Hyperlipidemia (5 questions) Flashcards
Approximately ____ % of adults in the US-a total cholesterol of ≥240mg/dL; _____% of all U.S. -a total cholesterol > 200mg/dL.
25~ 30% - ≥240mg/dL
>50% - > 200mg/dL.
Types of lipoproteins
- Chylomicrons
- Very low density lipoprotein (VLDL)
- Intermediate density lipoprotein (IDL)
- Low density lipoprotein cholesterol (LDL-C)
- High density lipoprotein cholesterol (HDL-C) (cardioprotective
Composition of lipoproteins
- a lipid core containing cholesterol ester and triglycerides
- An outer layer of phospholipids and apo-proteins is wrapped around the core
- One molecule of Apo B is present for each LDL
Significance of Apo B
- One molecule of Apo B is present for each LDL
- This allows lipoproteins to travel in the blood
- They are very small particles and are more atherogenic than normal size
(We don’t routinely measure Apo B)
Explain the exogenous pathway
- Cholesterol and TG from diet travel through GI system to small intestine and are packaged into Chylomicrons
- These are transported and deposited in muscle and fat tissue
- Some break down into free fatty acid for energy
- Others are taken to the liver where they bind to LDL receptor (most LDL receptors in liver – genetic probs, consider)
- The liver metabolizes cholesterol into bile for elimination in feces
Explain the endogenous pathway
- In the liver, cholesterol & TG are made into VLDL, transported to muscle and fat tissue and broken down for energy and storage
- VLDLs break down into IDL
- Some IDL return to liver, others break down into fat and muscle tissues to form LDL
- LDL binds to LDL receptor and is taken into cells for cell wall synthesis
- Excessive LDL goes int oblood
- macrophages – foam cells - plaque*
5 atheroprotective roles of HDL
- Reverse Cholesterol Transport
- Antioxidant property
- Maintenance of endothelial function
- Protection against thrombosis
- Low blood viscosity via permitting red cell deformability (high blood viscosity related to inflammation)
ATP III: when should adults begin getting lipid profile screening, and how often?
over age 20- lipid profile every 5 years
Who should get screened for lipids regardless of age?
- Atherosclerosis, other CHD, DM, Metabolic syndromes or HTN regardless of age
- FHx of premature CVD
- Clinical hyperlipidemia (Xanthomas, Acanthosis nigrans, Arcus corneus)
- CRF, Erectile dysfunction, HIV infection with HAART tx, autoimmune diz (lupus, RA, psoriasis)
When should we start screening lipids in children of patients w/ severe dyslipidemia?
start at the age of 10
Goal of dyslipidemia management
prevent future ASCVD
- Definition: Clinical ASCVD (acute coronary syndrome, hx of MI, stable or unstable angina, coronary or other arterial revascularization, stroke , TIA or peripheral arterial disease based on RCT inclusion criteria)
- Primary and secondary prevention
Examples of primary, secondary, and tertiary prevention in the context of ASCVD
- Primary: diet. For anyone w/history of CAD, checking lipids for screening
- Secondary: had MI last year and you are treating them
- Tertiary: full blown symptoms, trying to slow progression/stop symptoms
normally think prmary prevents dz, secondary detects and cures while asymptomatic, tertiary reduces complications
When did ATP III come out?
2001
What is involved in ATP III screening?
- Determine lipoprotein levels using a 9-12 hour fast (most require 12)
- Identify presence of clinical atherosclerotic disease that confer high risk for CHD or equivalent
- Determine the presence of major risk factors
- If 2+ risk factors (other than LDL) are present w/o CHD or CHD equivalent, assess 10-yr risk
- Determine risk category
Why is a fasting lipid panel recommended?
TGs increase after food–
new evidence shows may not change >10%, so not so important
Secondary causes of elevated LDL and TG
Diet, medications, comorbid conditions, disordered/altered metabolism
altered metabolism is most common
ATP III Guidelines: Total cholesterol (mg/dL)
Optimal/desirable, near optimal, borderline high, high
- Optimal/desirable:
- borderline high: 200-239
- high: > 240
ATP III Guidelines: LDL cholesterol (mg/dL)
Optimal/desirable, near optimal, borderline high, high
- Optimal/desirable:
- near optimal:
- borderline high: 130-159
- high: 160-189
- very high: _>_190
ATP III Guidelines: TGs (mg/dL)
Optimal/desirable, borderline high, high
- Optimal/desirable:
- near optimal
- borderline high: 150-199
- high: _>_200
ATP III Guidelines: HDL Cholesterol (mg/dL)
Optimal/desirable, near optimal
- Optimal/desirable: > 60
- Low: < 40 men, < 50 women
ATP III Guidelines
Former guidelines based on risk factors
2013 ACC/AHA Guidelines
- Replaced ATP III
- no longer to Tx LDL chol targets
- Non statin therpay discouraged in most cases
- Lifestyle modification rec’d for all pts
- 10yr ASCVD risk calculator - risk category determines what level of statin therapy
Presence of clinical atherosclerotic disease that confer high risk for CHD or equivalent (ATP III)
- Clinical CHD
- Symptomatic carotid artery disease
- Peripheral arterial disease
- Abdominal aortic aneurysm.
