Ever wondered what all those blood tests are for?

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Blood Simple

What You Should Know About Blood Work

by John Meadows, CSCS – 6/06/2011
Most T NATION readers take a proactive approach to their health. They train hard, follow a nutritious diet, and supplement wisely. As such, the annual physical for a T-Man is typically brief – about thirty-seconds of routine diagnostic checks, squeezed in between a few nervous comments from the physician like, "If all my patients were like you I'd be out of business."
Let's suppose that next time something is different. Looking at your blood work, the doctor gravely tells you that you have high cholesterol and your AST is slightly elevated. Do you panic?
If blood work confuses you, you're not alone. The goal of this article is to outline a few major tests that you should have done and where you should sit to be considered healthy.
Disclaimer #1: This is NOT meant to be an all-inclusive list. I couldn't possibly cover all the tests in one article, though I did attempt to choose tests that apply to most hard training lifters.
Disclaimer #2: I'm not going to get into reference ranges as these can vary between labs. Wherever you choose to get blood work done, your results will include the lab's ranges so you'll be able to clearly see where you stand.
Disclaimer #3: Let me be clear that each of these tests is interwoven with other tests and clinical significance can get really complex. Covering all the possible impacts of high and low levels of each is way beyond both the scope of this article and my level of expertise.
For example, calcium in your blood could mean:

• Lymphoma
• Metastatic tumor to bone
• Vitamin D intoxication
• Addison's disease
• Acromegaly

Get the picture? Let's dive in.

Hepatic Function



AST (or SGOT) – Aspartate Aminotransferase: This indicates the presence of an enzyme found in very high concentrations in skeletal, heart, and liver cells. This particular enzyme rises due to disease or injury.
To give you an example of high it can get, hepatitis can cause this enzyme to elevate up to 20 times the normal value.
ALT (or SGPT) – Alanine Aminotransferase: An enzyme found primarily in the liver and rises with hepatocellular diseases. This enzyme is more specific to liver dysfunction than AST is.
Important Point – Intense exercise can cause chronic elevations in both of these values due to muscle damage. Don't freak out if you're a little out of range on this one. Also, pain relief medications such as Tylenol can elevate these enzymes.
Alkaline Phosphatase: When this enzyme is elevated, it usually indicates bone or liver disorders. Young children often have elevated levels of this simply because they're growing.
Bilirubin: High levels of this will result in jaundice. If you see someone in the gym with yellowish skin or eyes (remember Ben Johnson's eyes?), their liver is likely taking a beating due to too much "ergogenic aid."
TIP – For a healthy liver, I suggest milk thistle, ALA (or r-ALA), and Liv 52. I've seen this trio do amazing things in people who were beating the tar out of their livers.

Renal Function

BUN (Blood Urea Nitrogen): This is a measure of urea nitrogen (a waste product). If your body can't excrete the urea, it builds up in the blood. Renal diseases all have this marker.
Important Point – This is also a measure of liver function as the liver is where free ammonia is formed from the catabolization of amino acids. Also, a high protein diet can elevate this marker.
Creatinine: This measures the amount of creatinine in the blood. Creatinine is a catabolic product of creatine phosphate, which is used in skeletal muscle contraction.
Important Point – This can be elevated by creatine supplements, your muscle mass, or even a high meat diet. So if you're a little high, don't panic. Even Motrin, Advil, etc., can raise this.
TIP – If you want to improve this panel, be sure to stay properly hydrated! I've seen people "fix" this reading just by reducing the stress on their kidneys and drinking more water. Also, be sure to include plenty of fruits and veggies in your diet. Shoot for 1-2 servings of fruit and 3-4 servings of veggies (at a minimum) daily.

