Association of Depression With the Progression of Multimorbidity in Older Adults: A Population-Based Cohort Study

BACKGROUND

The relationship between depression and the risk of multimorbidity progression has rarely been studied in older adults. This study was aimed to determine whether depression is associated with progression in the severity and complexity of multimorbidity, considering the influence of depression's severity and subtype.

METHODS

As a part of the Korean Longitudinal Study on Cognitive Aging and Dementia, this population-based cohort study followed a random sample of community-dwelling Koreans aged 60 and older for 8 years at 2-year intervals starting in 2010. Participants included those who completed mood and multimorbidity assessments and did not exhibit complex multimorbidity at the study's outset. Depression was assessed using the Geriatric Depression Scale, while multimorbidity was evaluated using the Cumulative Illness Rating Scale. The study quantified multimorbidity complexity by counting affected body systems and measured multimorbidity severity by averaging scores across 14 body systems.

FINDINGS

The 2,486 participants (age = 69.1 ± 6.5 years, 57.6% women) were followed for 5.9 ± 2.4 years. Linear mixed models revealed that participants with depression had a faster increase in multimorbidity complexity score (β = .065, SE = 0.019, p = 0.001) than those without depression, but a comparable increase in multimorbidity severity score (β = .001, SE = .009, p = 0.870) to those without depression. Cox proportional hazard models revealed that depression was associated with the risk of developing highly complex multimorbidity affecting five or more body systems, particularly in severe or anhedonic depression.

INTERPRETATION

Depression was associated with the worsening of multimorbidity in Korean older adults, particularly when severe or anhedonic. Early screening and management of depression may help to reduce the burden of multimorbidity in older adults.

A Preliminary Study on the Potential Protective Role of the Antioxidative Stress Markers of Cognitive Impairment: Glutathione and Glutathione Reductase

Objective

: To investigate the relationship between reduced glutathione (GSH), a key molecule of the antioxidant defense system in the blood, and glutathione reductase (GR), which reduces oxidized glutathione (glutathione disulfide [GSSG]) to GSH and maintains the redox balance, with the prevalence of Alzheimer's dementia and cognitive decline.

Methods

: In all, 20 participants with Alzheimer's dementia who completed the third follow-up clinical evaluation over 6 years were selected, and 20 participants with normal cognition were selected after age and sex matching. The GSH and GR concentrations were the independent variables. Clinical diagnosis and neurocognitive test scores were the dependent variables indicating cognitive status.

Results

: The higher the level of GR, the greater the possibility of having normal cognition than of developing Alzheimer's dementia. Additionally, the higher the level of GR, the higher the neurocognitive test scores. However, this association was not significant for GSH. After 6 years, the conversion rate from normal cognition to cognitive impairment was significantly higher in the lower 50th percentile of the GR group than in the upper 50th percentile.

Conclusion

: The higher the GR, the lower the prevalence of Alzheimer's dementia and incidence of cognitive impairment and the higher the cognitive test scores. Therefore, GR is a potential protective biomarker against Alzheimer's dementia and cognitive decline.

What is the impact of one's chronic illness on his or her spouse's future chronic illness: a community-based prospective cohort study

BACKGROUND

Integrating a joint approach to chronic disease management within the context of a couple has immense potential as a valuable strategy for both prevention and treatment. Although spousal concordance has been reported in specific chronic illnesses, the impact they cumulatively exert on a spouse in a longitudinal setting has not been investigated. We aimed to determine whether one's cumulative illness burden has a longitudinal impact on that of their spouse.

METHODS

Data was acquired from a community-based prospective cohort that included Koreans aged 60 years and over, randomly sampled from 13 districts nationwide. Data from the baseline assessment (conducted from November 2010 to October 2012) up to the 8-year follow-up assessment was analyzed from October 2021 to November 2022. At the last assessment, partners of the index participants were invited, and we included 814 couples in the analysis after excluding 51 with incomplete variables. Chronic illness burden of the participants was measured by the Cumulative Illness Rating Scale (CIRS). Multivariable linear regression and causal mediation analysis were used to examine the longitudinal effects of index chronic illness burden at baseline and its change during follow-up on future index and spouse CIRS scores.

RESULTS

Index participants were divided based on baseline CIRS scores (CIRS < 6 points, n = 555, mean [SD] age 66.3 [4.79] years, 43% women; CIRS ≥ 6 points, n = 259, mean [SD] age 67.7 [4.76] years, 36% women). The baseline index CIRS scores and change in index CIRS scores during follow-up were associated with the spouse CIRS scores (β = 0.154 [SE: 0.039], p < 0.001 for baseline index CIRS; β = 0.126 [SE: 0.041], p = 0.002 for change in index CIRS) at the 8-year follow-up assessment. Subgroup analysis found similar results only in the high CIRS group. The baseline index CIRS scores and change in index CIRS scores during follow-up had both direct and indirect effects on the spouse CIRS scores at the 8-year follow-up assessment.

CONCLUSIONS

The severity and course of one's chronic illnesses had a significant effect on their spouse's future chronic illness particularly when it was severe. Management strategies for chronic diseases that are centered on couples may be more effective.

Manganese level and cognitive decline in older adults with the APOE e4 allele: a preliminary study

This study examined the relationship between serum manganese level and cognition, and the moderating effect of apolipoprotein E ε4 (APOE4) on this relationship. A total of 164 non-demented participants underwent clinical assessments including serum manganese level and cognition [episodic memory score (EMS), non-memory score (NMS) for executive function/attention/language/ visuospatial skill, and total score (TS)]. Serum manganese × APOE4 interaction had a significant effect on EMS and TS. Serum manganese level was inversely associated with EMS and TS in APOE4-positive but not APOE4-negative participants. APOE4 should be considered a key component in Alzheimer's disease studies that included manganese imbalance as a risk factor.

Parental history of dementia and the risk of dementia: A cross-sectional analysis of a global collaborative study

BACKGROUND

Parental history of dementia appears to increase the risk of dementia, but there have been inconsistent results. We aimed to investigate whether the association between parental history of dementia and the risk of dementia are different by dementia subtypes and sex of parent and offspring.

METHODS

For this cross-sectional study, we harmonized and pooled data for 17,194 older adults from nine population-based cohorts of eight countries. These studies conducted face-to-face diagnostic interviews, physical and neurological examinations, and neuropsychological assessments to diagnose dementia. We investigated the associations of maternal and paternal history of dementia with the risk of dementia and its subtypes in offspring.

RESULTS

The mean age of the participants was 72.8 ± 7.9 years and 59.2% were female. Parental history of dementia was associated with higher risk of dementia (odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.15-1.86) and Alzheimer's disease (AD) (OR = 1.72, 95% CI = 1.31-2.26), but not with the risk of non-AD. This was largely driven by maternal history of dementia, which was associated with the risk of dementia (OR = 1.51, 95% CI = 1.15-1.97) and AD (OR = 1.80, 95% CI = 1.33-2.43) whereas paternal history of dementia was not. These results remained significant when males and females were analyzed separately (OR = 2.14, 95% CI = 1.28-3.55 in males; OR = 1.68, 95% CI = 1.16-2.44 for females).

CONCLUSIONS

Maternal history of dementia was associated with the risk of dementia and AD in both males and females. Maternal history of dementia may be a useful marker for identifying individuals at higher risk of AD and stratifying the risk for AD in clinical trials.

The rocky road to freedom: number of countries transited during defection and risk of metabolic syndrome among North Korean Refugees in South Korea

OBJECTIVES

North Korean Refugees (NKRs) undergo defection, and this has been shown to impact their current health status in South Korea. However, little is understood about how the defection process is related to metabolic syndrome (MetS). This study regarded the defection process to be a quasi-measurement of traumatic experience and investigated whether defection was a risk factor for MetS among NKRs living in South Korea.

STUDY DESIGN

This cross-sectional study obtained data from the Korea University Anam Hospital in Seoul. NKRs (N = 847) voluntarily completed questionnaires and underwent at least one medical examination between October 2008 and July 2021.

METHODS

Multivariable logistic regression models were used to evaluate whether the number of countries transited by NKRs was associated with MetS by controlling for covariates.

