Hyaluronic acid (HA) is a polysaccharide found in the extracellular matrix of the epithelial, nervous, and connective tissues of vertebrates. It is widely used in the treatment of ocular surface diseases (OSDs), including dry eye, due to its high water-retaining capacity, viscoelasticity, and role as a signaling molecule in inflammation and wound healing. This paper reviews the physicochemical and biological properties of HA related to the treatment of OSDs and the results of published preclinical studies, clinical trials, and meta-analyses on the effects of HA eye drops on the tear film, the mechanism of action of HA eye drops, and its clinical effects and adverse events in OSDs, such as corneal/conjunctival epithelial defects, dry eye, and postoperative dry eye. This review should help inform clinical judgments by providing clinical evidence and precautions on the use of HA eye drops in OSDs, including dry eye.

Objective: This study sought to investigate the association between plasma cell-free hemoglobin (pHb) and mortality in sepsis or septic shock. Methods: We performed a retrospective analysis of the prospective collected data of patients with sepsis or septic shock. Patients were divided into 4 groups according to their pHb concentrations using a restricted cubic spline: group I (pHb ≤20 mg/dL), group II (20 < pHb ≤40 mg/dL), group III (40 < pHb ≤60 mg/dL), and group IV (pHb >60 mg/dL). The primary outcome was the 28-day mortality, and a multivariate Cox proportional hazard regression method was used for analysis. Results: A total of 372 patients were included in the analysis and the overall 28-day mortality rate was 16.7%. The median pHb concentration of the patients was 24.8 mg/dL (reference range, 0-5). The mortality rate did not increase in proportion to the pHb concentrations and was the lowest in group II (20.3%, 11.0%, 16.3%, and 26.7% in groups I, II, III, and IV, respectively). In the Cox proportional hazard regression analysis, group I was independently associated with 28-day mortality compared with group II (hazard ratio, 2.19; 95% confidence interval, 1.18-4.07). Group IV had a higher mortality rate compared to group II, but it was not statistically significant (hazard ratio, 2.17; 95% confidence interval, 0.85-5.56). Conclusion A low concentration of pHb (pHb ≤20 mg/dL) was associated with 28-day mortality in patients with sepsis or septic shock.

Objective: This study estimated the incidence of driving-related adverse events and examined the association of cognitive function with the risk of future driving-related adverse events in the elderly Korean male population. Methods: We analyzed 1,172 male drivers aged 60 years or older in the Korean Longitudinal Study on Cognitive Aging and Dementia (KLOSCAD). Using the data from Korean National Police Agency, we classified the participants into three groups: safe driving (drove for 2 years after baseline without a traffic accident or repeated violations), driving cessation (stopped driving), and risky driving (one or more traffic accidents or repeated violations). We estimated the incidences of driving cessation and risky driving, and examined the effect of cognitive function on their risks. Results: The incidence of driving cessation and risky driving in the Korean male drivers aged 60 years or older was 19.3 and 69.9 per 1,000 person-years respectively and increased in the late 80s. Drivers with better baseline Word List Memory Test scores showed less risky driving (OR=0.94, p=0.039). Conclusion Driving-related adverse events increased in late 80s, and better memory function was protective against these events.

Objective: Cardiovascular diseases are representative risk factors for the onset of cognitive decline. The purpose of this study was to confirm the relationship between diastolic blood pressure and cognitive function in elderly people in Korea. Methods: Data from subjects who were enrolled in the prospective Korean Longitudinal Study on Cognitive Aging and Dementia were used in this study. Data from 701 subjects whose diastolic blood pressure range did not change (≤79 mm Hg or ≥80 mm Hg) over 2 years were analyzed. To analyze the differences in cognitive function between the groups at the 2-year follow-up, an analysis of covariance was performed with covariates, which were significantly different between the two groups, and the baseline cognitive function. Results: Significant differences were observed between the two groups, and the mean scores on the constructional praxis (η2=0.010) and word list recall tests (η2=0.018) in the diastolic blood pressure ≥80 mm Hg group were higher than those in the diastolic blood pressure ≤79 mm Hg group at the 2-year follow-up. Conclusion These results indicate that maintaining a DBP below 79 mm Hg presents a greater risk of cognitive decline in Korean elderly people.

