Low Levels of Low-Density Lipoprotein Cholesterol and Mortality Outcomes in Non-Statin Users.

We aimed to test the association between low-density lipoprotein cholesterol (LDL-C) and cardiovascular disease (CVD), cancer, and all-cause mortality in non-statin users. A total of 347,971 subjects in Kangbuk Samsung Health Study (KSHS.57.4% men, mean follow up: 5.64 ± 3.27 years) were tested. To validate these associations, we analyzed data from another cohort (Korean genome and epidemiology study, KoGES, 182,943 subjects). All subjects treated with any lipid-lowering therapy and who died during the first 3 years of follow up were excluded. Five groups were defined according to baseline LDL-C concentration (<70, 70-99, 100-129, 130-159, ≥160 mg/dL). A total of 2028 deaths occurred during follow-up in KSHS. The lowest LDL-C group (LDL < 70 mg/dL) had a higher risk of all-cause mortality (HR 1.95, 1.55-2.47), CVD mortality (HR 2.02, 1.11-3.64), and cancer mortality (HR 2.06, 1.46-2.90) compared to the reference group (LDL 120-139 mg/dL). In the validation cohort, 2338 deaths occurred during follow-up. The lowest LDL-C group (LDL < 70 mg/dL) had a higher risk of all-cause mortality (HR 1.81, 1.44-2.28) compared to the reference group. Low levels of LDL-C concentration are strongly and independently associated with increased risk of cancer, CVD, and all-cause mortality. These findings suggest that more attention is needed for subjects with no statin-induced decrease in LDL-C concentrations.

Pesticide metabolite and oxidative stress in male farmers exposed to pesticide.

BACKGROUND: The objective of this study was to measure malondialdehyde (MDA) and isoprostane which has been used as an index of lipid injury, 8-hydroxy-2'-deoxyguanosine (8-OHdG), which has been used as an index of DNA damage, and dialkyl-phosphate (DAP), which has been used to quantify pesticide exposure, and to investigate the relationship between pesticide exposure and oxidative stress. METHODS: This study was a cross-sectional study that evaluated 84 male farmers exposure to pesticide. In this study, 8-OHdG, isoprostane, and MDA were measured as oxidative stress indices, and dialkyl-phosphate (dimethylphosphate(DMP), diethylphosphate(DEP), dimethylthiophosphate(DMTP), and diethylthiophosphate (DETP)) excreted in the urine was also measured to evaluate pesticide exposure. A linear regression analysis was performed to investigate the relationship between pesticide metabolites, and oxidative stress biomarkers. RESULTS: A Correlation analysis was performed for pesticide exposure month (PEI), cumulative exposure index (CEI), and DAP as well as the concentration of the oxidative stress biomarkers. The PEM significantly and positively correlated to the levels of 8-OHdG, isoprostane, CEI, and DMP. CEI showed a correlation to 8-OHdG and PEM. DMP, DEP, and DETP showed a positive correlation to 8-OHdG, isoprostane, and MDA. A correlation analysis was adjusted some demographic characteristics, such as age, smoking, drinking, and exercise to determine the relationship between pesticide exposure and oxidative stress. The 8-OHdG, isoprostane, and MDA levels were significantly related to the DMP (ß = 0.320), DEP (ß = 0.390), and DETP (ß = 0.082); DMP (ß = 0.396), DEP (ß = 0.508), and DETP (ß = 0.504); and DMP (ß = 0.432), DEP (ß = 0.508), and DETP (ß = 0.329) levels, respectively. CONCLUSIONS: The concentration between oxidative stress biomarkers and the pesticide metabolite were a positive correlation. Indicators of oxidative stress was associated with a pesticide metabolite DMP, DEP, and DETP. Therefore, Pesticide exposure and oxidative stress were relevant.

Association of hearing impairment with chronic kidney disease: a cross-sectional study of the Korean general population.

