Ask the Doctor About Coronary Heart Disease (CHD)

Answers to questions submitted during March 2005. Request for more questions will be asked for in the future.

Disclaimer

"Ask the Doctor" is an informational and educational program provided by National Rehabilitation Hospital ("NRH") to provide general information on spinal cord injury. Information posted on the "Ask the Doctor" site is provided solely for informational and educational purposes only and is not intended nor implied to be the diagnosis or treatment of a medical condition or a substitute for professional medical advice relative to your specific medical conditions. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding your medical condition.

We would like your feedback and suggestions.

Dr. Larry Hamm is a clinical exercise physiologist at the National Rehabilitation Hospital who is a Principal Investigator on two of the RRTC research studies. He also has many years of experience with CVD and cardiac rehabilitation.

Editor’s Note: Though this “Ask the Doctor” segment deals with Coronary Heart Disease, a couple of questions came in on other issues. Those answers (in red) were provided by Dr. Suzanne Groah, Director of the RRTC on SCI: Promoting Health and Preventing Complications through Exercise, as well as Director of spinal cord injury research at the National Rehabilitation Hospital in D.C.

Thanks to all of you for some great questions related to coronary heart disease (CHD) and I hope you find the information helpful.

Question: What are the risk factors for coronary heart disease (CHD)?

Answer: CHD is caused by a progressive build-up of fatty deposits (called plaque) in the arteries that supply blood and oxygen to the heart muscle. It is the same disease (atherosclerosis) that can take place in arteries supplying blood to other parts of the body, such as the brain or the legs, but CHD is limited to the arteries of the heart. There are a number of factors that affect a person’s risk for developing CHD. They include:

• Diet that is high in fat and cholesterol; elevated low density lipoprotein (LDL-cholesterol)
  • Less than 130 mg/dL recommended; less than 100 mg/dL optimal
• Low high density lipoprotein (HDL-cholesterol)
  • Less than 40 mg/dL is low; 60 or greater mg/dL is high (good)
• High blood pressure (hypertension)
• Overweight and obesity
• Cigarette smoking
• Physical inactivity
• Diabetes mellitus
• Other risk factors determined to be conditional or predisposing for CHD are:
  • Age
  • Male sex
  • Family history of premature CHD
  • Depression
  • Inflammation
  • Infection
  • Blood clotting factors

Question: Will exercise stop or rehabilitate a person with CHD?

Answer: This is a two-part question. Let’s talk about primary prevention (before any CHD is present in a person) and secondary prevention (prevention of a subsequent CHD event).

There is good scientific evidence that exercise and/or physical activity is effective at delaying or preventing CHD. This is mostly from studies that are called epidemiological research and they measure the level of exercise and physical activity in large groups of people and then follow these people for years to determine if and when they have a problem with CHD. The results of these studies show that people who are regularly active have less incidence of CHD compared to people who are less active or participate in no physical activity.

Many people who have a heart attack or surgery for CHD participate in cardiac rehabilitation programs. These are multidisciplinary programs that include medically supervised exercise training, patient education, and risk factor modification. Medical research shows that exercise reduces the risk of dying by about 25-30% in people who complete cardiac rehabilitation compared to those who do not.

What age group is at risk? As you can see in my response to Question 1, age is a risk factor for CHD. This is because the atherosclerotic process that is CHD takes years to develop to the point where it causes symptoms or other medical problems. The older we are, the longer the time has been for the disease to develop to an advanced stage. In general, the increased possibility of developing clinical signs or symptoms of CHD begins at about age 45 years in men and 55 years for women.

Question: What are the risk factors for CHD in people with SCI?

Answer: The risk factors for developing CHD in a person with SCI are the same as for the general population. An issue related to individuals with SCI is that because the medical management of SCI has improved greatly over the past years, persons with SCI are living longer. This is obviously a good thing but it is a bit of a two-edged sword. As we all age, our risk for the development of diseases that typically become problems as we get older (CHD, stroke, diabetes, etc.) increases. The primary factors that increase the risk of developing CHD in persons with CHD are abnormal blood lipids (fats), especially low HDL-cholesterol and high LDL-cholesterol, and low levels of physical activity.

