Chronic kidney disease has recently
been named the ninth leading cause of death in the United States. The kidneys
are an important part of the body and are responsible for filtering the body’s
entire plasma volume 60 times each day. Filtration specifically takes place in
the glomerulus where as reabsorption and secretion take place in the renal
tubules. Once filtered, the renal tubules reabsorb substances like NaCl, NaHCO3,
filtered nutrients (glucose and amino acids), divalent ions (Ca2+,
HPO24-, and SO42-), and water back
into the blood. Substances like NH4+, endogenous, and exogenous solutes that
were not filtered in the glomerulus are secreted into the lumen of the tubule
and prepared for excretion. Chronic kidney disease (CKD) is when the kidneys
lose their ability to filter the previously mentioned products. When patients are
diagnosed with CKD, dialysis and a kidney transplant are their only options
moving forward.
In a recent study, researchers at a
hospital in Portugal looked at the association of caffeine consumption and
mortality rate among patients with chronic kidney disease. The sample included
2328 patients between 1999-2010. The subjects were divided up into four groups
based on their daily caffeine intake. The first group were those who consumed
under 29.5 milligrams, the second group consumed 30.5-101 milligrams, the third
group consumed 101.5-206 milligrams, and finally the fourth group consumed
206-1378.5 milligrams. For comparison, a normal cup of coffee is said to have
round 95 milligrams of caffeine in it.
The results showed a dose-dependent
inverse association between caffeine and all-cause mortality. The second group
showed a 12% lower risk of dying, the third group showed a 22%, and finally the
last group showed 24% lower risk of dying than group one. Given that the study
was observational, they are unable to prove cause an effect between caffeine
intake and reduced mortality in patients with CKD. It is a good place to start
thinking about clinical trials though!
On the contrary, long term
hypertension has been linked to kidney failure. We also know that caffeine can
increase blood pressure. Any thoughts?
Caffeine consumption may help kidney disease patients live longer. NewsRx Health, 26 Nov. 2017, p. 32. Health & Wellness Resource Center
What an interesting topic and blog post! I have to wonder though how exactly the analysis was done and how the researchers figured out the difference in mortality rates and also when the subjects started drinking caffeine and for how long. I found an interesting research article published in 2002 that showed long term caffeine intake increased renal failure in obese diabetic rats. I have to wonder if similar results would happen in humans as well. Since caffeine is a stimulant, it can increase blood pressure by stimulating blood flow, which can in turn create more stress on the kidneys. It has also been shown that overconsumption of drinks such as coffee and tea can lead to increased thirst in patients with chronic kidney disease which could lead them to consume too much liquid and risk fluid overload. Here are some of the websites I found interesting:
ReplyDeletehttps://www.kidneybuzz.com/coffee-or-tea-which-is-better-for-dialysis-and-kidney-transplant-patients-with-ckd/2015/8/3/coffee-or-tea-which-is-better-for-dialysis-and-kidney-transplant-patients-with-ckd
https://www.ncbi.nlm.nih.gov/pubmed/11918750