Lipids/Obesity Flashcards
- Lipoprotein lipase (LPL) - function?
- LPL deficiency results in?
- other names for this?
- specific physical features include?
- Treatment?
- breaks down TGs
- severely elevated TGs >1000 mg/dl increasing risk for pancreatitis AND total cholesterol (chylomicronemia)
- Familial hypercholesterolemia, familial defective apolipoprotein B, and familial chylomicronemia syndrome
- tendinous xanthomas
- Dietary and lifestyle interventions. Fibrates are ineffective. Plasmapheresis rarely has a role.
- Apolipoprotein CII is a cofactor of?
- APO CII deficiency (and LPL deficiency) leads to?
- Lipoprotein lipase (LPL)
- severely elevated TGs >1000 mg/dl
- Cholesterol ester transferase protein (CETP) function?
- CETP deficiency leads to?
- More common in?
- transfers cholesterol esters from HDL to VLDL, IDL, and remnant particles in exchange for TG, essentially clearing HDL cholesterol
- HIGH HDL usually >100 mg/dl (“HIGH HDL CETPoint)
- more common in individuals of Asian descent
Identify monogenic forms of early-onset childhood obesity (prevalence, pathophysiology, characteristics)
Melanocortin 4 Receptor (MCR4)
prevalence 8%
- pathophysiology - loss of satiety, hyperphagia
- characteristics - increased linear growth, tall for age, increased lean mass
Identify monogenic forms of early-onset childhood obesity (prevalence, pathophysiology, characteristics)
Leptin (LEP)
prevalence < 1%
- pathophysiology - leptin from adipocytes acts centrally to promote satiety
- characteristics - hyperphagia, hypothyroidism, hypogonadism, impaired immune function
Identify monogenic forms of early-onset childhood obesity (prevalence, pathophysiology, characteristics)
Leptin Receptor (LEPR)
prevalence < 1%
- pathophysiology - receptor to mediate effects of leptin
- characteristics - same as for leptin (hyperphagia, hypothyroidism, hypogonadism, impaired immune function)
Identify monogenic forms of early-onset childhood obesity (prevalence, pathophysiology, characteristics)
Pro-opiomelanocortin (POMC)
prevalence 1%
- pathophysiology - regulates energy expenditure and appetite. POMC is cleaved into melanocyte stimulating hormone and ACTH. Important for adrenal function.
- characteristics - hyperphagia (like LEP/LEPR), ACTH deficiency, adrenal insufficiency, hypopigmentation
Identify monogenic forms of early-onset childhood obesity (prevalence, pathophysiology, characteristics)
Fat mass and obesity gene (E. FTO)
prevalence: most common, associated with generalized obesity, not early childhood-onset obesity
- mechanism - largely unknown, increased food intake
common medications used in combination with statins that can increase the risk of myositis (5)
“Eric and Gemma Cycled then ate Ketos and Proteins (and got myositis stat)” Erythromycin Gemfibrozil (combined hyperlipidemias) Cyclosporin (transplant) Ketoconazole Protease inhibitors
Identify the physical findings of hyperlipidemias (see phone for pictures)
A. Lipemia retinalis
B. Corneal arcus
C. Eruptive xanthomas
D. Palmar xanthomas
E. Arthropathy
A. severe hypertriglyceridemia >3000 mg/dl
B. Familial hypercholesterolemia: increased TC/LDL ratio (ApoB) + premature CAD Homozygous - atherosclerosis before 20-30 yo. Treatment is liver translplant. Treatment for both hetero- and homozygous is high dose statin
C. severe hypertriglyceridemia >2000 mg/dl
D. Dysbetalipoproteinemia: high TC and TGs
E. NOT a sign of hyperlipidemia
Case: A patient who was diagnosed with low cholesterol as an infant. Total cholesterol is low, LDL is low, Apo B is low.
- What does this patient have? Caused by?
- function of this protein?
- absence of this results in?
- Abetalipoproteinemia, a rare autosomal recessive disorder caused by MICROSOMAL TRIGLYCERIDE TRANSFER PROTEIN (MTTP) deficiency
- crucial in making apolipoprotein B-containing lipoproteins in the endoplasmic reticulum through transfer of TGs or phospholipids
- NO apolipoprotein B protein
What are the rare genetic disorders in the differential diagnosis of severe hypolipidemias? 3 total
(MATTY Peed on APO wearing a SAR1)
- Abetalipoproteinemia - MTTP deficiency. Patients present with failure to thrive, steatorrhea, NEUROLOGIC SYMPTOMS (weakness/balance problems as adults)
- Familial hypobetalipoproteinemia - defective Apolipoprotein B. Cannot efficiently secrete lipoproteins from the liver and hence NAFLD. Homozygous form - cholesterol between 50-100 mg/dL Heterozygous form - APOB gene defect
- Chylomicron retention syndrome - SAR1B gene. Very low circulating cholesterol and TGs
What are the commonly performed bariatric surgical procedures? 5 total
- biliopancreatic diversion - most weight loss (32-35%) and largest effect on glucose levels, but more frequent complications and adverse effects (severe and potentially difficult-to-treat vitamin deficiencies)
- Roux-en-Y gastric bypass - criterion standard operation. Second to the most weight loss (25-28%) and often dramatically improves glucose levels in patients with T2DM. Also results in lifelong need for vitamin supplementation and at risk for metabolic bone disease
- laparoscopic banding - less weight loss (18-22%) and more mechanical problems
- sleeve gastrectomy - good weight loss (22-25%), easy surgery to perform. Not as effective as gastric bypass in either producing weight loss or improving glucose control in T2DM.
- endoscopically placed dual balloon device - weight loss 7% 6 months after placement). Temporary weight loss.
- HYPObetalipoproteinemia results in a reduction of?
- How is hypobetalipoproteinemia distinguished from Abetalipoproteinemia?
- both LDL (cholesterol) and VLDL (TG) The inability to inefficiently secrete lipoproteins from the liver can lead to NAFLD, due to a defect in the production of Apo B in the liver
- Abetalipoproteinemia is a rare A.R. disorder. MTTP deficiency. Patients present with failure to thrive, steatorrhea, neurologic symptoms (weakness/balance problems as adults)
- Abetalipoproteinemia results in?
- symptoms?
- low LDL and TG (much lower than hypobetalipoproteinemia)
- neurologic symptoms (weakness) and balance problems as adults
