Healthy and unhealthy metabolic ‘forms’ of obesity linked to increased risk of obesity-related cancers

New research will be presented this week at the European Obesity Congress in Dublin, Ireland (May 17-20) and published in the Journal of the National Cancer Institute shows that metabolically healthy and unhealthy “forms” of obesity are associated with an increased risk of various obesity-related cancers, with the relationship being stronger in metabolically unhealthy obesity. The study is carried out by Dr Ming Sun, Lund University, Malmö, Sweden and his colleagues.

Studies on how cancer is related to obesity with metabolic complications (commonly called metabolically unhealthy obesity) or without such complications (healthy obesity) are rare.
In this new research, the authors investigated body mass index (BMI, normal weight/overweight/obesity) in conjunction and interaction with metabolic health status in relation to obesity-related cancer risk (n =23,630) in 797,193 European individuals.

A metabolic score including blood pressure, plasma glucose, and triglycerides (blood fat) was used to define metabolically healthy and unhealthy status, and statistical modeling was used to estimate any relationship.

Participants were therefore divided into six different categories – metabolically unhealthy obesity (6.8% of participants); metabolically healthy obesity (3.4%), metabolically unhealthy overweight (15.4%), metabolically healthy overweight (19.8%), metabolically unhealthy normal weight (12.5%), metabolically healthy normal weight (42.0% ).

Metabolically unhealthy obesity was, compared to metabolically healthy normal weight, associated with an increased relative risk of any obesity-related cancer and cancer of the colon, rectum, pancreas, endometrium, liver, gallbladder and kidney cell cancer, with the highest risk estimates for endometrial, liver and kidney cell cancer (2.5- to 3.0-fold increased risk).

Among women, compared to metabolically healthy, normal-weight women, metabolically unhealthy and obese women had a 21% increased risk of colon cancer, a 3-fold increased risk of endometrial cancer, and a 2.5 times higher for kidney cancer. Metabolically healthy obese women had a 2.4 times higher risk of endometrial cancer and an 80% increased risk of kidney cancer – but the relationship with colon cancer was no longer statistically significant.

In men, compared to metabolically healthy, normal-weight men, metabolically unhealthy and obese men had a 2.6-fold increased risk of kidney cancer, an 85% increased risk of colon cancer, and a 32% increase in pancreatic and rectal cancer. Metabolically healthy obese men had a 67% increased risk of kidney cancer and a 42% increased risk of colon cancer, but the relationship with pancreatic cancer and rectal cancer was no longer statistically significant. In an unusual finding, metabolically healthy and unhealthy overweight (not obese) men had about a 50% increased risk of blood cancer multiple myeloma – but neither metabolically healthy or unhealthy men with obesity had an increased risk of this cancer.

The authors say that, in men only, the data suggest that obesity, in conjunction with metabolic complications, increases the risk of these obesity-related cancers more than expected from the sum of either other risk factors individually. They say: “This has important implications for public health, suggesting that a significant number of cancer cases could potentially be prevented by targeting the coexistence of metabolic problems and obesity, particularly for obesity-related cancers. at men’s.”

The authors conclude: “This study highlights that the type of metabolic obesity phenotype is important when assessing obesity-related cancer risk. for the prevention of obesity-related cancers.