Handgrip Strength and All-Cause Mortality in Middle-Aged and Older Koreans.

Aging-related decline in handgrip strength has been associated with adverse functional and metabolic morbidity and mortality. Korea is one of the fastest aging countries, and the prospective relationship of handgrip strength with all-cause mortality in Korean adults has not been studied. We conducted a prospective observation study to examine whether baseline handgrip strength predicted mortality over eight years of follow-ups in Korean adults aged 45 years or older. We analyzed the nationwide survey data based on 9393 Korean adults (mean age of 61 ± 10.7 years) from the 2006⁻2014 Korean Longitudinal Study of Aging. The mean handgrip strength values measured using a dynamometer, and were divided into quartiles for each gender. Cox models were conducted in order to estimate the hazard ratios (HRs) of all-cause mortality with 95% confidence intervals (CIs) in relation to handgrip strength adjusting for covariates. There was a robust independent relationship between a weaker handgrip strength and higher all-cause mortality in both women and men, adjusting for selected covariates (e.g., age, income, smoking, exercise, and comorbidities). Compared to the strongest quartile (i.e., reference), women and men in the weakest group had higher HRs of mortality, 2.5 (95% CI: 1.7⁻3.8) vs. 2.6 (95% CI: 1.8⁻3.9), respectively. The robust independent relationships between weaker handgrip strength and higher all-cause mortality found in the study suggest that simply assessing and monitoring the handgrip strength during adulthood demonstrates great potentials for the public health of aging populations, and protects against premature death in Korean adults.

Risk Factors for Hepatitis C Virus (HCV) Infection in Areas with a High Prevalence of HCV in the Republic of Korea in 2013.

BACKGROUND/AIMS: The prevalence of hepatitis C virus (HCV) infection in Busan, Gyeongnam, and Jeonnam Provinces in Korea is more than twice the national average. This study aimed to examine whether demographic and lifestyle characteristics are associated with HCV infection in these areas. METHODS: A case control study was performed at three study hospitals. HCV cases were matched with two controls for sex and age. Patient controls were selected from non-HCV patients at the same hospital. Healthy controls were subjects participating in medical checkups. Conditional logistic regression models were used. RESULTS: A total of 234 matched-case and patient- and healthy-control pairs were analyzed. The significant risk factors for both controls were sharing razors (adjusted odds ratio [aOR], 2.39 and 3.29, respectively) and having more than four lifetime sexual partners (aOR, 2.15 and 6.89, respectively). Contact dockworkers (aOR, 1.91) and tattoos (aOR, 2.20) were significant risk factors for the patient controls. Transfusion (aOR, 5.38), a bloody operation (aOR, 5.02), acupuncture (aOR, 2.08), and piercing (aOR, 5.95) were significant risk factors for the healthy controls. Needle stick injuries and intravenous drug abuse were significant in the univariate analysis. CONCLUSIONS: More education concerning the dangers of sharing razors, tattoos and piercings is required to prevent HCV infection. More attention should be paid to needle stick injuries in hospitals and the community.

The influence of regional deprivation index on personal happiness using multilevel analysis.

OBJECTIVES: The objective of the present study was to identify the factors that influence the happiness index of community residents, by considering personal and regional aspects, and to use as evidence of efforts for improvement of the happiness index. METHODS: The study was conducted based on information from 16,270 participants who met the data requirement among those who participated in the 2011 South Gyeongsang Community Health Survey. Of the factors that can influence the happiness index, socioeconomic characteristics, health behavior, morbidity, and healthcare use, social contact, and participation in social activities were classified as personal factors; for regional factors, data from the 2010 census were used to extrapolate the regional deprivation indices at the submunicipal-level (eup, myeon, and dong) in South Gyeongsang Province. The happiness index for each characteristic was compared to that for others via t-test and ANOVA, and multilevel analysis was performed, using four models: a basic model for identification of only random effects, model 1 for identification of personal factors, model 2 for identification of regional factors, and model 3 for simultaneous consideration of both personal and regional factors. RESULTS: The mean happiness index was 63.2 points (64.6 points in males and 62.0 points in females), while the mean deprivation index was -1.58 points. In the multilevel analysis, the regional-level variance ratio of the basic model was 10.8%, confirming interregional differences. At the personal level, higher happiness indices were seen in groups consisting of males with high educational level, high income, high degree of physical activity, sufficient sleep, active social contact, and participation in social activities; whereas lower happiness indices were seen in people who frequently skipped breakfast, had unmet healthcare needs, and had accompanying diseases, as well as those with higher deprivation index. CONCLUSIONS: The study confirmed that the happiness index of community residents was influenced by not only personal aspects but also various regional characteristics. To increase the happiness index, interests at both personal and regional levels, as well as community emphasis on creating social rapport and engaging in selective efforts, are needed in vulnerable regions with relatively high deprivation index.

