Extending life: disease pattern shift

The ageing of the world population points up many problems and new aspects. At economical level, extending life is connected with evident social and economic problems. Life after retirement can be extended by many decades and while some necessities more connected with the life of younger adults decrease in the older age groups, others rapidly increase. Coping with chronic-degenerative diseases is one of the major issues, which continuously increases with further ageing. Comorbidity is quite common in the later stages of human life. Residual functional capacities are reduced and extended medical support is necessary. Greater understanding of what the new needs of an aged population are is more and more important especially in the Western countries. In fact, extending life is connected to a disease pattern shift. This pattern is different in different aged groups of people, i.e. in people over 65 it is not the same as in people over 90. Greater understanding of what the health conditions in the extreme ages of life are can give an index pattern of the health problems which will affect a large proportion of a future aged population.

1. Epidemiology of ageing

The northeastern Italian province of Trieste has one of the oldest populations in the world and this gives us the opportunity to take a look at the probable future of Western countries in about 30 years.
The recent population ageing history, as estimated by the Trieste data, is something that started in an evident way only in the past century. Looking at the survival shift by age groups, it is possible to note that the first ageing process of the Trieste area population begins with a rapid decrease in perinatal deaths in the 1930s, due to better hygienic conditions. In the 1940s and 1950s a rapid increasing of survival is noted in children and young adults. This fact is probably connected with the development of anti-infective agents. But a real increased survival of people over 65 is evident only in the 1960s and 1970s, a period in which better life conditions affected the entire Italian population3. During the 20-year period from 1985 to the present time, the proportion of the male population over 65 went from 15% to 21%, while the over-65 females fraction moved from 25% to 31% and that of those over 75 is now 17% of the female population and is expected to increase in the next 20 years (Fig. 1 and 2).

Fig. 1: Trieste male population 1985-2005 and expected up to 2025
Source: Servizio Autonomo della Statistica – Regione Friuli Venezia Giulia

Fig. 2: Trieste female population 1985-2005 and expected up to 2025
Source: Servizio Autonomo della Statistica – Regione Friuli Venezia Giulia

This population ageing shows a disease pattern shift. An easy method to monitor these changes consists in analyzing the causes of death in different age groups for different periods of time. If the rank order of the causes of death is taken into account in people who die before the age of 65, those between 65 and 95 years and those in the extreme ages of life (over 95), it is possible to understand how different the disease pattern is in the very old population. If this fact is socially not too important in a young population, in which the fraction of people who die in the extreme ages of life is not significant, it can be relevant to the population ageing process. Cardiovascular diseases and tumors are the first two causes of death in both those under and those over 65 years (Table 1). In the extreme ages of life, cardiovascular diseases are still in second place in the rank order, but tumors are only in fifth place. Pneumonia can be found in first place among causes of death in people over 95 years of age. This fact is not too surprising if we think that ageing is associated with a progressive decline in the functional reserve of many organs, and this functional restriction can compromise the tolerance of stress. Functional capacity is critically reduced in the so-called ‘frail elderly’, who use their functional reserve for basic living and present negligible tolerance for stress4. In this way an infection of the respiratory tree is the final cause of death in a compromised organism.
In these old persons, accidents are surprisingly reported in third place in the rank order of causes of death. These are peculiar accidents, characteristic of people over 95 years of age, such as pathological falls involving hip fracture, immobilization to bed connected with pneumonia due to the immobilization itself and consequent death.

Tab. 1 Rank order of causes of death by age
It is possible to identify two distinct pathological patterns in the old and in the oldest old. Among persons aged 65-90, chronic diseases are more prominent, whereas among the oldest old the most prevalent lesion is diffuse organ atrophy. The selective sparing of cerebral and coronary circulation among centenarians suggests that preservation of these circulatory beds may represent a precondition to advanced ageing5.

Giorgio Stanta: University of Trieste and International Centre for Genetic Engineering and Biotechnology, Trieste (
Davide Brunetti: Registro dei tumori (cancer registry) della Regione Friuli Venezia Giulia.
3 Original data from the Trieste Cancer Registry.
4 L. Balducci, G. Stanta, “Cancer in the frail patient: a coming epidemic”, Hematol. Oncol. Clinics North Am. 14:235-250 (2000).
5 G. Stanta, “Morbid anatomy of aging”. In L. Balducci, G.W. Lyman, W.B. Erlsher, Comprehensive Geriatric Oncology, Harwood Academic Publisher, Amsterdam, 229-235 (1998).

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