Metabolic syndrome and risk of lung cancer: An analysis of Korean National Health Insurance Corporation database

Introduction: Metabolic syndrome is known to increase the risk of several
cancers. However, the association between lung cancer and metabolic
syndrome remains unclear. Thus, we investigated the impact of metabolic
syndrome on the incidence of lung cancer. Methods: This study enrolled
participants in a health screening program provided by the Korean National
Health Insurance Service between January 2009 and December 2012. The
incidence of lung cancer was observed until December 2016. We analyzed the
risk of lung cancer according to the presence of metabolic syndrome,
metabolic syndrome components, and number of metabolic syndrome
components. Results: During the study, 45,635 new cases of lung cancer
were recorded among 9,586,753 participants. The presence of metabolic
syndrome and all its components was positively associated with the risk of
lung cancer in males after multivariate adjustment (hazard ratio (HR) of
metabolic syndrome 1.15, 95% confidence interval (CI) = 1.12–1.18). The
risk of lung cancer increased with the number of components present. The
effect of metabolic syndrome on the increasing risk of lung cancer is may
be higher in underweight male ever smokers than in other participants.
Conclusion: Metabolic syndrome was associated with an increased risk of
lung cancer in males. Moreover, the higher the number of metabolic
syndrome components, the higher the risk of lung cancer.

引言：代谢综合征（metabolic syndrome）已知会升高多种癌症的发病风险。然而，肺癌与代谢综合征之间的关联仍尚不明确。为此，本研究探讨了代谢综合征对肺癌发病率的影响。
方法：本研究纳入了2009年1月至2012年12月期间，参与韩国国民健康保险服务（Korean National Health Insurance Service）提供的健康筛查项目的受试者。随访至2016年12月，记录肺癌发病情况。本研究根据代谢综合征的存在与否、代谢综合征组分情况以及代谢综合征组分数量，分析肺癌的发病风险。
结果：本研究共纳入9,586,753名受试者，随访期间累计记录到45,635例新发肺癌病例。经多因素校正后，男性群体中代谢综合征及其所有组分的存在均与肺癌发病风险呈正相关（代谢综合征的风险比（hazard ratio, HR）为1.15，95%置信区间（confidence interval, CI）为1.12~1.18）。肺癌发病风险随代谢综合征组分数量的增加而升高。相较于其他受试者，代谢综合征对曾吸烟的低体重男性群体的肺癌发病风险升高的促进作用可能更强。
结论：代谢综合征与男性肺癌发病风险升高相关。此外，代谢综合征组分数量越多，肺癌发病风险越高。