Thursday, August 15, 2013

Electrolyte Supplement Blocks Exercise Induced Elevations in LDH, Urea, Leucocyte Infiltration into the Heart & the Congestion of Renal Blood Vessels

For the average gymrat it is probably not a question of life or death, but an increase in recovery due to a decrease in detrimental muscle damage in response to dehydration should be an very good argument to get some salt and glucose in after / around your workouts.
Electrolytes have been at the heart of several SuppVersity articles as of late (check them out). Few of them did however have a direct link to exercise. Reason enough to discuss the results of a pertinent paper that was published by two scientists from Cairo University (Osman. 2013). At first sight, the study Hala F. Osman and  Azza M. Atya conducted does not appear to be very exciting. After all, the effects of electrolyte supplements on re-hydration after a workout are nothing that would not have been analyzed in previous studies. Moreover, the study at hand, which has been published in the latest issue of the World of Applied Sciences Journal, is a rodent study and the results would actually be pretty boring if the poor critters had not been sacrificed right after a lengthy HIIT session comprising 5x4 min intervals at 25m/min with 2min break in between, in order to beyond the conventional blood analyses and take a look at their hearts and kidneys.

Rodents don't complain

Now based on human studies we already know what happens in the blood, when we exercise vigorously, CK rises, LDH rises, the serum electrolyte levels get messed up, etc.
Figure 1: Changes in serum electrolyte levels (chloride, magnesium, calcium, phoporus, potassium, natrium) after the HIIT-esque workout w/ or w/out electrolyte supplementation (Osman. 2013)
The exercise induced changes in the electrolyte levels Osman & Atya observed in the rodents were in fact very similar to those that have been reported in human studies. What's more important, though is the fact that they persisted only those rats that did not receive the Rehydran-N solution daily for 45 days + immediately after the workout (see figure 1).
"[...] sodium ions decreased significantly  (P 0.05) after exercised while after  supplementation  by  Rehydran-n  and  Rehydran-n+ (Mg+Ca) citrate in group III and IV the level of sodium ion restored near to the control value. While  potassium ions level increased significantly (P 0.05) in exercised group. The supplementation by Rehydran-n and Rehydran  n+ (Mg+Ca) citrate in group III and IV not affected on the level of potassium and not return the value near to control value." (Osman. 2013)
One thing that is at odds with previous research in humans, is the acute -18.6% drop in magnesium levels. Interestingly, this drop was blunted even when the rodents received the magnesium free NaCl + K electrolyte supplement. The immediate provision of magnesium in the Rehydran-n + Mg + Ca arm of the study, on the other hand, raised the Mg2+ levels by +18% and did thus also result in a transient electrolyte imbalance.

Rehydration prevents organ stress

As I already hinted at in the introduction, having slightly screwed electrolyte levels, as well as elevated amounts of creatine kinase, lactate dehydrogenase and urea in the blood are more or less negligible problems compared to any direct ill health effects the dehydration and the corresponding loss of electrolytes could have on the structural integrity and health of your heart and kidneys. Effects such as those Osman and Atya saw when they analyzed the organs of the animals who did not compensate for the electrolyte loss by the immediate provision of adequate amounts of salt after a workout:
Figure 2: Sections of heart tissue after the workout (Osman. 2013)
"Figure [2] microscopic sections of heart from exercised group [2b] showed leucocytic cells infiltration in cardiac myocytes. Whereas other sections from Rehydran-n treatment  group [2c]  revealed  few  focal intermuscular  inflammatory  cells  infiltration.  While  Rehydran-n+  (Mg+Ca)citrate  treatment  group [2d] showing  no  histopathological  changeslike  those  in control group [2a]." (Osman. 2013)

Kidney sections of rat from control group revealed no histopathological changes. While in  prolonged exercising group showing hyalinosis [=degeneration] of  glomerular tufts. Moreover in Rehydran-n group vacuolations of epithelial lining renal tubules [=accumulation of waste that will be flushed out later on]. Rehydran  n+ (Mg+Ca) citrate treatment group congestion of renal blood vessel was observed [=one reason the better stick to salt, only].
Now, these results certainly sound more frightening than they actually are. Our bodies are (just like those of rodents, by the way) well equipped to handle the occasional cell / organ damage. And the heart is - believe it or not - "only" a muscle. It works slightly different, but can take at least as much beatings as our skeletal muscle tissue. Beatings of which the creatine kinase (CK) and lactate dehydrogenase (LDH) levels in the supplemented groups clearly show that they are are ameliorated by the the provision of electrolytes.
Figure 3: Creatine kinase (CPK), lactate dehydrogenase (LDH) and urea elevations (in %) after 5x4min treadmill runs with 2 min rest in-between (Osman. 2013)
"The present results are in accordance with the exhausted exercised rats resulted in an increased growth in serum CPK activity. This increase, however was markedly reduced in the rats after administration of antioxidant. For instance, 16h exercise in rats caused a marked rise in  activity levels of serum LDH. Increase in serum LDH  activity is mainly due to release from heart and skeletal muscles into blood stream. [...] Different  types  of  stressors  cause  an  increase in activities of serum creatine phosphokinase and lactate dehydrogenase in humans and animals which is an indication of tissue damage." (Osman. 2013)
Now you may be asking yourselves, whether similar effects can be expected in human beings!? Well, the answer should be obvious: "Similar", yes. 100% identical, no. Maughn et al., for example, demonstrated similar (re-)hydration benefits in human subjects in the 1994 - it should be obvious thought that they refrained from cutting their subjects open and checking what happened to their hearts so that we can only speculate about the extend of cellular / structural damage and the corresponding compensatory effects in humans.

