# Exercise as it relates to Disease/Medication vs. exercise in reducing dyslipidemia
## Brief background

Dyslipidemia are abnormal lipid levels (cholesterol,triglycerides or both) carried by lipoproteins in the blood. This term includes hyperlipidemia which refers to abnormally high levels of total cholesterol, low density lipoprotein (LDL) "the bad” cholesterol, or triglycerides, as well as an abnormally low level of high density lipoprotein (HDL) "the good” cholesterol. In Australia, about 32% of adults are diagnosed with abnormal high cholesterol where the levels are above 5 mmol/L.

## Risk factors

Having any of the following risk factors puts you at a higher likelihood of developing dyslipidemia:
* Smoking: Smoking damages the walls of your blood vessels, making them likely to accumulate fatty deposits. It also lowers your level of HDLs.
* Obesity: Having a body mass index of 30 or higher puts you at risk of dyslipidemia.
* Poor eating habits: Foods that are high in cholesterol, full fat dairy products and certain meats increase total cholesterol. Eating saturated fats and trans fats raise your total cholesterol.
* Sedentary lifestyle: Exercise helps raise HDL "good" while lowering your LDL "bad" cholesterol.
* High blood pressure: Increased pressure on your artery walls damages your arteries which can speed the accumulation of fatty deposits.
* Diabetes: High blood sugar contributes to higher LDL cholesterol and lower HDL cholesterol also damaging the lining of arteries.
* Family history: If a parent or sibling developed heart disease before the age of 55, lipid levels places an above average risk of developing heart disease.

## Associated Health Issues

Dyslipidemia can cause atherosclerosis which is an accumulation of cholesterol on the walls of arteries. These plaques can reduce blood flow through arteries which can cause complications such as:
* Chest pain: If the arteries that supply your heart with blood are affected, chest pain may develop and other symptoms of coronary artery disease.
* Heart attack: If plaques tear or rupture, a blood clot may form restricting blood or breaking free and clogging another artery. If blood flow to part of the heart stops, a heart attack will occur.
* Stroke: Similar to a heart attack, if blood flow to part of the brain is blocked a stroke occurs.

## Treatment

Lifestyle changes such as exercising and eating a healthy diet are the first line of treatment against high cholesterol. But if these changes are made and total cholesterol remains high, doctors may recommend medication.

## Exercise and Diet

Making lifestyle changes such an increasing physical activity levels and making suitable dietary changes is the preferred form of treatment across all levels of dyslipidemia. Studies on the link between exercise, diet and dyslipidemia show that low saturated fat diets combined with exercise lowered total cholesterol, LDL, and triglyceride concentrations by 7-18, 7-15, and 4-18% respectively, while increasing HDL levels by 5-14%. The findings suggested that lifestyle changes are effective improving cholesterol levels and should be implemented in place of medication when cholesterol levels fall just above normal range.

## Medication

At present, dyslipidemia is most commonly treated with drug therapy. The specific choice of medication or combination of medications depends on various factors, including individual risk factors, age, current health and possible side effects. The main drugs used for treatment are:
* Statins: Stop enzymes that control the rate at which the body produces cholesterol. They have been shown to reduce LDLs at 20-55%, lower triglycerides and raise HDL.
* Ezetimibe: Reduces the amount of cholesterol absorbed by the body lowering LDLs by 18–25%.
* Bile acid resins: These bind with cholesterol containing bile acids in the intestines and are then eliminated from the body through stool.They lower LDL cholesterol by 15–30%.
* Nicotinic acid: A B vitamin that improves total cholesterol when taken in larger doses. LDL levels are usually reduced by about 5–15% and up to 25%.

## Consensus

While there is overwhelming evidence for benefits of both lifestyle and pharmaceutical interventions, medication reduces dyslipidemia the most while lifestyle changes are a large factor in combating dyslipidemia among all levels. The National Vascular Disease Prevention Alliance (NVDPA) guidelines for combating dyslipidemia and reducing the likelihood of CVD outline where the need for pharmaceutical interventions to come into place as they are not for everyone due to some of the side effects especially when beginning exercise program. It recommends lifestyle intervention for all individuals as well as medication depending on the level of risk. The risk stratification is as follows:
* Low risk (<10% risk of CVD within the next 5 years) – lifestyle intervention (diet and exercise).
* Moderate risk (10-15% risk of CVD within the next 5 years) – lifestyle intervention initially, consider medication after 6-12 month review.
* High risk (>15% risk of CVD within the next 5 years) – lifestyle intervention and pharmacological therapy.

## Recommendations

Prevention is the key in reducing dyslipidemia. Adopting a healthy lifestyle continues to be the first and best way to lower your risk of problems and in doing so can also help control other risk factors such as CVD, high blood pressure and Type 2 diabetes. Some ways to do this are by:
* Eating a diet rich in fruits, vegetables and whole grains which includes low fat dairy products, poultry, fish, legumes, and nuts and limiting the intake of sweet foods and drinks and red meats.
* Participating in regular exercise (30 minutes a day).
* Maintaining a healthy weight or losing weight if overweight.
* Not smoking or getting help quitting.
* Staying on top of your health, risk factors and medical appointments.
* Remaining compliant with prescribed medications.

## Further reading

Australian Guide to Healthy Eating Treatment and Management of high cholesterol Australian Government Department of Health Physical Activity Guidelines

## References

* ↑ 1. Aafp.org. Clinical Evidence Handbook: Primary Prevention of CVD: Treating Dyslipidemia - American Family Physician [Internet]. 2014 [cited 29 September 2014]. Available from: http://www.aafp.org/afp/2011/0515/p1207.html
* ↑ Heartfoundation.org.au. Cholesterol [Internet]. 2014 [cited 30 September 2014]. Available from: http://www.heartfoundation.org.au/healthy-eating/fats/Pages/cholesterol.aspx
* 1 2 3 4 Philip et al. B. Lipid Management Guideline-2001. The Medical Journal of Australia. 2014;175(1).
* 1 2 4. Varady K, Jones P. Combination diet and exercise interventions for the treatment of dyslipidemia: an effective preliminary strategy to lower cholesterol levels?. The Journal of nutrition. 2005;135(8):1829--1835.
* ↑ US department of Health and Human Services. Lowering Your Cholesterol with TLC. America: US department of Health and Human Services; 2001 p. 15.
* ↑ The Heart Foundation Australia. The National Heart Foundation of Australia’s summary of the recommendations for Cholesterol Management. Australia: Heart Foundation; 2014 p. 3.
* ↑ Heartfoundation.org.au. High cholesterol Management [Internet]. 2014 [cited 27 September 2014]. Available from: http://www.heartfoundation.org.au/your-heart/cardiovascular-conditions/Pages/high-cholesterol.aspx