the kidneys, which may not be recognized or appropriately scaled back in dosage/frequency to [reduce] kidney damage," Daniel said. "The currently insufficient clinical methods to measure kidney function and detect CKD for people with cerebral palsy also misses opportunities for early detection and thus early prevention efforts."

Daniel elaborated on the 'insufficient clinical methods,' saying, "People with cerebral palsy have low levels of serum creatinine due to low muscle mass [which can result from low physical activity]. The way the creatinine-based kidney function estimating algorithms work is that the lower the creatinine level, the higher the estimated kidney function, holding everything else constant [such as muscle mass]. This can lead to the [incorrect] interpretation that kidney function/health is better than it actually is." He said this can lead to primary care providers not suspecting kidney damage in people with cerebral palsy and therefore not referring them to see a nephrologist. 

Work needs to be done to develop a scientifically proven "correction" factor to these kidney function estimating equations, or to develop a new equation altogether that better estimates kidney function for people with cerebral palsy, Daniel said. "The goal is to improve assessment of kidney function so better clinical decisions can be made, such as referrals to nephrologists," he added. 

When asked why there is so little research about the prevalence of CKD among people with neurodevelopmental disabilities, Daniel said there are many reasons, but noted that the late start of noticeable kidney disease symptoms is a key factor. "CKD does not lead to obvious signs, like turning skin a different color," he said. "Given all the other problems clinicians treat for these populations that are visually obvious and are patient-reported, kidney dysfunction and CKD can go unnoticed." 

Still, Daniel emphasized that preventing CKD in people with cerebral palsy and neurodevelopmental disabilities is not a hopeless cause; researchers just need to be willing to put the work in to move the needle on this issue. "In order to mitigate the burden of CKD among people with cerebral palsy and other neurodevelopmental disabilities, we must know the specifics of their CKD burden, as information regarding the CKD burden from the general population may not fully translate," he said. 

Click here to learn more about the study Daniel co-authored about CKD in adults with neurodevelopmental disabilities