Question

Case Study – Atherosclorosis Francois was shoveling some light snow off of the driveway when he suddenly experienced a severe chest pain. He felt a weight on his chest and was having trouble breathing. A stab of pain also radiated across the left side of his neck and down his left arm. His wife called 911 and an ambulance picked him up and brought him to the local hospital. The resident told him that he was suffering from angina pectoris. As he lay there resting, the pain subsided and he began paying attention as the doctor asked him some questions and did a few basic measurements. He was 52 years old, 5’10” tall and weighed 210 lbs. His girth at the waist was 42 inches. An MRI of his neck revealed artherosclerotic plaque buildup in his carotid arteries. He told the doctor that he smoked about 3 packs of cigarettes per week, did not drink alcohol and had a relatively sedentary lifestyle. They took a blood sample and did a variety of tests.

The results follow: Low density lipoprotein was 210mg/dl

Triglycerides were 195mg/dl

High density lipoprotein was 28mg/dl

Creatine kinase was elevated The doctor set him home the next day with a prescription for a statin drug and instructions to get regular, moderate exercise and carefully monitor his diet. He was told to try to get his BMI down to 25 and his girth to 36”.

2. What is Francois’ BMI? What does the combination of BMI and waist girth tell you about his risk factors for cardiovascular disease?

3. What do the LDL, triglyceride and HDL measurements tell you about his risk factors? What other risk factors does he have?

4. What does the elevated CPK mean? How did this enzyme get into his plasma?

5. What are statins and how do they work?

Answer 1

Francois is a middle aged male who has a habit of smoking and leading a relatively sedentary lifestyle. Smoking, lack of exercise and unhealthy food habits can leads to build up Plaque inside the arteries due to fat accumulation, known as atherosclerosis and finally result in cardiovascular diseases.

2) The body mass index can be calculated by the formula

Weight ( lb) x 703 Height ( inch) 2  = BMI   ( 703 is the conversion factor for lbs/inch 2 to kg/m2 )

The patients weight = 210lbs, height = 5.10" = 70 inches ( 1 feet = 12 inches, 5 feet = 60 inches)

so, BMI = (210 x 703) 4900 ( 70 2 = 4900)

= 147630 4900

= 30.12 lbs/in2

BMI values	Remarks
Less than 18.5	Underweight
18.5 to 24.9	Normal weight
25 to 29.9	Over weight
30 and above	obese

Francois’ BMI is 30.12 which means he is obese and has high risk of cardiovascular disease and diabetes.

The accumulation of fat in the body leads to obesity, which is one of the indicator for possible cardiovascular events. The Body mass index is the indicator which gives clue about total body fatness and the measurement of waist circumference can be reliable to predict the increased risk of cardiovascular events and possibility to develop non - insulin dependent diabetes Mellitus in a in middle aged man.

3. HDL or high density lipoprotein is known as good cholesterol because it helps to remove cholesterol from the circulation. The desirable value for HDL is >60 mg / dl or more, 40 - 59 mg/ dl is border line and less the 40 mg / dl is low. The low level of HDL indicate the the person is at high risk of cardiovascular disease.

LDL or Low density lipoprotein is known as bad cholesterol because it delivers cholesterol to the body. The desirable value is 60 - 130 mg / dl, borderline value is 130 - 159 mg/ dl and 160 - 189 mg / dl is high which means the person is at high risk for cardiovascular disease.

Triglycerides are type of lipid or fat stored in the body. The triglyceride levels indicate the stored fat in the body. The desirable value is < 150 mg / dl, borderline value is 150 - 199 mg / dl and 200 - 499 mg / dl is high. High level indicate risk for cardiovascular events.

Blood test	Mr.  Francois’ blood values	Remark
Low density lipoprotein	210mg/dl	High
Triglycerides	195mg/dl	High
High density lipoprotein	28mg/dl	Low

Mr.  Franco’s blood values indicate the risk for cardiovascular events like coronary artery disease and stroke.

4. CPK or creatinine phosphokinase is an enzyme highly present in cardiac muscles, skeletal muscles and brain. If CPK is high, it indicate that any of these muscle has damaged. When muscle damage occur, CPK leake into the plasma. Mr.  Franco’s elevated CPK level can be due to cardiac muscle damage as a result of atherosclerosis in the carotid artery.

5. Stains are lipid lowering agent ( cholesterol synthesis inhibitors), coming under the pharmacological category of HMG-CoA (3- Hydroxy-3-methylbutaryl CoA) reductase inhibitors. The rate limiting step in the cholesterol synthesis pathway is reduction of HMG- CoA to mevalonic acid. This reaction is catalyzed by an enzyme called HMG-CoA reductase. Statins inhibit cholesterol synthesis by inhibiting this enzyme. That will help to decrease the cholesterol level in the body