Most articles reporting research on weight loss fail to provide important information on patients, which may confound the results. This is the conclusion of a study published in BMC Medical Research Methodology.
A team from the University of Kansas, led by Cheryl Gibson, has shown that over 90 percent of the studies do not describe diets that make patients work properly or understood, making it difficult for users to interpret the conclusions.
The researchers analyzed 231 papers reporting on the crucial factors for weight loss: restrictive diet, exercise or diet plus exercise only. Also reviewed the research, from 1966-2003, with the participation of obese adults.
The study showed that taking drugs was the most neglected feature in the articles, and that 92 percent of them or mention.
The general health status was a fact ignored by 34 percent of the publications and ethnicity was not indicated in 86 percent. The age had no reference whatsoever in 11 percent of the articles, and analyzing the reference to the size of the sample the researchers concluded that, “without knowing the number of subjects who lost weight, readers are unable to judge the reliability of a treatment. “
Weight loss can be the presenting problem or an incidental finding in a query for other reasons. There are no published guidelines on how to investigate and treat patients with unintentional weight loss, and behaviors ranging from doing nothing (considering the weight loss as a normal part of the aging process) or resulting in many studies for fear there is an underlying cancer. Observational studies have shown that up to 25% of cases there is no identifiable cause, despite much research e. It is unclear to what extent doctors should investigate elderly patients with involuntary weight loss in the absence of obvious medical cause.
We review the available evidence (mainly epidemiological and observational studies) and outlines a structured approach to the investigation and management of elderly patients with unintentional weight loss.
When is that unintentional weight loss is clinically important?
Physiological age produces significant changes in the elderly and contributes to the “anorexia of aging.” These modifications include the reduction in lean body mass, bone mass and basal metabolic rate, decreased sense of taste and smell, and signs of gastric disturbance causing early satiety. However, observational studies of healthy older adults have shown that this weight loss associated with normal aging is 0.1-0.2 kg / yr and older patients maintain weight over a period of time reasonably long, 5-10 years. The major weight loss should not be dismissed by the age-related changes naturally and should be investigated.
Although there is no universally accepted definition of clinically significant weight loss, most observational studies define it as a reduction of ≥ 5% of body weight in 6-12 months. To account for the variability of baseline weight, weight loss is best expressed in percent rather than an absolute value that is a loss of 3.2 kg is less important in a patient of 90 kg in an elderly patient enfeebled already underweight. Mortality at 1-2.5 years to maintain clinically significant weight loss going from 9% to 38%, being particularly at risk frail elderly, elderly with low baseline body weight and elderly patients recently admitted to hospital.
The major weight loss has been shown to be associated with an increased risk within the hospital and disease-related complications, increased disability and dependency, high rates of admission to nursing homes or nursing homes, and worse quality of life. In extreme cachexia (disproportionate loss of skeletal muscle rather than body fat, which leads to loss of skeletal and cardiac muscle, visceral protein loss and changes in physiological functions, including impaired immunity and systemic inflammatory response) contribute to adverse results, through increased rates of infection, poor wound healing, decubitus ulcers, reduced response to medical treatment, and increased risk of mortality.
Weight loss in older people significantly increases the rate of bone loss at the hip and the risk of hip fracture. In a prospective cohort study of 6,785 elderly women, weight loss, both intentional and unintentional, was 5% compared to baseline weight.
What might be the causes of unintentional weight loss in older adults?
Although involuntary weight loss in younger adults often have a medical cause, in older patients the causes are more diverse, with psychiatric and socioeconomic factors play an important role.
Studies conducted in the U.S. and several European countries vary considerably in terms of country, age of patients (most is not limited to the elderly), duration of follow up, and type of patients recruited. However, cancer, non-malignant gastrointestinal diseases and psychiatric problems (including dementia and depression) were constant among the most common causes of unintentional weight loss. Various aids have been developed to allow physicians to consider the multiple possible causes of involuntary weight loss in elderly patients, among which include “9 D weight loss in the elderly” and the mnemonic “MEALS ON WHEELS “
9 D of weight loss in the elderly
Mnemonic “MEALS ON WHEELS”
M: Effects of M edicación,
The authors grouped the possible causes of weight loss in organic (malignant and non-malignant), psychosocial and unknown causes.
