Chapter 79: Weight loss

In family practice complaints of loss of weight are more frequent than complaints about being too thin. Of great significance is the problem of recent loss of weight. A very analytical history is required to determine the patient’s perception of weight loss. The equivalent problem in children is failure to gain weight or thrive.

Weight loss is an important symptom because it usually implies a serious underlying disorder, either organic or functional. It may or may not be associated with anorexia and thus diminished food intake.

A summary of the diagnostic strategy model is presented in TABLE 79.1.

Probability diagnosis

Excluding planned dietary restriction, psychological factors are the most common cause, particularly recent stress and anxiety.¹ Elderly people with adverse psychological factors, neglect and possibly drug effects can present with wasting.

Serious disorders not to be missed

Many of the problems causing weight loss are very serious, especially malignant disease.

Malignant disease

Weight loss may be a manifestation of any malignancy. With cancer of the stomach, pancreas and caecum, malignant lymphomas and myeloma, weight loss may be the only symptom. Occult malignancy must be regarded as the most common cause of weight loss in the absence of major symptoms and signs. The mechanisms may be multiple, with anorexia and increased metabolism being important factors.

Chronic infections

These are now less common but tuberculosis must be considered, especially in people from less developed countries. Some cases of infective endocarditis may progress only very slowly with general debility, weight loss and fever as major features.²

Other infections to consider are brucellosis, and protozoal and systemic fungal infection. Infection with HIV virus must be considered, especially in high-risk groups.

Pitfalls

Drug dependency, including alcohol and narcotic drugs, must be considered, especially when the problem may result in inappropriate nutrition. Apart from malignant disease there is a whole variety of gastrointestinal disorders that require consideration—these include malabsorption states, gastric ulceration, and intestinal infestations, especially in people returning from a significant stay in tropical and under-developed countries.

Addison disease (CHAPTER 23) can be very difficult to diagnose. Symptoms include excessive fatigue, anorexia, nausea and postural dizziness. Hyperpigmentation is a late sign.

Seven masquerades checklist

Depression and the endocrine disorders, diabetes mellitus and hyperthyroidism, are important causes.

Diabetes

The diabetic who presents with weight loss will be young and insulin-dependent. The initial presentation may be ketoacidosis. The triad of symptoms is thirst + polyuria + weight loss.

Hyperthyroidism

This is usually associated with weight loss although in some, such as an elderly male, it may not be obvious. An important clue will be weight loss in the presence of an excellent appetite and this helps to distinguish it from a psychoneurotic disturbance.

Depression

Weight loss is a common feature of depression and is usually proportional to the severity of the disease. In the early stages of depression, weight gain may be present but when the classic loss of the four basic drives (appetite, energy, sleep and sex) becomes manifest, weight loss is a feature.

Drugs

Any prescribed drugs causing anorexia can cause weight loss. Important drugs include digoxin, narcotics, cytotoxics, NSAIDs, some antihypertensives and theophylline. Be mindful of inappropriate use of thyroxine and laxatives.

Psychogenic considerations

Weight loss is a feature of anxiety as well as depression. Some patients with psychotic disturbances, including schizophrenia and mania, may present with weight loss.

Anorexia nervosa is quite common and is almost entirely confined to females between the ages of 12 and 20 years. The main differential diagnosis is hypopituitarism, although anorexia nervosa can cause endocrine disturbances through the hypothalamic pituitary axis.

History

It is important to document the weight loss carefully and evaluate the patient’s recordings. The same set of scales should be used. It is also important to determine the food intake. However, in the absence of an independent witness such as a spouse or parent, this can be difficult. Food intake may be diminished with psychogenic disorders and cancer but increased or steady with endocrine disorders, such as diabetes and hyperthyroidism, and with steatorrhoea. FIGURE 79.1 shows the possible causes of weight loss.

General questions

• Exactly how much weight have you lost and over how long?

• Have you changed your diet in any way?

• Has your appetite changed? Do you feel like eating?

• Have your clothes become looser?

• What is your general health like?

• How do you feel in yourself?

• Do you feel uptight (tense), worried or anxious?

