Free Shipping on All Orders $75 Or More!

Your Trusted Brand for Over 35 Years

Life Extension Magazine

<< Back to May 2004

A Comprehensive Guide to Preventive Blood Testing

May 2004

By Penny Baron

Antiquated Hormone “Reference Ranges”
Conventional medicine tends to neglect the hormone imbalances that develop in both men and women as part of growing older. The result is that aging people suffer a variety of discomforts and lethal diseases that are correctable and preventable if simple hormone adjustments are made.

Aging men, for instance, often suffer from excess production of insulin and estrogen, with simultaneous deficiencies of free testosterone and dehydroepiandrosterone (DHEA). If a physician were to test blood levels of all four of these hormones, the standard “reference ranges” are so wide that most men would fall into the so-called “normal” category. Standard reference ranges indicate that dangerously high insulin and estrogen levels are “normal” in elderly men (but so are heart attack, stroke, cancer, benign prostate enlargement, weight gain, type II diabetes, kidney impairment, and a host of other diseases that are associated with excess insulin and estrogen).

The standard reference ranges for free testosterone and DHEA show that very low levels are perfectly “normal” for aging men. It is no coincidence that these same aging men (with low levels of testosterone/DHEA) have high rates of depression, memory loss, atherosclerosis, senility, impotency, high cholesterol, abdominal obesity, fatigue, and a host of other diseases related to low blood levels of testosterone and DHEA.4-15

Another example of flawed reference ranges can be seen in a blood test used to assess thyroid status known as the thyroid stimulating hormone (TSH) test. The TSH reference range used by many laboratories is 0.2-5.5 mU/L. A greater TSH level is indicative of a thyroid hormone deficiency. That is because the pituitary gland is over-signaling TSH due to low levels of thyroid hormone in the blood. Any reading over 5.5 alerts a doctor to a thyroid gland problem and that thyroid hormone therapy may be warranted.

The trouble is that the TSH reference range is so broad that most doctors will interpret a TSH reading as low as 0.2 to be as normal as a 5.5 reading. The difference between 0.2 and 5.5, however, is 27-fold, a parameter far too great to indicate optimal or even normal thyroid function.

A review of published findings about TSH levels reveals that readings over 2.0 may be indicative of adverse health problems relating to insufficient thyroid hormone output. One study showed that individuals with TSH values over 2.0 have an increased risk of developing overt hypothyroid disease over the next 20 years.16 Other studies show that TSH values over 1.9 indicate abnormal pathologies of the thyroid, specifically autoimmune attacks on the thyroid gland itself that can result in significant impairment.17

A more startling study showed that TSH values over 4.0 increase the prevalence of heart disease, after correcting other known risk factors.17 Another study showed that administration of thyroid hormone lowered cholesterol in patients with TSH ranges of 2.0-4.0 but had no effect in lowering cholesterol in patients whose TSH range was 0.2-1.9.18 It also showed that in people with elevated cholesterol, TSH values over 1.9 could indicate that a thyroid deficiency is the culprit, causing excess production of cholesterol, whereas TSH levels below 2.0 would indicate a normal thyroid hormone status.

Doctors routinely prescribe cholesterol-lowering drugs to patients without properly evaluating their thyroid status. Based on the evidence presented to date, it might make sense for doctors to first attempt to correct a thyroid deficiency (based on a TSH value over 1.9) instead of resorting to cholesterol-lowering drugs.

In a study done to evaluate psychological well being, impairment was found in patients with thyroid abnormalities who were nonetheless within “normal” TSH reference ranges.19 The authors of a study published in the August 3, 2002, issue of The Lancet stated that “the emerging epidemiological data begin to suggest that TSH concentrations above 2.0 (mU/L) may be associated with adverse effects.”