BACKGROUND: We aimed to evaluate the association between hearing impairment and the prevalence of chronic kidney disease (CKD) in the largest population-based cross-sectional study to date. METHODS: This cross-sectional study was based on the Korean National Health and Nutritional Examination Survey (KNHANES). It included 5226 participants ≥19 years of age whose estimated glomerular filtration rate (eGFR) and hearing threshold had been measured. We diagnosed CKD as an eGFR <60 mL/min/1.73 m(2). The participants were also evaluated for the presence of other contributing factors related to kidney dysfunction. We divided the participants at the 40-dB threshold into hearing-impairment and no-hearing-impairment groups, using the average threshold of all six frequencies (500, 1000, 2000, 3000, 4000, and 6000 Hz) for both ears. RESULTS: The odds of hearing impairment was 1.25 times higher (95 % confidence interval: 1.12-1.64, p-value < 0.001) in participants with an eGFR <60 mL/min/1.73 m(2) than in those with an eGFR ≥60 mL/min/1.73 m(2) after adjustments for age, sex, smoking, alcohol, body mass index, diabetes mellitus, hypertension, dyslipidemia, and microalbuminuria. Among the risk parameters of CKD associated with hearing impairment, linear regression analysis adjusted for age and sex determined that each increase of serum creatinine or blood pressure was positively associated with an increase in hearing threshold (p-value < 0.01). CONCLUSION: The odds of hearing impairment were greater with lower eGFR than with normal eGFR. Individuals with CKD were more likely to also have hearing impairment. We recommend screening the hearing of patients with CKD to provide earlier identification of hearing impairment and earlier intervention, thereby preventing progression of hearing impairment and providing appropriate treatment strategies.

Oxidative damage markers are significantly associated with the carotid artery intima-media thickness after controlling for conventional risk factors of atherosclerosis in men.

BACKGROUND: This study aimed to assess the association between oxidative damage markers and carotid artery intima-media thickness (CIMT) after controlling for conventional risk factors of atherosclerosis in multiple logistic regression models. METHODS AND FINDINGS: Fifty-one case male participants (CIMT ≥ 0.9 mm) were enrolled during their visits to Korean Genomic Rural Cohort Study of Wonju centers between May 1 and August 31, 2011, along with 51 control participants (CIMT < 0.9 mm) selected using frequency matching by age group. The levels of oxidative damage markers, 8-hydroxy-2'-deoxyquuanosine (8-OHdG), malondialdehyde (MDA), and 8-iso-prostaglandin F2α (Isoprostane), were measured. Conditional logistic regression models were used to evaluate relative relationships between the oxidative damage markers and the risk of high CIMT. RESULTS: The markers of oxidative lipid (Isoprostane and MDA) and DNA (8-OHdG) damage were associated with CIMT after controlling for the conventional risk factors, including age, low density lipoprotein, body mass index, smoking history, alcohol consumption, and metabolic syndrome (ORs [95% CI] for Isoprostane: 3rd tertile, 8.47 [2.59-27.67]; for MDA: 3rd tertile, 8.47 [2.59-27.67]; for 8-OHdG: 3rd tertile, 5.58 [1.79-17.33]). When all the oxidative damage markers were incorporated in the same logistic regression model, only Isoprostane was significantly related to CIMT (OR [95% CI]: 4.22 [1.31-13.53] in 2nd tertile and 14.21 [3.34-60.56] in 3rd tertile). CONCLUSIONS: In this nested case-control study, the oxidative damage markers of lipid and DNA were associated with CIMT even after controlling for the conventional risk factors of cardiovascular diseases.

The Relationship between Injury and Socioeconomic Status in Reference to the Fourth Korean National Health and Nutrition Examination Survey.