Question: What are the risk factors for someone 35 plus years post injury?

Answer: See the answer for Question 3.

Question: Exercise helps but what types of exercise for people with mobility impairment?

Answer: The best type of exercise to reduce the risk for CHD is called “aerobic”. This means that the body is able to deliver the amount of oxygen to the exercising muscles that is required to continue to perform the exercise. This type of exercise involves using as much of our muscles at the same as possible and doing exercise that is rhythmic and repetitive. For persons with SCI, this could include arm calisthenics, arm biking (cranking), propelling yourself in your manual wheelchair, body weight-supported walking, and, for some who are ambulatory, walking. To be effective, exercise should be done for at least 30 minutes (could be 30 minutes continuous or intermittent – such as three 10-minute bouts of exercise throughout the day) and 3-5 days per week.

Question: Why are persons with SCI at greater risk?

Answer: See answer to Question 3.

Question: Are there proven methods other than exercise for reducing risk?

Answer: Absolutely there are. Increasing your level of exercise is important but it is also very important to do what you can to improve all aspects of your risk factor profile. If you smoke cigarettes, make up your mind to quit and select a program or support system to help you achieve this goal. If your blood pressure is elevated (>140/>90 mm Hg), follow your physician’s advice regarding dietary restrictions, exercise, and/or taking medications to control your blood pressure. If you have diabetes, follow your doctor’s advice for controlling it. And so on. CHD is known as a multifactorial disease because many risk factors interact to cause the development of the disease. This means that all risk factors that apply to you need to be addressed and managed as best as possible. However, if you have several risk factors, it is usually best to work on one at a time in order to increase the chances of success.

Question: What about weight loss? Any suggestions for losing weight?

Answer: Ask anyone who has tried to lose weight – it is not easy for most people. The concept is simple but the reality is not. The foods that we eat contain calories. Some foods are low in calories while others are high. All of the food we eat in a day will total a certain amount of calories – let’s say 2,500 calories for example. Our body requires energy (same as calories) to maintain our normal resting functions (called resting metabolic rate or RMR). In addition to these calories, our body will use additional calories whenever we are physically active. For this example, let’s say that a daily total of calories needed for our RMR and physical activity equals 1,500. This results in 1,000 calories (2,500 eaten – 1,500 used) left over at the end of the day. These extra calories are stored in the body as fat. If this energy imbalance continues like this day after day after day, we will have a significant number of the se extra calories stored as fat. If this 1,000 calorie excess was true for the next 10 days, we would have stored 10,000 calories as fat. To put this in perspective, one pound of fat equals 3,500 calories and the 10,000 extra calories translates to almost 3 pounds of body fat.

The concept for weight loss is to use more calories every day than we eat. This will result in a negative calorie balance and some of our reserve calories (fat) will need to be used to provide the energy to get through the day. A good way to increase calories used is to exercise. Ask your physician or a registered dietician for assistance with losing weight.

Question: How does one identify his/her ideal weight when living with SCI?

Answer: The most frequently used health-related measure of body weight is called the body mass index (BMI). This measure relates body weight (mass) to body height. It is expressed in terms of kilograms (kg) of body weight divided by body height in meters (m) squared (kg/m^2;). Here’s an example of the calculation.

Body weight: 150 pounds (150 pounds ÷ 2.2 = 68 kilograms of body weight)
Body height: 5 feet 10 inches (70 inches x 2.54 = 177.8 centimeters; 178 centimeters ÷ 100 = 1.78 meters)

BMI = 68 kg ÷ 1.78^2; = 68 ÷ 3.168 = 21.5 kg/m^2;

Question: I am 28 years post-injury, a C 4-5 quadriplegic who works full-time and has an active life. For the past year and a half, I have been having a bad problem with increased muscle spasms. I do not have any pressure sores, bladder problems or the other usual culprits. My neurologist increased my dosage of baclofen to 80 mg per day and that is helped, but I still have some severe spasms. At times, they can be dangerous while driving the power wheelchair. Any suggestions?