• Do you get very irritable or tremulous?

• Do you feel depressed?

• Do you ever force yourself to vomit?

• Are you thirsty?

• Do you pass a lot of urine?

• Do you have excessive sweating?

• Do you experience a lot of night sweats?

• What are your motions like?

• Are they difficult to flush down the toilet?

• Do you have a cough or bring up sputum?

• Do you get short of breath?

• Do you have any abdominal pain?

• Are your periods normal (for females)?

• What drugs are you taking?

• How many cigarettes do you smoke?

Examination

A careful general examination is essential with special attention to:

• vital parameters, e.g. BMI, temperature, BP

• the thyroid and signs of hyperthyroidism

• the abdomen (check liver, any masses and tenderness)

• rectal examination (test stool for occult blood)

• reflexes

• look for acid dental erosion on surface of upper teeth (bulimia)

Investigations

Basic investigations include:

• haemoglobin, red cell indices and film

• white cell count

• ESR/CRP

• thyroid function test

• random blood sugar

• urea and electrolytes

• chest X-ray

• urine analysis

• faecal occult blood

Others to consider:

• upper GIT (endoscopy or barium meal)

• HIV serology

• ultrasound of abdomen (or CT if suspected abnormality not found)

• colonoscopy

• LFTs

• tumour markers, e.g. CA-125, CEA

Weight loss in children can be considered as:

1. failure to thrive (FTT): the child up to 2 years below 3rd percentile (refer to CHAPTER 91)

2. weight loss in a child after normal development

Loss of weight in the older child

Acute or chronic infections are the most common causes of weight loss in children beyond infancy.³ In acute infections the weight loss is transient, and once the infection clears the child generally regains the lost weight. In chronic infections signs may be more difficult to detect (e.g. urinary tract infection, pulmonary infection, osteomyelitis, chronic hepatitis). In common with the younger child who fails to thrive, the older child may be suffering from malabsorption syndrome, chronic infection of the urinary tract or a rare chromosomal or metabolic disorder.⁴ Tuberculosis, diabetes and malignant disease may present as weight loss and it is necessary to exclude organic disease before considering the more common emotional disorders.

Concerns about body image and dieting are very common among young women in modern society. Among these dieters 5–10% become abnormally preoccupied with dieting and slimness and progress to the eating disorders of anorexia nervosa and bulimia. Sufferers often have extremely low self-esteem and feel ineffective. They tend to be perfectionists with obsessive–compulsive traits. A history of childhood sexual abuse may be relevant. Media images alone do not cause eating disorders but have a role—genetic vulnerability, temperament, psychological and environmental factors also mediate these illnesses: ‘Genes load the gun—the environment pulls the trigger’.

The DSM-5 criteria for diagnosing these disorders, which have serious physical and psychological consequences, are presented in TABLE 79.2. The differential diagnosis of anorexia nervosa includes most of the problems listed in TABLE 79.1.

The history⁵

These patients are often secretive, tend to minimise their symptoms and may be in denial of their problem. Dr Suzy Redston and psychiatric colleagues encourage GPs to engage these patients and keep in close contact with them, referring them as necessary. The validated screening tool SCOFF is recommended.

Anorexia nervosa

See FIGURE 79.2.

Anorexia nervosa is a syndrome characterised by the obsessive pursuit of thinness through dieting with extreme weight loss and disturbance of body image.⁷ The main symptoms are anorexia and weight loss. The mortality rate may be as high as 18%. It has the highest mortality and suicide rate of any psychiatric disorder.⁶

Typical features

• Adolescent and young adult females

• Up to 1% incidence among schoolgirls aged 16⁸

• Bimodal age of onset: 13–14 and 17–18 years⁶

• Unknown cause

• Poor insight

• Severe emaciation

• Amenorrhoea

• Loss of body fat

• Sallow, dry and scaly skin, hair loss

• Increased lanugo body hair

• BMI <17.5

• Continuing behaviour directed at weight loss

Bulimia nervosa

Bulimia is episodic secretive binge eating followed by self-induced vomiting, fasting or the use of laxatives or diuretics. This binge–purge syndrome is also referred to as bulimarexia. It is more difficult to detect than anorexia nervosa but has a higher incidence. There are two types—the purging type and the non-purging type where fasting or excessive exercise are the compensatory behaviours. The purging type is the most life-threatening behaviour because of the danger of hypokalaemia.

