Most lab tests and blood tests are designed to diagnose and treat illness and disease with medications or surgery. Strength and power athletes present a unique blood profile that most physicians will simply write off as "normal," even though performance is declining and the athlete is unsure why. Lab tests that come back as normal may still be problematic for a healthy athlete and may indicate some deficiencies that could be causing decreases in performance. The standard reference ranges for "normal" are compiled based on average of individuals ranging in age from 18-80 that had their lab tested by the organization that drew them. One lab panel from company A may have different reference ranges than company B, and this poses a problem for physicians and athletes alike.

In this series, we will cover some lab metrics that can be useful for an active exerciser looking to increase their performance or ensure they are not at risk for developing any nutritional, recovery, or health deficiencies. We are going to look at Optimal Reference ranges as a way to interpret results, which can outline parameters of good health and performance. Since the body and its systems are interconnected, we are going to look for patterns and correlations between lab markers that show more of an overall look at how the body is responding to its environment currently (stress, sleep, nutrition, exercise, etc.) Using the optimal reference ranges, we can address some metrics before they become a big problem. We can start to see trends and see a composite of connected lab metrics that rise together, address them, and get everything working at peak capacity before any performance slow-down occurs. These labs can also help us determine if further testing is needed for certain conditions or problems.

Throughout this three-part series, we will cover labs that are commonly done as part of an annual checkup at the doctor's office and some other more specific labs done to get a larger picture of body functions. There are a multitude of available lab metrics to have tracked by your doctor, so we will cover some labs that you might have had done but never had explained before. We will also cover some labs that could be particularly useful for performance athletes. By going over these labs and giving you a little bit of background on what they are used for and what contributes to higher or lower levels, we hope to give you clues as to what diet or exercise changes to make to your programs to help you function at your best.

In the first part of this series we covered labs dealing with blood sugar regulation, blood cells and composition, electrolytes, male and female sex hormones, bone and muscle health, digestion and lipid levels. This month’s installment covers oxygen deliverability, liver function, and kidney function. The third and final part of this series will cover the NMR lipoprofile test and an insulin resistance score. This last test goes more in depth as to cholesterol, lipid management and risk for insulin resistance and diabetes. It can also tell us more information about inflammation and give us clues as to what is driving inflammation in the body. These labs would normally be indicated on lab slips as a Complete Blood Count (CBC), Comprehensive Metabolic Panel (CMP), Male hormones, female hormones, and NMR Lipoprofile.

Oxygen

Oxygen is one of the, if not, THE MOST important nutrients we need to function optimally for health and performance. The lab numbers below can help us to see if there is an issue with oxygen deliverability that could lead to or be the reason for decreased performance. Even if the numbers on the following tests run normal according to standard reference ranges, oxygen may not be being delivered optimally. If oxygen is not being delivered properly, then there are a number of causative factors that are within our control to try and change. For the issues outside of our control to change, consultation with a medical professional can help to guide further testing. As you will see from the lab metrics below, a lot of these numbers act synergistically to identify a deficiency or area of concern. A single metric is not indicative of any deficiency unless also compared to the other markers. However, there are some markers that can start to point us to possible issues and allow us to ask the right questions in regards to diet and possible deficiencies. There are optimal reference ranges below to ensure adequate movement of oxygen to the body and the cells for energy production and cellular health. Standard reference ranges are included with these markers because issues with oxygen and Red Blood Cells (RBCs) may be due to serious medical conditions and should be looked at by a medical professional.

Hemoglobin

Hemoglobin (Hgb) serves as a vehicle for oxygen and carbon dioxide transport throughout the body. The oxygen-carrying capacity of the blood is determined by the Hgb concentration, and Hgb also acts as an important acid-base buffer system. Too little Hgb puts a strain on the heart to maintain good oxygen-carrying capacity, and critically low levels can lead to some serious issues. When Hgb levels are too high because of too many RBCs, this can lead to stroke and other organ infarction. What is interesting about Hgb is that the levels are highest around 8am. and lowest around 8pm and can vary as much as 1 g/dL. Factors that lead to increase Hgb levels include smoking, living at high altitude, congenital heart disease, severe dehydration, and bone marrow producing too many RBCs. Decreased level of Hgb are indicative of anemia, reduced RBC survival rates, overhydration, hemorrhage, dietary deficiency of iron, B12 or folate, bone marrow failure to produce enough RBCs, kidney problems, pregnancy, autoimmune disease (lupus, sarcoidosis, rheumatoid arthritis) and some cancers. Optimal levels of hemoglobin for males are: 14-15 g/dl and females are; 13.5-14.5 g/dl. Standard reference ranges for males are 14-18g/dL, and females 12-16g/dL.

