NEWSLETTER October 2012

PREVENTIVE HEALTH - Screening for Cardiovascular Disease

Cardiovascular disease is the main cause of mortality in western societies and is expected to become the main cause of death in most countries within the next decade, however the good news is that deaths from cardiovascular disease have declined sharply from the peak levels of the 1960s. This decline has been attributed to better detection and treatment and the implementation of improved preventive measures. Despite these improvements, there is no widely accepted comprehensive preventive health strategy to combat cardiovascular disease. Preventive measures tend to be scattered and disproportionate. The focus tends to switch back and forward from smoking to cholesterol or obesity or exercise or salt in a random and confusing manner.

There is also no universal agreement on the effectiveness of screening, or whether screening should be applied to all individuals or only those identified as high risk. There is also concern that programmes such as the UK’s national screening programme offer only one screening event rather than a series of screening tests over a period of years.

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Risk Factors

Cardiovascular disease is caused by a build up of plaque on the arterial walls, causing narrowing and reduced blood circulation. This reduction in circulating blood can result in oxygen starvation of tissue, particularly heart muscle, causing pain and eventual failure of this vital muscle. Although the mechanism of plaque formation can be explained, the cause of the initial damage to the vessel wall is not known, however a number of factors that are thought to increase the risk of heart disease have been identified, including the following

Screening Tests

Some individuals who have no obvious risk factors may be at risk of cardiovascular disease, and many of these can be detected using some relatively simple screening tests. Individuals who are not part of an existing cardiovascular screening programme may wish to consult their medical practitioner or health professional about a screening programme utilising some relatively simple tests such as

Lipid US Europe Definition

Total cholesterol <200mg/dl <5.2mmol/l Desirable

200-240 5.2-6.2 Borderline

>240 >6.2 High

LDL <70 <1.8 For high risk heart dis

<100 <2.6 For at risk heart dis

100-130 2.6-3.3 Optimal normal level

130-160 3.4-4.1 Borderline high

160-189 4.1-4.9 High

HDL-men <40 <1 Low –not good

women <50 <1.3 Low – not good

50-60 1.3-1.5 Normal

>60 >1.5 Good

Triglycerides <150 <1.7 Desirable

150-200 1.7-2.2 Borderline

>200 >2.2 High

Low risk (less than 1.0 milligrams per liter, or mg/L)

Average risk (1.0 to 3.0 mg/L)

High risk (above 3.0 mg/L)

Other laboratory markers for cardiovascular risk which may be included in a screening programme include homocysteine and natriuretic peptides

Preventive Measures

Age is a risk factor that is to some extent beyond our control, however we can delay the ageing process by leading an active, productive life, taking regular exercise, eating a healthy diet and minimising stress.

Individuals with a family history of heart disease can minimise their risk by early screening and the adoption of appropriate preventive measures.

Excessive waist measurement indicates increased fat deposition. This can be reduced by exercise and appropriate changes in diet.

High blood pressure may respond to increased exercise and changes in diet or stress levels. Alternatively it may be controlled by medication.

Cholesterol levels may be lowered by exercise or changes in diet. Individuals at increased risk of heart disease may require cholesterol lowering medication

Individuals with diabetes or rheumatoid arthritis should be screened regularly for heart disease.

Regular exercise is good for the heart as it assists blood circulation and strengthens the heart muscles.

DID YOU KNOW – The Heart is a Muscle

The heart is a fist sized organ consisting of a powerful muscle which surrounds four chambers. The involuntary contraction of this muscle squeezes blood out of the heart chambers and around the blood vessels. Like most muscles in the body, heart muscle benefits from exercise.

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Exercise causes progenitor cells to divide producing new muscle and increasing muscle bulk. Exercise also increases the number of small blood vessels and improves blood circulation to the expanding muscle. The stronger heart muscle is able to pump blood more efficiently and improve oxygen and nutrient supply to all organs. As the heart muscle grows stronger it becomes more efficient and can pump more blood in each beat. This results in a reduction in heart rate and blood pressure.

There are two main types of exercise recommended to maintain or improve cardiac function. The first category includes less strenuous forms of exercise such as walking or jogging. It has been shown that 30 minutes of brisk walking or 10000 steps (measured with a pedometer) each day will improve cardiac function

The second form of exercise includes strength or resistance training using weights or exercise machines. Three to four 30 minute sessions per week of strenuous exercise which causes a significant increase in heart rate have been shown to significantly improve cardiac function and reduce body fat.

To avoid excessive strain on the heart, the required heart rate increase should take into account age and general fitness. This can be calculated from the following formula

Target heart rate at end of exercise session = 220-age x 0.75 or ¾

For a sixty year old this would be 220 – 60 = 160 x 0.75 = 120 .

Pulse should be taken at the wrist before and after exercise to ensure there is an appropriate increase in heart rate.

Recent studies have compared these two forms of exercise and shown an average decrease in systolic blood pressure of 9% in the strenuous exercise group compared with 3% in the walking group, a 15% versus 4% respiratory improvement and a 10% versus 0 increase in general muscle power.

Strenuous exercise is any exercise that significantly increases the heart rate. This can include sport, household chores, gardening, dancing or any other leisure or work related activity.

One of the simplest forms of strenuous exercise is skipping. Vigorous use of a skipping rope 30 minutes a day, three to four times a week with the appropriate increase in heart rate, is a simple inexpensive form of exercise that is readily available and will significantly improve heart muscle function..

No form of exercise offers significant benefit unless it is maintained and this means establishing a routine. Maintaining an exercise routine on your own can be difficult and for this reason most people choose to exercise in groups at an exercise club or gymnasium.

Benefits from an exercise programme may take six months to become obvious and should continue to accrue thereafter.

NEWS – Exercise Improves Prostate Cancer Survival

The benefits of regular exercise continue to unfold. A recent study by the Harvard School of Public Health has demonstrated impressive improvements in survival rates for men who have received treatment for prostate cancer and who exercise.

Researchers followed 2,686 prostate cancer patients from 1986 through 2008. The researchers assessed each man's physical activity both before and after prostate cancer treatment.

The study concluded that men who engaged in vigorous physical activity for 30 minutes per week (jogging, biking, swimming, or playing tennis) had a 35% lower risk of dying from any cause. Men who walked 4 or more hours per week had a 23% lower risk of dying from any cause than men who walked for less than 20 minutes. Power walkers – those who walked 90 minutes or more at a normal to brisk pace -- saw their risk decline even more, by 51%, as compared to men who walked less (less than 90 minutes at an easy pace).

The study also indicated that men who exercised vigorously for more than 5 hours each week were less likely to die from prostate cancer.

Regular exercise also has many other benefits. It can help reduce the bone-weary fatigue many cancer patients feel even after treatment has stopped. It improves your cardiovascular (heart and circulation) fitness, strengthens your muscles, lowers anxiety and depression, and can help you feel better about yourself. Exercise such as weight-lifting can also help combat the side effects – fatigue, functional decline, loss of lean body issue, and increased body fat – associated with hormone therapy.

DEM