Lipid Panel

Total Cholesterol: This measurement is supposed to offer clues as to the chance of developing coronary heart disease (CHD). The higher the number, the greater the risk, right? Wrong. This test by itself doesn't predict much. In fact, lower total cholesterol is associated with greater CHD risk in older women and men.
Don't worry much about this number unless it's sky high or very low. I consider this test to be basically worthless, unless someone has very low levels of hormones, which could be due to not enough available cholesterol.
Triglycerides: This is another test used to identify potential CHD. TG's are a form of fat in the bloodstream. They also act as a storage source for energy. When levels get to high, TGs can be deposited into fatty tissues.
Important Point – I'd watch triglyerides closely. High carb diets tend to raise it. Excess carbs get converted into TG, causing levels to rise in the blood. If carbs are low, saturated fats have no negative impact on this measure at all. This can also be elevated by pancreatitis.
LDL (low density lipoproteins): This is another important test to determine the likelihood of CHD. Most think this is cholesterol but it's not. It's as the name says, a lipoprotein that carries cholesterol from the liver to the cells of the body. Instead of calling it "bad cholesterol," we should call it "bad lipoprotein."
There's evidence that smaller particles of LDL are more dangerous than large or "fluffy" particles, and that we should be more concerned about managing the oxidation of LDL.
Important Point – This is the formula for calculating LDL:
LDL = Total cholesterol - HDL - (Triglycerides / 5)
HDL (high density lipoproteins): These are lipoproteins that carry cholesterol back to the liver from the body's tissues and vascular endothelium. I'd agree with the experts that a low number is a very bad thing. Strive to keep this number as high as possible.
My mentor Dr. Serrano believes that you should watch out for low HDL and high triglycerides. If one of those two readings is out of whack, you could be headed for trouble. If they're both out of whack, you are headed for trouble.
TIP – If you want to improve this panel, do NOT stop eating cholesterol rich foods, but do start eating organic sources of animal protein. Also use grass fed meats, raw dairy when possible, reduce carb intake, and take a glucose disposal agent with your heavier carb meals. This is the exact formula I personally used to completely change my panels.

Thyroid Screening Panel

TSH (thyroid stimulating hormone): If your pituitary has to work hard to force your thyroid to pump out thyroxine, this number will be elevated. This usually means the thyroid is under active.
Free T4: First, by measuring for free T4, you're only measuring for what's metabolically active. Approximately 99% of the Total T4 is bound to thyroxine-binding globulin, so this will give you an accurate picture of how much active T4 is present.
Free T3: T4 will eventually need to be converted to its active form T3 in the liver. Although globulin binding is not as bad in T3 as it is in T4, it does occur, so a free reading is a good way to see what's really active.
TIP – For a healthier thyroid eat a source of selenium like Brazil nuts and be sure not to over-diet for long periods. I also like people to use tyrosine and kelp in their meal plans if thyroid issues are suspected.

Adrenal Function

Cortisol: For some background info on adrenal issues, see my article on adrenal fatigue here.
Blood work isn't necessarily the best way to test this, and it needs to be taken multiple times during the day to provide any value. (Usually a test is done around 8 AM and again at around 4 PM.) The evening test level should be 1/3 to 2/3 of the morning test level. Remember that cortisol usually peaks from 6 to 8 AM. My advice is to get a saliva test – it's better.
DHEA (dehydroepiandrosterone): An adrenal evaluation should include this test. Along with checking for virilization syndromes, this test can provide clues if there's adrenal issues such as Cushing's syndrome, adrenal carcinomas, etc. Too much stress lowers this reading in some cases. Also, levels that are too low could lead to low sex drive.
TIP – The best tip is to get enough rest, learn to relax, have fun, and stop stressing out. I know it sounds simplistic, but it's better than any pill you can pop.

Diabetes Management

Fasting glucose: This is a very big deal. With high carb diets, particularly those loaded with refined carbohydrates, the chances of getting diabetes skyrockets. Your pancreas can only take so much, and every time you "spike" insulin you're causing an insulin dump to get blood sugar back to a normal level. Post workout insulin spike, okay; repeated insulin spikes throughout the day, not so much.
TIP – Unless you want to get diabetes, don't repeatedly spike your insulin with high carb meals, primarily refined sources.

Testosterone and Estrogen Levels

Total Testosterone: If I were a betting man, I'd say that this item is the lab value of most importance to T NATION readers! To be brief, a low T level is often associated with feeling like crap, no sex drive, and depression.
For those unfamiliar with this reading, it's a measure of the bound and unbound Testosterone levels in the body. Bound T means literally attached to SHBG (sex hormone binding globulin) or albumin and is inactive. The rest is unbound or free Testosterone.
Free Testosterone: That little bit of T that isn't bound is active and floating around in the blood, doing magical things. Most doctors like this to be in a certain percentage (unbound versus bound) range. I think that's silly because if T is sky high, free T is likely off the chart high as well, though still not in that desired percentage. Does that still mean T is low? Hardly.
Estradiol: For guys with hormonal issues such as feminization, this is must-have have measure, especially those who manage their own "TRT."
TIP – Make sure to get enough healthy fats (polyunsaturated, monounsaturated, and saturated) in the diet to optimize test levels. Also, remember that cholesterol is a raw material for making hormones, so if the body has trouble producing enough you'll need to take in some extra by way of nutrition.

