A Comprehensive Guide to Preventive Blood TestingMay 2004
By Penny Baron
Gastric Tests (Stomach)
Helicobactor pylori, IgG antibodies
Hepatobiliary Tests (Liver)
Gamma glutamyl transpeptidase (GGT)
Carcinoembryonic antigen (CEA)
Production usually halts before birth, and blood levels are undetectable in healthy adults. CEA can be seen in people who are heavy smokers, and in patients with certain cancers, particularly those of the pancreas, colon, rectum, breast, and lung. A tumor marker, CEA is not used to diagnose disease, but to determine the extent of disease and patient prognosis, and to monitor treatment efficacy. CEA is often the first marker to elevate in response to a cancer relapse and may show up months before patients become symptomatic or show a response with other laboratory tests.
CEA levels may also be elevated in patients with inflammations (i.e., infections, inflammatory bowel disease, and pancreatitis), hypothyroidism, and cirrhosis.
Cancer Antigen (CA) 15-3
have antigen levels in the same range as healthy individuals.
Increased CA 15-3 levels may also be seen in cancers of the pancreas, lung, ovary, and liver, as well as in (non-malignant) hepatitis and cirrhosis.
Women in particular are at increased risk for development of osteoporosis (decrease in bone density). At risk are persons of low body weight (relative to height), cigarette smokers, alcohol abusers, individuals with low dietary calcium and vitamin D intake, women undergoing early menopause, young women who are not menstruating, and persons not getting enough weight-bearing exercise. Family history and advanced age are also risk factors. People with osteoporosis are at increased risk for bone fractures, which may lead to chronic pain, disability, and even death. Osteoporosis can be prevented by determining risk through laboratory testing of biochemical markers, and then taking the proper steps (diet, exercise, drug therapy, supplementation) to reduce bone loss.
A highly accurate and inexpensive test of bone resorption (breakdown) is Pyrilinks-D or Dpd (deoxypyridinoline), which involves testing of the second voided urine specimen of the day. DpD, along with pyridinoline (Pyd), forms the rigid crosslinks of mature Type I collagen in bone. During bone resorption, DpD is released into the circulation and is excreted unmetabolized in the urine. Increased levels of Dpd in the urine have been correlated to risk of osteoporosis77 and response to hormone replacement therapy.78
Interleukin-6 (IL-6), which is produced in a variety of tissues including bone, stimulates the differentiation and proliferation of osteoclasts (cells that play an active role in bone resorption), which may then lead to increased bone resorption. Increased blood levels of IL-6 have been found to be a major predictor of bone loss in postmenopausal women, specifically through the first postmenopausal decade.79 Increased levels have also been seen in women with hyperparathyroidism with subsequent bone loss.80
Biochemical markers for bone remodeling (growth) can assess a patient’s status or risk for significant decrease in bone mass by providing a means of measuring bone turnover. In a clinical trial of 7,598 women, increased Ntx (bone resorption marker) was associated with increased risk of hip fractures.
While bone densitometry can give an accurate snapshot of bone density, one to two years between evaluations are necessary to detect a bone loss of only 3-5%. Changes to bone metabolism can be assessed using biochemical markers beginning three to six months after initiation of therapy.
Bone markers may be classified as bone formation or resorption. Resorption, the breaking down of collagen, occurs prior to bone formation, and biochemical markers provide a direct indication of efficacy of antiresorptive therapy. No change in marker levels may indicate therapy is ineffective (or the patient is noncompliant). An increase in marker levels indicates bone loss (ineffective therapy); a decrease in marker levels indicates therapy is working.
To get a clear understanding of one’s physiological well being, simple and noninvasive blood analysis should be performed annually, or more often if assessment of therapeutic efficacy (or for other reasons) is indicated. Especially when test values are at the high or low end of the normal range, periodic testing will be able to pick up positive or negative trends.
For example, moderately high cholesterol or C-reactive protein levels may not be flagged in a one-time test, but over a period of time a slight increase will send up a red flag, alerting a patient to a potential problem—increased risk of heart disease. Conversely, following trends will also let you know that you are on the correct path following diet, supplement, or pharmaceutical intervention.
Preventable disorders often can be detected years before they manifest as problems with deleterious, and sometimes irreversible, consequences that can substantially impair your quality of life. A yearly blood test is a relatively inexpensive investment (compared to the cost of disease-related health care and prescription medications) to protect your health, increase your quality of life now and in the future, and protect your most precious commodity—you! Get more information about mail order blood testing, including the recommended male and female panels.
Penny Baron is a retrovirologist at a prominent New York City hospital, and has been researching HIV/AIDS since 1983. She holds masters degrees in microbiology and clinical nutrition.