Test Your Knowledge of GLP-1 Organ Physiology
Images from the public domain (1918) textbook Gray’s Anatomy
Answers and Discussion on Quiz Page
Pancreas:
GLP-1 Effects on the Pancreas
- Increase insulin secretion (and production)
- Insulin gene expression
- Decreased glucagon secretion
- Stimulates proliferation of pancreatic β-cells
- Pancreatitis (? incidence)
Quiz: What is the effect of chronic treatment with GLP-1 and GLP-1R agonists on insulin and blood glucose in type 2 diabetics ?
Brain
GLP-1 Effects On The Brain
- Decreased Appetite, control of satiety, water intake and stress reduction
- The Vagus Nerve stimulates signals to the brain from GLP-1 relased from the intestines, to the portal vein
- Brain GLP-1 receptors modulate mitochondrial function protein aggregation, neuroinflammation, synaptic plasticity, learning and memory in experimental models of Parkinson’s and Alzheimer’s disease
Quiz: Does the brain make GLP-1 as well as have receptors that get stimulation from the vagus nerve?
Stomach
GLP-1 Effects on the Stomach
- Inhibits (slows) gastric emptying and gastric acid secretion
- Potential severe delayed gastric emptying with prolonged retention of food (potential aspiration pre anesthesia)
- Nausea and vomiting (mild, transient or severe)
- 10% of people that start GLP-1 meds discontinue them due to severe nausea, vomiting, diarrhea, constipation and abdominal pain
Quiz: How long should you stop your semaglutide med before anesthesia ?
Small Intestines
GLP-1 Effects on the Small Intestine
- Potential for decreased peristalsis resulting in prolonged ileus
- The FDA label for Novo Nordisk’s weightloss drug Ozempic now acknowledges some users’ reports of ileus, or intestinal blockage
- Intestinal obstruction should be considered as a potential for all GLP-1 containing meds
Quiz: Did the FDA directly link bowel obstruction to Ozempic?
Colon
GLP-1 Effects on the Colon
- Decreased motility, constipation, potential obstruction
Quiz: Why is it important to tell you gastroenterologist you are taking a semaglutide?
Thyroid Gland
GLP-1 Effects on the Thyroid GLand
- The risk of thyroid C cell tumors seen in rodent studies. No human reports to date.
- It is not known if semaglutide will cause thyroid tumors or a type of thyroid cancer called medullary thyroid carcinoma (MTC) in people
- Lowering effect on the TSH level without altering fT4 and fT3 levels in patients without thyroid disease or autoimmunity
Quiz: At least one patient has proven the association of semaglutide and thyroid cancer. (True/False)
Heart
GLP-1 Effects on the Heart
- Increased exercise tolerance, decreased mortality in patients with CV disease and obesity, including non-diabetics
- GLP-1 agonists reduced all-cause mortality and cardiovascular death, stroke in people with type 2 diabetes as well as obesity with associated comorbidities
Quiz: Semaglutide (2.4 mg once weekly) was approved by the Food and Drug Administration for obesity in patients without diabetes. (True/False)
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Liver
GLP-1 Effects on the Liver
- Increased insulin secretion
- Inhibits the release of glucagon
- Increased glycogen storage
- Decreases liver fat
- Evidence is building on the efficacy of GLP-1 RAs in NAFLD (non alcoholic fatty liver disease). Although not completely understood mechanism of action, GLP-1 RAs seem to improve liver damage, favoring a reduction in the degree of steatosis (fat), inflammation and hopefully liver fibrosis
Quiz: To date, non-alcoholic fatty liver disease (NAFLD) is the most frequent liver disease, affecting up to what percent of patients with diabetes. (20%,50%,70%,95%)
Gallbladder
GLP-1 Effects on the Gallbladder
- Increased incidence of gallstones
- GLP-1 RAs may directly inhibit gallbladder and biliary duct motility
- Rapid weight loss associated with GLP-1 RA use may lead to supersaturation of cholesterol in the bile and gallstones
Quiz: Obesity in general is associated with some increase in gallstones. (True/False)
Kidney
GLP-1 Effects on the Kidney