RESULTS

The prevalence of MetS among male and female NKRs in South Korea was 12.3% and 13.3%, respectively. The highest prevalence of MetS (33.4%) was among NKRs who had transited two countries. The number of months in transit countries (mean: 49.9 ± 51.7) and period of residence in South Korea (mean: 40.9 ± 40.9 months) were also considered. NKRs who transited three countries had a higher probability of MetS (odds ratio [OR] 2.660, 95% confidence interval [CI] 1.161-6.097) than those who travelled directly to South Korea. NKRs who transited three countries and had only resided in South Korea for a short period had a higher probability of MetS (OR 3.424, 95% CI 1.149-10.208) than those who have lived in South Korea for a longer period.

CONCLUSIONS

Considering the social vulnerability of NKRs and consequential health problems, there is an urgent need for appropriate support from the government and society.

Spicy food intake predicts Alzheimer-related cognitive decline in older adults with low physical activity

A plausible association exists among spicy food consumption, physical activity, and Alzheimer's disease (AD) or cognitive decline, but it remains poorly investigated. We aimed to examined the association between spicy food and AD-related memory decline or global cognitive decline in older adults under the moderating effect of physical activity. Total 196 non-demented older adults were included. Participants underwent comprehensive dietary and clinical assessments including spicy food intake, AD-related memory, global cognition, and physical activity. The strength of spicy food was stratified into three categories: 'not spicy' (reference), 'low spiciness', and 'high spiciness'. Multiple linear regression analyses were performed to examine the relationships between spicy level and cognition. The spicy level was the independent variable in each analysis; it was entered as a stratified categorical variable using the three categories. We found a significant association between a high level of spiciness in food and decreased memory ([Formula: see text] - 0.167, p < 0.001) or global cognition ([Formula: see text] - 0.122, p = 0.027), but not non-memory cognition. To explore the moderating effects of age, sex, apolipoprotein E ε4 allele-positivity, vascular risk score, body mass index, and physical activity on the associations between spicy level and memory or global cognition, the same regression analyses were repeated including two-way interaction terms between the spicy level and each of the six variables as an additional independent variable. An interactive effect was detected between a high level of spiciness in food and physical activity on the memory ([Formula: see text] 0.209, p = 0.029) or global cognition ([Formula: see text] 0.336, p = 0.001). Subgroup analyses showed that the association between a high level of spiciness in food and a lower memory ([Formula: see text] - 0.254, p < 0.001) and global score ([Formula: see text] - 0.222, p = 0.002) was present only in older adults with low physical activity, but not in older adults with high physical activity. Our findings suggest that spicy food intake is predictive of AD-related cognitive decline, i.e., episodic memory; this relationship is worsened by physically inactive lifestyle.

The impact of the COVID-19 pandemic on depression in community-dwelling older adults: a prospective cohort study

BACKGROUND

There are growing concerns about the impact of the COVID-19 pandemic on the mental health of older adults. We examined the effect of the pandemic on the risk of depression in older adults.

METHODS

We analyzed data from the prospective cohort study of Korean older adults, which has been followed every 2 years. Among the 2308 participants who completed both the third and the fourth follow-up assessments, 58.4% completed their fourth follow-up before the outbreak of COVID-19 and the rest completed it during the pandemic. We conducted face-to-face diagnostic interviews using Mini International Neuropsychiatric Interview and used Geriatric Depression Scale. We performed generalized estimating equations and logistic regression analyses.

RESULTS

The COVID-19 pandemic was associated with increased depressive symptoms in older adults [b (standard error) = 0.42 (0.20), p = 0.040] and a doubling of the risk for incident depressive disorder even in euthymic older adults without a history of depression (odds ratio = 2.44, 95% confidence interval 1.18-5.02, p = 0.016). Less social activities, which was associated with the risk of depressive disorder before the pandemic, was not associated with the risk of depressive disorder during the pandemic. However, less family gatherings, which was not associated with the risk of depressive disorder before the pandemic, was associated with the doubled risk of depressive disorder during the pandemic.

CONCLUSIONS

The COVID-19 pandemic significantly influences the risk of late-life depression in the community. Older adults with a lack of family gatherings may be particularly vulnerable.

Shared Risk Factors for Depressive Disorder Among Older Adult Couples in Korea

Importance

Although couples may share many risk factors for depressive disorders in their lifetime, whether these factors mediate the shared risk of depressive disorders has rarely been investigated.

Objectives

To identify the shared risk factors for depressive disorder in couples and investigate their mediating roles in the shared risk of depressive disorders among older adult couples.

Design, Setting, and Participants

This nationwide, multicenter, community-based cohort study assessed 956 older adults from the Korean Longitudinal Study on Cognitive Aging and Dementia (KLOSCAD) and a cohort of their spouses (KLOSCAD-S) between January 1, 2019, to February 28, 2021.

Exposures

Depressive disorders of the KLOSCAD participants.

Main Outcomes and Measures

The mediating roles of shared factors in couples on the association between one spouse's depressive disorder and the other's risk of depressive disorders was examined using structural equation modeling.

Results

A total of 956 KLOSCAD participants (385 women [40.3%] and 571 men [59.7%]; mean [SD] age, 75.1 [5.0] years) and their spouses (571 women [59.7%] and 385 men [40.3%]; mean [SD] age, 73.9 [6.1] years) were included. The depressive disorders of the KLOSCAD participants were associated with an almost 4-fold higher risk of depressive disorders in their spouses in the KLOSCAD-S cohort (odds ratio, 3.89; 95% CI, 2.06-7.19; P < .001). Social-emotional support mediated the association between depressive disorders in the KLOSCAD participants and their spouses' risk of depressive disorders by itself (β = 0.012; 95% CI, 0.001-0.024; P = .04; mediation proportion [MP] = 6.1%) and through chronic illness burden (β = 0.003; 95% CI, 0.000-0.006; P = .04; MP = 1.5%). Chronic medical illness burden (β = 0.025; 95% CI, 0.001-0.050; P = .04; MP = 12.6%) and presence of a cognitive disorder (β = 0.027; 95% CI, 0.003-0.051; P = .03; MP = 13.6%) mediated the association.

Conclusions and Relevance

The risk factors shared by older adult couples may mediate approximately one-third of the spousal risk of depressive disorders. Identification of and intervention in the shared risk factors of depression among older adult couples may reduce the risk of depressive disorders in the spouses of older adults with depression.

Finger injuries by eyebrow razor blades in infants

Infants are occasionally injured while playing with their mother's eyebrow razor, and we have treated several infants with flexor tendon injuries, which in some cases were accompanied by damage to the corresponding digital nerves and/or vessels. Here, we report the outcomes in a retrospective case series, with a review of literature. Between January 2013 and October 2019, 8 patients who met our inclusion criteria were initially investigated. The inclusion criteria were: (1) injured by an eyebrow razor during fiddling or grasping, and (2) the availability of complete medical records and radiological data, with follow-up of at least 2 years. The core sutures were performed using a modified Becker (4-strand) method for flexor digitorum profundus (FDP). Nerves and/or vessels were repaired under microscopy. A long-arm mitten cast was then applied, with the fingers slightly flexed in a resting position, for 3 weeks. Then, the children were allowed to return to unrestricted activity. Formal outpatient hand therapy was not performed. Mean postnatal age was 6.3 months. The FDP was injured in zones 1 and 2 in 3 and 5 infants, respectively. Most of the infants were injured near a dressing table, in the bedroom used by their mother. The colors of these razors were all bright, except for one achromatic (white) razor. All of the razors had been left uncovered, without their cap, or were left open in the case of hinged razors. At a mean follow-up of 35.8 months, range of motion was evaluated by the Strickland and modified Strickland methods; all results were "excellent". We encountered no significant complications in any digit: neuroma, tendon retear, stiffness or necrosis. Uncapped or unfolded colorful eyebrow razors pose a high risk of tendon section with concurrent neurovascular injury in infants. Although satisfactory outcomes can be expected, it seems important to prevent the injury through fastidious parental care and changing razor design and color. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Evidence of risky driving in Korean older adults: A longitudinal cohort

OBJECTIVES

The aim of this study was to determine the differences in the risk factors for dangerous driving between older adults with normal cognition and those with cognitive impairment.

