Understanding Unexplained Weight Loss: A Comprehensive Approach
This episode explores unintentional weight loss, its potential causes, and the diagnostic approach to uncover underlying medical or psychiatric conditions. It emphasizes the importance of targeted history, physical exams, and basic tests in patient evaluation. Transcript [00:00] Hello and welcome back once again to Surgery 101. The podcast series brought to you with the help of the Department of Surgery at the University of Alberta. I’m Dr Jonathan White. Coming to you live from the Royal Ag Center [00:20] Hospital in Edmonton. This is the latest episode in our series of episodes on general surgery. This week we’ll be hearing again from Dr. Leah Gramlich, my gastroenterology colleague here from New Orleans, Alexandria, about the topic of unexplained weight loss. And this is one of those topics that I’m afraid to say we don’t teach very well in medical school, because it’s a fairly general [00:40] presentation and it’s not necessarily connected with any one particular system. So Leah will be exploring the topic for us. She’ll be defining what is significant in terms of weight loss. She’ll be explaining what happens when you lose weight and what are some of the possible causes and she’ll be describing an approach to trying to figure out what’s happening in a patient who’s had a significant [01:00] significant amount of unintentional weight loss. So let’s get ready to investigate the case of the missing weight here on Surgery 101. [01:20] Welcome. My name is Leah Gramlich. I’m a gastroenterologist and a physician nutrition specialist and on this surgery podcast today I’m going to talk to you about approach to the patient with unexplained weight loss. There are four learning objectives in this talk. [01:40] The first is to describe significant weight loss, to discuss the impact of unintentional weight loss, to talk about the causes of unintentional weight loss, and to describe an approach to the patient with unexplained weight loss. [02:00] Weight loss is a very common problem seen by generalists whether they’re in family medicine, surgery, or in internal medicine. Patients who are overweight or obese may intentionally lose weight to improve their health. However, progressive weight loss [02:20] without trying or involuntary weight loss often indicates a serious medical or psychiatric illness. We’re going to discuss an approach to unintentional weight loss in the adult patient. Let’s start with a definition. Unintentional weight loss is also referred to as involuntary or unintended weight loss. I refer to it as [02:40] non-volitional weight loss. This term excludes weight loss as an expected consequence of treatment, for instance weight loss from diuretic therapy with heart failure or weight loss following bariatric surgery or as a result of known illness. Clinically important weight loss is often defined as a weight loss of more than 5% of usual weight over [03:00] 6 to 12 months. Involuntary weight loss of 5% to 10% of weight is potentially significant, and involuntary weight loss of over 10% of usual weight is always of consequence. The strongest independent predictors of unintentional weight loss include age, smoking, and poor self-reaction. [03:20] health. And the prevalence of unintended weight loss increases with age and is also higher amongst those with obesity, a group that’s particularly difficult to nail down the diagnosis in. Although there are many causes of unintentional weight loss [03:40] At a basic level, there are four key mechanisms. The first is reduction in nutrient intake. The second is increased energy utilization, such as in the case of fever or hyperthyroidism. The third cause is increased loss of [04:00] that might be from malabsorption or short bowel syndrome. And the fourth cause is altered metabolism. In the absence of fever or other causes for increased energy expenditure such as hyperthyroidism, in fact, weight loss is predominantly in [04:20] usually do to reduction in food intake, and you’ve got to elicit that on history. Progressive unintentional weight loss often indicates a serious medical or psychiatric illness. Any chronic illness affecting any organ system can cause anorexia and weight loss. In studies that looked at ueology [04:40] for unintentional weight loss, cancer is eventually identified as the primary cause in 15 to 35% of patients. Non-malignant GI causes count for about 10 to 20% of patients. Psychiatric causes account for 10 to 23% of patients. And in a quarter of cases, we don’t understand the cause. [05:00] Cancer is particularly of the lung, gastrointestinal tract, kidney, and prostate often cause weight loss and there are multiple mechanisms including anorexia and reduction in poor intake. The prevalence of weight loss is highest in [05:20] those with really complex cancers. Non-malignant GI tract diseases such as pepidoculcer disease, celiac, inflammatory bowel disease can also present with weight loss. And these patients often have GI symptoms including abdominal pain, early satiety, dysphasia, or oodinephasia, diarrhea, [05:40] or stioderia. They might even have evidence of chronic bleeding. In patients with psychiatric disorders, depression in particular accounts for weight loss in a third to almost two-thirds of patients with unintentional weight loss. This is more prominent [06:00] in nursing home patients and seniors. Eating disorders and other conditions such as bipolar may also contribute to weight loss in patients with psychiatric disorders. Endocrinopathies such as hyperthyroidism and diabetes contribute to altered nutrition [06:20] metabolism and both of these conditions can be associated with weight loss. Another condition we need to consider in patients who present with weight loss is adrenal insufficiency, although clearly this is less common. Infectious diseases such as HIV, tuberculosis, hepatitis C, and chronic halmuthic infections can also [06:40] contribute to non-volitional weight loss. Another area of medicine where we see non-volitional weight loss is in patients with advanced chronic diseases such as chronic cardiac, lung, or renal disease. Intercurrent illness in patients with chronic illness can also impact non-volitional weight loss. [07:00] As physicians, we also must consider social factors leading to inadequate dietary intake, such as food insecurity or the absence of enough money to buy food and