OBJECTIVE: This study aimed to examine the association between normal-but-low folate levels and cognitive function in the elderly population using a prospective cohort study. METHODS: We analyzed 3,910 participants whose serum folate levels were within the normal reference range (1.5–16.9 ng/mL) at baseline evaluation in the population-based prospective cohort study named the “Korean Longitudinal Study on Cognitive Aging and Dementia.” The association between baseline folate quartile categories and baseline cognitive disorders [mild cognitive impairment (MCI) or dementia] was examined using binary logistic regression analysis adjusting for confounding variables. The risks of incident MCI and dementia associated with the decline of serum folate level during a 4-year follow-up period were examined using multinomial logistic regression analysis. RESULTS: The lowest quartile group of serum folate (≥1.5, ≤5.9 ng/mL) showed a higher risk of cognitive disorders than did the highest quartile group at baseline evaluation (odds ratio 1.314, p=0.012). Over the 4 years of follow-up, the risk of incident dementia was 2.364 times higher among subjects whose serum folate levels declined from the 2nd–4th quartile group to the 1st quartile than among those for whom it did not (p=0.031). CONCLUSION: Normal-but-low serum folate levels were associated with the risk of cognitive disorders in the elderly population, and a decline to normal-but-low serum folate levels was associated with incident dementia. Maintaining serum folate concentration above 5.9 ng/mL may be beneficial for cognitive status.
Aged ; Cognition ; Cognition Disorders ; Cognitive Aging ; Cohort Studies ; Confounding Factors (Epidemiology) ; Dementia ; Folic Acid ; Follow-Up Studies ; Humans ; Logistic Models ; Longitudinal Studies ; Prospective Studies ; Reference Values

OBJECTIVE: We investigated the impact of depressed mood (dysphoria) and loss of interest or pleasure (anhedonia)on the risk of dementia in cognitively-normal elderly individuals. METHODS: This study included 2,685 cognitively-normal elderly individuals who completed the baseline and 4-year follow-up assessments of the Korean Longitudinal Study on Cognitive Aging and Dementia. We ascertained the presence of dysphoria and anhedonia using the Mini International Neuropsychiatric Inventory. We defined subjective cognitive decline as the presence of subjective cognitive complaints without objective cognitive impairments. We analyzed the association of dysphoria and anhedonia with the risk of cognitive disorders using multinomial logistic regression analysis adjusted for age, sex, education, Cumulative Illness Rating Scale score, Apolipoprotein E genotype, and neuropsychological test performance. RESULTS: During the 4-year follow-up period, anhedonia was associated with an approximately twofold higher risk of mild cognitive impairment (OR=2.09, 95% CI=1.20–3.64, p=0.008) and fivefold higher risk of dementia (OR=5.07, 95% CI=1.44–17.92, p=0.012) but was not associated with the risk of subjective cognitive decline. In contrast, dysphoria was associated with an approximately twofold higher risk of subjective cognitive decline (OR=2.06, 95% CI=1.33–3.19, p=0.001) and 1.7-fold higher risk of mild cognitive impairment (OR=1.75, 95% CI=1.00–3.05, p=0.048) but was not associated with the risk of dementia. CONCLUSION: Anhedonia, but not dysphoria, is a risk factor of dementia in cognitively-normal elderly individuals.
Aged ; Anhedonia ; Apolipoproteins ; Cognition Disorders ; Cognitive Aging ; Cohort Studies ; Dementia ; Depression ; Education ; Follow-Up Studies ; Genotype ; Humans ; Logistic Models ; Longitudinal Studies ; Mild Cognitive Impairment ; Neuropsychological Tests ; Pleasure ; Prospective Studies ; Risk Factors

