Relationship between Shift Work and Subclinical Hypothyroidism

Background@#To date, only a few studies have reported the relationship between shift work and subclinical hypothyroidism. Therefore, this study aimed to investigate this relationship. Subclinical hypothyroidism is defined as normal thyroxine (free T4) and thyrotropin (thyroid stimulating hormone, TSH) levels above 10 mU/L. @*Methods@#This study included 12,126 male participants who visited Ulsan University Hospital health promotion center from March 1, 2016 to February 28, 2017. Participants answered a self-administered survey about their marital status, educational level, smoking habits, alcohol intake, and frequency of physical activity. Venous blood sampling was performed after maintaining fasting state for at least 8 hours to test for fasting glucose, hemoglobin A1c, total cholesterol, TSH, and free T4. @*Results@#The TSH level was significantly higher in shift workers than that in the non-shift workers, whereas free T4 level did not show any difference between the two groups. In the shift work group, the odds ratio for subclinical hypothyroidism was significantly higher (odds ratio, 1.99, 95%; confidence interval, 1.16–3.40). This result persisted after adjusting for covariates of age, body mass index, educational level, smoking habits, alcohol intake, and frequency of physical activity. @*Conclusion@#The odds of subclinical hypothyroidism were higher in the shift work group. Therefore, clinicians should pay more attention to detect subclinical hypothyroidism in shift workers.

Relationship between Obesity and Serum 25-Hydroxyvitamin D Concentrations

BACKGROUND: Vitamin D has been known to play an important role in calcium homeostasis and bone metabolism. It has also been implicated in diabetes mellitus, cardiovascular disease, and immune diseases. Several cross-sectional studies conducted worldwide have found that vitamin D is negatively correlated with obesity. In Korea, however, the results of similar studies were found to be inconsistent.METHODS: The study consisted of 585 adults over 18 years of age, who visited a health promotion center at a university hospital from March, 2015 to February, 2016 and their serum vitamin D levels were recorded. They were divided into two groups according to their sex. The correlation coefficients were calculated using Pearson correlation analysis between obesity and vitamin D. Finally, subjects with vitamin D levels less than <20 ng/mL were classified as deficient. Bivariate logistic regression analysis was used to determine the odds ratio of vitamin D deficiency.RESULTS: We observed a significant negative correlation between obesity and vitamin D (P<0.05) among the women but not in the men. The following are the details of the findings: ≥25 in body mass index (model 3 adjusted odds ratio [OR], 4.11; 95% confidence interval [CI], 1.59–10.67), ≥85 cm in waist circumference (model 3 adjusted OR, 1.81; 95% CI, 1.02–4.01), ≥30% in body fat (model 3 adjusted OR, 2.29; 95% CI, 1.17–4.62).CONCLUSION: Based on the results of this study, we suggest that obesity and vitamin D are negatively correlated and that obesity in women predisposes them to vitamin D deficiency.

Association between Benign Prostate Hyperplasia and Occupational Group

BACKGROUND: Insufficient physical activity is well known to increase benign prostate hyperplasia (BPH). However, only few studies have been conducted on the relationship between occupational physical activity and BPH. This study aimed to investigate the relationship between occupational physical activities and BPH in South Korea.METHODS: The study subjects included 4,102 workers who visited the health promotion center at Ulsan University Hospital and underwent transrectal ultrasonography between January 2016 and December 2017. The subjects were divided into two groups according to occupational physical activity (manual or non-manual workers). BPH was defined as a prostate volume of >25 mL. We performed a multivariate regression analysis to investigate the associations between the occupational groups and BPH. In addition, we divided the subgroups according to age and body mass index and analyzed the relationship between occupational physical activities and BPH in each subgroup.RESULTS: The risk of BPH was significantly higher in the non-manual workers than in the manual workers. This result was consistent after adjusting for other risk factors of BPH (odds ratio, 1.26; 95% confidence interval, 1.05–1.51). Likewise, in the subgroup analysis according to age and body mass index, the non-manual workers had higher BPH risk than the manual workers.CONCLUSION: The risk of BPH was significantly higher in the non-manual workers than in the manual workers. To prevent BPH, more attention should be paid to the physical activities and education of non-manual workers.