Answer: It is correct that an increase in muscle spasms is often caused by some other irritating issue, such as a pressure sore or a bladder infection, and that addressing the underlying issue then decreases the spasms. It is sometimes necessary to really dig deep to make sure that there are no underlying or hidden causes. One that comes to mind is a syrinx or spinal cord cyst. These are fairly common, especially in people who have been injured for many years and can cause subtle symptoms such as mild motor or sensory loss, autonomic dysreflexia, or spasticity, to name a few.

Question: As an individual with elevated LDL-cholesterol "bad cholesterol” what impact can drugs such as Lipitor have with regards to CHD and CVD, and can it be beneficial without exercise for a C 5-6 Quad? Also, it's my understanding that cholesterol not only comes from food, but is also generated by the body; Should a quad with elevated LDL-cholesterol look at a drug that addresses both? Finally, what can be used to justify accessible exercise equipment under private insurance?

Answer: 1. Lipitor (generic name atorvastatin) is a prescription drug in a group of medications called statins. The chemical classification for this group of drugs is HMG-Co-A reductase inhibitor so we can all be happy that they are referred to as statins. These drugs are very effective at lowering total cholesterol and specifically lowering LDL-cholesterol. It is likely that using Lipitor or another statin will lower both total cholesterol and LDL-cholesterol values that are within the recommended ranges of less than 200 and less than 130 or 100 mg/dL, respectively. Achieving the recommended cholesterol values is a good thing, whether this is accomplished as a result of medication, exercise, diet, or a combination of these interventions. There is no general reason why a person with SCI should not use a statin medication or any other drug that can lower cholesterol values. However, you will need to consult with your physician before starting any new medication and the use of some medications may require periodic blood tests to make sure that there are no side-effects to the drug.

2. You are correct in that the liver does manufacture and secrete cholesterol. Cholesterol does have good uses in the body and is involved in skin, the production of certain hormones, and digestion. The cholesterol that is produced by the liver is called endogenous (from within the body) but the cholesterol that enters the blood stream from the food we eat is called exogenous (from outside the body). Except in very cases, the result of high cholesterol levels in the blood is the result of too much exogenous cholesterol in the diet.

3. Your question about justifying accessible exercise equipment is a tough one. What is justifiable to one insurance company may not be to another. The decision to cover these types of expenses or not is usually based on the medical necessity of the equipment. The equipment would need to be prescribed by your physician and justified as medically necessary. This is something you should discuss with your personal physician. Of course, there is nothing wrong with submitting the paperwork to the insurance company and wait to see what the response is. In general, it is difficult to get this type of expense covered by insurance.

Question: I am interested in how a spinal cord injury, head injury, massive neurological damage will have on my cardiovascular health. Specifically I have autonomic dysreflexia- where my autonomic nervous system does not work appropriately. Can you be a resource on this issue? Please let me know if I should send you more complete information about my condition.

Answer: Issues related to the risk factors for CHD have been discussed in several questions above. Autonomic dysreflexia (AD) is a condition that results in a sudden increase in blood pressure that is sometimes accompanied by a slow heart rate. It is a temporary condition resulting from a dysfunction of the sympathetic nervous system. AD can result from many conditions including bowel or bladder distention, pressure sores, sunburn or spasticity. If AD occurs during an exercise session, it can be a serious complication. Blood pressure increases as a result of exercising and the added increase in blood pressure from AD can potentially result in the blood pressure getting dangerously high for a period of time. Heart rate normally increases in response to exercise and if AD results in the heart rate decreasing to a low rate; this can also be a potentially dangerous situation. There are also some who theorize that repeat bouts of autonomic dysreflexia over the course of many years may have an effect on the arteries that causes them to develop CHD more readily. In that situation it might be worthwhile to be more aggressive in screening for CHD and CVD.