DESIGN

The driving risk questionnaire (DRQ) that was applied to a community-dwelling older adult cohort and 2 years of accident/violation records from the National Police Agency were analyzed. We conducted regression analyses with the presence or absence of risky driving based on records (accidents + violations) 2 years before and after evaluation as a dependent variable and dichotomized scores of each risky driving factor as independent variables.

RESULTS

According to four identified factors-crash history, safety concern, reduced mileage, and aggressive driving-significant associations were found between risky driving over the past 2 years and crash history and for aggressive driving in the normal cognition group. In the cognitive impairment group, only crash history was significantly associated, although safety concerns showed a trend toward significance.

CONCLUSIONS

In this study, it was suggested that the factors of DRQ have a significant association with actual risky driving. Our results are expected to contribute to establishing the evidence for evaluating and predicting risky driving and advising whether to continue driving in clinics.

Association of Low Emotional and Tangible Support With Risk of Dementia Among Adults 60 Years and Older in South Korea

IMPORTANCE

The association between social support and dementia risk has been debated. Most previous prospective studies have not differentiated the subtypes of social support.

OBJECTIVE

To examine whether the association between social support and risk of dementia differs by subtype of social support and by sex.

DESIGN, SETTING, AND PARTICIPANTS

This nationwide prospective cohort study included randomly sampled South Korean adults 60 years or older. The study was launched November 1, 2010, with follow-up every 2 years until November 30, 2020. The 5852 participants who completed the assessment for social support and were not diagnosed as having dementia, severe psychiatric disorders including major depressive disorder, or major neurological disorders at the baseline assessment were included in the analysis.

EXPOSURES

Geriatric psychiatrists administered the structured diagnostic interviews and physical examinations to every participant based on the Korean version of the Consortium to Establish a Registry for Alzheimer Disease (CERAD-K) Assessment Packet Clinical Assessment Battery.

MAIN OUTCOMES AND MEASURES

Baseline levels of emotional and tangible support using the Medical Outcomes Survey Social Support Survey.

RESULTS

Among the 5852 participants (mean [SD] age, 69.8 [6.6] years; 3315 women [56.6%]; mean [SD] follow-up duration, 5.9 [2.4] years), 237 (4.0%) had incident all-cause dementia and 160 (2.7%) had incident Alzheimer disease (AD) subtype of dementia. Compared with women who reported having emotional support, those with low emotional support had almost a 2-fold higher incidence of all-cause dementia (18.4 [95% CI, 13.6-23.2] vs 10.7 [95% CI, 9.0-12.5] per 1000 person-years) and AD (14.4 [95% CI, 10.2-18.6] vs 7.8 [95% CI, 6.3-9.3] per 1000 person-years). Adjusted Cox proportional hazard analysis revealed that low emotional support was associated with increased risk of all-cause dementia (hazard ratio, 1.61 [95% CI, 1.10-2.36]; P = .02) and AD (hazard ratio, 1.66 [95% CI, 1.07-2.57]; P = .02) only in women. Low tangible support was not associated with a risk of all-cause dementia or AD regardless of sex.

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that older women with low emotional support constitute a population at risk for dementia. The level of emotional support should be included in risk assessments of dementia.

Mood disorders increase mortality mainly through dementia: A community-based prospective cohort study

OBJECTIVE

The effects of mood disorders on mortality may be mediated by their effects on the risk of dementia, and interventions to reduce the occurrence of dementia may reduce their overall mortality. This study aimed to investigate the direct effects of depressive and bipolar disorders on the 6-year risk of mortality and also their indirect effects on mortality due to their effect on the risk of dementia.

METHODS

A total of 5101 Koreans were selected from a community-based prospective cohort study, and 6-year risks of mortality and dementia in participants with depressive and bipolar disorders were estimated by Cox proportional hazard analysis. The direct and indirect effects of depressive and bipolar disorders on the risk of mortality were estimated using structural equation modeling.

RESULTS

The depressive and bipolar disorder groups showed 51% and 85% higher 6-year mortality, and 82% and 127% higher risk of dementia, respectively, compared to euthymic controls. The effects of depressive and bipolar disorders on mortality were mainly mediated by their effects on the risk of dementia in a structural equation model. The direct effects of each mood disorder on mortality were not significant.

CONCLUSION

Both depressive and bipolar disorders increased the risks of mortality and dementia, and the effects of mood disorders on mortality were mainly mediated through dementia. As dementia occurs later in life than mood disorders, measures to prevent it may effectively reduce mortality in individuals with a history of mood disorders, as well as being more feasible than attempting to control other causes of death.

Exploration of Cognitive Outcomes and Risk Factors for Cognitive Decline Shared by Couples

Importance

Although couples could share many risk factors of cognitive disorders in their lifetime, whether shared risk factors mediate the shared risk of cognitive disorders has rarely been investigated.

Objective

To identify the risk factors of cognitive decline shared within couples and investigate their mediating roles in the shared risk of cognitive disorders and cognitive functions within couples.

Design, Setting, and Participants

A prospective cohort study was launched in November 1, 2010, and 784 participants were followed up every 2 years until December 31, 2020. This nationwide, multicenter, community-based study included older couples from the Korean Longitudinal Study on Cognitive Aging and Dementia (KLOSCAD) and a cohort of their spouses (KLOSCAD-S).

Exposures

The cognitive disorder of a spouse was defined as mild cognitive impairment or dementia.

Main Outcomes and Measures

The mediating roles of factors shared within couples on the association between one spouse's cognitive disorder and the other's risk of cognitive disorders was examined with structural equation modeling.

Results

Included were 784 KLOSCAD participants (307 women [39.2%] and 477 men [60.8%]; mean [SD] age, 74.8 [4.8] years) and their spouses (477 women [60.8%] and 307 men [39.2%]; mean [SD] age, 73.6 [6.2] years). The cognitive disorder of the KLOSCAD participants was associated with almost double the risk of cognitive disorder of their spouses in the KLOSCAD-S cohort (odds ratio, 1.74; 95% CI, 1.12-2.69; P = .01). History of head injury (β = 0.50; 95% CI, 0.09-0.90; P = .02) and age (β = 2.57; 95% CI, 1.37-3.76; P < .001) mediated the association between cognitive disorder in the KLOSCAD participants and their spouses' risk of cognitive disorder. Physical inactivity mediated the association through major depressive disorder (β = 0.33, 95% CI, 0.09-0.57, P = .006 for physical inactivity; β = 0.28, 95% CI, 0.13-0.44, P < .001 for major depressive disorder). These factors similarly mediated the association between spousal cognitive disorder and cognitive functions such as memory and executive function.

Conclusions and Relevance

These findings suggest that the risk factors shared within couples may mediate approximately three-quarters of the spousal risk of cognitive disorders. Identification of and intervention in the shared risk factors of dementia within couples may reduce the risk of cognitive disorders in the spouses of people with dementia.

A 9-Year Comparison of Dementia Prevalence in Korea: Results of NaSDEK 2008 and 2017

BACKGROUND

In many high-income Western countries, the prevalence of dementia had been reduced over the past decades.

OBJECTIVE

We investigated whether the prevalence of all-cause dementia, Alzheimer's disease, vascular dementia, and mild cognitive impairment (MCI) had changed in Korea from 2008 to 2017.

METHODS

Nationwide Survey on Dementia Epidemiology of Korea (NaSDEK) in 2008 and 2017 was conducted on representative elderly populations that were randomly sampled across South Korea. Both surveys employed a two-stage design (screening and diagnostic phases) and diagnosed dementia and MCI according to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders and the consensus criteria from the International Working Group, respectively. The numbers of participants aged 65 years or older in the screening and diagnostic phases were 6,141 and 1,673 in the NaSDEK 2008 and 2,972 and 474 in the NaSDEK 2017, respectively.

RESULTS

The age- and sex-standardized prevalence of all-cause dementia and Alzheimer's disease showed nonsignificant decrease (12.3% to 9.8%, odds ratio [OR] = 0.89, 95% confidence interval [CI] = 0.54-1.48 for all-cause dementia; 7.6% to 6.8%, OR [95% CI] = 0.91 [0.58-1.42] for Alzheimer's disease). Vascular dementia decreased in the young-old population aged less than 75 years (2.7% to 0.001%, OR [95% CI] = 0.04 [0.01-0.15]) and in women (1.9% to 0.5%, OR [95% CI] = 0.27 [0.10-0.72]) while MCI remained stable (25.3% to 26.2%, OR [95% CI] = 1.08 [0.67-1.73]).