When it comes to assessing hormone status, the use of standard reference ranges has failed aging people because reference ranges are adjusted to reflect a person’s age. Since it is normal for an aging person to have imbalances of critical hormones, standard laboratory reference ranges are not flagging dangerously high levels of estrogen and insulin or deficient levels of testosterone, thyroid, and DHEA. The table above shows standard hormone blood reference ranges for men (age 60) and compares them to what the “optimal” ranges should be.

or nor
Optimal Hormone Levels for Aging Males
Hormone Standard Reference Range Optimal Range
DHEA 42-290 ug/dL 280-500 ug/dL
Insulin (fasting) 6-27 uIU/mL Under 6 uIU/mL
Free testosterone 6.6-18.1 pg/mL 16-22 pg/mL
Estradiol 3-70 pg/mL 10-30 pg/mL
TSH* 0.35-5.5 mU/L Under 2.1 mU/L
  *Thyroid stimulating hormone  

Defying the Reference Ranges
Traditional medical thinking accepts that imbalances of life-sustaining hormones are “normal” in aging people. Traditional practitioners almost never test hormone levels because they think that nothing should be done to restore hormone profiles to youthful ranges. More and more, however, aging people are seeking the health and vitality of a younger person. If you are 80 years old and are told that your hormone profile is normal for your age, tell your doctor that you would prefer the hormone profile of a 25-year-old because you perceive a 25-year-old as having more vitality and a reduced risk of contracting lethal diseases.

The Most Important Blood Tests
The Life Extension Foundation suggests that a basic battery of tests be performed annually. The recommended “Male Panel” consists of a complete blood count (CBC)/chemistry test, homocysteine, total and free testosterone, estradiol, prostate-specific antigen (PSA), and DHEA. The recommended “Female Panel” consists of the complete CBC/chemistry test, estradiol, progesterone, total and free testosterone, DHEA, and homocysteine.

If a serious abnormality is detected—such as elevated homocysteine, hormone imbalance, high PSA—testing should be repeated more often to determine the benefits of whatever therapy you are using to correct the potentially life-shortening abnormality.

We also recommend that you consult with your physician regarding any other test that may be appropriate for your individual condition. The remainder of this article provides detailed information about individual tests and ranges that can be used to assess your health and longevity. At the end of this article, we provide information about the new lower-cost blood testing available to Life Extension members.

Male and Female Testing Panels

The Male and Female Testing Panels are a terrific place to begin to proactively take charge of your health.

These panels comprise the most requested tests, which also happen to be the best and most comprehensive screening tests capable of identifying many common and not-so-common conditions, identifying risk factors for future disease, and offering a clinical snapshot of your current physiologic well being.

Both panels consist of a full chemistry and complete blood count (CBC) measuring 35 different blood components, which assess cholesterol and triglyceride levels, blood glucose, iron and mineral levels, kidney and liver function, and blood cell components.

The male and female panels also test for levels of total and free testosterone, DHEA-S (an indicator of adrenal cortical function), estradiol, homocysteine, and C-reactive protein. Both homocysteine and C-reactive protein, along with levels of cholesterol lipoproteins, are powerful predictors of cardiovascular disease.

The male panel also includes the PSA (prostate-specific antigen) test, which is a very sensitive marker for prostate cancer. The female panel includes a test for progesterone levels, providing information concerning female fertility, ovulation cycles, and possible hormonal tumors.

Following are snapshots of the various tests offered in the male and female test panels.

Chemistry and complete blood count (CBC) PANEL

The chemistry panel provides a wide range of information to assess cardiovascular, endocrine (glucose levels), hepatobiliary, and kidney function. The CBC panel provides information on the presence of infectious organisms, anemias, nutritional deficiencies, lymphoproliferative disorders (i.e., leukemia), and other hematological disorders.

Chemistry cardiovascular system tests include total cholesterol, HDL- and LDL-cholesterol, triglycerides, and the ratio between total cholesterol and HDL levels, which is more valuable as a predictor of heart disease than total cholesterol or HDL levels alone. When assessed along with C-reactive protein and homocysteine blood levels, the information attained offers a very powerful indicator of cardiovascular status, including risk of future heart disease.

The chemistry panel also looks at fasting glucose levels in the plasma. Skewed values may indicate problems with glucose metabolism, such as hyperglycemia (diabetes mellitus) or hypoglycemia (low blood sugar, which may preempt hyperglycemia in some individuals), acidosis or ketoacidosis, and further problems with carbohydrate metabolism.

