The Connection Between Kidney Disease and Dementia
In the past few years, studies have been conducted that have suggested a link between Chronic Kidney Disease (CKD) and cognitive disorders such as dementia. The findings drew this correlation due to abnormalities in the capillaries, the smallest type of blood cell in the human body. Capillary abnormalities are found in the brain of every patient that dies from dementia; and recent findings have shown that significant, similar capillary damage is found in the kidneys of patients that suffer from albuminuria, a symptom of CKD that is classified by the presence of the protein albumin in urine. Albuminuria is most commonly caused by diabetes and hypertension, which in turn, cause issues with blood flow and blood cell health. This has led professionals to the conclusion that vascular damage in the brain and capillary abnormalities in the kidneys are connected.
How Does Kidney Disease Affect the Brain?
The human body is a network of functioning organs that all rely on each other to pull their equal weight. We don't often think everything is so intricately interconnected, but it really is. Think of the body as a piece of machinery -- every cog, gear, belt, and piston needs to be in working order for everything to function properly. If one part starts to deteriorate or loses function, other parts are affected or strained to make up for the weight that part used to pull.
Since the brain and kidneys are both organs that rely heavily on healthy cardiovascular systems, it comes as no surprise that diabetes and hypertension, causes of disrupted blood flow, can easily and significantly damage the kidneys and the brain. In the brain, untreated hypertension and/or diabetes can lead to white matter lesions that contribute to cognitive decline, while in the kidneys, they lead to strained and weakened blood cells from which it becomes harder to filter waste (you can read more about this in our article on renal hypertension.)
What Studies Have Been Done?
The Cardiovascular Health Cognition Study tested 2000 people over the age of 65. They took measurements of albumin levels and concluded that 15% of the group had cognitive impairment and 12% had dementia. Those tested that had albuminia were 50% more likely to have dementia than those that do not.
The Journal of the American Society of Nephrology published a study in 2015 that monitored 2,600 people in the Netherlands, which found that those with lower kidney function was strongly associated with low blood flow, risk of stroke and dementia.
"Given that kidney disease and (reduced blood flow to) the brain are both possibly reversible, there might be an opportunity to explore how improving these conditions can ultimately reduce one's risk of developing brain disease," Dr. M. Arfan Ikram, an assistant professor of neuroepidemiology at Erasmus University Medical Center in the Netherlands, said in a journal news release.
Adam Davey, associate professor of public health in Temple's College of Health Professions and Social Work, published a study in the journal Nephrology, Dialysis and Transplantation. It came to similar conclusions, he states,
"As we get older, our kidney function tends to decrease naturally, so if there's an extra issue involved in renal function like chronic kidney disease, we need to know about it as soon as possible. That is something that needs to be managed, just like you would manage hypertension. Patients are still going to be able to take their medicine on time and without assistance, as well as understand the information that their physician is sharing with them about their disease."
Over time, it's no debate that the human body will decrease in efficiency and functionality. But if some parts of our proverbial well-oiled machine start to give, so too do other areas. Having kidney disease will exacerbate other illnesses -- even mental ones. So if you feel that you or a loved one are at risk or are currently suffering from CKD, please see a specialist as soon as possible.