CONCLUSION

We found that the prevalence of dementia in Korea showed a nonsignificant decrease between 2008 and 2017.

Chronic subsyndromal depression and risk of dementia in older adults

OBJECTIVES

Subsyndromal depression is prevalent and associated with poor outcomes in late life, but its effect on the risk of dementia has barely been investigated. This study is aimed to investigate the effect of subsyndromal depression on dementia risk in cognitively normal older adults and patients with mild cognitive impairment.

METHODS

Data were collected from a nationwide, population-based, prospective cohort study on a randomly sampled Korean elderly population aged 60 years or older, which has been followed every 2 years. Using 6-year follow-up data of 4456 non-demented elderly, the authors examined the risk of dementia associated with late-onset subsyndromal depression using multivariate Cox proportional hazard models. After standardized diagnostic interviews, subsyndromal depression and dementia were diagnosed by the operational diagnostic criteria and Diagnostic and Statistical Manual of Mental Disorders, 4th edition criteria, respectively.

RESULTS

Subsyndromal depression tripled the risk of dementia in non-demented elderly individuals (hazard ratio = 3.02, 95% confidence interval = [1.56, 5.85], p < 0.001). In subgroup analyses, subsyndromal depression was associated with the risk of dementia in cognitively normal participants only (hazard ratio = 4.59, 95% confidence interval = [1.20, 17.54], p = 0.026); chronic/recurrent subsyndromal depression with increasing severity during the follow-up period was associated with the risk of dementia (hazard ratio = 15.34, 95% confidence interval = [4.19, 56.18], p < 0.001).

CONCLUSION

Late-onset subsyndromal depression is a potential predictor of incident dementia when it is chronic or recurrent with increasing severity in cognitively normal older adults.

Association between plasma monocyte trafficking-related molecules and future risk of depression in older adults

BACKGROUND

The recruitment of monocytes to the brain plays an important role in the development of depression. However, the association between plasma biomarkers of monocyte trafficking and depression is unclear. This study is aimed to examine the effects of plasma monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) on the risk of depression.

METHODS

Data were acquired from an ongoing prospective cohort study involving randomly sampled, community-dwelling Korean older adults, which has been followed every two years. We included 1,539 euthymic older adults (age = 68.2 [5.6] years; 51.7% were women) without a history of major psychiatric disorders, and dementia and neurological diseases. Geriatric psychiatrists diagnosed incident depression through a structured interview using the Korean version of the Mini International Neuropsychiatric Interview.

RESULTS

Depression had developed in 134 (8.7 %) participants during the follow-up period of 5.7 (0.8) years. The high plasma MCP-1 tertile group showed two-fold higher risk of depression than the low plasma MCP-1 tertile group (hazards ratio [HR] = 2.00, 95% confidence intervals [CI] = 1.27 - 3.13, p = 0.003). The association between high levels of plasma MCP-1 and future risk of depression was significant in the middle plasma ICAM-1 and VCAM-1 tertile groups; the high plasma MCP-1 tertile group showed about four-fold higher risk of depression than the low plasma MCP-1 tertile group.

CONCLUSIONS

Molecules involved in monocyte trafficking may be good candidates as diagnostic biomarkers and/or therapeutic targets for late life depression.

Disease Burdens of Alzheimer's Disease, Vascular Dementia, and Mild Cognitive Impairment

OBJECTIVES

Understanding disability-adjusted life-years (DALYs) based on dementia subtypes and mild cognitive impairment (MCI) is essential for optimal resource allocation. This study aimed to investigate disease burdens of various dementias and MCI in a representative South Korean population.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

6481 Korean older adults.

METHODS

We estimated the disease-specific DALYs.

RESULTS

DALYs due to MCI and all-cause dementia are estimated to increase from 1295 per 100,000 in 2016 to 9501 per 100,000 in 2065. In 2016, DALYs attributed to Alzheimer's dementia, vascular dementia, and MCI accounted for 33% (423 per 100,000), 20% (316 per 100,000), and 24% (123 per 100,000), respectively, of the total DALYs due to MCI and all-cause dementia. In 2065, DALYs due to Alzheimer's dementia, vascular dementia, and MCI will account for 38% (3654 per 100,000), 17% (1654 per 100,000), and 27% (2585 per 100,000) of total DALYs due to MCI and all-cause dementia, respectively. The years of life lived with disability (YLDs) due to MCI and all-cause dementia are estimated to rise from 479 per 100,000 in 2016 to 2807 per 100,000 in 2065. In 2016, YLDs due to Alzheimer's dementia, vascular dementia, and MCI composed 37% (177 per 100,000), 18% (85 per 100,000), and 15% (70 per 100,000), respectively, of the total YLDs due to MCI and all-cause dementia. In 2065, YLDs due to Alzheimer's dementia, vascular dementia, and MCI will account for 48% (1358 per 100,000), 15% (410 per 100,000), and 10% (290 per 100,000), respectively, of total YLDs due to MCI and all-cause dementia.

CONCLUSIONS AND IMPLICATIONS

Considering the rapidly growing disease burden, resources should be allocated to continuously monitor and manage the MCI and dementia burden. Particular attention to Alzheimer's dementia is required considering its significant contribution to current and future disease burden, especially to YLD.

Detection of free-living amoebae in domestic cats with and without naturally-acquired keratitis

Pathogenic free-living amoebae, most notably Acanthamoeba spp., are important pathogens of the human cornea. The importance of infection with free-living amoebae in cats with keratitis is currently unclear. The aim of this study was to determine the frequency of amoeba detection in corneas of cats with naturally-acquired keratitis and in the ocular surface microflora of cats without ocular disease. Clinical ophthalmic and in vivo corneal confocal microscopic examinations were performed on 60 cats with keratitis. Corneal scrapings were analyzed by amoeba culture; cytological evaluation; and Acanthamoeba, Hartmannella, and Vahlkampfia PCR assays. Following ophthalmic examination, conjunctival specimens collected from 60 cats without clinically apparent ocular disease were analyzed similarly. In one cat with ulcerative keratitis, amoeba cysts and trophozoites were detected by in vivo corneal confocal microscopy; an Acanthamoeba sp. was isolated from corneal specimens and detected by Acanthamoeba PCR assay; and suppurative corneal inflammation was present cytologically. An Acanthamoeba sp. was isolated from conjunctival specimens from one cat without clinically apparent ocular disease, but with suppurative inflammation demonstrated cytologically. Both Acanthamoeba isolates belonged to the T4 genotype. Naegleria-like amoebae were isolated in samples from two cats with keratitis and seven cats without clinical ocular disease, but amoebae were not detected by the other assays in these samples. Amoeba detection by culture was significantly (P = 0.01) associated with cytologically diagnosed corneoconjunctival inflammation. This study identified naturally-acquired Acanthamoeba keratitis in cats. Detection of Naegleria-like amoebae in samples from cats with and without keratitis is of uncertain pathological significance.

Hypohomocysteinemia may increases the risk of dementia and Alzheimer's disease: A nationwide population-based prospective cohort study

BACKGROUND

Hyperhomocysteinemia has been repeatedly found to increase the risk of dementia. However, the effects of hypohomocysteinemia on the risk of dementia have been barely investigated. If hypohomocysteinemia, like hyperhomocysteinemia, increases the risk of dementia, misuse or overuse of homocysteine-lowing agents such as vitamin supplements may increase the risk of dementia.

AIMS

To investigate whether hypohomocysteinemia, like hyperhomocysteinemia, could increase the risk of dementia and Alzheimer's disease (AD) in a large population-based cohort of older adults.

METHODS

This prospective cohort study followed 2655 randomly sampled, community-dwelling, non-demented individuals aged 60 years or older from 2010 to 2018. We measured baseline serum total homocysteine (tHcy) levels and examined the effect of serum tHcy on the risks of dementia and AD using Cox proportional hazards models.

