Research has shown that people with poor metabolic health are at a greater risk of certain forms of cancer, regardless of their body weight.
A study has followed nearly 800,000 people in Sweden, Norway and Austria over the last 40 years, tracking their body mass index (BMI) and metabolic health. The study monitored the participant’s blood pressure, blood glucose levels and blood fats. Now, researchers have used this data to understand how these factors affect the risk of obesity-related cancers.
It is already known that obesity is associated with more than ten different cancers. As part of a European collaboration led by Lund University, researchers have studied the relationship between metabolic health, body weight, and cancer.
The study has been published in the Journal of the National Cancer Institute.
People can be of normal weight and be metabolically unhealthy
The researchers analysed data from health surveys and national registries containing information from almost 800,000 individuals from 1972-2014. The research team use the data on blood pressure, blood glucose and blood fats in the form of triglycerides, to produce a metabolic score for each participant, allowing them to determine whether the people were considered metabolically healthy or unhealthy. Participants were also divided into categories based on whether they were of normal weight, overweight or obese.
“Being metabolically unhealthy is often linked to obesity, but you also don’t have to be overweight to have a metabolically unhealthy status. Therefore, it is relevant to study how this status plays a role in the relationship between BMI and obesity-related cancer”, sais Tanja Stocks, an epidemiology researcher who led the study.
Over the 40-year follow-up period, 23,630 individuals were diagnosed with obesity-related cancer. As the researchers expected, those with a higher BMI had an iincreased risk of cancer, as were those who were classified as having poor metabolic health.
Obesity combined with poor metabolic health led to the highest risk
The highest risk was found among individuals who had poor metabolic and were simultaneously obese. This combination was associated with a particularly high risk of liver and kidney cancer and endometrial cancer among women.
The researchers also found that poor metabolic health on its own led to an increased risk of obesity-related cancer, regardless of whether the individual was of normal weight, overweight or obese.
The study was unable to identify the cause of these associations. However, the researchers did find that obesity and metabolic health interacted in a way that increased the risk of certain cancers more than had previously been thought, especially when combined.
“The study shows the importance of assessing different metabolic risk profiles in addition to obesity, in order to be able to identify the groups that can benefit most from interventions to reduce their risk of suffering from obesity-related cancers”, concluded Ming Sun, a PhD student and first author of the study.