Growth Hormone Levels

GH stimulation tests: This is essentially measuring the body's ability to produce GH under certain circumstances. You'll be made hypoglycemic through insulin to see how your body reacts.
The test Dr. Serrano prefers is another stimulation test called an arginine test. An IV with arginine is administered to see if the infusion raises GH levels. Most insurance companies want to see the results of this before approving coverage of replacement GH.
IGF-1: This can also be valuable, because if GH levels are too low, the liver won't make as much IGF-1 as it should.
Important Point – Growth Hormone is released when you train, sleep, are hypoglycemic, or when you consume a protein-only meal. It increases protein synthesis, and the breakdown of fatty acids in adipose tissue.

Other Important Readings

Specific C-reactive protein: This detects inflammation. It could also be a marker for future cardiovascular events, although it might just mean that you have an infection. Either way, we know that excess inflammation is detrimental to health long term, so a wise person will keep tabs on this.
Homocysteine: This test measures homocysteine in the blood. It's an intermediate amino acid that's formed during metabolism of methionine. This test can give an early warning for coronary, cerebral, and peripheral vascular diseases. It also appears to promote the progression of atherosclerosis, which can happen even with normal HDL and LDL.
Important Point – Many times elevated homocysteine levels are caused by B6, B12, or folate deficiency.
Calcium: This test is used to evaluate parathyroid function and calcium metabolism. Calcium is necessary for muscle contraction, heart function, blood clotting, and neural transmission.
Important Point – If you eat a diet that's unbalanced in acidic and alkaline foods, your blood pH can become too acidic. As a response, the alkaline minerals calcium and phosphorous gets leeched from the bones as a homeostatic mechanism. When this occurs, calcium levels can get out of range quickly.
Vitamin D: Doctors used to be irrationally concerned about taking in too much Vitamin D. The truth is that most of us in non-tropical climes are scoring far too low in this important measure.
I use this reading more as a general health marker since low Vitamin D levels are tied closely to cancer and myriad of other serious issues. It's also important for bone growth and remodeling as Vitamin D promotes calcium absorption in the kidneys.
PSA (prostate specific antigen): All males should be very aware of this test. High PSA levels are associated with prostate cancer, and this test is used for catching prostate cancer early on. There may be a better test emerging called "prostate specific membrane antigen," as it's more frequently present in advanced forms of prostate cancer. I'll keep you posted.
Important Point – Instead of just looking at your reading and reference ranges, you should also look at how your level trends. In other words, if you have a year where this reading spikes, that should worry you. If your reading is always a little high but not changing much, that isn't as worrisome.

About Bloody Time To Wrap Up

Blood work is anything but a simple topic, and there are many other important readings such as hemoglobin and CBC (complete blood cell counts). Hopefully this article has at least prompted you to start looking a little closer at those numbers on the sheet so you can go into your next doctor's visit a little more informed.
Got questions? Head over to the Livespill.

 

[dannieboy255]

Thank you Maurice. Very good information to have.

 

[This is NOT a Brothel]

You did it again Maurice, thanks.

Double thanks for the pic :happy:

 

[Philip]

A lot of stuff I never new. Much appreciated, Maurice.

 

[daa]

Yeah I figured we'd kill two birds with one stone on this board if I left that pic in,lol.

 

[Tee<3]

9.75/10 :666:

Thanks Doctor Bosco :great:

 

[~*Tisha*~]

You couldn't delete this one.

I get bad flashbacks when my doctor was ready to.... :frown:

 

[MixedMojo]

Not anymore. Thanks Maurice.

 

[chinamigarden]

Dr. Bosco, I appreciate the information on blood tests, however I must admit some of it is simply over my head.

 

[not a top con & proud]

The doctor with the smile and glove resembles the leader of the official opposition. Jack Layton!

 

[Pompal 09.]

I wonder if that is the same smile he has after visiting his favourite Asian MP.

 

[Sneha R]

I don't know about the rest of you, but if I'm giving blood for testing, I've consulted with my doctor what exactly the tests are for.

I had surgery in 2005, and I used my own blood that's right I donated blood to myself.

 

[irish83]

Some good info there. Thanks.