Table 1: Ingredients of a single sachet of Rehydran-N which was bought by the reaserchers at a local pharmacy - no sponsorship involved
What can be said for with some certainty, though, is that it is unlikely that you would need more than one sachet of the electrolyte formula with its 0.3g K, 0.7g NaCl, 0.58g tri-sodium citrate and 4g glucose to achieve similar effects. After all, Osman & Atya modeled the amount of electrolytes the rodents received to what human beings would get from one serving of Rehydran-N. It is thus for once not necessary to calculate a human equivalent dose of the electrolytes in the water of the lab animals.

No glucose no effective rehydration

What is however necessary is the inclusion of the sugar or rather glucose in the rehydration formula, because the latter increases the efficacy of the formula significantly.
"The discovery that sodium transport and glucose transport are coupled in the small intestine so that glucose accelerates absorption of solute and water was potentially the most important medical advance this century."(Anonymous in Lancet. 1978)
So don't skip on the miniscule amount of glucose - even if you are suffering from carbophobia and believe that any amount of carbohydrates is going to make you hold water. Trust me, if anything will make you hold water its their absence and the suboptimal uptake of the electrolytes in the absence of glucose that will make you look like a watery version of the Michelin Man.

NaHCO3 loading increases performance & decrease LDH activity.
Bottom line: Despite the fact that they may have been derived in a rodent study, the results Osman and Atya present in their most recent paper re-emphasis the need for adequate (re-)hydration before, during and even more so after workouts. In the vicinity of a workout, the latter is best achieved, using a simple salt + glucose mixture that can, but does not necessarily have to include ~360mg magnesium- and ~800mg calcium-citrate. You should yet keep in mind that the the increased levels of Mg2+ and Ca2+ can become burden on your kidney, although they appear to have beneficial effects on the heart (see figure 2).

And as far as the ostensibly beneficial decrease in LDH in the Rehydran-N + Mg + Ca group is concerned, this may well be a simple result of the alkalizing effect of magnesium and calcium ions. Assuming this is correct, similar benefits should occur in response to sodium bicarbonate, aka baking soda supplementation (learn more). The latter is after all part of the standard anti-rhabdomyolysis (=rapid breakdown of damaged skeletal muscle tissue) protocol where it does prevent both, further damage to the musculature and permanent damage to the kidneys (Vanholder. 2000).

References: 
  • Anonymous. Water with sugar and salt. Lancet. 1978 Aug 5;2(8084):300-1.
  • Maughan RJ, Owen JH, Shirreffs SM, Leiper JB. Post-exercise rehydration in man: effects of electrolyte addition to ingested fluids. Eur J. Appl. Physiol. Occup Physiol., 69: 209-15.
  • Vanholder R, Sever MS, Erek E, Lameire N. Rhabdomyolysis. J Am Soc Nephrol. 2000 Aug;11(8):1553-61. Review.

5 comments:

  1. On the subject of sodium bicarbonate; wouldn't I kill two birds with it?
    After all, it contains the needed sodium.

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  2. Dr. Andro, once again, thank you for all of your work. SuppVersity can truely make my day simply because it's always so darn interesting not to mention thorough. (:

    Given your previous thoughts on zinc, I was wondering if you could comment on this study, should you find the time for it. There was a link to it at Mark's Daily Apple today.

    http://www.ncbi.nlm.nih.gov/pubmed/16648789

    It was a fairly interesting study, but fully aware that most readers of your blog or MDA are not elite wrestlers, is there a chance that normal, non-metabolically deranged (and physically active, not couch potato) people can benefit from 2-3x the RDA in zinc (Testosterone-levels and thyroid wise)?

    I seem to remember 22 mg of zinc gluconate in cyclists leading to higher HOMA2-IR levels, while also having "no effect on thyroid metabolism" in your "Zinc, a BodyBuilder's Favorite Mineral: All That Glitters is not Gold" article.

    And just 20 mg of zinc gluconate supplementation vs. the zinc yeast in "Absurd: Will Supplemental Zinc Gluconate Deplete Your Zinc Levels?" may have lead to a negative zinc balance as a natural consequence of excessive zinc intake.

    So when is more zinc actually necessary? And how does one know? And why the heck does zinc supplementation lead to worsened glucose homo-stasis (as indicated by elevated HbA1c) in type 1 diabetics?

    http://www.sciencedirect.com/science/article/pii/0026049594900167

    Presuming it does so (worsens glucose homo-stasis) in normal individuals too then, as people with T1DM should theoretically have higher requirements of zinc like people with T2DM as a result of higher urinary excretion of zinc due to elevated glucose levels which drastically increases zinc excretion / decreases zinc retination.

    I guess the only way to go about zinc is the same as Vit-D. Get your serum levels checked? Supplement if low, DON'T if they're not? Any thoughts?

    (Was really glad to see all your posts on artificial sweeteners and your facebook link to the CoQ10 supplementation for OA - got a friend who will likely benefit. Never got to thank you for replying on my comment there on how to convert rat doses to human equivalents. I'd multiplied by 6 instead of dividing by 6. Your input really helped. ;) Thanks.)

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  3. Would coconut water be appropriate for this purpose?

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  4. Is a standard electrolyte drink like lucozade or powerade okay? I've looked at the nutrition and they don't have anywhere near 0.3g K, 0.7g NaCl, 0.58g tri-sodium citrate. Plus they have too much sugar, with the lite versions having no sugar. I too am curious if coconut water would work.

    Alternatively, would the cheap option, water with a bit of sugar and salt added, be okay?

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  5. Forgive my ignorance again, but why so much sodium? 1.28 grams of sodium is 85% of the RDA. Is this more then the amount lost through the HIIT exercise? If so, won't this cause water retention?

    Knowing that tomato juice also decreases LDH and CK, is it necessary to take both tomato juice and an electrolyte formula? Just trying to save money :)

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