Baby, It’s Hot Outside.

As a person with arthritis among other maladies, I regularly see my rheumatologist. “A rheumatologist is a board certified internist or pediatrician who is qualified by additional training and experience in the diagnosis and treatment of arthritis and other diseases of the joints, muscles, and bones,” according to HSS at https://www.hss.edu/rheumatology-rheumatologist.asp. During my appointment, she mentioned that my GFR (Glomerular Filtration Rate) was 46.

Panic! It’s almost always in the low 50s. She calmed me down by telling me that GFR is usually lower during the Arizona heat (I know, I know: but it’s a dry heat.) of the summer. I don’t know why I was surprised. It made sense.

Think about it. Let me re-enforce this with a statement taken from study on PubMed at https://pubmed.ncbi.nlm.nih.gov/21617334/.

“However, the percent change in eGFR from spring to summer was greater in hypertensive patients with CKD… than in those without CKD …. “

PubMed is part of the National Institutes of Health’s National Library of Medicine’s National Center for Biotechnology Information.

I know hypertension (high blood pressure) is included in this statement, but the fact that GFR is lowered t than it’s lowered in those without hypertension leads us to the realization that those without hypertension DO have lower GFRs during the summer heat.

Another study from EuropePMC at https://europepmc.org/article/med/28946962 tells us:

“Recurrent dehydration in people regularly exposed to high temperatures seems to be resulting in an unrecognised cause of proteinuric chronic kidney disease, the underlying pathophysiological mechanism of which is becoming better understood. However, beyond heat waves and extreme temperatures, there is a seasonal variation in glomerular filtration rate that may contribute to the onset of renal failure and electrolyte disorders during extremely hot periods.”

Here are a couple of definitions you may need to understand the above statement. The first is from The Mayo Clinic at https://www.mayoclinic.org/symptoms/protein-in-urine/basics/definition/sym-20050656.

“Protein in urine — known as proteinuria (pro-tee-NU-ree-uh) — is excess protein found in a urine sample. Protein is one of the substances identified during a test to analyze the content of your urine (urinalysis).

Low levels of protein in urine are normal. Temporarily high levels of protein in urine aren’t unusual either, particularly in younger people after exercise or during an illness.

Persistently high levels of protein in urine may be a sign of kidney disease.”

The following definition is from MedicineNet at https://www.medicinenet.com/script/main/art.asp?articlekey=10691.

“Pathophysiology: Deranged function in an individual or an organ due to a disease.”

So, it looks like dehydration is a key factor in lowering the GFR during the summer heat. We know that dialysis patients need to limit their liquid intake, but what about those of us who are not on dialysis but do have CKD (Chronic Kidney Disease)?

I went to MedicalNewsToday at https://www.medicalnewstoday.com/articles/153363#symptoms for some facts about dehydration:

“Around three-quarters of the human body is water.

The causes of dehydration include diarrhea, vomiting, and sweating.

Individuals more at risk of dehydration include athletes, people at higher altitudes, and older adults.

Early symptoms of dehydration include dry mouth, lethargy, and dizziness.”

Did you notice “sweating” and for those of a certain age like me “older adults”?

So, I gather I’m sweating out more liquids than I’m taking in. But how does that work exactly? I thought I was drinking sufficient amounts of fluid.

Biology Online at https://www.biologyonline.com/dictionary/sweating was a bit of an eye opener.

“Sweating is a way of our body to regulate body temperature. It is commonly used as a synonym for perspiration but in stricter sense perspiration pertains to the water loss as a cooling mechanism of the body and therefore It (sic) includes both the release of watery, salty fluid through the pores of the skin from the sweat glands and the evaporation of water from the skin (trans-epithelial) and respiratory tract. Thus, there exist two forms of perspiration, the sensible and the insensible water loss. In sweating, the process always entails the loss of both water and solutes…. The salty fluid is secreted as droplets or moist on the skin and is called as sweat. Environmental cues that could stimulate the body to produce sweat are high temperature and humidity of the surroundings.”

Oh, solutes. Those include the electrolytes that are so important to us as CKD patients. Orthology at https://orthology.com/myth-debunked-need-electrolytes-work/ offers us a simple explanation:

“The warmer the weather and the more you sweat, the more likely you’ll need electrolyte replacement. Again, this is just a general guideline and will differ by individual, activity and other factors. Pay attention to signs that your electrolyte levels are too low, such as muscle cramps, fatigue, dizziness, nausea or mental confusion.”

Aha, it’s excessively hot out. We drink more, but more sweat is being produced the higher the temperature is. When we sweat or perspire (since the two words are often used interchangeably), we are also exuding electrolytes. Now it all makes sense. An imbalance of electrolytes could lower your GFR. I turned to Tampa Cardio at https://tampacardio.com/causes-electrolyte-imbalance-body/ for confirmation.

“Electrolyte imbalances can cause a wide range of symptoms, some mild and some potentially life threatening. Electrolyte imbalances are commonly caused by loss of fluids through prolonged diarrhea, vomiting, sweating or high fever.”

But we’re already having problems with our electrolytes. No wonder excessive heat affects our GFR. As the University of Michigan’s Michigan Medical at https://www.uofmhealth.org/conditions-treatments/kidney/fluid-and-electrolyte-disorders states:

“Changes in the body’s levels of minerals including potassium, magnesium, calcium and sodium—and the corresponding impact these have on the body’s function, muscle strength and heart rhythm can be associated with disorders of kidney or endocrine glands.

Got it. Let’s all just stay in the air conditioning so we don’t lower our GFRs even more than the excessive heat does. In Arizonia, that probably means until November this year. That was a joke (I hope).

Until next week,

Keep living your life!

