News Centre

6 Feb 2007

Male Home Smoking Strikingly Increases Spouse’s Risk of Coronary Heart Disease

6 Feb 2007

The amended Smoking (Public Health) Ordinance, aiming to provide protection against second hand smoking in indoor workplace and public places, has been effective January this year. Although it provides a smoking-free environment in the public domains, smokers might have to choose either quitting smoking or continuing their smoking habit in the household setting. Active smoking is a known risk factor for coronary heart disease (CHD), a top killer as a single disease in Hong Kong and worldwide. In the recent few years, overseas research data also suggests that passive smoking (or second-hand smoking) could be a risk factor for heart diseases. In Hong Kong, passive household smoking is a potential problem, in particular for female subjects whose spouses are smokers.

Between 2004 and 2006, a research project has been conducted by the S.H. Ho Cardiovascular and Stroke Centre and Division of Cardiology of the Department of Medicine and Therapeutics at The Chinese University of Hong Kong. The study consisted of a total of 507 subjects, including 239 female patients with CHD and 268 patients without CHD as controls, all of them never smoke. These patients were enrolled from major hospitals of New Territories East Cluster, and mainly from Prince of Wales Hospital. A detailed questionnaire was conducted face to face to each of them, and data about their exposure to passive household smoking from spouses were analyzed.

The results showed that 34% of patients with CHD and 25% of patients without CHD were exposed to passive household smoking. Also, passive household smoking exposure will increase the risk of CHD by 1.6 fold. Moreover, the risk will be increased to nearly 3.6 fold if their spouses smoked for 10 years or more. Similarly, the risk will be strikingly increased to 3.9 fold if their male spouses smoked for 1 pack of cigarette per day or more.

In conclusion, passive household smoking increases the risk of CHD in female if their spouses are active smokers. The risk is proportional to the intensity and duration of exposure to passive household smoking. With the implementation of new anti-smoking measures in Hong Kong, household smoking will increase inevitably. This may create another health care problem to the society.