Organic causes weight loss include cancer, non-malignant medical conditions and side effects of drugs.
Observational studies published report that psychiatric problems, especially dementia and depression are the main cause of unexplained weight loss in 10-20% of elderly patients. This figure rises to 58% in nursing home residents.
Patients with cognitive impairment who suffer agitation or have a tendency to “wander” and can spend considerable energy. Others may forget that they have to eat or have suspicious paranoid ideas about food. The progression of Alzheimer’s disease is accompanied by loss of the capacity to feed themselves can be developed dysphagia.
Depression can lead to weight loss due to loss of appetite or decreased motivation to buy and prepare food. Often, depression is associated with weight loss in the elderly than in younger adults. In a systematic review of elderly patients (> 65 years) living in the community, depression is associated with increased mortality (relative risk for mortality with depression: 1,73). Another systematic review of 34 community-based studies found that the prevalence of depression varies considerably advanced age (> 55 years), but can be as high as 35% depending on the criteria used to define depression. The highest prevalences have been reported in institutionalized elderly.
In older people, poverty or social isolation can contribute to weight loss due to inadequate nutrition and malnutrition. Physical or cognitive impairment can prevent older people make purchases for themselves, thereby reducing the availability of preferred foods. The inability to cook or feed themselves can contribute to inadequate food intake, since they depend on their families or caregivers who do not attend on a scheduled basis.
In the 16 to 28% of patients participating in prospective observational studies and retrospective, the cause of weight loss is unknown, despite extensive research over periods ranging from 6 months to 3 years. This may be because elderly patients often have multiple comorbidities instead of a serious illness, are under the effect of several drugs and can have psychological or social problems. Each individual factor may not be sufficient to cause significant weight loss, but the cumulative effect of all factors could lead to a clinically significant weight loss.
How Unintentional weight loss in older adults undergoing studies?
The authors present their approach to the study of these patients, based on an extensive literature review. They report that they know of no systematic clinical guidelines or standards for the investigation of this common and complex problem.
The initial patient assessment involves a detailed history, clinical examination and basic research. According to the results, will decide whether or not to continue with the investigation.
They should try to determine the exact extent of weight loss during a specified time. Data on appetite may help to elucidate whether the weight loss is caused by inadequate caloric intake or has occurred despite adequate intake. In patients with cognitive impairment, questioning family members or caregivers can help. The previous and current medical history can identify conditions that could have led to weight loss and drugs that may have contributed through their side effects. Among the side effects are significant anorexia (antibiotics, digoxin, opiates, selective inhibitors of serotonin reuptake, anticonvulsants, antipsychotics, amantadine, metformin, benzodiazepines), nausea and vomiting (antibiotics, bisphosphonates, digoxin, dopamine agonists , levodopa, opioids, selective inhibitors of serotonin reuptake, tricyclic), dry mouth, anticholinergics, diuretics, antihistamines), altered taste and smell (inhibitors of angiotensin converting enzyme, channel blockers calcium, propranolol, spironolactone, iron, antiparkinsonians (levodopa, pergolide, selegiline, opiates, gold, allopurinol), dysphagia (bisphosphonates, antibiotics, levodopa, gold, iron, NSAIDs.
Social history can provide information on the consumption of alcohol (which may contribute to nutritional or vitamin deficiency) and cigarettes (a risk factor for cancer and other organic diseases). To elucidate the social circumstances of the patient, it is important to know: Where do you live? Who buys and prepares the food? Is there any home help or the help of family members?
A story that includes a review of systems may show symptoms that may lead to further investigation. Moreover, standardized tools can be applied to detect patients with cognitive impairment and depression. Some authors recommend a nutritional assessment only when there is no evidence of organic disease. However, the authors of this study believe that all elderly patients presenting Involuntary weight loss should undergo a nutritional assessment by a dietitian. This is because malnutrition is highly prevalent in the elderly and may be present even if it falls an organic cause weight loss. The authors suggest that patients seen in primary care (for general practitioners) where services (and time) to assess cognitive function, mood and nutritional status are not always readily available should be referred to gerontologists .