OBJECTIVES: This study aims to investigate the relationship between the total injury experience rate and socioeconomic status based on the fourth Korea National Health and Nutrition Examination Survey (KNHANES). METHODS: By analyzing data from the fourth KNHANES conducted from 2007 to 2009, we estimated the injury experience rate according to socioeconomic status, including the occupational characteristics of 11,837 subjects. Setting the injury experience rate as a dependent variable and socioeconomic status as an independent variable, we performed logistic regression to calculate odds ratios reflecting the likelihood of injury according to socioeconomic status while controlling for relevant covariates. RESULTS: In 797 subjects who had injury experience over the past 1 year, 290 persons (36.4%) had a work-related injury. As their income, home value, and educational status increased, their injury experiences decreased. Among occupational groups, the craft, equipment, machine operating, and assembling workers showed the highest rate (10.6%) of injury experience, and the lowest rate (5.7%) was found in the unemployed group. After adjusting for the confounding variables, the experience of injury was significantly related to several socioeconomic factors: high income (OR = 0.54; 95% CI: 0.34-0.86), high home value (OR = 0.65; 95% CI: 0.43-0.96), low education status (OR = 1.28; 95% CI: 1.07-1.52), and specific occupations such as craft, equipment, machine operating, and assembling work (OR = 1.99; 95% CI: 1.60-2.47), skilled agriculture, forestry and fishery work (OR = 1.43; 95% CI: 1.02-2.01), and simple labor (OR = 1.38; 95% CI: 1.04-1.82). CONCLUSIONS: The injury experience rate differed depending on the socioeconomic status. A negative correlation was found between the injury experience rate and income, low home value, and education level. Moreover, a higher rate of injury experience was found in occupation groups and physical worker groups in comparison to the unemployed group and white-collar worker groups. This study would be useful in selecting appropriate priorities for injury management in Korea.

Night Shift Work, Sleep Quality, and Obesity.

BACKGROUND: The aims of this study were to examine the relationship between night shift work and sleep, to investigate the correlations with various biomarkers that show the influence of sleep on obesity, and ultimately, to analyze factors that have an impact on obesity. METHODS: This study used data from the National Survey of Midlife Development in the United States II (MIDUS II study) and the MIDUS II Biomarker Project. After connecting the MIDUS II study data with the MIDUS II Biomarker Project data, we analyzed data from 883 subjects to investigate the relationship between night shift work and sleep quality. We also examined the correlations with biomarkers and sleep quality. Lastly, we performed logistic regression analyses to investigate factors that had an impact on obesity. RESULTS: Sleep quality was found to be low among night shift workers. Sleep quality was positively correlated with HbA1c, total cholesterol, and triglyceride levels, and inversely correlated with DHEA levels. Sleep quality was highly correlated with inflammatory markers and inversely correlated with antioxidant markers. Sleep quality was significantly associated with obesity (OR: 1.10, 95% CI: 1.03-1.18). Biomarkers that had an influence on obesity included diastolic blood pressure, HbA1c and triglyceride levels, inflammatory markers, and antioxidant values. CONCLUSION: Poor sleep quality due to night shift work disturbs the circadian rhythm, causing negative changes in metabolic, inflammatory, neuroendocrine, and antioxidant biomarkers. These changes may eventually play a role in increasing the incidence of obesity.

The Relationship between Waist Circumference and Work-related Injury in Reference to the Fourth Korea National Health and Nutrition Examination Survey.

OBJECTIVE: This study aims to investigate the relationship between waist circumference and work-related injury in reference to the fourth Korea National Health and Nutrition Examination Survey. METHODS: By analyzing data from the fourth Korea National Health and Nutrition Examination Survey conducted from 2007 to 2009, we estimated the rate of injury experience according to socioeconomic status, including occupational property, of 8,261 subjects. We performed logistic regression analysis with work-related injury experience rate as dependent variable and waist circumference as an independent variable, Odds ratios (OR) were calculated, which reflect the likelihood of work-related injury experience rate, and 95% confidence interval (95% CI) while controlling for relevant covariates with stratifying by sex, age, nature of injury, site of injury and occupational group. RESULTS: Among 797 persons who had injury experience over the past 1 year, 293 persons (36.8%) had work-related injury experience. After adjusting the confounding variables, the work-related injury was related to abnormal waist circumference (OR = 1.35; 95% CI: 1.02 ~ 1.78). In subgroups, ORs were higher in men (OR = 1.42; 95% CI: 1.02 ~ 1.98), professional, manager, and administrator (OR = 2.41; 95% CI: 1.10 ~ 5.28). Higher rate of injuries were noted in back and waist (OR = 2.92; 95% CI: 1.49 ~ 5.73), and transport accident had increased risk (OR = 1.60; 95% CI: 1.13 ~ 2.28). CONCLUSIONS: Work-related injury rate differed depending on the waist circumference. The abdominal obesity was associated with higher risk of work-related injury. This study would be useful in selecting appropriate priorities for work-related injury management in Korea.