RESULTS

During the follow-up period (mean = 5.4 years, SD = 0.9), dementia and AD developed in 85 and 64 participants, respectively. Not only the participants with high serum tHcy (≥10.6 μmol/L) but also those with low serum tHcy (≤8.9 μmol/L) were 4-5 times more likely to develop dementia and AD compared to those with serum tHcy levels between 9.0 and 10.5 μmol/L. With the increase in serum tHcy concentration, the use of vitamin supplements decreased, and 41.2% of the participants with low serum tHcy (≤8.9 μmol/L) were taking vitamin supplements.

CONCLUSIONS

Not only hyperhomocysteinemia but also hypohomocysteinemia considerably increased the risk of dementia and AD in older adults. The risk of dementia that results from overuse or misuse of vitamin supplements should be acknowledged and homocysteine-lowering health policies should be tailored to consider dementia risks that are associated with hypohomocysteinemia.

Executive dysfunction and risk of suicide in older adults: a population-based prospective cohort study

OBJECTIVE

It is uncertain what factors increases the risk of suicide in older adults without depression, and it is unknown whether executive dysfunction (ED) is one of those factors. We aimed to examine the effect of ED on the risk of suicide in non-demented older adults without depression.

METHODS

In an ongoing population-based prospective cohort of Korean older adults, we identified suicide using the National Mortality Database and suicidal ideation or attempt (SIA) based on the Korean version of the Mini International Neuropsychiatric Interview. We defined ED as performing below -1.5 SD of age-adjusted, gender-adjusted and education-adjusted norms in any of following tests: Frontal Assessment Battery, Trail Making Test A, Digit Span Test or Verbal Fluency Test.

RESULTS

The mean age of the 4791 participants at baseline was 69.7 (SD 6.4) years, and 57.1% of them were women (mean follow-up duration=4.9 years). ED at baseline increased the risk of suicide by about seven times (HR 7.20, 95% CI 1.84 to 28.12, p=0.005) but did not change the risk of SIA. However, cognitive impairment without ED did not change the risks of suicide and SIA. In participants with ED, being aged 75 years or above, living alone, and having a low socioeconomic status were associated with the risk of suicide.

CONCLUSION

ED is a strong risk factor of late life suicide independent from depression, particularly in very old adults living in disadvantaged environments.

Dual Sensory Impairment and Cognitive Impairment in the Korean Longitudinal Elderly Cohort

OBJECTIVE

To investigate the effects of single sensory impairment (SSI; visual or auditory) or dual sensory impairment (DSI; visual and auditory) on dementia and longitudinal changes of neuropsychological test scores.

METHODS

In this nationwide, prospective, community-based elderly cohort study, KLOSCAD (the Korean Longitudinal Study on Cognitive Aging and Dementia), 6,520 elderly individuals (58-101 years) representing the general population were included. We defined visual and auditory sensory impairment via self-report questionnaire: 932 had normal sensory function, 2,957 had an SSI, and 2,631 had a DSI. Demographic and clinical variables including cognitive outcomes were evaluated every 2 years over 6 years. Through logistic regression, Cox regression, and linear mixed model analysis, the relationship between SSI or DSI and dementia prevalence, dementia incidence, and change in neuropsychological scores were evaluated.

RESULTS

At baseline, DSI was significantly associated with increased dementia prevalence compared to normal sensory function (odds ratio [OR] 2.17, 95% confidence interval [CI] 1.17-4.02), but SSI was not (OR 1.27, 95% CI 0.66-2.41). During the 6-year follow-up, the incidence of dementia was significantly higher in the DSI group than in the normal sensory function group (hazard ratio 1.9, 95% CI 1.04-3.46) and neuropsychological scores significantly decreased (β -0.87, 95% CI [-1.17 to -0.58]).

CONCLUSIONS

Our results suggest that coexisting visual and hearing impairments facilitate dementia prevalence, dementia incidence, and cognitive decline, but visual or hearing impairment alone do not. Visual and hearing impairment may lead to dementia or cognitive decline independent of Alzheimer pathology.

Early Trauma and Relationships among Recent Stress, Depressive Symptoms, Anxiety Symptoms, and Suicidal Ideation in Korean Women

BACKGROUND

Evidence continues to accumulate that the presence or absence of early trauma (ET) implies unique characteristics in the relationships between suicidal ideation and its risk factors. We examined the relationships among recent stress, depressive symptoms, anxiety symptoms, and suicidal ideation in Korean suicidal women with or without such a history.

METHODS

Using data on suicidal adult females, 217 victims and 134 non-victims of ET, from the Korean Cohort for the Model Predicting a Suicide and Suicide-related Behavior, we performed structural equation modeling to investigate the contribution of recent stress, depressive symptoms, and anxiety symptoms on suicidal ideation within each group according to the presence or absence of a history of ET.

RESULTS

Structural equation modeling with anxiety and depressive symptoms as potential mediators showed a good fit. Recent stress had a direct effect on both depressive symptoms and anxiety symptoms in both groups. Only anxiety symptoms for victims of ET (standardized regression weight, 0.281; P = 0.005) and depressive symptoms for non-victims of ET (standardized regression weight, 0.326; P = 0.003) were full mediators that increased suicidal ideation. Thus, stress contributed to suicidal ideation by increasing the level of anxiety and depressive symptoms for victims and non-victims, respectively.

CONCLUSION

Tailored strategies to reduce suicidal ideation should be implemented according to group type, victims or non-victims of ET. Beyond educating suicidal women in stress-management techniques, it would be effective to decrease anxiety symptoms for those with a history of ET and decrease depressive symptoms for those without such a history.

Suicide risk factors across suicidal ideators, single suicide attempters, and multiple suicide attempters

Few studies have compared the three suicidality groups-suicidal ideators (SIs), single suicide attempters (SSAs), and multiple suicide attempters (MSAs)-in relation to the suicidal process. This cross-sectional study investigated trends and differences in suicide risk factors across suicidality groups. Using the baseline data of the Korean Cohort for the Model Predicting a Suicide and Suicide-related Behavior, we analyzed trends (Jonckheere-Terpstra or Mantel-Haenszel χ² test) and differences (analysis of covariance or logistic regression) in sociodemographic and clinical factors, psychiatric diagnoses, as well as clinical rating scores on psychopathology (suicidal ideation, depressive symptoms, anxiety symptoms, and problem drinking), trait impulsiveness, and stress across suicidality groups. Across suicidality groups comprising 193 SIs, 207 SSAs, and 376 MSAs, we observed a decreasing trend in age and increasing trends in history of early trauma, familial histories of suicide attempts and suicide, most diagnoses and psychopathologies (suicidal ideation, anxiety symptoms, and problem drinking), trait impulsiveness, and stress-with MSAs more likely to have histories of early trauma and familial suicide, almost uniformly higher proportions of diagnoses, and higher psychopathology rating scores. Overall, increasing trends in suicide risk factors were found across all suicidality groups. Notably, MSAs presented greater proportions of most psychiatric diagnoses and higher degrees of most psychopathologies, motor impulsiveness, and stress, indicating they were at more severe clinical states and were closer to suicide. Mental health professionals should ascertain the number of suicide attempts to identify MSAs, implement more thorough evaluations, and employ additional measures for reducing motor impulsiveness.

Sex differences in subjective age-associated changes in sleep: a prospective elderly cohort study

Subjective age-associated changes in sleep (AACS) and sex differences in AACS have never been prospectively investigated in elderly populations. We compared the AACS every 2 years over a total of 6 years between 4,686 community-dwelling healthy men and women aged 60 years or older who participated in the Korean Longitudinal Study on Cognitive Aging and Dementia. Sleep parameters including sleep duration, latency, and efficiency, mid-sleep time, daytime dysfunction, and overall subjective sleep quality were measured using the Pittsburgh Sleep Quality Index at baseline and at each follow-up. The effects of time and sex on subjective sleep parameters were analyzed using linear mixed-effects models. During the 6 years of follow-up, we observed that overall, sleep latency increased, while daytime dysfunction and sleep quality worsened. Significant sex differences in AACS was found, with women showing shortened sleep duration, delayed mid-sleep time, and decreased sleep efficiency over 6 years. Sleep quality worsened in both groups but a more pronounced change was observed in women. Clinicians should be cautious in determining when to treat declared sleep disturbances in this population.

