Background: Shift work has been hypothesized as a risk factor for obesity. In this study, we investigated the association between current shift work and body mass index (BMI) among female nurses in Korea. The relationship between duration of shift work and BMI of the participants was also evaluated. Methods: This cross-sectional survey evaluated participants in the Korean Nurses’ Survey, conducted from October to December 2011, using web-based self-administered questionnaires. A total of 9,989 nurses were included among 10,000 who registered on the survey web site (5,287 shift workers and 4,702 non-shift workers). Current shift workers were divided into tertiles of shift work duration (0.08–3.00 years, n = 1,732; 3.08–6.75 years, n = 1,731; and 6.83–38.00 years, n = 1,686). The BMI thresholds of overweight and obesity were ≥23 kg/m² and ≥25 kg/m², respectively. Data were analyzed using SPSS software. Results: Mean participant age was 33.2 ± 8.6 years and the mean BMI was 20.9 ± 2.5 kg/m². There were statistically significant differences in current smoking status, regular drinking habit, dietary habits, regular exercise, sleep problems and self-perceived health status according to duration of shift work. The overall prevalence of overweight/obesity (18.6%) and obesity (7.4%) increased significantly as shift work duration increased from the lowest to highest tertile (P for trend <0.001). Multivariate logistic regression analysis revealed no association between current shift work and BMI. However, after adjusting for potential confounders, the participants with the longest duration of shift work were 1.63 (95% CI, 1.22–2.17) times more likely to be overweight or obese than those with the shortest duration. There was a significant positive association between obesity and shift work duration in the unadjusted analysis; however, it was attenuated and no longer significant in the multivariate model. Conclusions: The duration of shift work was positively associated with prevalence of overweight/obesity in nurses in Korea. Although these findings need to be confirmed in prospective studies, they suggest that special attention should be paid to female nurses with a long duration of shift work.

Physical activity may be an effective way of preventing or attenuating menopause-related symptoms, and it has been shown to improve quality of life in menopausal women. However, there have been some inconsistencies regarding between exercise and menopausal symptoms, and study investigating this association has been scarce in Korea. In this study, the association between physical activity and menopausal symptoms in perimenopausal women in Korea was assessed.

Background: Elevated blood pressure (BP) is a major risk factor for the progression of chronic kidney disease (CKD). However, little is known about the influence of prehypertension on CKD. In this study, we investigated the relationship between prehypertension and CKD in a middle-aged Korean population. Furthermore, we prospectively evaluated the effect of active BP control on deterioration of kidney function during the two-year follow-up. Methods: The Korean Genome and Epidemiology Study is a community-based prospective cohort study started in 2001, with a follow-up survey conducted every two years. A total of 9509 participants aged 40–69 years were included in a baseline study. BP was classified according to the Seventh Report of the Joint National Committee on High BP (JNC-7) categories and CKD was defined as the presence of proteinuria or eGFR< 60mL/min/1.73m². A multivariable logistic regression model was used to identify associations between BP and CKD. Results: The overall prevalence of CKD was 13.2%, and significantly increased with BP level. The multivariable-adjusted odds ratio of CKD was 1.59 for prehypertension and 2.27 for hypertension, compared with a normal BP. At the two-year follow-up, among the participants with prehypertension, subjects whose BP was poorly controlled had a significantly higher risk of eGFR drop (OR, 1.37; 95% CI, 1.13-1.67), as compared to controls. The prevalence of eGFR drop was 57.8% in the controlled BP group and 66.0% in the poorly-controlled BP group. Conclusions: Prehypertension, as well as hypertension, is significantly associated with CKD among middle-aged Koreans. Our results indicate that active control of the blood-pressure of prehypertensive individuals is needed to prevent deterioration of kidney function.