OBJECTIVE: Due to an unprecedented rate of population aging, South Korea is facing a dementia epidemic. For this reason, the Korean Longitudinal Study on Cognitive Aging and Dementia (KLOSCAD) was launched in 2009 with support from the Korean Health Industry Development Institute to investigate the epidemiology, biopsychosocial risk factors, and outcomes of dementia and dementia-related conditions. METHODS: The KLOSCAD is the first nationwide multi-center population-based prospective cohort study. In October 2010, 12,694 individuals were randomly sampled from residents aged 60 years or older who lived in 13 districts across South Korea. In the baseline assessment, which was conducted from November 2010 through October 2012, 6,818 (53.7%) individuals participated. Follow-up assessments have been conducted every two years, with the first follow-up assessment conducted between November 2012 and October 2014, and the second between November 2014 and October 2016. The third is now in progress, and will span from November 2016 to October 2018. Diagnosis of cognitive disorders, neuropsychological battery, behavioral and psychological symptoms of dementia, activities of daily living, physical and neurologic examination and laboratory tests, life styles, quality of life, and identification of death were evaluated in each assessment. RESULTS: The cumulative drop-out rate at the second follow-up assessment was 38.7%. Dementia and mild cognitive impairment were 5.0% and 27.0%, respectively. CONCLUSION: The KLOSCAD may provide strong scientific evidence for advancing the fight against dementia both in Korea and globally.
Activities of Daily Living ; Aging ; Cognitive Aging* ; Cohort Studies ; Dementia* ; Diagnosis ; Epidemiology ; Follow-Up Studies ; Korea ; Life Style ; Longitudinal Studies* ; Mild Cognitive Impairment ; Neurologic Examination ; Prospective Studies ; Quality of Life ; Risk Factors

BACKGROUND: It is a very important social issue for Korea to have a healthy old age as an aged society. Aging causes a lot of physical changes, especially sarcopenia. Sarcopenia is defined as a persistent decrease in skeletal muscle and muscle strength. Sarcopenic obesity is a phenomenon in which fat is replaced instead of muscle. The purpose of this study was to examine the prevalence of sarcopenia and sarcopenic obesity in Korean elderly and to analyze the relationship with chronic disease. METHODS: Data from the 2008 to 2011 the Korea National Health and Nutrition Survey were used. A total of 3,492 patients were classified into 3 groups (non-sarcopenia, sarcopenia, sarcopenic obesity), and general, anthropometry, health behavior, nutrient intake and chronic disease status were compared by the statistical analysis. RESULTS: The rate of moderate exercise was significantly lower in the sarcopenia and sarcopenic-obesity group than in the non-sarcopenia group (P=0.007). The sarcopenic obesity group had significantly higher energy (P=0.005), protein (P=0.046) and fat (P=0.001) intake than the sarcopenic group. The sarcopenic-obesity group had the highest ratio of diabetes (P=0.023) and dyslipidemia (P=0.004) in the 3 groups. Compared with the non-sarcopenia group, in the sarcopenia and sarcopenic obesity groups, the odds ratios (ORs) of diabetes was increased by 1.24 and 2.16 while the ORs of dyslipidemia was increased by 1.12 and 1.50, respectively. CONCLUSIONS: Regular exercise and adequate nutrient intake (energy, protein and fat) are essential for the prevention of sarcopenia in Korean elderly, and management of chronic disease in sarcopenic obesity elderly is important.
Aged* ; Aging ; Anthropometry ; Chronic Disease* ; Dyslipidemias ; Health Behavior ; Humans ; Korea ; Muscle Strength ; Muscle, Skeletal ; Nutrition Surveys ; Obesity* ; Odds Ratio ; Prevalence ; Sarcopenia*