MEDICAL NECESSITY

from the library of Robert L. Talley, DDS.

VITAMINS, MINERALS, ANTIOXIDANTS and OTHER ESSENTIAL MICRONUTRIENTS *

As adults age, they experience a higher incidence of health-related problems, especially chronic illnesses including cardiovascular disease, non-insulin-dependent diabetes mellitus, arthritis, osteoporosis and other degenerative diseases. Stress-inducing events are positively correlated with diminishing health in most age groups and are strongly associated with increased morbidity and mortality (often from respiratory infections) in the aging population.

The increase in morbidity and mortality observed following stressors in adults, is believed to be mediated by the stress response that is, through impulses from the sympathetic nervous system, increased secretion of selected hormones and deficiencies of various factors which suppress immune function. It is well established that deficiencies of various vitamins, minerals and antioxidants suppress T-lymphocyte proliferation and, thusly, cell-mediated immune functions.

Currently, health changes in adults often are detected by insensitive and subjective measures such as interviews or surveys that require self-reporting or by retrospective reviews of medical records (counting episodes of illness, visits to physicians, bed days, etc.). Using either method, the discovery of declining health status is often made late, possibly too late to intervene effectively through more cost-effective methods. The clinical laboratory can play a critical role in the future evaluation of the health effects of stress on the older adult through the performance of analyses assessing hormonal and other factors affecting immune system performance.

Many physicians are increasingly requesting (previously rarely ordered) hormone, vitamin, mineral and immune function analyses to monitor adults for stress-related declines in health. In 1992, Zola reviewed the detection of lymphocytic markers for use in clinical diagnoses and notes that, "tests for lymphocyte function tend to be slow and tedious and lack clinically useful discriminatory power." Technological advances are causing Zola’s quote to rapidly become obsolete. Advances in the development of monoclonal antibodies with specificities to lymphocyte membrane markers, technological advances in flow cytometry and tissue culture assays assessing lymphocyte function are increasingly available. The performance of diagnostic tests of endocrine, nutritional and immune function that allow early detection of the dysfunctional immune system performance and the eventual health deterioration in aging adults would permit the implementation of intervention strategies with opportunities to prevent disease and reduce health care costs.

Impairment of immune system function in older adults is more critical to detect than in young adults because of the natural breakdown of the aging immune system, leaving aging adults at greater risk for disease processes. The older population has a higher incidence of infections, neoplasias, and cardiovascular and autoimmune diseases. The increased susceptibility to such diseases may be attributed to immuno-senescence. Various infections are the leading cause of admissions to the acute care hospital. Infections are also the major complication during hospital stays, especially in the older adult. Clinical diagnosis is often delayed, however, because severe infections present more subtly in older patients. Many older patients who are hospitalized for infection initially have only vague symptoms including poor appetite, weakness, and disinterest in surroundings and decline in their performance of daily activities.

The total number of circulating mature T-lymphocytes decreases or remains unchanged as adults age. Numbers of circulating helper/inducer (CD4+) and suppressor/cytotoxic (CD8+) T-lymphocytes decrease. Authors agree that the proliferative ability following stimulation by mitogenic agents, such as PHA (phyto-hemagglutinin), is diminished in T-lymphocytes as patient’s age. This is regarded as the key age-related decrement of immune system performance. Because of the immunoregulatory functions of helper and suppressor T-lymphocytes, a diminished proliferative response in these cell populations impacts virtually all immune processes. These decreases may then cause other immune decrements such as impaired immunoregulation manifested as increased susceptibility to infection, reduced ability of B-lymphocyte proliferation, decreased cytokine production, and increased incidence of neoplasias, autoimmune and cardiovascular diseases.

In summary, because aging adults are already at greater risk of immune impairment, it is far more critical to detect and manage the immunosuppressive effects of stress events in this growing population. The clinical laboratory, by employing analyses of stress hormone levels, immune function tests, and the determination of those factors limiting proliferative responses, plays a dynamic role in the maintenance of health and the prevention of disease. The clinical laboratory can provide data to the physician allowing early detection and treatment of many deficiencies that contribute to immune function-related health deterioration by the performance of assays assessing cell-mediated immune function, hormonal assays and assays to identify factors that may limit lymphocyte proliferation. The latter would include vitamins, minerals, antioxidants and other micronutrients shown to be essential for optimal lymphocyte performance.

* Abstracted from article appearing in MLO, October 1997 by D.M. Cearlock and M. Laude-Flaws.