Study links rising metabolic syndrome scores to increased cancer risk

By Dr. Priyom Bose, Ph.D.Mar 12 2024Reviewed by Benedette Cuffari, M.Sc.

A recent study in the journal Cancer investigates the association between metabolic syndrome (MetS) score trajectories and cancer risks using a large-scale prospective cohort.

Study: The association of metabolic syndrome scores trajectory patterns with risk of all cancer types. Image Credit: Sebastian Kaulitzki / Shutterstock.com

How does MetS impact health?

MetS is associated with multiple conditions that co-occur and increase the risk of type 2 diabetes, stroke, and heart disease. Some of the conditions associated with MetS include excess body fat around the waist, high blood pressure, abnormal cholesterol and triglyceride (TG), and high blood sugar levels. 

Recently, several studies have highlighted the association between MetS and an increased risk of developing different cancer types, such as colon, breast, and liver cancer. Although certain factors, such as insulin resistance, chronic inflammation, and altered hormone levels that enhance the risk of MetS and cancer, have been identified, the exact mechanism responsible for this association remains elusive. 

Previous studies have shown that the severity of MetS can vary, which determines the metabolically healthy or unhealthy status of individuals. Due to this dynamic status, it is difficult to assess the progression of MetS based on a single measurement.

The analysis of MetS trajectories is an emerging tool to study epidemiology, better understand disease progression, and identify its underlying determining factors. This trajectory analysis helps identify the precise patterns and shifts in blood sugar levels, blood pressure, waist circumference (WC), and lipid profiles related to disease manifestation.

About the study

The current prospective cohort study began in June 2006 and was conducted in Tangshan, China. A total of 101,510 employees from the Kailuan Group were recruited, which consisted of 81,110 men and 20,400 women.

All participants underwent initial clinical examinations, questionnaire assessments, and laboratory tests. Between 2006 and 2010, three follow-up studies were conducted to construct MetS degree trajectories.

A total of 59,927 participants completed the initial and follow-up studies. Individuals with a history of cancer or missing data were excluded, which led to a total of 44,115 participants being considered for the final assessment. WC, blood pressure, blood glucose, TG, total cholesterol (TC), alanine aminotransferase (ALT), C-reactive protein (CRP), and creatinine levels were assessed.

Study findings

About 11% of the cohort consistently maintained low MetS scores, which reflected a low-stable pattern, 40.8% exhibited consistent moderate to low MetS scores, or a moderate-low pattern, and 41.5% maintained moderate to high MetS scores or a moderate-high pattern. Approximately 7% of participants exhibited MetS scores that increased over time, which was denoted as an elevated-increasing pattern. 

Unlike the low-stable MetS score trajectory pattern, a positive correlation between elevated-increasing MetS score trajectory pattern and risks of all cancer types, including breast, liver, colorectal, endometrial, and kidney cancers, was observed. Individuals with high MetS scores and chronic inflammation were associated with a higher risk of breast, liver, colorectal, and endometrial cancers. However, the risk of kidney cancer was more significant among individuals with MetS without chronic inflammation. Importantly, these findings were further validated through sensitivity and competing risk analyses.

Obesity is an important MetS component that is inherently associated with the incidence of pancreatic, colorectal, and gastroesophageal cancers. To date, the association between dyslipidemia and cancer risk remains unclear. 

Individuals with concurrent chronic inflammation that was estimated through CRP levels and persistently high MetS scores were associated with the highest risk of colon, liver, and breast cancers. This finding was consistent with previous studies reporting an association between MetS, inflammation, and an increased risk of liver cancer.

Study limitations

The current study has some limitations, including the lack of detailed information regarding other cancer-related factors, such as dietary habits, Helicobacter pylori infection for stomach cancer, and hepatitis C virus infection for liver cancer.

Another limitation is that all study participants belonged to the Kailuan community, thus limiting the generalizability of the study findings. Since the industrial Kailuan community is dominated by a male workforce, a gender imbalance was observed in the study cohort.

Conclusions

The study findings highlight the importance of heterogeneous MetS score trajectories in determining the overall risk of cancer. Individuals with chronic inflammation have a higher risk of developing different types of tumors.

The current study emphasizes the importance of long-term intervention and control of MetS in preventing cancer incidence. Future studies are needed to better understand whether modifiable metabolic factors can mitigate subsequent cancer risks.

Notably, CRP assessment of the MetS diagnosis could effectively identify individuals at a higher risk of cancer. This approach can facilitate early diagnosis and prevent different types of cancer.