dyslipidaemia Flashcards
definition of dyslipidaemia
Hypercholesterolaemia, an elevation of total cholesterol (TC) and/or low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (HDL-C) (defined as the subtraction of HDL-C from TC) in the blood,
often referred to as dyslipidaemia because - might be accompanied by a decrease in HDL-C, an increase in triglycerides, or qualitative lipid abnormalities
lipid transport
Lipids travel in blood packaged with proteins as lipoproteins. There are four classes: chylomicrons and VLDL (mainly triglyceride), LDL (mainly cholesterol), and HDL (mainly phospholipid)
RF for dyslipidaemia
FH
corneal arcus <50yrs
xanthomata/xanthelasmata
insulin resistence and t2dm
BMI >25kg/m2
hypothyroidism
cholestatic liver disease
types of hyperlipidaemia
common primary hyperlipidaemia
familial primary hyperlipidaemia
secondary hyperlipidaemia
mixed hyperlipidaemia
common primary hyperlipidaemia
70% of hyperlipidaemia
raised LDL only
familial primary hyperlipidaemia
multiple phenotypes
risk of increased CVD
protection from CVD achieved with lower doses of statin than for common primary hyperlipidaemia
secondary hyperlipidaemia
raised LDL
treat the cause first
causes include:
- cushings syndrome
- hypothyroidism
- nephrotic syndrome
- cholestasis
mixed hyperlipidaemia
both high LDL and triglycerides
causes
- t2dm
- metabolic syndrome
- alcohol abuse
- chronic renal failure
epidemiology of dyslipidaemia
Half the UK population have a serum cholesterol putting them at significant risk of CVD.
sx of dyslipidaemia
FH of early onset coronary heart disease or dyslipidaemia in 1st degree relatives
history of CVS disease
consumption of saturated fats and trans-fatty acids
excess body weight - especially abdo obesity
xanthelasmas
signs of dyslipidaemia
xanthomata - yellow lipid deposits may be:
- eruptive - itchy nodules in crops in hypertrigluceridaemia
- tuberous - plaques on elbows and knees
- planar (palmar) - orange streaks in palmar creases
- tendons
- eyelids - xanthelasma
- corneal arcus
- diagnostic of remnant hyperlipidaemia
lipaemia retinalis - When viewed through the ophthalmoscope, the retina is pale and the retinal vessels are white.
dm
coronary artery disease
angina/claudication
Ix for dyslipidaemia
fasting TG - ≥2.3 mmol/L (200 mg/dL)
lipid profile - Consists of TC, triglycerides, and LDL-, HDL-, and non-HDL-cholesterol.
- total cholesterol (TC) >5.18 mmol/L (>200 mg/dL);
- LDL-cholesterol >2.59 mmol/L (>100 mg/dL);
- non-HDL-cholesterol <3.4 mmol/L (<130 mg/dL);
- HDL-cholesterol <1.04 mmol/L (<40 mg/dL) for men and <1.29 mmol/L (<50 mg/dL) for women;
- triglycerides >1.7 mmol/L (>150 mg/dL)
TSH - elevated in primary hypothyroidism
lipoprotein (a) - Lipoprotein(a) is an LDL particle with apolipoprotein(a) covalently bound to apolipoprotein B of LDL.
- values >50 mg/dL or >125 nmol/L are considered high
treatment priorities for dyslipidaemia
identify familial or secondary hyperlipidaemias
top priority - people with known CVD
second - primary prevention in pts with chronic kidney disease or t1dm, and those with a 10yr risk of CVD >10% irrespective of baseline lipids
1st line mx of dyslipidaemia
atorvastatin 20mg PO at night for primary prevention, 80mg for secondary prevention and primary prevention in the people that have kidney disease
Simvastatin 40mg, is an alternative.
mechanism of statins
reduce cholesterol synthesis in the liver by inhibiting HMGCOA reductase
CI: porphyria, cholestasis, pregnancy
SE: myalgia +- myositis (stop if increasing CK≥10-fold; if any myalgia, check CK; risk is 1 per 100000 treatment-years), abdo pain and raised LFTs (stop if AST >100u/L)
Cytochrome P450 inhibitors increase serum concentrations - grapefruit juice
target plasma cholesterol reduction of ≥40 % in those with CVD.
2nd line mx of dyslipidaemia
Ezetimibe—a cholesterol absorption inhibitor,
may be used in statin intolerance or combination with statins to achieve target reduction
3rd line Mx of dyslipidaemia
Alirocumab—a monoclonal antibody against PCSK9 (acts to reduce hepatocyte LDL receptor expression).
- Very effective in reducing LDL
- expensive and injection every 2wks
fibrates eg bezafibrate (useful in mixed hyperlipidaemias)
anion exhange resins eg cholestyramine
nicotinic acid - raise HDL, lower LDL
- SE: severe flushes - aspirin 300mg ½h pre-dose helps this
what does hypertrigluceridaemia respond best to
fibrates, nicotinic acid, or fish oil.
complications of dyslipidaemia
coronary events
acute pancreatitis
IHD
PVD
acute coronary syndrome
stroke
erectile dysfunction
Px of dyslipidaemia
improved significantly with lowering of triglyceride levels
require ongoing long-term therapy with monitoring of plasma lipids as well as side effects.
Once plasma lipid levels have achieved goals and are stable they can be monitored along with liver function tests every 6 months.
vast majority of patients do well with statin therapy without adverse events.