Hematocrit

Hematocrit abbreviated Hct is a measure of the percentage of the total blood volume that is made up by the Red Blood Cells (RBCs). The Hct in percentage points is usually approximately three times the Hemoglobin concentration in grams per deciliter when RBCs are of normal size and contain normal amounts of Hgb. Decreased levels indicate anemia, low survival rate of Red Blood Cells (RBCs), fluid overload (overhydration), extremely elevated White Blood Cell count (WBC), hemorrhage, and dietary deficiency of iron, B-12 or folate. Increased levels indicate illness from an increased number of RBCs, congenital heart disease, bone marrow production disorders, severe dehydration, and chronic obstructive pulmonary disease. Chronic states of low oxygen can increase RBCs and raise Hct levels. This is common in smokers, people suffering from chronic allergies, nasal polyps impeding oxygen intake, and living at high altitudes. Optimal levels are 39 percent – 50 percent for males, and 37 percent – 44 percent for females. Standard reference ranges are 42 percent – 52 percent for males and 36 percent – 47 percent for females.

Ferritin

Ferritin is the most sensitive test to determine iron-deficiency anemia. This test is a good indicator of available iron stores in the body because ferritin is the major iron-storage protein in the body. Ferritin levels rise persistently in males and postmenopausal females, and remain constant for premenopausal women due to monthly menses. Ferritin levels affected by malnutrition are usually only present for severe protein depletion. Although this test may tell us a lot about anemia, it can show some false readings because it is an acute-phase reactant that responds to inflammation, infections, cancer, or lymphoma. Also, recent blood transfusion or recent ingestion of a meal containing a high iron content may cause elevated ferritin levels. Increased levels can be due to hemochromatosis, anemia, liver disease, inflammatory disease, advanced cancers, or chronic illnesses. Decreased levels may be due to iron-deficiency anemia, severe protein deficiency, and hemodialysis. This test combined with an Iron test, Total Iron Binding Capacity test, and a Transferrin Saturation test can help clinicians to address various clinical states related to different types of anemia or something more serious. Acute inflammation indicated by these 4 tests is shown by an elevated ferritin level, normal iron level, low total iron binding capacity and elevated transferrin saturation level. Optimal levels of ferritin should be between 10 – 122 ng/mL for females, and 33-263 ng/mL for males

Total Iron Binding Capacity (TIBC)

This is a measurement of all proteins available for binding mobile iron. This level is increased in about 70 percent of patients with iron deficiency. TIBC varies minimally with iron intake, and is more reflective of liver function and nutrition that it is of iron metabolism. Increased levels may be due to late stage pregnancy, estrogen therapy and iron deficiency anemia. Low levels might be due to malnutrition, low levels of protein in the body (severe protein calorie malnutrition), inflammatory diseases, fluid overload, hemolytic, pernicious, and sickle cell anemia. Optimal levels of TIBC should be between 250-350 mcg/dL. Standard reference ranges 250-460 mcg/dL.

Iron

70 percent of the iron in the body is found in the hemoglobin of red blood cells, while the other 30 percent is stored in the form of ferritin and hemosiderin. About 10 percent of the iron ingested from food is absorbed in the small intestine and transported to the plasma. Iron-deficiency anemia can be due to insufficient iron intake, inadequate gut absorption, increased requirements for iron in the body, and loss of blood (internal bleeding, menses, bleeding peptic ulcer). Serum iron levels fluctuate throughout the day and testing should be done in the morning, fasted while avoiding meals the day before with a very high iron content (red meat). Increased serum iron levels can be from iron poisoning, hemochromatosis, hemolytic anemia or blood transfusions. Decreased serum iron levels can be due to insufficient dietary iron, chronic blood loss, inadequate intestinal absorption of iron, and iron deficiency anemia. Optimal levels of iron should be between 85-130 ug/dL. Standard reference ranges are 80-180 mcg/dl for Males and 60-160 mcg/dL for females.

Transferrin

Transferrin is a negative acute phase reactant, so with acute inflammatory conditions, transferrin levels decrease. Pregnancy and estrogen therapy are associated with increased transferrin levels, as well as iron-deficiency anemia. Decreased transferrin levels are found with malnutrition, decreased levels of proteins in the body, inflammatory disease, overhydration, hemolytic, pernicious and sickle cell anemia. Optimal reference ranges are 200-370 mg/dL for males and females. Standard reference ranges are 215-365 mg/dL for males and 250-380 mg/dL for females.