A Laboring Electrolyte

It’s Labor Day here in the United States. I feel a special affinity for this holiday and wanted to explain the day some more. Oh, I already did in SlowItDownCKD 2016:

“For those of you in the United States, here’s hoping you have a healthy, safe Labor Day. I come from a union family. So much so that my maternal grandfather was in and out of jail for attempting to unionize brass workers. That was quite a bit of pressure on my grandmother, who raised the four children and ran a restaurant aimed at the men who were saving up funds to bring their families here from Europe. I knew there was more than my personal history with the holiday so I poked around and found this from http://www.usatoday.com/story/news/nation/2016/09/04/labor-day-history/89826440/

‘In the late 1800s, the state of labor was grim as U.S. workers toiled under bleak conditions: 12 or more hour workdays; hazardous work environments; meager pay. Children, some as young as 5, were often fixtures at plants and factories. The dismal livelihoods fueled the formation of the country’s first labor unions, which began to organize strikes and protests and pushed employers for better hours and pay. Many of the rallies turned violent.

On Sept. 5, 1882 — a Tuesday — 10,000 workers took unpaid time off to march in a parade from City Hall to Union Square in New York City as a tribute to American workers. Organized by New York’s Central Labor Union, It was the country’s first unofficial Labor Day parade. Three years later, some city ordinances marked the first government recognition, and legislation soon followed in a number of states.’”

Now, how do I transition from Labor Day to magnesium? Hmmm, my hard working daughter brought up the subject in today’s phone conversation, but that doesn’t seem like a good transition. Aha! Magnesium is a hard working electrolyte. Okay, that works for me.

Let’s start off with the basics. This passage from What Is It and How Did I Get It? Early Stage Chronic Kidney Disease will give you an idea of what magnesium is and what it may have to do with you as a CKD patient:

“In order to fully understand the renal diet, you need to know a little something about electrolytes. There are the sodium, potassium, and phosphate you’ve been told about and also calcium, magnesium, chloride and bicarbonate. They maintain balance in your body. This is not the kind of balance that helps you stand upright, but the kind that keeps your body healthy. Too much or too little of a certain electrolyte presents different problems.”

Problems? With magnesium? Maybe we need to know what magnesium does for us. The medical dictionary part of The Free Dictionary by Farlex at http://medical-dictionary.thefreedictionary.com/magnesium tells us:

“An alkaline earth element (atomic number 12; atomic weight 24.3) which is an essential mineral required for bone and tooth formation, nerve conduction and muscle contraction; it is required by many enzymes involved in carbohydrate, protein and nucleic acid metabolism. Magnesium is present in almonds, apples, dairy products, corn, figs, fresh leafy greens, legumes, nuts, seafood, seeds, soybeans, wheat germ and whole grains. Magnesium may be useful in treating anxiety, asthma and cardiovascular disease; it is thought to prevent blood clots, raise HDL-cholesterol, lower LDL-cholesterol, reduce arrhythmias and blood pressure, and to help with depression, fatigue, hyperactivity and migraines.”

All this by an electrolyte that constitutes only 1% of extra cellular fluid? I’m beginning to suspect that magnesium is the under explained electrolyte.

All right then, what happens if you have too much magnesium? Keep in mind that as CKD patients, electrolytes are not being as effectively eliminated by our kidneys as they could be since we have some degree of decline in our kidney function.

The U.S. Dept. of Health & Human Services of the National Institutes of Health at https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/ lays it out for us:

“Early signs of magnesium deficiency include loss of appetite, nausea, vomiting, fatigue, and weakness. As magnesium deficiency worsens, numbness, tingling, muscle contractions and cramps, seizures, personality changes, abnormal heart rhythms, and coronary spasms can occur …. Severe magnesium deficiency can result in hypocalcemia or hypokalemia (low serum calcium or potassium levels, respectively) because mineral homeostasis is disrupted….”

Well, who’s at risk for magnesium deficiency? The same source tells us:

“Magnesium inadequacy can occur when intakes fall below the RDA but are above the amount required to prevent overt deficiency. The following groups are more likely than others to be at risk of magnesium inadequacy because they typically consume insufficient amounts or they have medical conditions (or take medications) that reduce magnesium absorption from the gut or increase losses from the body.

People with gastrointestinal diseases
The chronic diarrhea and fat malabsorption resulting from Crohn’s disease, gluten-sensitive enteropathy (celiac disease), and regional enteritis can lead to magnesium depletion over time …. Resection or bypass of the small intestine, especially the ileum, typically leads to malabsorption and magnesium loss ….

People with type 2 diabetes
Magnesium deficits and increased urinary magnesium excretion can occur in people with insulin resistance and/or type 2 diabetes…. The magnesium loss appears to be secondary to higher concentrations of glucose in the kidney that increase urine output ….

People with alcohol dependence
Magnesium deficiency is common in people with chronic alcoholism…. In these individuals, poor dietary intake and nutritional status; gastrointestinal problems, including vomiting, diarrhea, and steatorrhea (fatty stools) resulting from pancreatitis; renal dysfunction with excess excretion of magnesium into the urine; phosphate depletion; vitamin D deficiency; acute alcoholic ketoacidosis; and hyperaldosteronism secondary to liver disease can all contribute to decreased magnesium status ….

Older adults
Older adults have lower dietary intakes of magnesium than younger adults …. In addition, magnesium absorption from the gut decreases and renal magnesium excretion increases with age …. Older adults are also more likely to have chronic diseases or take medications that alter magnesium status, which can increase their risk of magnesium depletion ….”

Notice how many times the kidneys were mentioned. Quick, go check your lab results. You’ll notice there’s no magnesium level. If you’d like your magnesium tested, you or your doctor need to order a specific test for that. Some labs will allow you to order your own magnesium test; others will require a doctor’s orders.

Until next week,
Keep living your life!