Poor agreement between QuantiFERON-TB Gold test and tuberculin skin test results for the diagnosis of latent tuberculosis infection in rheumatoid arthritis patients and healthy controls.

BACKGROUND/AIMS: We investigated the agreement between the QuantiFERON-TB Gold (QFT-Gold) test and the tuberculin skin test (TST) in the diagnosis of latent tuberculosis infection in patients with rheumatoid arthritis (RA), compared with healthy controls, in Korea. METHODS: We recruited 64 patients with RA and 79 healthy controls at two university hospitals in South Korea. The participants underwent both the QFT-Gold test and the TST simultaneously between August 2006 and February 2009. All patients were diagnosed using the classification criteria for RA revised in 1987 by the American College of Rheumatology. Bacillus Calmette-Guérin vaccination status and current medications were evaluated, and disease activities were assessed using the Disease Activity Score in 28 joints. Eleven patients with RA produced indeterminate QFT-Gold test results and were thus excluded from the kappa analysis. RESULTS: Based on an induration of 10 mm in diameter as the TST cutoff value, the QFT-Gold test and TST demonstrated 75.0% agreement (κ = 0.23) in patients with RA and 75.9% agreement (κ = 0.19) in healthy controls. Among the 56 patients with RA who had negative TST results, 11 patients (17.2%) also yielded indeterminate QFT-Gold results. CONCLUSIONS: Our study showed poor agreement between the results of the QFT-Gold test and the TST in both RA patients and healthy controls. Based on these findings, we emphasize the importance of making clinical decisions in the diagnosis of latent tuberculosis in Koreans with or without RA.

[The prevalence of high myopia in 19 year-old men in Busan, Ulsan and Gyeongsangnam-do].

OBJECTIVES: The purpose of this study was to estimate the prevalence and correlated factors of high myopia in 19 year-old men in Southeast Korea. METHODS: This retrospective study was based on the medical checkup data of conscription during 2005. The study subjects were 19 years old men in Busan, Ulsan and Gyeongsangnam-do. The health checkup data of the conscripts consisted of noncycloplegic autorefraction test, the biometric data and social factors. To analyze the social and biometric effects, we classified the biometric factors into 4 or 5 groups and the social factors into 3 groups. High myopia was defined as a spherical equivalent of under -6.0 diopter. Data analysis was performed using the chi square test for trends and multiple logistic regression analysis. The SAS (version 9.1) program was used for all the analyses. RESULTS: The prevalence of high myopia was 12.39% (6256 /50,508). The factors correlated with high myopia were the residence area (OR, 2.07; 95% CI, 1.77 to 2.4 for small city; OR, 2.01; 95% CI, 1.72 to 2.34 for metropolis; the reference group was rural area), academic achievement (OR, 1.43; 95% CI, 1.34 to 1.53 for students of 4-and 6-year-course university; the reference group was high school graduates & under) and blood pressure (OR, 1.54; 95% CI, 1.10 to 2.16 for hypertension; OR, 1.09; 95% CI, 1.02 to 1.17 for prehypertension; OR, 1.10; 95% CI, 1.01 to 1.20 for hypotension; the reference group was normal blood pressure). CONCLUSIONS: More than one tenth of the young men were high myopia as one of the risk factor for visual loss. Further studies on high myopia and its complications are needed to improve eye health in Southeast Korea.

Effect of medicine adherence on the occurrence of cerebrovascular disorders in diabetes mellitus patients.