Transferrin Saturation

Transferrin is a percentage of serum iron level x 100 percent divided by the Total Iron Binding Capacity (TIBC). This calculation is helpful in determining the cause of abnormal iron and TIBC levels. It can help us distinguish between different types of anemia and various other iron storage issues. Increased levels are found in individuals with hemochromatosis, increased iron intake, and hemolytic anemia. Decreased levels are found in iron-deficiency anemia and chronic illnesses. Optimal levels should be between 15-55 percent. Standard reference ranges are 20 percent to 50 percent in males and 15 percent to 50 percent in females.

RBC

Red Blood Cell (RBC) Count is closely related to Hemoglobin (Hgb) and Hematocrit (Hct) levels in the blood. RBC count is stimulated by erythropoietin and produced by the erythroid elements in the bone marrow. RBCs typically survive in the bloodstream for 120 days and then as they age they are broken down and removed from circulation by the spleen. RBCs can have a shorter than normal lifespan driven by high levels of glycohemoglobin (1, 2).

Glycohemoglobin, also called hemoglobin a1c (HbA1c) may not be as valuable for determining glycemic control because of the shorter lifespan of RBCs, and fructosamine appears to more closely correlate with dietary carbohydrate intake, but it only accounts for the past three weeks and not the past three months like a HbA1c test (3). Low levels of RBCs are caused by GI bleeding or trauma, iron or B-12 deficiency, genetic abnormalities, organ failure, bone marrow failure, and tumors or sepsis. High levels can be due to the body's requirements for greater oxygen-carrying capacity (high altitudes, COPD, smoking, allergies, or anything that would alter someone's ability to adequately breathe). It is important to note that RBCs, Hgb, and Hct levels can be altered based on fluid status. For example, if you are dehydrated then the RBCs, Hgb, and Hct will be more concentrated in the blood and the counts will be falsely high and vice versa. Optimal levels for males; 4.2 – 4.9 x 106 /uL, females 3.9 – 4.5 x 106 /uL. Standard reference ranges 4.7 - 6.1 x106 /uL for males and 4.2 - 5.4 x 106 /uL for females.

Liver Health
AST

Aspartate aminotransferase (AST) formerly called Serum Glutamic Oxaloacetic Transaminase (SGOT) is a liver enzyme and is found in highly metabolic tissues in the body such as the heart, liver, skeletal muscle and to a lesser degree in the kidneys, pancreas, and red blood cells. When any of these tissues are injured, the AST levels rise and the elevation is directly related to the extent of the injury. Some medications and vitamin/mineral supplements cause this number to be elevated and care should be used when starting or taking higher doses of vitamin/mineral supplements. The AST level is also high in individuals with alcoholic cirrhosis, liver damage due to liver congestion or severe musculoskeletal injury. Excessive exercise may also lead to elevations in AST due to significant muscle breakdown generally found with bodybuilding style workouts and an increased protein turnover rate. Decreased levels of AST may be due to acute renal disease, diabetic ketoacidosis, renal dialysis, pregnancy, or a vitamin B1 deficiency. Optimal levels of AST should be between 10-26 units/L.

ALT

Alanine Aminotransferase (ALT) formerly known as Serum Glutamic-Pyruvic Transaminase (SGPT) is found predominantly in the liver and used to identify liver dysfunction. Unfortunately, there are many drugs that may cause an increased level of ALT including: acetaminophen, allopurinol, cephalosporins, codeine, oral contraceptives, salicylates, and tetracyclines, to name a few. Oral anabolic agents can also cause a rise in liver enzymes to sometimes dangerous levels. The level of elevation of the lab test for ALT indicates which type of abnormality is facing the liver, from hepatitis with significantly elevated levels, decreased flow of bile from liver in moderately increased levels, and myocardial infarction, shock and infectious mononucleosis in mildly increased levels. With any elevation in ALT levels above optimal ranges, we should start to question our intake of medications, vitamin/mineral supplements, alcohol intake, food quality, exposure to environmental pollutants, refined fructose consumption (fruit juices, soda, agave) and dietary fiber intake from fruits and vegetables. ALT elevations may be the deciding factor for individuals to clean up their diet and focus more on clean foods and less on junk food to hit macronutrient targets (4, 5). Optimal reference ranges are 10-26 units/L.

GGT

Gamma-Glutamyl Transferase (GGT) also referred to as Gamma-Glutamyl Transpeptidase (GGTP) is an enzyme that participates in the transfer of amino acids and peptides across the cell membrane. The highest concentration of this enzyme is found in the liver and biliary tract. This test is used to detect liver cell dysfunction but is also highly accurate in indicating even the slightest degree of bile duct blockage and/or gallstones. Another benefit of this test is that it can indicate chronic alcohol ingestion, and may show that the level of alcohol intake one is consuming might be a bit excessive for optimal performance. If levels are elevated, individuals might consider decreasing alcohol intake and increasing antioxidant content of the diet (6). The levels of GGT rise in correlation with Alkaline phosphatase, except when bone disease is present. Optimal reference ranges are 10-26 units/L.

