Part Two. The urgent need for action
Chapter One. Chronic diseases: causes and health impact
Childhood risk: a worrying trend
There is now extensive evidence from many countries that conditions before birth and in early childhood influence health in adult life. For example, low birth weight is now known to be associated with increased rates of high blood pressure, heart disease, stroke and diabetes (2). Rates of tobacco use among 13-15 year-olds are higher than previously expected. According to the Global Youth Tobacco Survey and Global School-based Student Health Survey, current tobacco use among males in this age group is 29% in India, 21% in Brazil, and 14% in China. Many children begin smoking before the age of 10 years.
Childhood obesity is associated with a higher chance of premature death and disability in adulthood. Worryingly, approximately 22 million children under the age of five years are obese. While affecting every country, overweight and obesity in children are particularly common in North America, the United Kingdom, and south-western Europe. In Malta and the United States, over a quarter of children aged 10-16 years are overweight. In the United Kingdom, the prevalence of overweight in children aged 2 to 10 years rose from 23% to 28% between 1995 and 2003.
Obesity is a known risk factor for type 2 diabetes. Until recently type 2 diabetes was mainly a disease of adults. The first cases of type 2 diabetes in young people were recognized in the United States in the 1970s. Fifteen years ago, they accounted for less than 3% of all cases of new-onset diabetes in children and adolescents, whereas today they account for up to 45% of new-onset cases. Subsequent studies conducted in Asia and Europe have revealed a similar pattern, and, more recently, reports on type 2 diabetes in children and adolescents have begun to mount worldwide (3).
Ageing is an important marker of the accumulation of modifiable risks for chronic disease: the impact of risk factors increases over the life course. A key lesson from many wealthy countries is that it is possible to delay deaths from chronic diseases by several decades, thereby avoiding deaths among middle-aged people. Successful interventions in middle and older age will reap major short-term benefits. In the longer term, interventions early in life have the potential to reduce substantially the chronic disease pandemic.