The loss of body weight and development of cachexia are common signs
associated with several diseases.
Net muscle protein catabolism is the result of a neuronal and endocrinological
response, the main hormone involved in this process being cortisol .
Besides this, a number of pathological situations (e.g. cancer, infection,
trauma, surgery) lead to activation of the immunological system which, in
particular, involves the release of mediators.
The nutritional status of older adults living at home is poor. On average,
persons over the age of 70 years consume one third less calories compared to
younger persons. In dietary intake studies, 10% of older men and 20% of
older women have intakes of protein below the United States Recommended
Daily Allowance (RDA), and one third consume fewer calories than the RDA.
Fifty percent of older adults have intakes of minerals and vitamins of less
than the RDA and 10–30% have subnormal levels of minerals and vitamins.
Sixteen to 18 percent of community-dwelling elderly persons consume less
than 1,000 kcal daily.
Enteral and parenteral nutritional support was developed to provide sustenance
to patients who ordinarily were unable to meet their nutritional
needs either because of an inability to eat or an inability to digest and absorb
food. Undernutrition has been associated with increased infection risk, poor
wound healing, increased postoperative complications, prolonged hospital
stay, respiratory, cardiac, and hepatic dysfunction, as well as increased
mortality. A clinical decision must be made about the provision of both nutrition
as well as hydration fluids for patients otherwise able to eat in the usual
It is now well recognized that a physiological anorexia of aging occurs that
is associated with gradual weight loss in older persons [1, 2]. A number of epidemiological
studies have shown that weight loss in older persons leads to
death (fig. 1) [3–6]. In addition, weight loss has been shown to be associated
with hip fracture . When an older person develops a disease, the disease
interacts with the propensity for anorexia, leading to severe weight loss and
The relationships between behavior and immune responses have been studied
for a long time. It is well recognized that persons under psychological
stresses, such as depression, marital problems, bereavement or alcoholism,
are more susceptible to infections. Nevertheless only a few studies were conducted
before the 1970s. Since then, progress in knowledge of the immune
system, improvement in questionnaires assessing the characterization and
quantification of different moods, and very recently the link between a psychological
approach and brain neuron cell functions (neuroimmunology) have
pushed to extend research in this new field, called psychoneuroimmunology.
The current literature concurs that the prevalence of malnutrition, and
stunting among children in particular, is a reasonably accurate reflection on
the prevailing socioeconomic status in a given environment. In this regard,
malnutrition is known to adversely impact on mental development, scholastic
achievement, productivity, child and woman morbidity and mortality as well
as the risk for infection. As such, it is hardly surprising that nutritional status
is one of the key Millennium Development Goals .
The indictment by Nightingale has persisted for over a century, aided by
the inadequate attention paid by physicians to nutritional status. Dietary
restrictions, improper dietary prescriptions, and keeping patients non per ora
for considerable lengths of time have contributed to nutritional problems in
the healthcare system [1, 2].
Age-related changes in nutritional status include weight loss as well as
weight gain. In the EURONUT-Seneca study on elderly subjects (age 75–80
years) who were investigated in different parts of Europe, the prevalence of
a 5-year weight gain of 5 kg was highly variable and reached a highest prevalence
of 9 and 17% in females and males, respectively .
Enteral nutrition is the act of receiving nutrients through the gut, either
orally or through an enteral access device. It has long been used in the hospital
and nursing home setting. The number of patients receiving home
enteral nutrition (HEN) in the United States has progressively increased, yet
the absolute numbers remain difficult to determine.
Enteral nutrition is the preferred way of feeding patients who cannot maintain
sufficient oral intake but have a functioning gastrointestinal tract. Enteral
feeding has been used for several decades for hospitalized patients, but for
the last 20 years home enteral nutrition (HEN) has been expanding in home
care in many industrialized countries throughout the world. Despite the fact
that the number of patients on HEN is now much higher than patients on
home parenteral nutrition (HPN), scientific interest and medical concern
were initially much higher for HPN [1–3].
Malnutrition has been defined as a deficiency of energy, protein or other
types of nutrients, which produces alterations in body function, is associated
with worse outcome from illness and is reversible by nutritional support .
Global malnutrition generally results from simple starvation or stress starvation
and has to be distinguished from deficiency of one micronutrient or
vitamin . Starvation results from a pure deficit of all macro- and micronutrients
and occurs for instance in hunger strikers, persons with anorexia,
or patients with intestinal diseases leading to malabsorption.
Artificial nutrition is a supportive medical therapy aiming at achieving predefined
objectives, which should be adjusted for changing clinical situations
. The goals of nutritional support must be clearly predefined within a global
therapeutic plan. First of all it is necessary to determine whether nutritional
support is a medical treatment or basic human care. If it is considered a medical
treatment, the goal of this treatment is to improve some parameters
related to disease progression and/or malnutrition (considered as a disease).
A report of the UK Royal College of Physicians entitled ‘Nutrition and
Patients: A Doctor’s Responsibility’, published in July 2002 , highlighted
again the importance of nutritional care for vulnerable groups such as undernourished
elderly people, particularly those who are hospitalized or institutionalized.
Older people have longer periods of illness and longer hospital
stays , and data show that up to 55% of elderly hospitalized patients are
undernourished on admission [3, 4].
Before attempting to analyze the potential efficacy of the two different
routes of administering nutrients to cancer patients, enteral nutrition (EN)
versus total parenteral nutrition (TPN), it should be appreciated that patients
who are usually fed via a vein are not the same as those who receive EN.
If fact, nowadays, the option for TPN only emerges if a patient is not suitable
for EN because his/her gut is not working.
The intestinal mucosa is the biggest surface of the body, which is
constantly in close contact with a high number of different bacteria and food
antigens. Furthermore it has to absorb nutrients and in this process to differentiate
between those molecules which have to pass the mucosal barrier and
be taken up as nutrition and those molecules and organisms which have to be
kept out to maintain the sterile condition in the organism. This is a complex
function which is regulated by different layers of the intestinal barrier as well
as specific transport systems.
In recent years there has been a growing interest in understanding the
influence of intestinal microbiota on the physiology of the body. Moreover,
with the available genomic studies, it is now possible to analyze how components
of the intestinal microbiota modulate features of human postnatal
development and physiology . An area of major interest has been the relationship
between the gut bacteria and the immune system, both at the intestinal
and systemic level .
Health has multiple dimensions. In a broad sense, health can be considered
in terms of physical, mental and social well-being, but this may be difficult to
measure, particularly in whole populations. The earliest population indices of
health were based on readily available and unambiguous indicators, such as
mortality; and these were applied to particular age groups, such as the first
year of life (infant mortality).
I think we have done very well and the speakers have been highly committed.
Some of you got very tough subjects assigned to you to speak on, and
we deeply appreciate your expertise and cooperation.