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The incidence of cancer is higher in developed than in developing countries, suggesting an association between lifestyle and metabolic risk factors and cancer risk.
The aim of the metabolic syndrome and cancer project (Me-Can) was to investigate body mass index (BMI), blood pressure, and blood levels of glucose, total cholesterol, and triglycerides as risk factors of cancer and cancer death.
Me-Can is a pooled cohort study with data from 578,700 participants from Norway, Sweden, and Austria involving 6 different prospective cohorts (in Norway – the Oslo study I (Oslo), Norwegian Counties Study (NCS), the Cohort of Norway (CONOR) and the Age 40 programme (40-y); in Sweden – the Västerbotten Intervention Project (VIP) and Malmö Preventive Programme (MPP); and in Austria – the Vorarlberg Health Monitoring and Prevention Programme (VHM&PP)). Data from metabolic factors were prospectively collected at health examinations and linked to the Cancer and Cause of Death registers in each country.
High levels of metabolic factors were associated with increased risk of cancer and cancer death, overall and at specific sites (ovarian, liver, brain, thyroid, endometrium, post-menopausal breast, gynaecological, pancreas, colon/rectum, bladder, cervix, skin, blood, gastric, kidney, esophagus and gallbladder).
Our findings suggest that a healthy lifestyle avoiding over-eating of energy-dense diet, and physical activity, which are key determinants of metabolic risk factors in our study, not only decreases risk of cardiovascular disease and diabetes but also lowers the risk for a person to develop cancer.
We hypothesised that men and women with high levels of measured metabolic factors had higher risk of cancer and cancer death. The measured metabolic factors were body mass index (BMI), blood pressure, glucose, cholesterol and triglycerides.
Cancer incidence is higher in the “Western” world suggesting a link to a lifestyle that includes over-eating of an energy-dense diet and little physical exercise. These factors are strongly linked to metabolic risk factors.
We collected data from health examinations in Norway, Sweden and Austria, which were linked to cancer and cause of death registers in each country. The Me-Can project consisted of 578,700 men and women. The metabolic risk factors investigated in this project were body mass index (BMI), blood pressure, glucose, cholesterol and triglycerides. The risk of cancer increases with increasing age, therefore we used age as timescale in all analyses and to minimise the influence of random measurement error, we corrected for that with data from individuals with repeated measurements.
Men and women with high levels of blood pressure, glucose, triglycerides and height had a higher risk of cancer overall. Specifically, men and women with high levels of metabolic factors had an increased risk of cancer in ovarian, liver, brain, thyroid, endometrium, post-menopausal breast, gynaecological, pancreas, colon/rectum, bladder, cervix, skin, blood, gastric, kidney, esophagus and gallbladder. For the largest male cancer site, prostate cancer, we did not find any association between high levels of metabolic factors and incident cancer, but an increased risk to death from prostate cancer. For the largest female cancer site, breast, we found that high levels of metabolic factors were associated to increased risk among post-menopausal women only. Our findings provide further evidence that a healthy lifestyle not only decreases risk of cardiovascular disease and diabetes but also lowers the risk for cancer.