Background: Both the incidence of lung cancer and the prevalence of metabolic abnormalities, specifically metabolic syndrome (MetS), have been increasing worldwide. The relationship between MetS and lung cancer remains controversial. We aimed to investigate the association of MetS, number of metabolic abnormalities, MetS components, and metabolic markers with risk of lung cancer.
Methods: Multivariable Cox regression models were used to estimate the hazard ratio (HR) of MetS-related variables on lung cancer risk, both overall and by histological subtype, in UK Biobank. Stratified analyses were conducted by sex, smoking status, and use of medication. HR curves were used to test the non-linear associations between the metabolic markers and the risk of lung cancer.
Results: Of the 331,877 participants included in this study, a total of 77,173 participants had MetS at enrollment. During a median follow-up of 10.9 years, 2425 participants developed lung cancer as the primary site. The HRs of MetS were 1.21 (95%CI: 1.09, 1.33), 1.28 (95%CI: 1.10, 1.50), and 1.16 (95%CI: 0.94, 1.44) on the risk of overall
lung cancer, adenocarcinoma, and squamous cell carcinoma, respectively. The HRs increased with the number of metabolic abnormalities from 1.11 to 1.4~1.5 for those with one to five disorders. Positive association with lung cancer was observed for low high-density lipoprotein cholesterol (HDL-C), elevated waist circumference, and hyperglycaemia. The relationship between MetS and lung cancer was modified by sex, with a stronger effect in women (p=0.031). The risk of lung cancer due to MetS was mainly elevated among smokers, although the modification effect of smoking was not statistically significant. A non-linear association was found between lung cancer and HDL-C, waist circumference, and glycated haemoglobin.
Conclusion: The increased risk of lung cancer associated with MetS suggests the importance of taking metabolic status and markers into the primary prevention of lung cancer and the selection of high-risk populations for lung cancer screening.
Audience Take Away Notes:
- Metabolic health status is closely linked to the risk of lung cancer. At an individual level, the findings of this study highlight the importance of maintaining metabolic health in the primary prevention of lung cancer
- At the population level, our study implies the value of taking metabolic status and markers into the selection of high-risk populations for lung cancer screening, which highlights a new direction of secondary lung cancer prevention
- It is a novel perspective to inspect the role of metabolism in the development of lung cancer. This study might inspire future research on the potential mechanism underlying these epidemiological findings
- With the rapid increase in the prevalence of metabolic abnormalities worldwide, our study suggests that the impact of this public health challenge is way beyond the common chronic diseases