The Causes Of Unintentional Weight Loss

 

I. Introduction

 

Patients who are overweight or obese may intentionally lose weight to improve their health. Unintentional weight loss often indicates a serious medical or psychiatric illness.

II. Definitions 

Unintentional weight loss: is referred to as involuntary or unintended weight loss. It can result from the consequences of treatment ( diuretic therapy in patients with heart failure) or result from a known illness. Clinically, weight loss is generally defined as the loss of more than 5 percent of usual body weight over 6 to 12 months.
Cachexia: is defined as weight loss from loss of muscle mass(with or without fat loss).
 Sarcopenia: is characterized by loss of muscle mass, strength, and performance.

III. Epidemiology 

It is estimated that 15 to 20 percent of adults ≥ 65 years have this problem if follower over 5 to 10 years.
The independent predictors of unintentional weight loss were age, smoking, and poor self-reported health.

IV. Causes

Major causes of unintentional weight loss :

–  Malignancy ( eg, gastrointestinal, lung, prostate cancer, renal, and lymphoma ) – Nonmalignant (peptic ulcer disease, celiac disease, inflammatory bowel disease ) – Psychiatric problems ( depression, eating disorders, a food-related delusional manifestation of other psychiatric disorder) -Endocrinopathies ( hyperthyroidism, diabetes, adrenal insufficiency) -infectious disease ( HIV, viral hepatitis, tuberculosis, chronic fungal or bacterial disease ) – Advanced chronic disease ( heart failure, pulmonary cachexia, renal failure ) – Neurologic disease ( stroke, dementia, Parkinson disease, amyotrophic lateral sclerosis ) – Medications – Rheumatologic disease ( severe rheumatoid arthritis, giant cell vasculitis ) – Chronic vigorous exercise

Medication and substances associated with weight loss

– Alcohol – Cocaine – Drug withdrawal syndromes – Tobacco – Adverse effect of anticonvulsant drugs, diabetes, or thyroid medication – Amphetamine – Nonprescription drugs: caffeine, chromium, herbal diuretics, nicotine, pyruvate…

 Causes of weight loss in older adults :

–  Medications ( eg,digoxin, theophylline,SSRIs,antibiotics )
– Emotional ( stress, anxiety )
-Alcoholism, older adult abuse
– Swallowing problems
– Oral factors: tooth loss, xerostomia
– Nosocomial infections ( eg, tuberculosis, pneumonia )
– Dementia-related factors
– Hyperthyroidism, hypercalcemia, hypoadrenalism
– Enteral problems ( esophageal stricture, gluten enteropathy)
– Low salt, low cholesterol
– Social isolation, stones ( chronic cholecystitis)

 Maginancy: the diseases that particularly cause weight loss are gastrointestinal, pancreatic, lung lymphoma, renal and prostate cancers). Anorexia and weight loss are present in 15 to 40 percent of all cancer patients at diagnosis but it appears higher with lung cancer (60 percent) or upper gastrointestinal cancer (80 percent)
 Nonmalignant gastrointestinal diseases: Gastrointestinal etiologies can cause weight loss such as peptic ulcer disease, diseases that cause malabsorption ( eg, celiac disease ), and inflammatory bowel disease.
 Psychiatric disorders:
– Depression: Depression can cause weight loss mentally and emotionally such as social isolation, physical disabilities, dementia, dysphagia, medication /drug use, and multiple chronic diseases.
-Eating disorder: it is the result of decreased food intake, excessive exercise, self-induced vomiting, drug medication use, or bulimia/anorexia nervosa.
– Other: Hyperactivity and preoccupations may interfere with normal eating patterns.
 Endocrinopathies :
– Hyperthyroidism: most patients have hyperphagia, in older patients, hyperthyroidism often causes anorexia with accelerated weight loss.
– Diabetes mellitus: it increases appetite, particularly with new-onset type 1 diabetes mellitus.Some patients with diabetes type 2 can present with diabetic neuropathic cachexia, unusual and poorly understood syndrome characterized by profound weight loss (60 percent of body weight ), and often severe neuropathic pain of the anterior thighs.
– Adrenal insufficiency: chronic primary adrenal insufficiency often presents with significant weight loss. It can be associated with other symptoms such as dehydration, anorexia, lassitude, fatigue, and weakness.
– Pheochromocytoma: theoretically, it causes ( hyperadrenergic state) weight loss with increased appetite, but only 5 percent of patients.
 Infectious disease  :
– HIV: weight loss in patients with HIV infection is usually episodic, secondary infection, or gastrointestinal disease.
– Tuberculosis: many patients with active tuberculosis experience weight loss.
– Hepatitis C: its virus can cause weight loss, in addition to nausea, anorexia, and weakness.
– Helminthic infections: can cause nutritional deficiencies.

V.  Diagnostic testing 

• Complete blood count with differential
• Electrolytes
• Glucose and hemoglobin A1c
• Calcium
• hepatic function
• Thyroid-stimulating hormone
• Stool hemoccult
• Erythrocyte sedimentation rate ( ESR ) Or  C reactive protein ( CRP )
• Human immunodeficiency virus ( HIV )
• Hepatitis C
• Chest radiograph ( for tuberculosis or malignancy )
• Age-appropriate cancer screening