Aging-associated diseases
Encyclopedia
An aging-associated disease is a disease
that is seen with increasing frequency with increasing senescence
. Age-associated diseases are to be distinguished from the aging
process itself because all adult animals age, but not all adult animals experience all age-associated diseases. Aging-associated diseases do not refer to age-specific diseases, such as the childhood diseases chicken pox and measles
. "Aging-associated disease" is used here to mean "diseases of the elderly". Nor should aging-associated diseases be confused with accelerated aging disease
s, all of which are genetic disorder
s.
Examples of aging-associated diseases are cardiovascular disease
, cancer
, arthritis
, cataracts, osteoporosis
, type 2 diabetes
, hypertension
and Alzheimer's disease
. The incidence of all of these diseases increases rapidly with aging
(increases exponentially
with age, in the case of cancer).
s have had cancer, whereas by age 85 about 30% of humans have had cancer. Humans, dog
s and rabbit
s get Alzheimer's disease, but rodent
s do not. Elderly rodents typically die of cancer or kidney disease
, but not of cardiovascular disease. In humans, the relative incidence of cancer increases exponentially with age for most cancers, but levels-off or may even decline by age 60–75 (although colon
/rectal
cancer continues to increase).
Victims of some of the so-called segmental progerias
are vulnerable to different sets of diseases. Victims of Werner's syndrome suffer from osteoporosis, cataracts and cardiovascular disease, but not neurodegeneration
or Alzheimer's disease. Victim's of Down syndrome
suffer type 2 diabetes and Alzheimer's disease, but not high blood pressure
, osteoporosis or cataracts. Victims of Bloom syndrome
most often die of cancer.
determines vulnerability or resistance between species and individuals within species. Some age-related changes (like graying hair) are said to be unrelated to an increase in mortality
. But some biogerontologists believe that the same underlying changes that cause graying hair also increase mortality in other organ systems and that understanding the incidence of age-associated disease will advance knowledge of the biology
of senescence just as knowledge of childhood diseases advanced knowledge of human development
.
Strategies for Engineered Negligible Senescence (SENS) is a research strategy which aims to identify a few "root causes" for age-related illness and degeneration, as well as develop medical procedures to periodically repair all such damage in the human body, thereby maintaining a youth-like state indefinitely. So far, the SENS programme has identified seven types of aging-related damage, and feasible solutions have been outlined for each. However, critics argue that the SENS agenda is extremely optimistic at best, and that the aging process is too complex and little-understood for SENS to be scientific or implementable in the foreseeable future.
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
that is seen with increasing frequency with increasing senescence
Senescence
Senescence or biological aging is the change in the biology of an organism as it ages after its maturity. Such changes range from those affecting its cells and their function to those affecting the whole organism...
. Age-associated diseases are to be distinguished from the aging
Ageing
Ageing or aging is the accumulation of changes in a person over time. Ageing in humans refers to a multidimensional process of physical, psychological, and social change. Some dimensions of ageing grow and expand over time, while others decline...
process itself because all adult animals age, but not all adult animals experience all age-associated diseases. Aging-associated diseases do not refer to age-specific diseases, such as the childhood diseases chicken pox and measles
Measles
Measles, also known as rubeola or morbilli, is an infection of the respiratory system caused by a virus, specifically a paramyxovirus of the genus Morbillivirus. Morbilliviruses, like other paramyxoviruses, are enveloped, single-stranded, negative-sense RNA viruses...
. "Aging-associated disease" is used here to mean "diseases of the elderly". Nor should aging-associated diseases be confused with accelerated aging disease
Accelerated aging disease
A DNA repair-deficiency disorder is a medical condition due to reduced functionality of DNA repair.DNA repair defects are seen in nearly all of the diseases described as accelerated aging disease, in which various tissues, organs or systems of the human body age prematurely...
s, all of which are genetic disorder
Genetic disorder
A genetic disorder is an illness caused by abnormalities in genes or chromosomes, especially a condition that is present from before birth. Most genetic disorders are quite rare and affect one person in every several thousands or millions....
s.
Examples of aging-associated diseases are cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
, cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
, arthritis
Arthritis
Arthritis is a form of joint disorder that involves inflammation of one or more joints....
, cataracts, osteoporosis
Osteoporosis
Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...
, type 2 diabetes
Diabetes mellitus type 2
Diabetes mellitus type 2formerly non-insulin-dependent diabetes mellitus or adult-onset diabetesis a metabolic disorder that is characterized by high blood glucose in the context of insulin resistance and relative insulin deficiency. Diabetes is often initially managed by increasing exercise and...
, hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
and Alzheimer's disease
Alzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...