Abnormal levels of protein/albumin/globulin, albumin/globulin ratio, bilirubin, alkaline phosphatase, lactic dehydrogenase (LDH), AST (SGOT), ALT (SGPT), iron, cholesterol, and cholesterol lipoproteins are indications of potential liver/biliary problems. These may include liver damage induced by alcohol or drug use, liver cancer, or obstruction of the bile duct, among others. Together, ALT and AST allow for differential diagnosis of disorders associated with the hepatobiliary system and the pancreas. High levels of alkaline phosphatase may also indicate abnormally high levels of vitamin D.

Kidney function may be assessed by evaluating blood levels of the following: blood urea nitrogen (BUN), uric acid, creatinine, BUN/creatinine ratio, sodium, potassium, and chloride ions. BUN measures the amount of urea nitrogen (a breakdown product of protein metabolism) in the blood. Most diseases involving the renal system affect urea excretion by the kidneys and will elevate BUN levels. Creatinine, a breakdown product of creatine metabolism (creatine is an important constituent of muscle), is excreted by the kidneys—abnormal levels may indicate renal failure or dehydration (elevated levels) or myasthenia gravis or late-stage muscular dystrophy (decreased levels). The ratio between BUN and creatinine may help determine the reason behind decreased kidney function (such as dehydration). Sodium, potassium, and chloride ion levels assist in the evaluation of hydration status and electrolyte balance. Low levels of potassium may indicate acute renal failure.

Hematological abnormalities and infection
Complete blood counts include red blood cells (RBCs) and white blood cells (WBCs) and their components: hematocrit, hemoglobin levels, and platelet counts.

RBC, hematocrit, and hemoglobin
Abnormally low RBC levels may indicate iron, folate, and vitamin B6 and B12 deficiencies. Low hemoglobin or hematocrit levels may indicate anemia; high hematocrit values may suggest dehydration. Abnormal distribution of the RBC width (RDW) compared with the mean corpuscular hemoglobin volume (hematocrit divided by RBC count) may detect such problems as aplastic anemia, thalassemia, anemias, and deficiencies of iron, folate, and vitamin B12.

Platelets are an essential part of the coagulation (clotting) cascade and normal levels are necessary to maintain hemostasis. Decreased platelet counts may be seen in patients undergoing chemotherapy, and in hemolytic anemia, leukemia, and other disorders that diminish clotting ability.

WBCs and their components (lymphocytes, monocytes, neutrophils, eosinophils, and basophils)
Increased levels of all types of WBCs in the blood are usually associated with bacterial, viral, parasitic, or protozoal infections. Neutrophils, which are the first WBCs to respond to infection, often indicate infection or emotional stress (increased levels) or chronic infection, bone marrow depression, or iron, folic acid, or vitamin B12 and B6 anemias (decreased levels). Differential assessment of the CD4/CD8 T-lymphocyte ratio (a separate test) may confer important information concerning immune status, especially in patients who are immune-suppressed (i.e., HIV/ AIDS). The presence of eosinophils in the blood is a good indication of parasitic or fungal infection, or a response to allergy. The number of monocytes in the blood is often increased (very high levels) in patients with leukemias and Hodgkin’s or non-Hodgkin’s lymphoma.

or nor
Optimal Ranges of Popular Blood Tests
(Some ranges differ for men and women)
  Current Laboratory
Reference Range
Glucose 65-99 mg/dL 70-85 mg/dL
Cholesterol 100-199 mg/dL 180-200 mg/dL
LDL 0-99 mg/dL Under 100 mg/dL
HDL 40-59 mg/dL Over 55 mg/dL
Triglycerides 0-149 mg/dL Under 100 mg/dL
PSA 0-4 ng/mL 0-2.5 ng/mL*
Homocysteine (male) 6.3-15 umol/L Under 7.0 umol/L
Homocysteine (female) 4.6-12.4 umol/L Under 7.0 umol/L
Fibrinogen 215-540 mg/dL 200-300 mg/dL
C-reactive protein 0-3 mg/L** Under 0.5 mg/L
*A PSA doubling time that occurs in less than 12 years may be a cause for concern.
**Reference ranges vary between laboratories. Women can have higher levels than men without increased cardiovascular risk.