4.7 Special circumstances?
Individuals can only attempt to alter risk factors they are aware of and need to be informed about what is relevant to them. Women and men have different considerations, and ethnic background can also have an influence on susceptibility to cardiovascular diseases. Such considerations require improved awareness based on reliable knowledge from scientific studies (see Box 4 on B vitamins). Women have extra protection from cardiovascular diseases during their reproductive years, due to their higher concentrations of the hormone oestrogen. (A hormone is a chemical messenger that travels via the blood.) However, this ‘protection’ may give women and their doctors less reason to suspect cardiovascular diseases and their gradual development may go unnoticed. Cardiovascular diseases remain the main cause of death in women in all European countries (Petersen et al., 2006), the USA (American Heart Association, 2006) and in many other countries. Even simply the awareness of cardiovascular disease risk has been found to be lower in black and Hispanic women compared with white women (around 30 per cent, compared with nearly 70 per cent) with more than 50 per cent of all respondents (average age of 50) confused about how to embark on cardiovascular disease prevention strategies (Christian et al., 2007).
Box 4: To supplement with B vitamins or not to supplement with B vitamins?
Some women take antioxidant dietary supplements because initial studies suggested they would lower the risk of developing a serious cardiovascular disease. A large medical study – the Women's Antioxidant and Cardiovascular Study (WACS) – is underway in the USA and it is designed to investigate whether the vitamins B6, B12, C and E, folic acid and beta-carotene reduce the risk of cardiovascular disease episodes specifically in women. The researchers have recruited nearly 5500 female health professionals throughout the country who are over 40 years old and have either an existing cardiovascular disease or a minimum of three cardiovascular disease risk factors. Seven years into the study, the investigators have found no differences between women receiving supplements and women taking a placebo (a ‘dummy pill’ with no active ingredient) in terms of the cardiovascular disease events that had been experienced during that time period: 15% for both groups. This study is the fourth large investigation that has found no benefit of taking B vitamins and folic acid to specifically avoid cardiovascular diseases in women and their use is not now recommended for this purpose alone.
Ethnicity is important in terms of health care because patterns of cardiovascular disease risk factors vary by ethnic group. In some situations, this is also complicated by socioeconomic status. In some cases, moving to live in different countries – from rural China to urban USA, for example – dramatically alters disease and cardiovascular disease risk. In contrast, South Asian people from the Indian subcontinent or East Africa have higher incidences of coronary heart disease regardless of whether or not they are indigenous to the area (Lip et al., 2007). African-American people have higher incidences of stroke – but, somewhat surprisingly, lower rates of coronary artery disease – in families with a number of members with diabetes (Freedman et al., 2005). These examples highlight the need for further extensive studies on cardiovascular disease risk factors in individuals from different ethnic backgrounds and localities.