In patients with involuntary weight loss, complete physical examination should aim to exclude major cardiovascular and respiratory diseases, as well abdominal tumors, organomegaly, enlarged prostate and breast lumps that may indicate cancer. Palpable lymphadenopathy could indicate infection, cancer or blood diseases. Mouth should be examined to exclude any obvious dental problems, poor oral hygiene, dry mouth or injuries that may hinder or make chewing difficult or painful swallowing.
Basic studies for all patients should include complete blood count (complete blood count, urea and electrolytes, liver function tests and thyroid C-reactive protein, glucose, lactate dehydrogenase), chest radiography, urinalysis and occult blood in stool.
Tumor markers are useful diagnostic tests and should not be used as part of the initial evaluation. Its function is to monitor the response to treatment of patients with cancer or detect early tumor recurrence after treatment. Abnormal findings on the initial evaluation should be used to guide future research on the etiology of weight loss. If history, physical examination and basic studies are normal, the published evidence suggests other research discontinue it immediately advised “watchful waiting” for three months, instead of a blind search with additional, more invasive studies or expensive. Because organic disease is only rarely in patients with normal results of physical examination and laboratory tests, it is unlikely that this waiting period has an adverse outcome. Although they have developed three scoring systems to help doctors identify which patients with weight loss are likely to have a physical cause or malignant and not a psychological or social causes, none have been validated in independent populations with loss weight.
Is reassuring basic studies finding normal?
The claim that a negative initial evaluation should reassure the clinician about the lack of serious underlying disease is based on small nonrandomized studies, most of which is not limited to elderly patients (in the UK is defined age advanced as> 70 years). However, most authors agree that it is very unlikely that elderly patients with involuntary weight loss clinically relevant and normal basic studies have a physical illness (especially malignant), and in this case, it is preferable to have a expectantly.
Currently no evidence that computed tomography (CT) as blind screening study is of great help in the investigation of these patients. The disadvantages of CT blind are high costs (low performance) and the probability of finding “incidentalomas.” Several studies have used abdominal ultrasound as part of their initial evaluation, but did not comment on its usefulness in this paper, except to note that 27% of patients with underlying cancer in the examination showed hepatomegaly and a similar percentage had a palpable tumor. Anyway, the abnormal findings on examination (or in liver function tests) require further investigation. Gastrointestinal disorders (malignant and non-malignant) account for approximately one third of all cases of unexplained weight loss in studies of adults of all ages, so that some authors advocate the use of upper endoscopy as first-line study . However, as endoscopy is an invasive procedure not without risk (particularly for elderly patients), the authors believe that should be reserved for patients in whom it is indicated, both by history, physical examination and by the basic studies (eg., history of gastrointestinal bleeding or iron deficiency anemia).
In a study of patients with a normal baseline assessment subject to further investigation by CT and endoscopy, it was only one additional diagnosis (one patient diagnosed with lactose intolerance).
Management of unexplained weight loss in the elderly
The fundamental principle of management is the identification and treatment of underlying causes. The optimal management often requires a multidisciplinary evaluation (doctors, dentists, dietitians, speech therapists, physiotherapists, occupational therapists, social services). The authors suggest reviewing drugs in order to eliminate side effects that may contribute to weight loss.
If the cause of weight loss is mental, such as depression, it is recommended evaluation by a psychogeriatrician or psychologist. In such cases, consider antidepressant treatment because depression is a potentially reversible cause weight loss. If the baseline is negative, recommend re-evaluate the patient at 3 months, to establish whether they be other symptoms or signs and weight control. In the meantime, because there is no evidence to support any drug treatment, you can use a variety of non-pharmacological interventions.
Non-pharmacological interventions for unexplained weight loss in elderly
– Optimize food consumption.
Oral nutritional supplements if recommended by the dietitian
Multivitamin tablets daily
Ensure proper oral health
Tips for non-specialists
• General practitioners and hospital doctors specialists must perform the initial history, examination, and basic analysis.
• Refer any abnormalities that suggest a possible organic cause weight loss to the relevant specialty.
• If there is no obvious cause, you can do a check at 3 months of watchful waiting or patient referral to secondary care (geriatrics), where you can make a multidisciplinary evaluation.
• If the initial assessment and watchful waiting are carried out in primary care, s must repeat history, examination, and investigations at the end of this period. If no cause is identified and the patient continues to lose weight, referred to secondary care.