Does parity matter in women's risk of dementia? A COSMIC collaboration cohort study

BACKGROUND

Dementia shows sex difference in its epidemiology. Childbirth, a distinctive experience of women, is associated with the risk for various diseases. However, its association with the risk of dementia in women has rarely been studied.

METHODS

We harmonized and pooled baseline data from 11 population-based cohorts from 11 countries over 3 continents, including 14,792 women aged 60 years or older. We investigated the association between parity and the risk of dementia using logistic regression models that adjusted for age, educational level, hypertension, diabetes mellitus, and cohort, with additional analyses by region and dementia subtype.

RESULTS

Across all cohorts, grand multiparous (5 or more childbirths) women had a 47% greater risk of dementia than primiparous (1 childbirth) women (odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.10-1.94), while nulliparous (no childbirth) women and women with 2 to 4 childbirths showed a comparable dementia risk to primiparous women. However, there were differences associated with region and dementia subtype. Compared to women with 1 to 4 childbirths, grand multiparous women showed a higher risk of dementia in Europe (OR = 2.99, 95% CI = 1.38-6.47) and Latin America (OR = 1.49, 95% CI = 1.04-2.12), while nulliparous women showed a higher dementia risk in Asia (OR = 2.15, 95% CI = 1.33-3.47). Grand multiparity was associated with 6.9-fold higher risk of vascular dementia in Europe (OR = 6.86, 95% CI = 1.81-26.08), whereas nulliparity was associated with a higher risk of Alzheimer disease (OR = 1.91, 95% CI 1.07-3.39) and non-Alzheimer non-vascular dementia (OR = 3.47, 95% CI = 1.44-8.35) in Asia.

CONCLUSION

Parity is associated with women's risk of dementia, though this is not uniform across regions and dementia subtypes.

Driving-Related Adverse Events in the Elderly Men: A Population-Based Prospective Cohort Study

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.

Role of tumour location and surgical extent on prognosis in T2 gallbladder cancer: an international multicentre study

BACKGROUND

In gallbladder cancer, stage T2 is subdivided by tumour location into lesions on the peritoneal side (T2a) or hepatic side (T2b). For tumours on the peritoneal side (T2a), it has been suggested that liver resection may be omitted without compromising the prognosis. However, data to validate this argument are lacking. This study aimed to investigate the prognostic value of tumour location in T2 gallbladder cancer, and to clarify the adequate extent of surgical resection.

METHODS

Clinical data from patients who underwent surgery for gallbladder cancer were collected from 14 hospitals in Korea, Japan, Chile and the USA. Survival and risk factor analyses were conducted.

RESULTS

Data from 937 patients were available for evaluation. The overall 5-year disease-free survival rate was 70·6 per cent, 74·5 per cent for those with T2a and 65·5 per cent among those with T2b tumours (P = 0·028). Regarding liver resection, extended cholecystectomy was associated with a better 5-year disease-free survival rate than simple cholecystectomy (73·0 versus 61·5 per cent; P = 0·012). The 5-year disease-free survival rate was marginally better for extended than simple cholecystectomy in both T2a (76·5 versus 66·1 per cent; P = 0·094) and T2b (68·2 versus 56·2 per cent; P = 0·084) disease. Five-year disease-free survival rates were similar for extended cholecystectomies including liver wedge resection versus segment IVb/V segmentectomy (74·1 versus 71·5 per cent; P = 0·720). In multivariable analysis, independent risk factors for recurrence were presence of symptoms (hazard ratio (HR) 1·52; P = 0·002), R1 resection (HR 1·96; P = 0·004) and N1/N2 status (N1: HR 3·40, P < 0·001; N2: HR 9·56, P < 0·001). Among recurrences, 70·8 per cent were metastatic.

CONCLUSION

Tumour location was not an independent prognostic factor in T2 gallbladder cancer. Extended cholecystectomy was marginally superior to simple cholecystectomy. A radical operation should include liver resection and adequate node dissection.

Epidemiological characteristics of subsyndromal depression in late life

OBJECTIVES

Subsyndromal depression is prevalent and associated with poor outcomes in late life, but its epidemiological characteristics have barely been investigated. The aim of this prospective cohort study is to compare the prevalence, incidence and risk factors of subsyndromal depression with those of syndromal depression including major and minor depressive disorders in community-dwelling elderly individuals.

METHODS

In a nationwide community-based study of randomly sampled Korean elderly population aged 60 years or older (N = 6640), depression was assessed with standardized diagnostic interviews. At baseline and at 2-year and 4-year follow-ups, the authors diagnosed subsyndromal depression by the operational criteria and syndromal depression by the Diagnostic and Statistical Manual of Mental Disorders (4th ed.) diagnostic criteria. Multivariate logistic regression analyses were conducted to identify the risk factors for incident depression.

RESULTS

The age- and gender-adjusted prevalence rate of subsyndromal depression was 9.24% (95% confidence interval = [8.54, 9.93]), which was 2.4-fold higher than that of syndromal depression. The incidence rate of subsyndromal depression was 21.70 per 1000 person-years (95% confidence interval = [19.29, 24.12]), which was fivefold higher than that of syndromal depression. The prevalence to incidence ratio of subsyndromal depression was about half that of syndromal depression. The risk for subsyndromal depression was associated with female gender, low socioeconomic status, poor social support and poor sleep quality, while that of syndromal depression was associated with old age and less exercise.

CONCLUSION

Subsyndromal depression should be validated as a clinical diagnostic entity, at least in late life, since it has epidemiological characteristics different from those of syndromal depression.

Low Diastolic Blood Pressure and Cognitive Decline in Korean Elderly People: The Korean Longitudinal Study on Cognitive Aging and Dementia

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.

Anhedonia and Dysphoria Are Differentially Associated with the Risk of Dementia in the Cognitively Normal Elderly Individuals: A Prospective Cohort Study

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.

Impact of Mild Cognitive Impairment on Mortality and Cause of Death in the Elderly

BACKGROUND

Mild cognitive impairment (MCI) is a cognitive state that lies on the continuum between normal aging and dementia, and the prevalence of MCI is higher than dementia. However, the risk for mortality of people with MCI has been far less studied than that of people with dementia, and the population attributable risk percent (PAR%) of death attributable to MCI has not been estimated yet.

OBJECTIVE

To investigate the impact of MCI on mortality and the cause of death in the elderly, and to estimate the PAR% of deaths attributable to MCI.

METHODS

Data came from 7,315 elderly subjects aged ≥60 years without dementia from two cohort studies with diagnostic assessments of MCI at baseline. Deaths among participants were confirmed through the nationwide mortality database of Statistics Korea.

RESULTS

MCI increased the risk of mortality in a multivariate Cox proportional model adjusting for age, sex, education, smoking, alcohol drinking, chronic illness, depression, vascular components, and cohort (hazard ratio = 1.59, 95% confidence interval 1.30, 1.94). PAR% of death attributable to MCI was 10.7% for age 65-74 years, 16.0% for age 75-84 years, and 24.2% for age ≥85 years. In the elderly with MCI, mortality risks from cerebrovascular disease, respiratory disease, and external causes were higher than in the cognitively normal elderly.

CONCLUSIONS

Our results suggest that the mortality risk of MCI in Asian countries may be comparable to that in Western countries, and MCI can contribute to the death of the elderly as much as dementia.

Normal-But-Low Serum Folate Levels and the Risks for Cognitive Impairment

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.

Pre-treatment 18F-FDG PET-based radiomics predict survival in resected non-small cell lung cancer

AIM

To assess the prognostic value of 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)-based radiomics using a machine learning approach in patients with non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Ninety-three patients with stage I-III NSCLC who underwent combined PET/computed tomography (CT) followed by curative resection. A total of 35 unique quantitative radiomic features was extracted from the PET images, which included imaging phenotypes such as pixel intensity, shape, and texture. Radiomic features were ranked based on score according to their correlation with disease recurrence status within a 3-year follow-up. The recurrence risk classification performances of machine learning algorithms (random forest, neural network, naive Bayes, logistic regression, and support vector machine) using the 20 best-ranked features were compared using the areas under the receiver operating characteristic curve (AUC) and validated by the random sampling method.

