Lipid lab diagnositcs questions

Question 1

1
After finding high lipid concentrations in the serum, what tests would you employ to confirm or exclude the secondary causes of hyperlipidemia?

Answer 1

Test for:
Cushing’s syndrome, ACTH and Cortisol levels

Hypothyroidism

Diabetes: Insulin levels and glucose levels.

Nephrotic syndrome: Albuminuria and Proteinuria

Cholestasis: Serum LPX, Urine Conjugated Bilirubin, cB, and very decreased or Absent Urine Urobilinogen UGB.

Alcoholism, fatty liver, intoxication.

Pregnancy

Obesity

Question 2

2
The laboratory parameters of a male having normal blood pressure, BMI 23 kg/m2 are:
serum TG: 1.5 mmol/l
serum LDL-cholesterol: 4.4 mmol/l
serum CRP: 5 mg/l
What is the risk of CHD for this person? What are the risk factors of atherosclerosis?

Answer 2

BMI normal range is 18.5 - 25 kg/m2
(I didn't get fat til I was 25)
Serum TG normal range 0.8-1.7 mM
Serum LDL cholesterol range < 3.4 mM
Total cholesterol range 3.6-5.2 mM
Serum CRP range: 1-8 mg/L BUT, anything over 3mg/L is considered low grade inflammation

He has type 2a hyperlipidemia with elevated LDL cholesterol, but normal TG levels. Along with low grade inflammation.
The risk for CHD and atherosclerosis is HIGH.

Risk factors:
Non-modifyable: Age, Male gender, Post menopause, and Family history

Modifyable
Hypertension
Hypercholesterinemia 
Elevated CRP
Smoking
Obesity
Diabetes
Sedentary life
Hyper Homocysteinemia
Hyper coagulative states
Chlamydia Herpes, other intracellular infections.

Question 3

3
A 45 year old man has the following parameters:
waist circumference: 110 cm
BP: 140/90 mmHg
HDLC: 0.9 mmol/l
fasting blood glucose: 6.3 mmol/l
What is your opinion about the risk of CHD for this person?

Answer 3

Metabolic syndrome:
Parameters, 
Waist larger than 100cm (40 inches)
Hypertension
HDL cholesterol is below 1.0 mM
Impaired Fasting Glucose

Very high risk of CHG, and is also at risk for Type 2 diabetes. Metabolic syndrome is sometimes classified as pre-T2DM.

Question 4

4
A 35 year old man wanted to be screened for possible ischemic heart disease because his father died early from a heart attack. The patient was not obese and was a nonsmoker.
On examination his blood pressure was normal and the only abnormality was tendon xanthomata arising from the Achilles tendons. An ECG taken at rest was normal but ischemic changes developed on exercise.
Fasting lipids: serum cholesterol 8.7 mmol/l,
triglyceride 1.1 mmol/l.
What is the most likely diagnosis and how can you confirm it?

Answer 4

Total cholesterol is above 5.2 mM and is considerably high.
TAGs are normal.

Tendinous xanthomas

Diagnosis: Familial hypercholesterinemia,
Test serum LDL levels,
Test OTHER family members for serum lipid levels as well.
Genetic testing on LDL receptor

Question 5

5
A middle-aged man saw his family doctor, because he got rashes. On examination he was found to have extensive yellowish papules, with an erythematous base, on his buttocks and elbows and orange-yellow discoloration of the palmar creases.
Fasting lipids: serum cholesterol 7.6 mmol/l,
triglyceride 8.1 mmol/l.
What is your diagnosis?

Answer 5

Serum cholesterol is about 5.2 mM
Triglyceride is also well above 1.7 mM.

Both Cholesterol and TAGs elevated is a Type 3 hyperlipidemia.

The palmar crease xanthomas and other xanthomas are extremely characteristic of
Type 3 familial Dysbetalipoproteinemia.
Which, even though its called dysbetaliporoteinemia, is caused by a defect in ApoE.
ApoE defect causes IDL accumulation and deposition.