. The incidence of all of these diseases increases rapidly with aging
Ageing
Ageing or aging is the accumulation of changes in a person over time. Ageing in humans refers to a multidimensional process of physical, psychological, and social change. Some dimensions of ageing grow and expand over time, while others decline...
(increases exponentially
Exponential growth
Exponential growth occurs when the growth rate of a mathematical function is proportional to the function's current value...
with age, in the case of cancer).
Patterns of differences
By age 3 about 30% of ratRat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s have had cancer, whereas by age 85 about 30% of humans have had cancer. Humans, dog
Dog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
s and rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...
s get Alzheimer's disease, but rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
s do not. Elderly rodents typically die of cancer or kidney disease
Nephrology
Nephrology is a branch of internal medicine and pediatrics dealing with the study of the function and diseases of the kidney.-Scope of the specialty:...
, but not of cardiovascular disease. In humans, the relative incidence of cancer increases exponentially with age for most cancers, but levels-off or may even decline by age 60–75 (although colon
Colon (anatomy)
The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...
/rectal
Rectum
The rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...
cancer continues to increase).
Victims of some of the so-called segmental progerias
Accelerated aging disease
A DNA repair-deficiency disorder is a medical condition due to reduced functionality of DNA repair.DNA repair defects are seen in nearly all of the diseases described as accelerated aging disease, in which various tissues, organs or systems of the human body age prematurely...
are vulnerable to different sets of diseases. Victims of Werner's syndrome suffer from osteoporosis, cataracts and cardiovascular disease, but not neurodegeneration
Neurodegeneration
Neurodegeneration is the umbrella term for the progressive loss of structure or function of neurons, including death of neurons. Many neurodegenerative diseases including Parkinson’s, Alzheimer’s, and Huntington’s occur as a result of neurodegenerative processes. As research progresses, many...
or Alzheimer's disease. Victim's of Down syndrome
Down syndrome
Down syndrome, or Down's syndrome, trisomy 21, is a chromosomal condition caused by the presence of all or part of an extra 21st chromosome. It is named after John Langdon Down, the British physician who described the syndrome in 1866. The condition was clinically described earlier in the 19th...
suffer type 2 diabetes and Alzheimer's disease, but not high blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
, osteoporosis or cataracts. Victims of Bloom syndrome
Bloom syndrome
Bloom's syndrome , also known as Bloom–Torre–Machacek syndrome, is a rare autosomal recessive chromosomal disorder characterized by a high frequency of breaks and rearrangements in an affected person's chromosomes. The condition was discovered and first described by dermatologist Dr...
most often die of cancer.
Theories
Aging (senescence) increases vulnerability to age-associated diseases, whereas geneticsGenetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
determines vulnerability or resistance between species and individuals within species. Some age-related changes (like graying hair) are said to be unrelated to an increase in mortality
Mortality rate
Mortality rate is a measure of the number of deaths in a population, scaled to the size of that population, per unit time...
. But some biogerontologists believe that the same underlying changes that cause graying hair also increase mortality in other organ systems and that understanding the incidence of age-associated disease will advance knowledge of the biology
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...
of senescence just as knowledge of childhood diseases advanced knowledge of human development
Human development (biology)
Human development is the process of growing to maturity. In biological terms, this entails growth from a one-celled zygote to an adult human being.- Biological development:...
.
Strategies for Engineered Negligible Senescence (SENS) is a research strategy which aims to identify a few "root causes" for age-related illness and degeneration, as well as develop medical procedures to periodically repair all such damage in the human body, thereby maintaining a youth-like state indefinitely. So far, the SENS programme has identified seven types of aging-related damage, and feasible solutions have been outlined for each. However, critics argue that the SENS agenda is extremely optimistic at best, and that the aging process is too complex and little-understood for SENS to be scientific or implementable in the foreseeable future.
See also
- Accelerated aging diseaseAccelerated aging diseaseA DNA repair-deficiency disorder is a medical condition due to reduced functionality of DNA repair.DNA repair defects are seen in nearly all of the diseases described as accelerated aging disease, in which various tissues, organs or systems of the human body age prematurely...
- Alliance for Aging ResearchAlliance for Aging ResearchThe Alliance for Aging Research is a non-profit organization based in Washington, D.C. that was founded to promote medical research to improve the human experience of aging. The Alliance also advocates and implements health education for consumers and health professionals.The Alliance is governed...
- GerontologyGerontologyGerontology is the study of the social, psychological and biological aspects of aging...
- SenescenceSenescenceSenescence or biological aging is the change in the biology of an organism as it ages after its maturity. Such changes range from those affecting its cells and their function to those affecting the whole organism...