Chang Hyung Hong

Systematic review of health behavioral risks and cognitive health in older adults

BACKGROUND An increasing body of evidence suggests that health behaviors may protect against cognitive impairment and dementia. The purpose of this study was to summarize the current evidence on health behavioral factors predicting cognitive health through a systematic review of the published literature. METHODS PubMed, Embase, and PsycINFO databases were searched for studies on community representative samples aged 65 and older, with prospective cohort design and multivariate analysis. The outcome--cognitive health--was defined as a continuum of cognitive function ranging from cognitive decline to impairment and dementia, and health behaviors included physical activity, smoking, alcohol drinking, body mass index, and diet and nutrition. RESULTS Of 12,105 abstracts identified, 690 relevant full-texts were reviewed. The final yield amounted to 115 articles of which 37 studies were chosen that met the highest standards of quality. Leisure time physical activity, even of moderate level, showed protective effects against dementia, whereas smoking elevated the risk of Alzheimers disease. Moderate alcohol consumption tended to be protective against cognitive decline and dementia, but nondrinkers and frequent drinkers exhibited a higher risk for dementia and cognitive impairment. Midlife obesity had an adverse effect on cognitive function in later life. Analysis showed vegetable and fish consumption to be of benefit, whereas, persons consuming a diet high in saturated fat had an increased dementia risk. CONCLUSION The review demonstrates accumulating evidence supporting health behavioral effects in reducing the risk of cognitive decline and dementia. Results indicate potential benefits of healthy lifestyles in protecting cognitive health in later life.

Peripheral Cytokines and Chemokines in Alzheimer’s Disease

A chronic inflammatory process has been implicated in the neuropathology of Alzheimer’s disease (AD). The present review focuses on the current knowledge of circulating serum and plasma biomarkers of AD that are linked to inflammatory reactions. There is abundant evidence that inflammatory mechanisms within the central nervous system contribute to cognitive impairment via cytokine-mediated interactions between neurons and glial cells. Interleukins 1, 4, 6, 10, 12, 16, and 18, tumour necrosis factor, and several chemokines have been suggested as biomarkers of AD. Nonetheless, data on circulating cytokine levels are somewhat inconsistent with regard to peripheral cytokine dysregulation in AD. In summary, definite statements concerning differences in inflammatory biomarkers between controls and AD patients will require the use of sensitive multiplex assays in large patient groups in conjunction with measures of disease severity.

Characteristic Profiles of Instrumental Activities of Daily Living in Different Subtypes of Mild Cognitive Impairment

Background/Aims: The purposes of this study were to describe restrictions in instrumental activities of daily living (IADL) in mild cognitive impairment (MCI) and to assess different patterns of IADL in each MCI subtype. Methods: A total of 566 participants, those not cognitively impaired (NCI; n = 311) and MCI patients (n = 255), 60–94 years old (71.25 ± 6.00), were examined. Neuropsychological tests were administered to participants, and each MCI patient was classified into one of four subtypes. They completed the Barthel ADL and Seoul-IADL (S-IADL) for ADL measures. Results: There was a significant difference between NCI and MCI in terms of total S-IADL scores. ANOVA and a post hoc Dunnett analysis revealed that MCI patients performed significantly worse on four out of a total 15 items (i.e. telephone, transportation, finances and household appliances). ANCOVA showed a significant difference in S-IADL-MCI (4 of 15 items) between NCI and amnestic MCI-multiple domains after adjusting for age, gender, education and Geriatric Depression Scale (F = 4.257, d.f. = 1,556, p = 0.002). Conclusion: These findings suggest that scorings of specific IADL items are different in MCI subjects, and these items can possibly help in the identification of MCI subtypes, especially amnestic MCI-multiple domains.