Alk phos

Alkaline Phosphatase is found mostly in the liver, biliary tract epithelium, intestinal mucosa, and bone. This test is often used to detect bone or liver issues and can be elevated during periods of bone growth. If levels of Alk Phos are high and no bone growth is occurring, further evaluation by a physician is recommended. Low levels of alkaline phosphatase may require nutritional changes to address the deficiency. Low alkaline phophatase can be due to insufficient phosphate in the diet, malnutrition, pernicious anemia, and even vitamin C deficiency. The therapy for correcting these deficiencies is relatively easy because it usually only requires an increase in meats, and vegetables. Optimal Reference ranges are 27-90 units/L.

Kidney
BUN

Blood Urea Nitrogen is an indirect and rough measurement of kidney function and usually comes standard on all lab tests. This test measures the amount of urea nitrogen in the blood, which is an end product of protein metabolism and digestion. This test also measures the metabolic function of the liver and the excretory function of the kidneys. Elevated levels can be due to shock, dehydration, congestive heart failure, GI bleeding, and excessive protein catabolism. Changes in protein intake will affect BUN levels, where low levels of protein intake will reflect a low BUN number and high-protein diets lead to an increased BUN number. The amount of muscle mass one carries also affects BUN levels as women and children tend to have lower BUN levels than men. Hydration status affects levels also due to dilution and concentration in the blood volume; overhydration leads to lower BUN levels and dehydration leads to higher BUN levels. There are also many drugs that can cause increased BUN levels also: diuretics, aspirin, methotrexate, methyldopa, antibiotics, and spironolactone to name a few. Decreased levels of BUN may be due to liver failure, overhydration, malnutrition, malabsorption, pregnancy, and protein in the urine. This measurement alone may not be enough to know exactly what is going on, but looking at the causes for highs/lows can start to guide us to asking more and better questions of how we can improve our nutrition to make sure our kidneys are working optimally. Optimal reference ranges are 13-18 mg/dL.

Creatinine

This test measures the breakdown product of creatine phosphate in the blood. The daily production creatinine in the blood usually remain constant because they are associated with levels of muscle mass. There are, however, some factors that can affect levels not indicative of kidney or liver issues including; dehydration, large quantities of meat in the diet, muscle mass, and rhabdomyolysis. High levels of creatinine may be due to decreased kidney function, rhabdomyolysis, gigantism, and creatine supplementation during the loading phase, but not during a standard 5 gram per day maintenance dosage. Low levels usually only related to decreased muscle mass and debilitation. The good folks over at Examine.com did a phenomenal write-up on creatine supplementation and its effects, I highly encourage anyone interested to learn about it for sports performance. Make sure to stay properly hydrated when you go to get your labs done so you can be assured that the numbers on your lab tests are going to be indicative of a normal functioning organ system, instead of one that has a bunch of wacky numbers that freak you or your doctor out because you forgot to drink enough water. Most doctors correlate a high creatinine level with supplementation of creatine, and this may be the case during the loading phase, or with a high protein intake and creatine supplementation, most times it is due to dehydration causing a larger concentration of creatinine in the blood. Optimal reference ranges for females are .65 - .9 mg/dL, and for males .85 - 1.1 mg/dL.

References
1. Peterson CM, Jones RL, Koenig RJ, Melvin ET, Lehrman ML: Reversible hematologic sequelae of diabetes mellitus. Ann Int Med 86:425–429, 1977
2. Virtue, Mark A., et al. "Relationship between GHb concentration and erythrocyte survival determined from breath carbon monoxide concentration."Diabetes Care 27.4 (2004): 931-935.
3. Misciagna, Giovanni, et al. "Fructosamine, glycated hemoglobin, and dietary carbohydrates." Clinica chimica acta 340.1 (2004): 139-147.
4. Fraser, A., et al. "A modified Mediterranean diet is associated with the greatest reduction in alanine aminotransferase levels in obese type 2 diabetes patients: results of a quasi-randomised controlled trial." Diabetologia 51.9 (2008): 1616-1622.
5. Kechagias, Stergios, et al. "Fast-food-based hyper-alimentation can induce rapid and profound elevation of serum alanine aminotransferase in healthy subjects." Gut 57.5 (2008): 649-654.
6. Huseini, H. F., Larijani, B., Heshmat, R., Fakhrzadeh, H., Radjabipour, B., Toliat, T. and Raza, M. (2006), The efficacy of Silybum marianum (L.) Gaertn. (silymarin) in the treatment of type II diabetes: a randomized, double-blind, placebo-controlled, clinical trial. Phytother. Res., 20: 1036–1039.