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Press releases Saturday 19 August 2006

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(1) CHINA FOLLOWS THE WEST TO BECOMING OBESE

(2) CHINESE MEN PUTTING WIVES AT RISK OF EARLY DEATH BY SMOKING

(3) LOWER BIRTH RATE AND FEWER GIRLS UNDER CHINA’S ONE CHILD POLICY

(4) LESSONS FROM SARS MAY HELP PREPARE FOR BIRD FLU

(1) CHINA FOLLOWS THE WEST TO BECOMING OBESE

(Editorial: Overweight and obesity in China)
http://bmj.com/cgi/content/full/333/7564/362

People in China are becoming overweight and obese at an alarmingly fast rate, according to an editorial in this week’s BMJ.

Numbers of people in China who are now classified as overweight and obese have risen sharply in a relatively short time, says Professor Yangfeng Wu from the Chinese Academy of Medical Sciences in Beijing.

They account for one fifth of the world’s population in this condition, despite China once being seen as country with a lean population.

Figures from the 2002 national nutrition and health survey in China showed 14.7% of Chinese were overweight and another 2.6% were obese – meaning that there were an estimated 184 million overweight people and a further 31 million obese people there.

Data from the China national surveys on the constitution and health in school children also showed that the prevalence of overweight and obesity in children aged 7-18 increased 28 times and obesity increased four times between 1985 and 2000.

The reasons for this can be attributed to a combination of factors including changes to traditional diet, reduced levels of physical activity, and a more sedentary lifestyle, says Professor Wu, for example, with a large rise in the number of cars being bought. Production of cars in China rose from 5,400 in 1980 to over 2 million in 2003.

“As in other countries, China’s epidemic of overweight and obesity poses a considerable public health problem, and it is becoming increasingly clear that we need to act now to prevent any further increase,” he writes.

Ways of doing this are uncertain, he suggests, but lifestyle education could help as well as listing the prevention and control of obesity as a goal in China’s framework and policy on health.

Contact:

Yangfeng Wu, Director of Clinical Research Program, Peking University Health Science Center, China
Email: yangfengwu@263.net; ywu@george.org.cn

(2) CHINESE MEN PUTTING WIVES AT RISK OF EARLY DEATH BY SMOKING

(Environmental tobacco smoke and mortality in Chinese women who have never smoked: prospective cohort study)
http://bmj.com/cgi/content/full/333/7564/376

Chinese men are putting their wives at increased risk of long-term illness and early death by smoking, finds a study in this week's BMJ.

Exposure to environmental tobacco smoke (passive smoking) is associated with a 15-35% excess risk of coronary heart disease and lung cancer. Environmental tobacco smoke may also be linked to stroke and other cancers, though evidence is scarce.

The rate of smoking in Chinese men is high, but most Chinese women do not smoke. This provides a good opportunity to evaluate this association in women.

Over 72,000 women took part in the study. They were aged between 40 and 70, had never smoked, and lived in seven areas of urban Shanghai, China.

Women were surveyed at the start of the study about smoking and other lifestyle factors, for themselves and for their husbands. Exposure was measured by the number of pack years (years of smoking multiplied by packs of 20 cigarettes) that the husband smoked during the marriage. Demographic details and disease history, reproductive history, family history, and dietary history were also recorded.

Two follow-up surveys were conducted during the course of the study to obtain information on death and common diseases diagnosed after the initial survey.

A high proportion of women (83.1%) were exposed to environmental tobacco smoke from their husbands, at work, or in early life (or in combination).

Exposure to tobacco smoke from husbands was associated with a moderately increased risk of death from all causes and more strongly with increased mortality due to cardiovascular disease and stroke.

Exposure in early life was also associated with increased mortality due to cardiovascular disease, while exposure to tobacco smoke at work was associated with increased mortality due to cancer, especially lung cancer.

These results are generally consistent with previous studies and suggest that exposure to environmental tobacco smoke at different times of life may contribute to the risk of different diseases, say the authors.

They also analysed the effect of duration of exposure to environmental tobacco smoke on mortality and found significant relations between deaths due to stroke and husband’s number of pack years, between deaths due to lung cancer and total years of exposure at work, and between deaths due to cardiovascular diseases and total years of exposure in early life.