RESULTS

Contrast and busyness texture features from neighbourhood grey-level difference matrix were found to be the two best predictors of disease recurrence. The random forest model obtained the best performance (AUC: 0.956, accuracy: 0.901, F1 score: 0.872, precision: 0.905, recall: 0.842), followed by the neural network model (AUC: 0.871, accuracy: 0.780, F1 score: 0.708, precision: 0.755, recall: 0.666).

CONCLUSION

A PET-based radiomic model was developed and validated for risk classification in NSCLC. The machine learning approach with random forest classifier exhibited good performance in predicting the recurrence risk. Radiomic features may help clinicians to improve the risk stratification for clinical practice.

Is Dementia More Fatal Than Previously Estimated? A Population-based Prospective Cohort Study

Dementia increases the risk of mortality (ROM) in the elderly and estimates of hazard ratio (HR) of dementia for mortality have ranged from 1.7 to 6.3. However, previous studies may have underestimated ROM of dementia due to length bias, which occurs when failing to include the persons with rapidly progressive diseases, who died before they could be included in the study. This population-based prospective cohort study conducted on 6,752 randomly sampled Koreans, aged 60 years or older (the Korean Longitudinal Study on Cognitive Aging and Dementia). Cognitive disorders were evaluated at baseline and 2-year follow-up using the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K), and prevalent and incident cases of dementia were identified. The participants' deaths were confirmed through the National Mortality Database of Statistics Korea. We compared the ROM between prevalent and incident dementia, and estimated HR of dementia for mortality using Cox proportional hazards model. Of the 5,097 responders to the 2-year follow-up assessment, 150 participants had dementia from the baseline (prevalent dementia), and 95 participants developed dementia during the 2-year follow-up period (incident dementia). The ROM of participants with incident dementia was about 3 times higher than the ROM of those with prevalent dementia (HR = 3.04, 95% confidence interval [CI] = 1.34-6.91). Compared to cognitively normal participants at both the baseline and 2-year follow-up assessments, the ROM of those with incident dementia approximately 8 times higher (HR = 8.37, 95 % CI = 4.23-16.54). In conclusion, the ROM of dementia using prevalent cases was underestimated due to length bias, and dementia may be much more fatal than previously estimated. In clinical settings, the ROM of dementia warrants the attention of physicians, particularly in recently incident dementia cases.

Characteristics of the "young-old" and "old-old" community-dwelling suicidal Ideators: A longitudinal 6-month follow-up study

BACKGROUND

Despite heterogeneity of older people in suicidal behavior, research identifying characteristics by age groups is scarce. We examined baseline features of older community-dwelling suicidal ideators by dichotomized age groups and the 6-month trajectory of their suicidal ideation along with its related psychopathology. Predictors of suicidal ideation within each group were investigated.

METHODS

Older community-dwelling suicidal ideators enrolled in the Korean Cohort for the Model Predicting a Suicide and Suicide-related Behavior study were subdivided into the "young-old (65-74 years)" and "old-old (≥75 years)" group. Baseline, 1-, and 6-month assessments were compared. Within each group, multiple regression analysis using rating scales (Patient Health Questionnaire-9, Beck Anxiety Inventory, Alcohol Use Disorders Identification Test, Stress Questionnaire for Korean National Health and Nutrition Examination Survey-Short Form, and Social Relationships Scale) was conducted to identify predictors of suicidal ideation measured with the intensity subscale of the Columbia-Suicide Severity Rating Scale. Two-way repeated-measures analysis of variance (RM-ANOVA) was used to compare changes in suicidal ideation, depression, anxiety between age groups over time, and one-way RM-ANOVA to examine changes within each age group.

RESULTS

Among 29 "young-old" and 53 "old-old" ideators, the latter were less likely to be receiving psychiatric treatment (odds ratio [OR] = 4.065) and make suicide attempts (OR = 2.874), whereas the former revealed greater levels of anxiety and stress. Baseline depression and stress in the "young-old" group and the "old-old" group, respectively, predicted the intensity of suicidal ideation at both baseline and 1-month assessments. No significant age group x time interactions on suicidal ideation and depression were found. However, within each age group, both suicidal ideation and depression significantly decreased only during the first month with no further improvement.

CONCLUSION

We speculate cautiously that more attention may need to be paid to the "old-old" ideators in the evaluation of psychiatric issues and for referral to psychiatrists. To decrease suicidal ideation, tailored approaches involving proactive, timely management of depression in the "young-old" and interventions focusing on stress reduction in the "old-old," would be helpful.

The Korean Cohort for the Model Predicting a Suicide and Suicide-related Behavior: Study rationale, methodology, and baseline sample characteristics of a long-term, large-scale, multi-center, prospective, naturalistic, observational cohort study

BACKGROUND

The Korean Cohort for the Model Predicting a Suicide and Suicide-related Behavior (K-COMPASS) study is a prospective, naturalistic, observational cohort study, aiming to identify predictors of suicide attempt and suicide characteristics in the Korean suicidal population. The findings intend to contribute to a thorough understanding of suicidal phenomena and development of suicide prevention guidelines. The present cross-section study examines the study rationale, methodology, and baseline characteristics of the participants.

METHODS

Participants were enrolled via the hospital and community gateways, establishing the hospital-based cohort (HC) and community-based cohort (CC), respectively. Baseline assessment was conducted on sociodemographic, clinical, diagnostic, and psychopathological aspects. The Columbia-Suicide Severity Rating Scale was used to investigate suicidality.

RESULTS

A total of 800 suicidal people aged 15 years or older were enrolled from 8 university hospitals and 8 community mental health welfare centers (CMHWCs), among whom 480 (60%) were suicidal ideators and 320 (40%) were attempters. The ideators comprised 207 CC and 273 HC participants, whereas the attempters, 34 CC and 286 HC participants. Despite their lower severity in some measures, including suicidal ideation, compared with their HC counterparts, the CC participants within each group of ideators or attempters presented clinically significant psychopathology. Moreover, alcohol use problems and past suicide attempt were more likely to be found in CC participants. Only 11.1% to 21.6% of the participants in each of the four groups (defined by the cohorts and the ideators/attempters) were on any type of psychiatric treatment.

CONCLUSIONS

Suicidal visitors to CMHWCs need to be as closely monitored as suicidal patients in university hospitals, especially considering their association with problem drinking and past suicide attempt. A cautious assumption is that the high suicide rate in Korea might be partly attributable to the low proportion of patients receiving psychiatric services.

Differential effects of completed and incomplete pregnancies on the risk of Alzheimer disease

OBJECTIVE

To investigate the effects of completed pregnancy with childbirth and incomplete pregnancy without childbirth on the late-life cognition and the risk of Alzheimer disease (AD) in women.

METHODS

Using the pooled data of 3,549 women provided by 2 population-based cohort studies, we conducted logistic regression analyses to examine retrospectively the associations of completed and incomplete pregnancy with the risks of mild cognitive impairment and AD. For women without dementia, we also conducted analyses of covariance to examine the associations of completed and incomplete pregnancy with Mini-Mental State Examination (MMSE) score.

RESULTS

Grand multiparous women who experienced ≥5 completed pregnancies showed an ≈1.7-fold higher risk of AD than those who experienced 1 to 4 completed pregnancies (odds ratio [OR] 1.68, 95% confidence interval [CI] 1.04-2.72), while those who had incomplete pregnancies showed half the level of AD risk compared with those who never experienced an incomplete pregnancy (OR 0.43, 95% CI 0.24-0.76 for 1 incomplete pregnancy; OR 0.56, 95% CI 0.34-0.92 for ≥2 incomplete pregnancies). In women without dementia, the grand multiparous had worse MMSE scores than those with 1 to 4 completed pregnancies (p < 0.001), while those who experienced ≥1 incomplete pregnancies had better MMSE scores than those who never experienced an incomplete pregnancy (p = 0.008).

CONCLUSIONS

Grand multiparity was associated with high risk of AD, while incomplete pregnancy was associated with low risk of AD in late life.

Overview of the Korean Longitudinal Study on Cognitive Aging and Dementia

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.

Prevalence Rates of Dementia and Mild Cognitive Impairment Are Affected by the Diagnostic Parameter Changes for Neurocognitive Disorders in the DSM-5 in a Korean Population

AIM

To examine the impact of the revised diagnostic criteria for neurocognitive disorders (NCDs) in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) on the prevalence of dementia and mild cognitive impairment (MCI).

