According to the study, obesity has been linked to an elevated risk of cancer in both healthy obesity and obesity associated with metabolic problems.
According to recent research, both metabolically healthy and unhealthy ‘forms’ of obesity are associated with an elevated risk of various malignancies related to obesity, with the association being stronger in metabolically unhealthy obesity. The studies were released in the National Cancer Institute Journal. The investigation was carried out by Dr. Ming Sun of Lund University in Malmo, Sweden, and associates.
Studies addressing the link between healthy obesity and cancer, as well as obesity with metabolic problems (commonly referred to as metabolically unhealthy obesity), are scarce.
Statistical modelling was employed to determine any association between a metabolic score that included blood pressure, plasma glucose, and triglycerides (blood fats) to identify metabolically healthy and unhealthy conditions.
The participants thus were put into six different categories – metabolically unhealthy obesity (6.8 per cent of participants); metabolically healthy obesity (3.4 per cent), metabolically unhealthy overweight (15.4 per cent), metabolically healthy overweight (19.8 per cent), metabolically unhealthy normal weight (12.5 per cent), metabolically healthy normal weight (42.0 per cent).
The highest risk estimates for endometrial, liver, and renal cell cancer (2.5 to 3.0 times increased risk) were found when compared to metabolically healthy normal weight. Metabolically unhealthy obesity was also linked to an increased relative risk of any obesity-related cancer, including colon, rectal, pancreatic, endometrial, liver, gallbladder, and renal cell cancer.
Metabolically unhealthy obese women had a 21% higher risk of colon cancer, a 3-times higher risk of endometrial cancer, and a 2.5-times higher risk of kidney cancer than metabolically healthy obese women of normal weight. Obese women who were metabolically healthy had a 2.4-fold higher risk of endometrial cancer and an 80% higher risk of kidney cancer, but the link to colon cancer was no longer statistically significant.
Metabolically unsound males with obesity had a 2.6-fold increased risk of kidney cancer in men compared to metabolically healthy men of normal weight, an 85% increased risk of colon cancer, and a 32% increased risk of pancreatic and rectal cancer. Obesity increased the risk of colon cancer by 42% and kidney cancer by 67% in metabolically healthy men, but it no longer had a statistically significant effect on the risk of rectal cancer or pancreatic cancer. The blood cancer multiple myeloma was found to have a roughly 50% increased risk in both metabolically healthy and unhealthy men who were overweight (not obese), but not in metabolically healthy or unhealthy men who were obese.
The authors say that, among men only, the data suggest that obesity jointly with metabolic complications increases the risk of these obesity-related cancers more than expected from the sum of either risk factor individually. They say: “This has important public health implications, suggesting that a significant number of cancer cases could potentially be prevented by targeting the co-existence of metabolic problems and obesity, in particular for obesity-related cancers among men.”
The authors conclude: “This study highlights that the type of metabolic obesity phenotype is important when assessing obesity-related cancer risk. In general, being metabolically unhealthy further increased the obesity-related cancer risk, suggesting that both obesity and metabolic conditions are useful targets for the prevention of obesity-related cancers.”