The dependence often depends on the life course

At what age begins the old age The World Health Organization, is 65. Organizations in charge of assistance to the elderly, it is 75 years. In retirement homes, using another filter: 85 years, average age of persons living in institutions. Biologists still blur cards citing a formula variable geometry: "it depends on both genes and lifestyle". In fact, this diversity reflects a clearly known of all: we are not equal to the time passing. By and large, the experts estimate that 30 of seniors health disorders are genetic nature (inheritance or random mutation), 40 are of environmental origin or arise out of the way of life (including food), the remaining from various causes (accidents).

Geriatricians ranked seniors in three groups: the "independent", majority and in good health, "partially dependents" with several diseases (Comorbidities) that restrict their freedom of action, and "fragile", which accumulate co-morbidities associated with acute ailments and sometimes significant psychological distress. This weekend is held at Unesco in Paris, a scientific forum devoted to research in Gerontology. Some specialists will try to answer a question in the air of time: how to ease the outrages of time

Many earthlings have already found the recipe. According to data of the United Nations (World Population Prospects), in developed countries, the proportion of the centenarians is currently between 0.02 and 0.05 of the population (approximately 20,000 in France). In 2025, Japan, countries where one lives longer, should count more than 200,000 trees. If the projections are met, about 0.3 of the French population will pass the Cape of 100 candles in 2050.

Biology of aging

The biology of aging was one of the lights of the last Congress of geriatric medicine held in Paris (IAGG). Two theories have currently the wind: the oxidative hypothesis and endocrine theory. The first is built on a mechanic analogy of the body, equated with a machine inexorably deteriorating over time. This biochemical wear is the result of an accumulation of atomic oxygen in the cells causing irreversible damage. The second runway, most recent, involves one of the stars of the human metabolism: insulin. According to proponents of this theory, peptide hormones regulate the entry stage of a guest no one wants to: senescence.

Studies of centenarians confirm that these lucky have a double advantage: a low level of IGF ("Insulin Growth Factor") and a very powerful immune system that protects them from infections. This trail would also explain why dietary restriction increases the longevity in mice. Last month, the Nobel Prize for medicine 2009 gave its letters of nobility to the molecular geriatrics. The three American victors found telomerase, the enzyme that protects the cells of a loss of information in each division. But many questions remain unanswered. Why the bat lives between ten and twenty years, while his cousin of the cities and fields does not exceed three years

Home maintenance

One thing is certain, the next year, the France will be more than 10 million more 65 years. By 2020, the country would have to host at least 2 million patients in 85 years of age. In this context, medical, public health officials and the political world pose only one question: how to take care of these populations "By keeping them at home as long as possible and by bringing medical services where they live," slice the Canadian Professor Réjean Hébert, université Sherbrooke in Quebec. The geriatrician regrets the resources-centrism of some countries (starting with the France), which ship the elderly in the hospital at the slightest alert. "You get out of this logic which uproots people and gives them the impression that they are burdens for society." Family caregivers are partners of medical services. "The future is in the" home care "", insists the Quebec specialist. John Morley, gerontologist at the University of St Louis, in the United States, is just as radical with another scourge: the unnecessary medicalization of the elderly. "Exercise is 6 times more effective than drugs," summarizes this expert. "Some depressive inpatients are permanently between demi-sommeil and demi-veille because of Neuroleptics," adds the psychiatrist, Dr. Patrick Lemoine in Lyon.

The fragile

But, unlike the aphorism expressed in its time by General de Gaulle, old age is not a shipwreck. According to official data, only 10 of those over 65 are dependent and approximately 20 are suffering from geriatric syndrome that intrigue researchers: fragility. This concept born in the United States ("frailty") is now the subject of numerous studies. 70 Years old, 20 of the subjects are fragile and 85 years old, this weakness concerns the majority of them. These people suffer from polypathologies, fall more frequently and have a surrisque to develop an Alzheimer's disease.

This fragility is often accompanied by loss of muscle wasting (sarcopenia) and a cognitive decline resulting in a high vulnerability. These weakened patients are also victims of abuse. Estimated 6 to 8 of people over 65 years suffering ill-treatment, often inadvertently or lack of attention. Fortunately, the concept of welfare based on the respect of the person made his way. "The identification and monitoring of these fragile patients are a stake in society", reported Professor Gabor Abellan Van Kan de Toulouse gérontopôle. A team of this centre has the speed of the walk which will detect persons at risk. "The dependence often depends on the life course." "Everyone is responsible for its own aging," concludes the geriatrician.