Question

Sample A is from a 35 year old male who visited his GP complaining of chest pain during exercise. An ECG taken at rest was normal but ischaemic changes developed on exercise. A family history revealed that his father died of a heart attack at the age of 45 years. The laboratory test results for his fasting blood sample were as follows:

Analyte                       Patient values                        Reference range for fasting

     blood sample

Sodium                                    139                              135-145 mmol/L

Potassium                                4.1                               3.0-5.0 mmol/L

Total protein                           69                                65-80 g/L

Albumin                                  35                                35-47 g/L

Calcium                                  9.3                               9.0-10.5 mg/dl

Lactate dehydrogenase           250                              90-190 IU/L

Creatine kinase                       129                              30-60 IU/L

Asparatate transaminase         70                                < 40 IU/L

Gamma glutamyl transferase 30                                < 50 IU/L

Total Bilirubin                        13                                0.4-15 μmol/L

Glucose                                   12                                3.5-5.5 mmol/L

Fructosamine                          351                              205-285 μmol/L

Cholesterol                             

            Total                            7.2                               <5.2mmol/L

            HDL                            1.4                               >1.5 mmol/L

            LDL                            ?                                  <3.5 mmol/L

Triglycerides                           2.95                             <1.7mmol/L

On the gradient gel electrophoresis, plasma sample for this patient showed the presence of small dense LDL particle.

Questions:

1. Calculate and comment on the LDL cholesterol values. What does the presence of small dense LDL mean?
2. How many cardiovascular risk factors does this patient have?
3. Discuss the type of hyperlipidaemia this patient is likely to have.

Answer 1

Ldl cholesterol = total cholesterol - hdl- tg/2.2

= 7.2 -1.4-(2.95/2.2)

= 5.8 - 1.35 = 4.45 mmol/l

The levels of ldl has been raised in this patient

Raised ldl is a risk factor for myocardial infarction because it causes increased risk for formation of atherosclerosis

Small dense ldl increases the risk of atherosclerosis

Ldl has many subtypes . In that subtype small ldl has increased atherogenesis potential in vessels compared to other subtypes. It acts as a biomarker for atherosclerosis.

Cardiovascular risk factors in this patient are

1. Risk factors for atherosclerosis

Increased total cholesterol levels, ldl, triglycerides level, carbohydrates.

Low hdl levels.

2. Due to myocardial infarction

Increased lactate dehydrogenase levels, creatinine kinase , gamma glutamic transverse, aspartate transaminase levels.

Type of hyperlipidemia is type 2b polymeric hypercholesterolemia.

Because increased total cholesterol, ldl , triglycerides.

It is most common occurence.

It is not a genetic cause and it is multifactorial cause.