Major risk factors for ACVD (ATP III)
- Cigarette smoking
- HTN (BP > 140/90 or on antiHTN med
- Low HDL (<40mg/dL)
- FH premature CHD (CHD in male 1st degree relative <55yo, CHD in female first degree relative <65yo)
- Age (men > 45yo, women > 55yo)
How many major risk factors need to be present in order to assess 10 year risk? (ATP III)
If 2+ risk factors (other than LDL) are present w/o CHD or CHD equivalent, assess 10-yr risk
What is a negative risk factor? (ATP III)
HDL > 6omg/dL counts as a “negative” risk factor. Its presence removes one risk factor from the total count
what is a CHD risk equivalent? (ATP III)
A CHD risk equivalent is a condition that carries an absolute 10-year risk for developing new CHD e_qual to the risk for having recurrent CHD events in persons with established CHD,_ i.e., >20% per 10 years.
10 year risk intervals (ATP III)
- >20% — CHD risk equivalent
- 10-20%
- <10%
ATP III Risk categories
- CHD or CHD Risk equivalents (10 yr risk >20%)
- 2+ risk factors (10 year risk < 20%)
- 0-1 risk factors
ATP III goal if CHD or CHD Risk equivalents (10 yr risk >20%)
- LDL Goal <100 mg/dL (<70 optional)
- LDL level at which to initiate TLC: > 100 mg/dL
- LDL Level at which to consider drug therapy: > 130 mg/dL (100-129 mg/dL: drug optional)
most important: risk is >20%. No matter how many risk factors, if risk is >20%, these are goals
ATP III Goal if 2+ risk factors (10 year risk < 20%)
- LDL Goal <130 mg/dL
- LDL level at which to initiate TLC: > 130 mg/dL
- LDL Level at which to consider drug therapy:
- 10yr risk 10-20%: > 130 mg/dL
- 10yr risk <10%: > 160mg/dL
ATP III Goal if 0-1 risk factors
- LDL Goal <160 mg/dL
- LDL level at which to initiate TLC: > 160 mg/dL
- LDL Level at which to consider drug therapy: > 190 mg/dL (160-189 mg/dL: LDL lowering drug optional)
(almost all have 10yr risk <10%, so 10yr risk assessment not necessary)
CHD Risk equivalents: Diabetes Mellitus
- calculate pt specific risks w/calculator. If cannot
- men >40yo w/DMII and any other risk factor
- men >50yo w/DMII
- women >45yo w/DMII and any other risk factor
- women >55yo
- men & women of any age w/DMI or DMII for >20yrs w/another risk factor
- men & women of any age w/DMI or DMII for >25yrs
UpToDate, class notes
CHD RIsk equivalents other than DM
- symptomatic carotid artery disease
- PAD
- AAA
- Multiple risk factors that confer a 10yr risk of CHD >20%
- CKD w/Cr >1.5mg/dL [133 umol/L] or eGFR <60 mL/min per 1.73m2
Components of physical exam for dyslipidemia
- Vital signs
- Cardiovascular
- Waist measurements
- Skin
- Eye
- PV
- Thyroid
some clinics do body fat measure
Dyslipidemia PE: what are you looking for on the skin
xanthomas, skin tags, acanthosis nigrans
Dyslipidemia PE: what are you looking for in the eye exam
corneal arcus, AV nicking, papilledema, hemorrhages, exudates
Dyslipidemia PE: what are you looking for in the PV exam?
Peripheral pulses, ABI (should be close to 1. Higher good, lower bad)
Corneal arcus, aka arcus senilis
More present in strong family history of hyperlipidemia
common in older adults w/o being a predictor of CV risk
Acanthosis nigrans
insulin resistance – often coexists w/high cholesterol (metabolic syndrome), diabetes, pcos, cushings
Xanthomas
can be anywhere in body, but usually elbow, joint, knee, tendon, buttock. Specific to hyperlipidemia
Eruptive xanthoma
Specific to hyperlipidemia
Secondary causes of lipid abnormalities
Secondary causes of increased TGs
obesity, DM, etoh use, CKD, OCPs, diuretics*
*short term effects only
Secondary causes of decreased HDL
obesity, sedentary lifestyle, BB*s
*short term effects only; BBs w/intrinsic sympathomimetic activity, e.g., pindolol and acebutolol, do not affect lipid levels
Secondary causes of increased HDL
etoh use
Secondary causes of increased total cholesterol
DM, hypothyroidism, nephrotic syndrome, CKD, obstructive liver disease, Cushing Dz, corticosteroid use, OCPs, Diuretics*, BBs*
*short term effects only; BBs w/intrinsic sympathomimetic activity, e.g., pindolol and acebutolol, do not affect lipid levels
Secondary causes of decreased total cholesterol
hyperthyroidism, liver dz (cirrhosis), malignancy
What is significant about TGL >500
needs to be treated. Affects accurate reading of LDL
How can you calculate LDL Cholesterol?
Total chol - VLDL (or 1/5 TG) - HDL
*validity depends on TGs <400mg/dL
*Measured directly if patients have profound TG
*Errors in TC, HDL, and TG can affect values
How can you calculate Non-HDL Cholesterol?
TC – HDL-C
All cholesterol in atherogenic lipoproteins including LDL, Lipoprotein a, IDL, VLDL
Therapeutic lifestyle changes for high cholesterol: how long a trial is appropriate before introducing pharm therapy?
Can do a 12 week trial unless high risk
Describe therapeutic lifestyle changes for high cholesterol
- Reduce saturated fat to <7% of total calories (teach to read nutr label) Reduce fats & carbs!
- Add plants and fiber
- Lose weight
- Increase physical activity. “
Time frame to give another try – 3-6 mths.
TLC for dyslipidemia: how can you help patients understand intensity of physical activity?
This table!