Cardiovascular Health

Disease of heart and blood vessels (cardiovascular diseases, CVD) is the leading cause of deaths in the United States and one of the most common causes of fatal diving accidents.1 The prevalence of CVD increases with age as does the risk of death2 (Table 1), but death may also occur in subjects who had no previous symptoms of CVD. Both apparently healthy subjects and those with diagnosed CVD may reduce their risk by modifying their lifestyle and controlling risk factors like smoking, physical inactivity, poor diet, alcoholism, high cholesterol, being overweight and having high blood glucose. A healthy lifestyle increases a diver's longevity, quality of life and safety. In this article we will review known cardiovascular risk factors, the evaluation of individual risks and preventive measures that reduce risk of CVD and related death.

Evaluate your risks
According to the results of the recent National Health Interview Survey conducted by Center for Disease Control and Prevention (CDC), 12 percent of adults 18 years and older had been told by a health professional they had heart disease; 6 percent had been told they had coronary heart disease; 24 percent had been told on two or more visits that they had hypertension; and 3 percent had been told they had experienced a stroke.2 These individuals are obviously at an increased risk of dying prematurely, and they must be treated for their conditions. Said individuals may benefit from physical activities, but the type and the vigor of activities must be discussed with their personal physicians.

People who do not have any symptoms may still have silent CVD, which can cause sudden death, or they may develop clinical manifestations of CVD later in their life. Scientists have identified risk factors as well as measured their individual and combined impacts. Testing for these risk factors is simple and affordable. Individual risk factor measurements may be combined into a single quantitative estimate of risk, known as a "global risk score" that can be used to guide preventive interventions. You can obtain your global risk score using one of the published global risk score calculators (Table 2). Before visiting the sites to take a test, you should obtain the requested information specified in the table.
Reduce your risk
  • Quit smoking
  • Moderate your drinking
  • Watch your diet
  • Exercise regularly
  • Visit your physician annually

These steps may help you reduce your weight and help control blood pressure, cholesterol and blood glucose levels.

Smoking is one of the most damaging abuses; it diminishes functions of lungs, causes hardening and narrowing of blood vessels, and increases risk of cancer. It is considered the largest preventable cause of death in the world. Health and functional integrity of the lungs and the circulation are main determinants of physical fitness. For divers, both organs are additionally important because of their role in the transfer of gasses in the body and response to gas bubbles.

Alcohol consumption affects many organs and functions in the body. Small amounts of alcohol may have some favorable effects, but overindulgence damages the brain, liver, heart and other organs. Alcohol is very rich with calories and, in excessive consumption, contributes to metabolic syndrome and obesity. Acute effects of alcohol are not compatible with diving.

Imbalance in food consumption and energy combustion is the main cause of obesity. Even physically active individuals may be overweight if they have an insatiable appetite. On the other hand, for people living a sedentary lifestyle, it is hard to shed weight despite limiting their food intake.

Certain ingredients may contribute to specific diseases. Three culprits include salt, sugar and flour. Salt may contribute to increased blood pressure, while too much sugar and flour can cause an individual to be overweight or increase risk for diabetes. People who have elevated cholesterol should limit red meats and bad fats in their diet.

The simplest solution for the average person to achieve a reasonable diet is to limit portion sizes and eat a variety of foods.

Exercise is the main factor in the health of modern people. Advances in our socio-economic environment eliminated the need for physical activities in everyday life; as a result most people should exercise purposefully. Both bursts of near-maximum exercise and periods of prolonged vigorous exercise are necessary to maintain body structures, physical working capacity, integrity of the cardiovascular system, the body's natural defense systems and its self-repair processes.

Participation in recreational diving may not provide sufficient exercise. Indeed, limiting exercise in diving is one of the strategies to control risk of decompression illness, but divers must be physically fit to respond to emergencies that may arise. There is no formal consensus about what the required minimum sustained exercise capacity for divers is or how to measure it. Currents of 1 knot (33 yards per minute) are not uncommon, and divers at the surface should be able to swim faster than that in case the need arises to swim against it. Dedicating some of your own exercise time to achieving this goal is worthwhile for divers.

Annual physical exams
For risk factors like smoking, alcoholism, excessive weight and inactivity, divers should not need a physician's warning; these are not contributors to good health. However, risk factors like blood pressure, blood glucose and cholesterol can be measured by simple and inexpensive tests, and all adults should be tested periodically. Most healthcare insurance companies provide incentives to their clients to visit primary physicians for annual evaluations.

For healthy divers, annual physicals are a great opportunity to review their general health and lifestyle as well as to obtain an advanced warning if anything changes in their blood chemistry. In cases of divers with known risks, the annual exams are an opportunity for physicians to check for early signs of possible organ damage and to adjust control measures if needed. Diabetes, high cholesterol and hypertension may benefit from lifestyle changes, but most patients need prescription medications for proper control of these risk factors and their possible consequences.
  1. Center for Disease Control and Prevention. FastStats. Deaths and Mortality

  2. Summary Health Statistics for U.S. Adults: National Health Interview Survey, 2009. Data From the National Health Interview Survey No. 249. DHHS Publication No. (PHS) 2011-1577.

  3. 2010 ACCF/AHA Guideline for Assessment of Cardiovascular Risk in Asymptomatic Adults. Posted: 12/22/2010; J Am Coll Cardiol. 2010;56(25):2182-2199. © 2010 Elsevier Science, Inc.