OBJECTIVES: To assess the association between the occurrence of cerebrovascular disorders and a medication adherence in diabetes mellitus patients. METHODS: Medical records from 1,114 new patients with diabetes mellitus were collected and the occurrence of cerebrovascular disorders was observed. Data was gathered from the health examination records of diabetes mellitus patients registered at the Korean Metabolic Syndrome Research from 1996 to 2005, medication records from the National Health Insurance Corporation and death data from the National Statistics Office from 1997 to 2007. Hazard ratios were analyzed using the Cox proportional hazard model to test the association between the occurrence of cerebrovascular disorders and the level of medication adherence. Medication adherence was calculated using Continuous measure of Medication Acquisition (CMA). RESULTS: Of 1,114 diabetes mellitus patients, cerebrovascular disorders occurred in 67 cases (6.1%). The mean duration for the development of a cerebrovascular disorder was 3.82 yr. Medication adherence (≥0.8 vs. <0.5: HR, 3.26; 95% CI, 1.47-7.21, ≥0.8 vs. 0.5-0.7 HR, 0.99; 95% CI, 0.33-2.95) was an independent factor associated with the occurrence of cerebrovascular disorders in diabetes mellitus. CONCLUSION: Increased medication adherence is necessary to prevent the occurrence of cerebrovascular disorders in diabetes mellitus patients. Furthermore we propose that CMA be considered as a method for monitoring medication adherence in clinics.

Blocking of monocyte-associated B7-H1 (CD274) enhances HCV-specific T cell immunity in chronic hepatitis C infection.

The establishment of a chronic hepatitis C (CHC) infection is associated with defective HCV-specific T cell responses. Recent studies suggest that negative T cell regulators such as programmed death 1 (PD-1) contribute to the impairment of virus-specific T cell functions in chronic viral infections. However, the implication of peripheral monocytes from CHC patients in the inhibition of HCV-specific T cell responses is only partially defined. In this study, we found that B7-H1, a ligand of PD-1, was significantly up-regulated on monocytes of CHC patients. Proliferation of T cells in response to anti-CD3 antibody was directly suppressed by B7-H1+CD14+ monocytes, and this suppression was reversed by addition of antagonistic B7-H1 mAb. Furthermore, blocking of monocyte-associated B7-H1 (moB7-H1) significantly enhanced the frequency of IFN-gamma-producing, HCV-specific CD4+ and CD8+ effector T cells and the production of Th1 cytokines, such as IL-2 but not Th2 cytokines, including IL-4 and IL-10. Upon B7-H1 blockade, production of perforin was also increased in CD8+ T cells stimulated with HCV peptides. Our findings suggest that moB7-H1 inhibits HCV-specific CD4+ and CD8+ T lymphocyte proliferation and suppresses Th1 cytokine production and perforin secretion. Blockade of the B7-H1 pathway thus represents an attractive approach in the treatment of chronic HCV infection.

Study of the association of -667 aquaporin-2 (AQP-2) A/G promoter polymorphism with the incidence and clinical course of chronic kidney disease in Korea.

BACKGROUND: Impaired urinary concentration is uniformly present with advanced disease in chronic renal failure. Aquaporin-2 (AQP-2) is known to be expressed in the renal collecting duct cells and participates in urinary concentration in response to vasopressin. Recently, the study of AQP expression in various forms of chronic kidney disease (CKD) demonstrated a reduction in AQP-2 expression associated with a loss of nephrons and the presence of chronic interstitial fibrosis. No information on aquaporin genetic variations in CKD is available to date. The aim of our study was to evaluate the possible impact of aquaporin-2 genotype on the development and clinical course of CKD. METHODS: Blood samples from 259 patients with CKD and 106 ethnicity-, age-, and sex-matched healthy controls were collected, and genomic DNA was extracted. AQP-2 -667 genotype was assessed by PCR, followed by restriction fragment length polymorphism analysis. RESULTS: There were no significant differences in genotype and allele frequencies between the patients and healthy controls (p = 0.3936, p = 0.2941, respectively). In all, 79 (30.5%) patients had the AQP-2 -667 wild-type A/A, 123 (47.5%) were heterozygous for the G allele, and 57 (22.0%) patients showed homozygosity. After subclassification of CKD according to underlying disease, no significant differences were observed between those patients and controls (p = 0.72 for diabetic nephropathy, p = 0.52 for hypertensive nephropathy, p = 0.27 for chronic glomerulonephritis, and p = 0.80 for unknown etiology). Genotype and allele frequencies of the AQP-2 gene polymorphism (rs3759126) of hypertensive patients in pre-ESRD did not show a noticeable difference compared with normal blood pressure patients in pre-ESRD (p = 0.50). No correlation was found to exist between the AQP-2 gene polymorphism (rs3759126) and serum electrolyte levels in pre-ESRD patients (p = 0.38 for serum sodium level and p = 0.44 for serum potassium level). CONCLUSION: Our data indicate that no association exists between the -667 AQP-2 A/G polymorphism and susceptibility to CKD or its clinical course.