Middle-aged people who do not smoke and do not have hypertension or obesity, will, on average, become ill nine years later.
Common risk factors
The study showed that as many as 90 percent of people 45 years and over of age will suffer from non-communicable diseases, including heart diseases, cancer, stroke, diabetes, chronic respiratory diseases (including COPD) or neurodegenerative diseases, such as dementia and Parkinson's disease later in life. At least a third of these people will be diagnosed with multiple diseases during their lifetime.
Arfan Ikram, Professor of Epidemiology: “We see that common risk factors such as smoking, high blood pressure, and obesity play a major role in the development of these diseases. Our findings underline the importance of a healthy lifestyle and show that prevention is effective. People can live healthy lives longer by not smoking and by preventing high blood pressure and obesity. This also means that once the first disease manifests in healthy people, the time that they will subsequently suffer from the consequences of these diseases will be shorter.”
“We also examined the distribution of these diseases in people with all of these risk factors and in people without these risk factors of smoking, overweight and high blood pressure”, Ikram explains. “In people who do not have these risk factors, we observed a lower risk for diabetes, lung diseases and heart diseases, but eventually an increased risk to develop dementia later in life. People without these risk factors generally live longer, and an advancing age is strongly related to dementia risk. Yet, this does not mean that for example smoking is protective for dementia risk, as we know that smokers have an increased risk of developing dementia compared to non-smokers, but they will more likely to be diagnosed with one of the other five diseases before they become at risk for dementia later on.”
The researchers also noted striking differences in the age at which these diseases first manifest in men and women. Ikram: “For example, men are more likely to develop these diseases at a slightly younger age than women. In addition, the distribution of the first manifestation of diseases between men and women was different. Compared to women, men are more likely to suffer from heart disease and chronic lung disease first, whereas women have a higher risk to develop neurodegenerative diseases as first disease manifestation compared to men. In this study, men were more often smokers than women which may have contributed to these findings, given that smoking is strongly related to heart disease and chronic lung disease. However, we do not yet have a conclusive explanation.”
The researchers based their findings on the data of more than 9,000 people participating in the ERGO population study also known as the Rotterdam Study.