Clinical Characteristics of a Nationwide Hospital-based Registry of Mild-to-Moderate Alzheimer's Disease Patients in Korea: A CREDOS (Clinical Research Center for Dementia of South Korea) Study

With rapid population aging, the socioeconomic burden caused by dementia care is snowballing. Although a few community-based studies of Alzheimers disease (AD) have been performed in Korea, there has never been a nationwide hospital-based study thereof. We aimed to identify the demographics and clinical characteristics of mild-to-moderate AD patients from the Clinical Research Center for Dementia of Korea (CREDOS) registry. A total of 1,786 patients were consecutively included from September 2005 to June 2010. Each patient underwent comprehensive neurological examination, interview for caregivers, laboratory investigations, neuropsychological tests, and brain MRI. The mean age was 74.0 yr and the female percentage 67.0%. The mean period of education was 7.1 yr and the frequency of early-onset AD (< 65 yr old) was 18.8%. Among the vascular risk factors, hypertension (48.9%) and diabetes mellitus (22.3%) were the most frequent. The mean score of the Korean version of Mini-Mental State Examination (K-MMSE) was 19.2 and the mean sum of box scores of Clinical Dementia Rating (CDR-SB) 5.1. Based on the well-structured, nationwide, and hospital-based registry, this study provides the unique clinical characteristics of AD and emphasizes the importance of vascular factors in AD in Korea.

Three cases of childhood nocturnal asthma due to buckwheat allergy

Background: Buckwheat flour (BF) is known as a potent food allergen. Sensitization to it usually occurs by ingestion but also by inhalation in occupational or domestic exposure. Buckwheat chaff‐stuffed pillows (BCP) can be contaminated with BF during the process of pilling, and many Korean children and adults use BCP for health reasons.

A new classification system for ischemia using a combination of deep and periventricular white matter hyperintensities.

The Clinical Research Center for Dementia of South Korea (CREDOS) group developed a new classification system for ischemia using a combination of deep and periventricular white matter hyperintensities (WMHs). In this study, we aimed to evaluate the validity of the CREDOS ischemia classification system. A total of 352 patients with cognitive impairments were included. Their WMH scores were rated using the CREDOS WMH visual rating scale. These patients were divided into 3 groups according to the CREDOS ischemia classification system. The volume of WMH was also automatically measured. The number of lacunes and microbleeds (MBs) were counted. The CREDOS ischemia classification system was revised with factor analysis using vascular risk factors and cerebrovascular disease (CVD) markers (WMH volume, lacunes, and MBs). External validation was performed in another group of patients with cognitive impairment using multinomial logistic regression analysis. The CREDOS WMH visual rating scale showed excellent correlation with the automatically measured volume of WMH. The factor analysis showed that the severe group was expanded to D3P1 and D3P2 in the revised CREDOS ischemia classification system. In the validation group, the presence of vascular risk factors and the severity of CVD markers could be distinguished according to the revised CREDOS ischemia classification. We validated a newly developed classification system for ischemia. This simple visual classification system was capable of providing information on vascular risk factors and CVD markers by simply rating WMH on magnetic resonance imaging.

Bioplex analysis of plasma cytokines in Alzheimer’s disease and mild cognitive impairment

Inflammatory mechanisms within the central nervous system contribute to cognitive impairment via cytokine-mediated interactions between neurons and glial cells. Sixty-nine subjects were consecutively recruited from October 2005 to February 2007. Fifteen individuals were excluded from the study and we ultimately enrolled 19 not cognitively impaired subjects, 25 mild cognitive impairment patients, and 10 Alzheimers disease patients. To examine the inflammatory markers of mild cognitive impairment and Alzheimers disease, we measured the plasma concentrations of 23 cytokines using a bioplex assay. The results showed that the macrophage migration inhibitory factor was higher in mild cognitive impairment and in Alzheimers disease patients compared with the not cognitively impaired group; the results also showed that monokine induced by gamma interferon was higher in Alzheimers disease patients than in not cognitively impaired subjects, as well as those of the mild cognitive impairment group [corrected].

