Caffeine And Low Blood Sodium? Huh? (x-ray, pain, kidney, thyroid)

[Calvert Hall '62]

Normal serum sodium is 135-145 mEq/L. For the past yr. mine has ranged 128-134. The MD has run all kinds of blood and urine tests to ascertain the etiology of this low blood sodium, known as hyponatremia and it can have severe neurological sequelae, as well as cause dangerous heart rhythms. To no avail, all known causes of hyponatremia have been ruled out. Both the primary MD and the specialist she consulted are scratching their heads.

During this past yr., I also discovered the joys of caffeine, i.e., the shot of energy it gives you. That's right, had my 1st cup of coffee at age 68. Upon advising the MD of this new habit, she now believes that the caffeine may be the culprit. Caffeine is mildly diuretic, but it apparently has a significant natriuretic effect. This simply means that caffeine causes the kidney to release excess sodium and then blocks it from being reabsorbed. The blocking mechanism is due to increased glomerular filtration rate. To put it bluntly, you **** your sodium away.

OK, enough with the gobble-de-****; here's the rub. I consumed five caffeine sodas a day. Total daily consumption of caffeine = 200 mg. Maybe two days a week, add a cup of instant coffee = 60 mg. So even on coffee days, total caffeine is only 260 mg. Even the anti-caffeine brigade will tell you that up to 300 mg. a day is insignificant. I'd say that the majority of people exceed 300 without sodium depletion.

So I have my doubts. Still, this problem started started when the caffeine habit began. Now consuming only one can of caffeine soda a day and no coffee = 40 mg. caffeine per day. Plan of action: get repeat serum electrolyte study in three weeks and see what shakes out.

[Miss Hepburn]

I had no idea there could be a block to reabsorb salt!
Learn something everyday. I have asked people for 25 yrs about their
caffeine intake (and alcohol) bec they just suck the magnesium right outta you.

I'm sorry to say this but bec if your age and who knows what your heart is like...
Keep your electrolytes balanced ! please, and drink 7up and decaf coffee....I know. I know...
it's a bummer...but ya gotta do it.

Its just not worth messing up your minerals, screws the curcuits up!
Good luck with this.

[ehealthguy]

Hyponatremia may be a side effect of caffeine intoxication, which does not likely happen by consuming less than 500 mg caffeine per day. The more likely cause of hyponatremia would be drinking large amounts of water (including coffee), but that would require at least about 5 liters of water per day and consuming very little salt.

There is a group of causes of hyponatremia, that can cause a Syndrome of Inappropriate ADH secretion (SIADH). Excessive secretion of the hormone ADH inhibits diuresis and causes water retention and hyponatremia. Causes include various cancers, brain and lung disorders and drugs. An experienced endocrinologist or internist should be able to find a cause.

[Calvert Hall '62]

Originally Posted by ehealthguy

There is a group of causes of hyponatremia, that can cause a Syndrome of Inappropriate ADH secretion (SIADH). Excessive secretion of the hormone ADH inhibits diuresis and causes water retention and hyponatremia. Causes include various cancers, brain and lung disorders and drugs. An experienced endocrinologist or internist should be able to find a cause.

Read you loud and clear but SIADH and all the other conditions known to my primary, an internist, and a consulting renal expert have been ruled out. As you suggested, maybe a visit to an endocrinologist is in order.

Funny thing: there have been no neuro symptoms as of yet that are typically associated with the disorder. Perhaps because the onset was gradual rather than sudden, or maybe 128-134 do not produce symptoms in all people.

[ehealthguy]

Yes, slowly developed hyponatremia between 128-134 may not cause any symptoms.
Have you ever checked your blood sodium levels before starting drinking coffee? One week without caffeine, as you said, should be probably enough to remove the eventual effect of caffeine...

Hyponatremia may develop due to:
1. Low salt (sodium) intake - very unlikely, but possible
2. Water intoxication: excessive water (or any beverage low in sodium) intake in combination with low salt intake: commonly occurs in women on a "water diet" - very little food + drinking a lot of water
3. Diuretics or other medications with a diuretic effect and even some herbs (herbal teas), such as Uva ursi can result in excretion of more sodium than water.
4. Hormone imbalance:
- Increased ADH secretion (SIADH): not only causes I mentioned earlier, but also vague causes such as physical effort (happens in marathoners), pain or other "stress." Blood tests: low sodium and blood osmolality; urine tests: increased sodium and specific gravity.
- Decreased aldosterone secretion (adrenal insufficiency)
5. Hypothyroidism
6. Cerebral salt-wasting syndrome
7. Salt-wasting nephropathies (certain kidney disorders)
8. Disorders with edema, like heart failure, nephrotic syndrome, liver cirrhosis...

[Calvert Hall '62]

Originally Posted by ehealthguy

Yes, slowly developed hyponatremia between 128-134 may not cause any symptoms.
Have you ever checked your blood sodium levels before starting drinking coffee? One week without caffeine, as you said, should be probably enough to remove the eventual effect of caffeine...

Hyponatremia may develop due to:
1. Low salt (sodium) intake - very unlikely, but possible
2. Water intoxication: excessive water (or any beverage low in sodium) intake in combination with low salt intake: commonly occurs in women on a "water diet" - very little food + drinking a lot of water
3. Diuretics or other medications with a diuretic effect and even some herbs (herbal teas), such as Uva ursi can result in excretion of more sodium than water.
4. Hormone imbalance:
- Increased ADH secretion (SIADH): not only causes I mentioned earlier, but also vague causes such as physical effort (happens in marathoners), pain or other "stress." Blood tests: low sodium and blood osmolality; urine tests: increased sodium and specific gravity.
- Decreased aldosterone secretion (adrenal insufficiency)
5. Hypothyroidism
6. Cerebral salt-wasting syndrome
7. Salt-wasting nephropathies (certain kidney disorders)
8. Disorders with edema, like heart failure, nephrotic syndrome, liver cirrhosis...

I've been a virtual pin cushion of dx. testing -- blood, urine chemistries, cortisol, even scanning, e.g., chest x-ray to rule out pulmonary ca as a possible cause. Maybe something as simple as caffeine removal will do the trick; maybe some folks are caffeine-sensitive in extremis. Thanx for your input.

[ehealthguy]

If caffeine withdrawal happens to increase your sodium levels, i would appreciate if you can report it here.

[Calvert Hall '62]

Originally Posted by ehealthguy

If caffeine withdrawal happens to increase your sodium levels, i would appreciate if you can report it here.

Yes sir; count on it.

[Calvert Hall '62]

Originally Posted by Calvert Hall '62

To no avail, all known causes of hyponatremia have been ruled out. Both the primary MD and the specialist she consulted are scratching their heads.

One I neglected to mention was replacement of the ACE inhibitor lisinopril which has been fingered as a culprit in hyponatremia with the ARB losartan potassium. Nope. Back to the drawing board.

[ehealthguy]

Losartan potassium can also cause hyponatremia
http://www.merck.com/product/usa/pi_.../cozaar_pi.pdf

You have not mentioned why are you taking losartan.