Question: I am the cardiovascular guy that has hipdysplaysia and cannot walk a lot -- that sort of thing. Weight is creeping up on me. The appropriate diet, what is it?

Answer: Please see the discussion around Question 7. Here are some general guidelines regarding a diet for weight loss. It is often referred to as a “Low-Calorie Step I Diet”. Before starting any diet, you should check with your physician and getting the advice of a registered dietician is a good idea.

• Reduce your daily calorie intake by 500 – 1,000 calories compared to your usual calorie intake
• Limit your daily intake of fat calories to 30% or less of total calories
• Keep calories from saturated fats between 8 – 10 % of total calories
• Monounsaturated fats should be up to 15% of total calories
• Polyunsaturated fats up to 10% of total calories
• Cholesterol should be less than 300 grams per day
• Protein should be about 15% of total calories
• Carbohydrate should make up about 55% or more of total calories
• No more than 6 grams of sodium chloride or 2.4 grams of sodium
• 1,000 – 1,500 milligrams of calcium
• 20 – 30 grams of fiber

An alternative dietary guideline from the American Heart Association is:

• 5 or more servings per day of fruits and vegetables
• 6 or more servings per day of grain products
• Achieve and maintain a healthy body weight (BMI<25 kg/m2 – see Question 8 for a discussion of BMI)
• Achieve and maintain a desirable lipid (fats in the blood) profile; to achieve this, the daily diet should contain no more than 7-10% saturated fats, 2-3% trans-fats, and 200-300 milligrams of cholesterol

Here is the Food Pyramid which is a graphic representation of the recommended daily dietary intake (for a text version of the following graphic click here):

Question: I acquired a SCI in 1982 and have been living a pretty active life. I had an operation to make the stoma at the supra-pubic cath site larger. However, my urologist recommended making the stoma larger because the catheter was getting harder to change each month.

I have been experiencing the worse Autonomic Dysreflexia, AD for over 7 days. I also think I've noticed signs of Reflex Sympathtic Dystrophy, RSD. Can RSD occur over a week’s time? I noticed both my legs from the knee down being very cold. My left foot more than the right. Then two of my toes on the left toe turned red. I kept an eye on the foot. Last night the toes were not red, however, when my Home Health Aide was doing my PT this AM, she noticed my nail on the red toe got longer and looks like there is build-up under the nail!

I've been looking up info on RSD, but would like your thoughts on this situation. My AD was so bad over these past three days that my Blood pressure reached 214/95 pulse 66; when my normal BP is around 90/60. Thanks, any advice would be greatly appreciated!

Answer: One way or another, whether this is RSD or not (could it be an ingrown toenail or could you have a circulation problem in your leg(s)?), this should be checked by your physician as soon as possible. Anything that is causing your AD to increase this much over this period of time needs a close assessment.

Question: I have had Herrington Rods in my back to correct my scoliosis since I was 16. I am now 29. My rods are all the way through my back. My question is, am I at low, moderate, or high risk of developing Coronary Heart disease??

Answer: Remember from the discussions of previous questions, the calculation of risk for CHD is an individual thing and can be done by your physician who has access to your health information. There is a system for calculating individual risk for CHD developed from the research done through the Framingham Heart Study. A person’s age, sex, total cholesterol, HDL-cholesterol, systolic blood pressure, absence or presence of diabetes, and whether or not you smoke is used to calculate a risk percentage for developing CHD in the next 10 years. The percent risk scores are divided into below average, average, moderately above average, and high risk categories. This is a used only with people who have no history of CHD. Perhaps you could discuss this with your doctor.

Following is a text version of Food Pyramid Graphic

The food chart is broken down in six boxes representing food groups. The size of the box corresponds with the size of a daily recommended intake of that food group. From the most amount recommended to the least amound recommended, the list is:

Breads and Cereal Group: 6 or more servings
Vegetable Group: 3-5 servings
Fruit Group: 2-4 servings
Milk Group: 2 servings
Meat or Alternatives Group: 2 servings
Fats, Oils, Sweets: use occasionally