High INR & summertime

[catwoman]

I was puzzled why some people say their INRs go up in the summer. I first thought they should drop, because people are more active -- swimming, traveling, water-skiing, volleyball, baseball -- than in cool weather months. Then I thought -- aha! maybe people are more apt to become dehydrated in the summer because of increased perspiration due to heat, which would cause warfarin to be more concentrated in the bloodstream. We would have to increase our water intake to keep INR level.

Ditto on any INR increase with alcohol consumption, since alcohol can cause dehydration.

Any thoughts? If I'm barking up the right tree, only after everyone else in the world has figured this out, perdoname.

 

[Karlynn]

Hmmm, dehydration? You may have stumbled on to something. Hadn't thought of it that way. All I know is that after our week of 100 + temps my INR went from 3.0 to 5.0.

 

[Guest]

Nothing conclusive that I know of.

 

[davidfortune]

Don't you know your blood thins in summer and thickens in winter....


Just kidding Al. Don't let your blood boil... I'm guessing that boiling blood would really screw up your INR - right Al?

 

[Karlynn]

Don't you know your blood thins in summer and thickens in winter....


Just kidding Al.

Thanks for the laugh! I needed it tonight.

 

[LUVMyBirman]

Have seen a major rise in my INR with heat. No dehydration to speak of. Tend to drink 6-8 bottles of water daily. I beleive it's the heat alone.

 

[catwoman]

It may be that more than the usual 6-8 glasses of water a day are needed during the summer for anyone who isn't housebound. What's sufficient during some months of the year may not suffice during hot weather, even if you don't feel dehydrated.

Gee, I wish there was an easy way to detect dehydration in humans. Can't check my husband the same way I can my cats: Grabbing the fur up at the back the neck; if it doesn't "snap" back down, the cat is dehydrated.
My husband keeps slapping my hands when I try the same test on him.

 

[Christine]

when I lived in Dallas and went to plano's coumadin clinic, my INR would always rise during the hot summer months.. the nurse actually told me that it is common for it to rise during hot weather.. the whole "thin" in summer, "thick" in winter thing... she also said, most professionals will not concede to that, but she saw enough to convince her.

Chris

 

[LUVMyBirman]

Christine....one of my INR spikes was upon returning from Dallas Others were at home under similar heat and humidity conditions. My INR tends to be way more stable in the winter months. And come to think of it....I was very unstable living in Memphis. Would be interesting to see a poll with INR ranges north vrs. south.

 

[Guest]

A few years back two of us looked at whether or not INRs changed during various seasons. Brian Gage in St. Louis looked at his by patients. He took each person who came to the clinic for more than one year and the took the difference between their highest INR and the lowest INR. No statistically significant difference.

I took the mean INR for each month of the year for all of my patient visits. No statistically significant difference.

What does it mean. Nothing. Most people live or work in climate controlled areas. Even those who work outside all day, usually go to an air conditioned or heated place to sleep. Few people in the world work, sleep and spend the rest of the day in the truly ambient outside temperature.