Methods: Data from the 2008–2012 Korean National Health and Nutrition Examination Survey (KNHANES)—a cross-sectional and nationally representative survey undertaken by the Korea Center for Disease Control and Prevention (KCDC)—were used. The KNHANES has a stratified multistage probability sampling design comprising health interviews, health behavior and nutrition survey, and health examination study. The SAS version 9.3 survey procedure (SAS Institute Inc., Cary NC, USA) used a complex sample design based on the survey data analysis; this provided sampling weights and nationally representative estimates. Differences in the ratios between the metabolic syndrome and its components by cancer type, gender, and age group were analyzed using chi-square tests.
Results: The results of the study are as follows. 1) Regarding the general characteristics of cancer survivors, 62.5% were female, the mean age was 57.7, 77.5% were urban residents, and 34.7% were elementary school graduates. As for economic status, 25.8% fell under the 2nd lowest quartile, and 44.4% were currently economically active. Among the cancer survivors, 7.4% were current smokers, 36.8% drank alcohol more than once a month, and 20.7% exercised regularly. Regarding cancer-related characteristics of cancer survivors, the mean age upon cancer diagnosis was 50.1, and 35.3% were currently undergoing treatment. In terms of the type of cancer diagnosed, gastric cancer accounted for 19.6%; thyroid cancer, 18.5%; cervical cancer, 13.8%; breast cancer, 12.40%; colorectal cancer, 10.3%; liver cancer, 2.77%; and lung cancer, 2.21%. 2) Based on the diagnostic criteria of the American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement, the prevalence of metabolic syndrome was 46.9% in cervical cancer, 43.9% in colorectal cancer, 38.6% in lung cancer, and 35.9% in breast cancer. 3) Regarding gender, the prevalence of metabolic syndrome in female cancer survivors was 38.3%, which was significantly higher than that in male cancer survivors (30.4%) (p = 0.022). In the components of metabolic syndrome, there were differences depending on gender in waist circumference, low HDL-cholesterol, and high blood sugar. The rates of waist circumference obesity and high blood sugar were higher in female cancer survivors, while the rate of low HDL-cholesterol was higher in male cancer survivors. 4) In terms of age, the prevalence of metabolic syndrome was higher as age increased, and the difference was statistically significant (p<.001): 18.4% in the young adult group (20-39 years), 27.9% in the middle age group (40-59 years), and 46.1% in the old age group (60 years and older). In the components of metabolic syndrome, high triglyceride, low HDL-cholesterol, and high blood sugar differed depending on the age group; as age increased, the rates of high triglyceride, low HDL-cholesterol, and high blood sugar became higher.
Conclusion: In summary, the prevalence of metabolic syndrome in cancer survivors was approximately 10 to 20% higher than that in healthy Koreans. Particularly, the prevalence of metabolic syndrome was higher in female cancers, including cervical cancer and breast cancer, and in colorectal cancer. Moreover, the prevalence of metabolic syndrome was higher in females and in the old age group. Therefore, management of metabolic syndrome should be actively carried out for groups with a high prevalence of metabolic syndrome, and consideration should be given to components with a high risk of onset for each group when developing programs for metabolic syndrome in cancer survivors.
This study was supported by the National Research Foundation of Korea (NRF) funding grant (NRF-2015R1C1A1A02036408).