Typical features⁶

• Young females (F:M ratio 10:1)

• Begins at later age, usually 17–25 years

• Associated psychoneurotic disorders

• Family history

• Fluctuations in body weight without extreme loss or gain

• Menstrual history usually normal but periods may be irregular—amenorrhoea rare

• Physical complications of frequent vomiting (e.g. dental decay, effects of hypokalaemia)

• Recurrent laxative, stimulant or enema abuse

• Preoccupation with food

• Exaggerated weight/body shape concern

• Impulse control disorders (e.g. gambling, substance abuse)

• Depressed mood with guilt after a binge

Laboratory evaluation should include electrolytes, FBE, iron studies, TFTs, kidney function tests, coeliac disease screening and LFTs, ESR.

Note: The other main eating disorder is ‘binge eating disorder’, which is defined as recurrent episodes of binge eating in the absence of regular use of inappropriate compensatory behaviours characteristic of bulimia nervosa. However, most of these patients are obese.

Early detection and intervention are essential to reduce the risk of chronicity. Treatment can be conducted on an outpatient basis but if there are marked trends, such as severe weight loss, a family crisis, severe depression and a suicide risk, the patient requires hospital admission. The burden on caregivers of people with eating disorders is high. There are often problematic family interrelationships that require exploration.

Important goals are:

• establish a good and caring relationship with the patient

• resolve underlying psychological difficulties

• restore weight to a level between ideal and the patient’s concept of optimal weight

• provide a balanced diet of at least 3000 calories per day (anorexia nervosa)

Structured behavioural therapy, intensive psychotherapy and family therapy may be tried but supportive care by physicians and allied health staff appears to be the most important feature of therapy.⁹ Psychotherapy may be arranged by referral to a psychologist or psychiatrist. The patient may need admission to hospital, especially if dehydration and hypokalaemia (from purging) and also suicide are concerns. Rapid weight loss, vomiting, especially with poor insight, are also ‘red flags’ for hospital admission. Antidepressants, especially of the SSRI group, may be helpful for selected patients with a comorbid depressive illness. Fluoxetine is the preferred agent for bulimia. It is important to provide ongoing support for both patient and family.

General weight loss is a relatively common physiological feature of many elderly people. However, abnormal weight loss is commonly encountered in the socially disadvantaged elderly, especially those who live alone and lack drive and interest in adequate food preparation. Other factors include relative poverty and poor dentition, including ill-fitting and painful false teeth. An important cause that should always be considered is malignant disease. Consider depression, dementia and drug interactions as potential causes of weight loss. Depression is the most common reversible cause of weight loss in elderly people, occurring in up to 30% of all medical outpatients presenting with undernutrition.¹⁰ Weight loss of more than 5% body weight in 6 months is significant and suggests undernutrition.¹⁰

Congestive cardiac failure, especially secondary to ischaemic heart disease, is a common cause of weight loss. This is due to visceral congestion.

The following conditions may lead to weight loss:

• coeliac disease

• poor oral hygiene

• chronic vomiting or diarrhoea (e.g. pyloric stenosis)

• gastric ulcer

• cancer of the stomach, oesophagus, large bowel

• problem alcohol drinking

• partial or total gastrectomy

• other GIT surgery

• inflammatory bowel disease (e.g. Crohn disease, ulcerative colitis)

• steatorrhoea

• lymphoma of the gut

• parasitic infestation

• cirrhosis of the liver

The mechanisms of weight loss include anorexia, malabsorption, obstruction with vomiting and inflammation.

• Any unexplained weight loss, especially if an endocrine cause or malignancy is suspected

• Weight loss related to a serious psychological illness

• A serious eating disorder

Hand-out sheets from Murtagh’s Patient Education 7th edition:

• Eating disorders