- A case report of acute kidney injury has been reported
- Decreased spillage of microalbumin (favorable)
- Preservation of kidney function and improved survival in patients with advanced kidney disease and diabetes (report)
- Some people have reported a change in the way their urine smells after taking Wegovy or other semaglutide products such as Ozempic, often describing it as now having a strong unusual odor
Quiz: Is there evidence that semaglutide causes kidney stones ? (True/False)
Eye
GLP-1 Effects on the Eye
- Semaglutide is more likely to worsen pre-existing retinopathy rather than cause the onset of it possible due to a rapid improvement in blood glucose to temporarily exacerbate symptoms of the condition
- No long-term studies have been carried out yet, we don’t know whether or not the retinopathy would improve over time
- Have not ruled out potential for long term beneficial effects in retinal inflammatory diseases
- Semaglutide Has Great Potential for the Prevention of Retinal Neurodegeneration
Quiz: The FDA has approved semaglutide drugs for improving Retinal Neurodegeneration. (True/False)
Muscle
GLP-1 Effects on Muscles
- Muscle mass loss can be a side effect of semaglutide
- While lean body mass decreased overall by nearly 10%, it made up a higher percentage of the person’s overall body weight. In other words, the proportion of lean body mass relative to total body mass increased, which is a good thing. Plus the more weight they lost, the better their ratio of lean muscle mass to fat mass
Quiz: Eli Lilly is conducting a study with two drugs to attempt to decrease muscle loss. (True/False)
Fat
GLP-1 Effects on Fat
- Semaglutide can reduce belly fat levels by 16% after 26 weeks of treatment
- stimulates browning on subcutaneous fat adipocytes and mitigates inflammation and endoplasmic reticulum stress in visceral fat adipocytes of obese mice
Quiz: Only obese patients reduce fat levels. (True/False)
Lungs
GLP-1 Effects on Lungs
- GLP-1 receptor agonists may represent a novel treatment for asthma associated with metabolic dysfunction
Quiz: The FDA has approved GLP-1 drugs for Chronic Obstructive Pulmonary Disease. (True/False)
Respiratory Effects of Treatment with a Glucagon-Like Peptide-1 Receptor Agonist in Patients Suffering from Obesity and Chronic Obstructive Pulmonary Disease
Bone
GLP-1 Effects on Bone
- GLP1 functions between a delicate balance between bone formation and bone resorption
- Overall clinical data indicated that GLP1RAs have a neutral impact on bone health and do not affect the rates of fracture, although a few published studies suggest risk of fracture
Quiz: The risk of fracture with GLP-1 is not fully settled. (True/False)
Tongue
GLP-1 Effects on Tongue
- Preclinical studies demonstrated that glucagon-like peptide 1 (GLP-1) is locally synthesized in taste bud cells
- Tongue fat tissue and fat proportion significantly reduced after semaglutide
- GLP-1 receptor exists on the gustatory nerves in close proximity to GLP-1-containing taste bud cells
- A change in taste (also called dysgeusia) is a commonly discussed side effect of Ozempic on blog sites
Quiz: Uncontrolled studies suggest semaglutide meds may decrease the urge to drink alcohol. (True/False)
Hair
GLP-1 Effects on Hair
- Some of the main symptoms of hair loss that may occur from Semaglutide include thinning hair, increased hair shedding, receding hair line, bald patches and an itchy or irritated
- In Wegovy (semaglutide) studies, hair loss (alopecia) was reported in 3% of adults using Wegovy and 1% using a placebo (inactive) treatment
- In children 12 years and older, hair loss was reported in 4% vs. 0% using a placebo
- Telogen effluvium is a common type of hair loss that affects people after they experience severe stress or a change to their body. Symptoms include thinning hair, usually around the top of your head. Hair will typically grow back in three to six months without treatment
Quiz: There is no evidence that semaglutide directly causes hair loss. (True/False)