Clock Drawing Test in Mild Cognitive Impairment: Quantitative Analysis of Four Scoring Methods and Qualitative Analysis

Background: The role of the clock drawing test (CDT) as a screening tool for dementia has been evaluated. However, studies focusing on mild cognitive impairment (MCI) are still lacking. The purpose of this study was to verify the validity of the CDT as a screening method for MCI. Methods: 524 subjects aged 60 years and older were recruited in the community. Of these, 241 were diagnosed as not cognitively impaired (NCI) and 224 were classified as MCI. The CDT was scored according to the Freedman, Rouleau, Todd, and CERAD CDT and an additional comprehensive scoring system incorporating elements of most CDT for qualitative analysis. Results: The sensitivity and specificity of the 4 CDT scoring systems for MCI ranged from 40.7 to 56.4% and from 71.8 to 85.3%, respectively. The likelihood ratio and the positive and negative predictive values of the 4 CDT ranged from 18 to 29, 18.2 to 24.5 and from 55.9 to 78.4%, respectively. In qualitative analysis, a significantly lower performance in the clock numbers category was observed in the MCI group. Conclusion: This study suggests that although some qualitative analyses could help in identifying MCI individuals, the CDT is insufficient as a screening method to distinguish MCI individuals from NCI individuals in a clinical setting.

Participation in Physical, Social, and Religious Activity and Risk of Depression in the Elderly: A Community-Based Three-Year Longitudinal Study in Korea

Background We examined the longitudinal association between participation in individual or combinations of physical, social, and religious activity and risk of depression in the elderly. Methods Elderly subjects aged ≥60 years who completed the Living Profiles of Older People Survey in Korea (n = 6,647) were included. The baseline assessment, Wave 1, was conducted in 2008, and a follow-up assessment, Wave 2, was conducted in 2011. We defined participation in frequent physical activity as ≥3 times weekly (at least 30 minutes per activity). Frequent participation in social and religious activity was defined as ≥1 activity weekly. The primary outcome was depression at 3-year follow up. Results Multivariable logistic regression analysis showed that subjects who participated in frequent physical, social, and religious activity had an adjusted odds ratio of 0.81 (95% confidence interval [CI], 0.69–0.96), 0.87 (95% CI, 0.75–1.00), and 0.78 (95% CI, 0.67–0.90), respectively, compared with participants who did not participate in each activity. Participants who participated in only one type of activity frequently and participants who participated in two or three types of activities frequently had an adjusted odds ratio of 0.86 (95% CI, 0.75–0.98) and 0.64 (95% CI, 0.52–0.79), respectively, compared with participants who did not participate in any type of physical, social, and religious activity frequently. Conclusion Participation in physical, social, and religious activity was associated with decreased risk of depression in the elderly. In addition, risk of depression was much lower in the elderly people who participated in two or three of the above-mentioned types of activity than that in the elderly who did not.

Effects of education on the progression of early- versus late-stage mild cognitive impairment.

BACKGROUND Highly educated participants with normal cognition show lower incidence of Alzheimers disease (AD) than poorly educated participants, whereas longitudinal studies involving AD have reported that higher education is associated with more rapid cognitive decline. We aimed to evaluate whether highly educated amnestic mild cognitive impairment (aMCI) participants show more rapid cognitive decline than those with lower levels of education. METHODS A total of 249 aMCI patients enrolled from 31 memory clinics using the standard assessment and diagnostic processes were followed with neuropsychological evaluation (duration 17.2 ± 8.8 months). According to baseline performances on memory tests, participants were divided into early-stage aMCI (-1.5 to -1.0 standard deviation (SD)) and late-stage aMCI (below -1.5 SD) groups. Risk of AD conversion and changes in neuropsychological performances according to the level of education were evaluated. RESULTS Sixty-two patients converted to AD over a mean follow-up of 1.43 years. The risk of AD conversion was higher in late-stage aMCI than early-stage aMCI. Cox proportional hazard models showed that aMCI participants, and late-stage aMCI participants in particular, with higher levels of education had a higher risk of AD conversion than those with lower levels of education. Late-stage aMCI participants with higher education showed faster cognitive decline in language, memory, and Clinical Dementia Rating Sum of Boxes (CDR-SOB) scores. On the contrary, early-stage aMCI participants with higher education showed slower cognitive decline in MMSE and CDR-SOB scores. CONCLUSIONS Our findings suggest that the protective effects of education against cognitive decline remain in early-stage aMCI and disappear in late-stage aMCI.