Given the high prevalence of exposure in this population, the impact of environmental tobacco smoke on all cause mortality could be substantial, they conclude.

Contact:

Wanqing Wen, Research Assistant Professor, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN, USA
Email: wanqing.wen@vanderbilt.edu

(3) LOWER BIRTH RATE AND FEWER GIRLS UNDER CHINA’S ONE CHILD POLICY

(Family size, fertility preferences, and sex ratio in China in the era of the one child family policy: results from national family planning and reproductive health survey)
http://bmj.com/cgi/content/full/333/7564/371

Since the start of the one child family policy in China, the total birth rate and preferred family size have decreased, and a gross imbalance in the sex ratio has emerged, finds a study in this week’s BMJ.

The one child family policy has been in force in China since 1979 and was intended as a short term measure. To examine the impact of this policy, researchers analysed data from the 2001 national family planning and reproductive health survey.

Data were obtained from 39,585 women aged 15-49. The total birth rate has dropped from 2.9 before the policy to 1.94 in women over 35 and 1.73 in women under 35.

Most women want small families: 35% would prefer one child, 57% preferred two, and only 5.8% more than two. The preferred number decreased with age and higher education, and was lower among women in urban areas.

The male to female ratio was 1.11 in 1980-9 but rose sharply to 1.23 in 1996-2001. The sex ratio for first births was higher in urban areas, where only one child is allowed, suggesting that some people select the sex of their child at first birth.

Over a third of women had no sex preferences. Of those who did, 72% preferred a girl and a boy, whereas 10% preferred girls (most of these were women under 25 who lived in urban areas).

It is not clear how much these demographic changes are due to the one child policy, they add. Many countries are seeing decreases in fertility rates, and neighbouring east Asian countries have some of the lowest total fertility rates in the world. Thus the fertility rate may have continued to fall even without the policy.

Likewise many other Asian countries that have declining birth rates and traditional preferences for male babies are seeing serious sex imbalances. Even without the policy, sex selective abortion would be likely to continue, although it would probably be less common.

This can only be solved by a change in attitudes towards female offspring. The finding that many younger women in urban areas now express a preference for girls provides evidence that attitudes may be changing.

These findings have clear implications for decisions about future population policy. A relaxation in the policy could be considered in the near future. It is unlikely that a baby boom would result, and such a change in policy might help to correct the abnormal sex ratio, they conclude.

An accompanying editorial discusses the impact of this policy on China’s economy.

Contact:

Therese Hesketh, Senior Lecturer, Centre for International Child Health, Institute of Child Health, London, UK
Email: t.hesketh@ich.ucl.ac.uk

(4) LESSONS FROM SARS MAY HELP PREPARE FOR BIRD FLU

(What we have learnt from SARS epidemics in China?)
http://bmj.com/cgi/content/full/333/7564/389

Lessons learnt from SARS epidemics in China may help us prepare for new epidemics, such as human avian flu, say experts in this week’s BMJ.

Mainland China experienced three outbreaks of SARS between November 2002 and May 2004. The first outbreak resulted in a pandemic and caused huge financial loss and social panic, but rigorous control policies prevented further pandemics.

Such efforts mean that SARS is currently under control. But what have we learnt and how can this help us tackle new epidemics in the future?

Lessons learnt include being honest with the public about what is happening, ensuring close collaboration between laboratory workers and health professionals, involving health professionals in developing official policies, and adhering to strict scientific regulations.

So how can we do better next time?

SARS has not been eradicated, and humans remain vulnerable to emerging infectious diseases like bird flu, say the authors. As we face up to the threat of future pandemics, we can take encouragement from the fact that many of the uncertainties that arose during the SARS outbreak were resolved over time.

Future strategies should focus on close collaboration between health professionals to contain emergent infections and constant consultation to develop appropriate official policies. An international monitoring network for the early alerting of infectious diseases is also needed.

Lessons taught by SARS have given us a new outlook on a devastating human health crisis, and have important implications worldwide, they write.

What has happened with the spread of the SARS virus must not be allowed to happen again with H5N1. Incessant efforts are needed to improve our preparedness, they conclude.

Contact:

Nanshan Zhong, President, Chinese Medical Association, Guangzhou Institute of Respiratory Diseases, Guangzhou, China
Email: nanshan@vip.163.com

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