The sodium intake of Koreans was higher than that recommended by the World Health Organization. Urinary sodium, which is correlated with sodium intake, can be easily calculated by the Tanaka's equation. This study aimed to evaluate the association between urinary sodium and metabolic syndrome in Korean adults using the 2010–2011 Korean National Health and Nutrition Examination Survey (KNHANES).

A total of 5,870 participants from the 2010–2011 KNHANES were included in this study. Twenty-four hour urinary sodium was calculated by the Tanaka's equation using spot urine. Participants were divided into tertiles based on urinary sodium levels. The association between urinary sodium and metabolic syndrome was analyzed using multivariate logistic regression analysis.

The odds ratios (ORs) and 95% confidence intervals (CIs) of metabolic syndrome for the 2nd and 3rd tertile of urinary sodium levels was 1.51 (1.16–1.97) and 1.56 (1.23–1.97) compared to the lowest tertile of urinary sodium in men. The ORs and 95% CIs of metabolic syndrome in women were 1.20 (0.95–1.51) for the 2nd tertile and 2.16 (1.68–2.78) for the 3rd tertile. These associations remained statistically significant, even after adjusting for multiple covariates such as age, education, regular exercise, smoking, and alcohol consumption.

These findings indicate that urinary sodium is significantly associated with metabolic syndrome in Korean adults.

There is little research regarding whether working as a physician affects cancer risk. Moreover, there is no research on cancer prevalence among physicians in Korea. This study utilized the Korea National Cancer Incidence Database to determine whether the prevalence of cancer among physicians differs from the prevalence of cancer within the general population.

We analyzed the medical records of a representative sample of 382 doctors who underwent a health examination between 2010 and 2013 at a health examination center in a Ewha Womans University Medical Center.Cancer incidence was measured as cases that were eventually diagnosed as cancer according to a biopsy.

We collected medical records from 382 physicians (mean age, 51.9±8.1 years) and calculated the standardized prevalence ratios compared to the general population. Thirty physicians (9 male and 21 female) were identified as having cancer. Physicians had a significantly higher prevalence of cancer compared to the general population.Cancer prevalence in male physicians was found to be 2.47 times higher than the prevalence expected within the general population (P=0.006). Among female physicians, cancer prevalence was 3.94 times higher than that in the general population (P<0.001).

This study revealed that physicians had a higher prevalence of cancer compared to the general population in Korea, which suggests that there may be a problem present in the health care of physicians. Changes to the working environment of physicians will be needed to reduce the high prevalence of cancer among physicians.

Lung age, calculated from sex, forced expiratory volume in one second (FEV₁), and height, was developed to illustrate premature changes to the lungs and could be used to motivate smoking cessation. However, this method has not been tested in association with smoking in Korea. The purpose of this study was to investigate the association of lung age with smoking and other factors in Korean males.

We reviewed the records of 1,100 healthy men who visited a health promotion center at Ewha Womans University Medical Center from January 2008 to June 2009. Lung age was calculated from FEV₁ and normal predictive values of spirometry according to age in the Korean population. The difference between lung age and chronological age was evaluated in relation to smoking status, weight, body mass index, waist, muscle mass, fat mass, and exercise.

The age difference was significantly higher in current smokers than in non-smokers (12.47 ± 19.90 vs. 7.30 ± 19.52, P < 0.001). Additionally, the age difference was positively correlated with life time pack-year (β = 0.223; P < 0.001) and fat mass (β = 0.462; P < 0.001). Lung age increased 1 year for 4.48 pack-year increase or for 2.16% increase in fat mass.

We found a significant relationship between lung age and both smoking status and fat mass in healthy Korean males. Lung age may be a useful tool for motivating cessation of cigarette smoking and management of risk factors related to obesity.