Age related illnesses, General | July 16, 2014 | Author: The Super Pharmacist
Your “chronological age” is the number of years you have been alive. Your “biological age,” which is related to your health, can differ greatly from your chronological age. Because the best treatment option often depends on your health rather than your age, calculating biological age can help doctors better tailor their treatments to individual patients.
In recent years, research has vastly improved our understanding of aging and the biology associated with getting older. As a result, it has been suggested that we may be able to develop biomarkers for aging that can help determine biological age, particularly when used to complement other pre-existing clinical techniques.
The idea of a biomarker for aging was introduced in 1988 and was described as a factor that allowed for better predictions about functional abilities than chronological age. Since the introduction of the idea of a biomarker for aging, several candidates have been explored.
Cellular aging appears to be a result of telomere length.
Telomeres are DNA-protein complexes that cap chromosome ends. Telomeres shorten with each cellular division, so their length can be used as an indicator of biological age.
Once telomeres lose a certain amount of their length, the likely lose certain functions. Shorter telomeres are associated with an increased risk for several conditions including diabetes, hypertension, atherosclerosis, heart attack, Alzheimer’s disease, and cancer.
Several factors influence the rate at which our telomeres shorten, including heredity and environmental factors. Males’ telomeres shorten faster than females’telomeres, which has been hypothesised to contribute to the longer lifespan observed in women. It has even been shown that people who are unmarried have shorter telomeres compared to married people of the same chronological age.
Obesity, lack of exercise, and smoking all increase the rate of telomere shortening.
Inflammation has become implicated with the aging process. Inflammation results from immune system activity. Cellular markers of inflammation are popular candidates for biomarkers of aging and functional decline.
Specific markers that may indicate that biological age is higher include high levels of interleukin-6 or C-reactive protein and low levels of serum cholesterol or albumin. Such changes may result from chronic inflammation, which is likely a sign of dysregulated immune processes. Studies have shown that people with elevated interleukin-6 levels were more likely to suffer disabilities in their mobility. Similarly, people with raised C-reactive protein were at higher risk for cardiovascular and non-cardiovascular death.
Advanced glycation end products (AGEs) are macromolecules that can be identified in blood and urine tests and are practical candidates for biomarkers of aging. AGE accumulation appears to increase biological age by damaging tissue and activation of the immune system.
AGEs may be consumed or may be produced by the body when breaking down sugars.
Highly processed foods are more likely to contain AGEs.
Laboratory studies on the link between AGEs and aging have shown that elevated AGE levels are associated with functional decline, cardiovascular problems, and earlier death.
Patients with diabetes are known to have enhanced AGE levels, and elevated AGE levels have been observed in plaques in the brains of Alzheimer disease patients.
A family of proteins called sirtuins appear to regulate aging and the development of diseases associated with aging. These proteins are involved in stress-response pathways, and reduced levels of sirtuins increase risk for diabetes, cancer, neurodegeneration, and osteoporosis, all of which are age-related conditions. In animal models, depletion of the gene that encodes sirtuin proteins has been shown to increase the risk for tumor development and age-related hearing loss.
In clinical practice, physicians often base decisions based on chronological age. For example, treatment of prostate and breast cancer tend to depend on the chronological age of the patient.
Biological age, however, often tells us more about the health of a patient than chronological age, so biomarkers of aging are likely to become an influential factor in decision making processes.
Further research is needed to help define the most useful biomarkers for aging as well as the conditions for which treatment success depends on biological age.
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