Questions remain as to the association between essential hypertension and increased incidence of type 2 diabetes (T2DM). The premise of this analysis is that insulin resistance/compensatory hyperinsulinemia is a major predictor of T2DM, and the greater the prevalence of insulin resistance within any population, normotensive or hypertensive, the more likely T2DM will develop. The hypothesis to be tested is that surrogate estimates of insulin resistance will predict incident T2DM to a significant degree in persons with normal blood pressure or prehypertension. Analysis of data from a population-based survey of 10, 038 inhabitants of rural and urban areas of Korea, ≥40 years-old, initiated in 2001, with measures of demographic and metabolic characteristics at baseline and 8-years later. Participants were classified as having normal blood pressure or prehypertension, and three simple manifestations of insulin resistance related to the pathophysiology of T2DM used to predict incident T2DM: (1) glycemia (plasma glucose concentration 2-hour after 75 g oral glucose challenge = 2-hour PG); (2) hyperinsulinemia (plasma insulin concentration 2-hour after 75 g oral glucose challenge = 2-hour PI); and (3) dyslipidemia (ratio of fasting plasma triglyceride/high/density lipoprotein cholesterol concentration = TG/HDL-C ratio). Fully adjusted hazard ratios (HR, 95 % CI) for incident T2DM were highest (P < 0.001) in the quartile of individuals with the highest 2-hour PG concentrations, ranging from 5.84 (3.37–10.1) in women with prehypertension to 12.2 (7.12–21.00) in men with normal blood pressure. T2DM also developed to a significantly greater degree in subjects within the highest quartile of TG/HDL-C ratios, with HRs varying from 2.91 (1.63–2.58) in women with prehypertension (P < 0.001) to 1.77 (1.12–2.81, P < 0.05) in men with prehypertension. The least predictive index of insulin resistance was the 2-hour PI concentration. Subjects with normal blood pressure in the highest quartile of 2-hour PI concentrations were significantly associated with incident T2DM, with HRs of 1.5 (1.02–2.20, P = 0.25) and 2.02 (1.35–3.02, P < 0.001), in men and women, respectively. Finally, incidence of T2DM in the highest quartile was somewhat greater in patients with prehypertension, irrespective of predictor. Metabolic variables associated with insulin resistance (glycemia, insulinemia, and dyslipidemia) predict the development of T2DM in patients with either normal blood pressure or prehypertension.

Background: Healthy eating behaviors may be related to mental health and health-related quality of life. This study investigates the associations between diet quality, mental health, and health-related quality of life among men and women in Korea. Methods: A total of 6823 participants, aged 19, from the 7th Korea National Health and Nutrition Examination Survey from 2016 to 2018 were included. Their overall diet quality was estimated using the Korean Healthy Eating Index (KHEI). Multivariate logistic regression was used to identify the associations between diet quality, mental health, and quality of life. Results: The prevalence of stress perception and depression was highest in the lowest tertile of the KHEI score and higher for women than men. Among men, a significant association was observed only for stress perception and depressive symptoms in the second tertile, with odds ratios of 0.745 (95% CI, 0.585–0.949) and 0.519 (95% CI, 0.275–0.980). In contrast, the multivariate-adjusted odds ratios for stress perception, depressive symptoms, and low EQ-5D index among women in the highest tertile were 0.668 (95% CI, 0.541–0.823), 0.464 (95% CI, 0.288–0.746), and 0.722 (95% CI, 0.566–0.920), and significant dose–response associations were observed. Conclusions: A higher-quality diet was associated with a lower risk of stress and depression and a better quality of life. Thus, healthy eating behaviors may improve mental health and quality of life.

Sarcopenia is an independent risk factor for cardiovascular disease (CVD) and mortality. However, the impact of longitudinal changes in sarcopenia remains unclear. We investigated the relationship between changes in sarcopenia status and the risk of CVD and mortality in older Korean adults. This study included 2,997 older adults aged ≥ 65 years from the Korea Urban and Rural Elderly Study. Sarcopenia status was classified as non-sarcopenia, possible sarcopenia, or functional sarcopenia. Changes in sarcopenia status were assessed at baseline and during a follow-up visit 4 years later. Incident CVD was defined as hospitalization for ischemic heart disease or cerebrovascular disease. All-cause mortality was determined using death records provided by Statistics Korea. Associations were evaluated using Cox proportional hazards regression models. During the follow-up, a total of 423 incident CVD cases and 438 deaths were identified. At baseline, individuals with functional sarcopenia had a higher risk of incident CVD and mortality than those without, after adjusting for all covariates. Similarly, participants who progressed from non-sarcopenia to sarcopenia or had stable sarcopenia showed increased CVD and mortality risk. Sarcopenia was associated with elevated risks of CVD and mortality. Early identification and management of sarcopenia may help reduce adverse outcomes in older adults.