METHODS

A total of 755 participants aged 65 years or older in the Nationwide Survey on Dementia Epidemiology in Korea 2012 were rediagnosed according to the DSM-5 criteria.

RESULTS

The estimated age-, gender-, education-, and urbanicity-standardized prevalence rates of major and mild NCDs were 8.35 and 11.10%, respectively, and those of dementia and MCI were 8.74 and 31.85%, respectively. Cohen's κ for dementia and major NCD was 0.988, and that for MCI and mild NCD was 0.273.

CONCLUSION

Diagnostic discrepancies between major/mild NCDs and dementia/MCI might depend on the operationalization of neuropsychological performance criteria.

Regenerative endodontics: a comprehensive review

The European Society of Endodontology and the American Association for Endodontists have released position statements and clinical considerations for regenerative endodontics. There is increasing literature on this field since the initial reports of Iwaya et al. (Dental Traumatology, 17, 2001, 185) and Banchs & Trope (Journal of Endodontics, 30, 2004, 196). Endogenous stem cells from an induced periapical bleeding and scaffolds using blood clot, platelet rich plasma or platelet-rich fibrin have been utilized in regenerative endodontics. This approach has been described as a 'paradigm shift' and considered the first treatment option for immature teeth with pulp necrosis. There are three treatment outcomes of regenerative endodontics; (i) resolution of clinical signs and symptoms; (ii) further root maturation; and (iii) return of neurogenesis. It is known that results are variable for these objectives, and true regeneration of the pulp/dentine complex is not achieved. Repair derived primarily from the periodontal and osseous tissues has been shown histologically. It is hoped that with the concept of tissue engineering, namely stem cells, scaffolds and signalling molecules, that true pulp regeneration is an achievable goal. This review discusses current knowledge as well as future directions for regenerative endodontics. Patient-centred outcomes such as tooth discolouration and possibly more appointments with the potential for adverse effects needs to be discussed with patients and parents. Based on the classification of Cvek (Endodontics and Dental Traumatology, 8, 1992, 45), it is proposed that regenerative endodontics should be considered for teeth with incomplete root formation although teeth with near or complete root formation may be more suited for conventional endodontic therapy or MTA barrier techniques. However, much is still not known about clinical and biological aspects of regenerative endodontics.

Effects of lifetime cumulative ginseng intake on cognitive function in late life

BACKGROUND

We investigated the effects of lifetime cumulative ginseng intake on cognitive function in a community-dwelling population-based prospective cohort of Korean elders.

METHODS

Community-dwelling elders (N = 6422; mean age = 70.2 ± 6.9 years, education = 8.0 ± 5.3 years, female = 56.8%) from the Korean Longitudinal Study on Cognitive Aging and Dementia were included. Among them, 3918 participants (61.0%) completed the 2-year and 4-year follow-up evaluations. Subjects were categorized according to cumulative ginseng intake at baseline evaluation; no use group, low use (< 5 years) group, and high use (≥ 5 years) group. One-way analysis of covariance (ANCOVA) was conducted to compare the impact of cumulative ginseng intake on baseline Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet neuropsychological battery total score (CERAD total score) and Mini-Mental State Examination (MMSE) score among the three groups while adjusting for potential covariates. A repeated-measures ANCOVA was performed to investigate the impacts on the changes in CERAD total scores and MMSE scores during the 4 years of follow-up.

RESULTS

The high use group showed higher CERAD total scores compared to the no use group after controlling for age, sex, education years, socioeconomic status, smoking, alcohol intake, presence of hypertension, stroke history, Geriatric Depression Scale, Cumulative Illness Rating Scale, and presence of the APOE e4 allele (F(2, 4762) = 3.978, p = 0.019). The changes of CERAD total score for 2 or 4 years of follow-up did not differ according to the use of ginseng.

CONCLUSIONS

Cumulative ginseng use for longer than 5 years may be beneficial to cognitive function in late life.

Dipeptidyl peptidase-4 inhibitor use and risk of diabetic retinopathy: A population-based study

AIMS

This study examined whether dipeptidyl peptidase (DPP)-4 inhibitor use is beneficial or harmful to diabetic retinopathy (DR) compared with other glucose-lowering agents in patients with type 2 diabetes (T2D).

METHODS

From a population-based cohort provided by the National Health Insurance Service in Korea, 67,743 adults with T2D were identified as having been treated with oral glucose-lowering agents between 2008 and 2013. Matching (1:1) was performed for two groups comparing ever-use (cases) and never-use (controls) of DPP-4 inhibitors (n=14,522 in each group). Cox regression analyses were used to assess risk of the following DR events: vitreous haemorrhage; vitrectomy or photocoagulation; intravitreal agent use; and blindness.

RESULTS

During a median follow-up of 28.4 (14.0-45.2) months, there were 305 (in controls) and 342 (in cases) composite DR events. DPP-4 inhibitor ever-use was not associated with overall risk of composite DR events [adjusted hazard ratio (HR): 1.08, 95% CI: 0.93-1.26] compared with never-use, nor was the risk of each DR outcome increased with DPP-4 inhibitor therapy either. However, DPP-4 inhibitor administration for<12 months was associated with a greater risk of composite DR events (adjusted HR: 1.31, 95% CI: 1.09-1.57) compared with other glucose-lowering agents over the same treatment period.

CONCLUSION

In comparison to other oral glucose-lowering agents, DPP-4 inhibitor treatment did not increase overall risk of DR. However, DPP-4 inhibitors may be associated with an increased risk of retinopathy events early in the treatment phase.

Sleep and cognitive decline: A prospective nondemented elderly cohort study

OBJECTIVE

To investigate sleep disturbances that induce cognitive changes over 4 years in nondemented elderlies.

METHODS

Data were acquired from a nationwide, population-based, prospective cohort of Korean elderlies (2,238 normal cognition [NC] and 655 mild cognitive impairment [MCI]). At baseline and 4-year follow-up assessments, sleep-related parameters (midsleep time, sleep duration, sleep latency, subjective sleep quality, sleep efficiency, and daytime dysfunction) and cognitive status were measured using the Pittsburgh Sleep Quality Index and Consortium to Establish a Registry for Alzheimer's Disease Assessment, respectively. We used logistic regression models adjusted for covariates including age, sex, education, apolipoprotein E genotype, Geriatric Depression Scale, Cumulative Illness Rating Scale, and physical activity.

RESULTS

In participants with NC, long sleep latency (>30 minutes), long sleep duration (≥7.95 hours), and late midsleep time (after 3:00 am) at baseline were related to the risk of cognitive decline at 4-year follow-up assessment; odds ratio (OR) was 1.40 for long sleep latency, 1.67 for long sleep duration, and 0.61 for late midsleep time. These relationships remained significant when these variables maintained their status throughout the follow-up period. Newly developed long sleep latency also doubled the risk of cognitive decline. In those with MCI, however, only long sleep latency reduced the chance of reversion to NC (OR = 0.69).

INTERPRETATION

As early markers of cognitive decline, long sleep latency can be used for elderlies with NC or MCI, whereas long sleep duration and relatively early sleep time might be used for cognitively normal elderlies only. Ann Neurol 2018;83:472-482.

First report of carp oedema virus infection of koi (Cyprinus carpio haematopterus) in the Republic of Korea

Twenty-five koi (Cyprinus carpio haematopterus) bought from a wholesale fish market in Korea, showed lethargic behaviour and 100% mortality within 20 days. Carp oedema virus (CEV) was detected by PCR in all 25 koi. Results of detailed histopathological and clinical examinations of 17 koi indicated loss of body balance, severe infiltration of inflammatory cells into the inter-lamellar spaces of the gills and vacuolization and inclusion bodies in gill epithelial cells. Sequence analysis of PCR products of these koi showed up to 99% identity to the previously reported sequences, suggesting that the observed mass mortality resulted from koi sleepy disease (KSD) due to CEV infection. To the best of our knowledge, this study is the first report of KSD in the Republic of Korea. Partial sequences of 4a protein from the virus indicated that the present CEV detected in koi from Korea is more closely related to that from the UK and Poland than from Japan. The present findings indicate that the prevalence and spread of KSD must be closely monitored in both European and Asian countries to avoid potential economic losses to the global koi industry.

Solid pseudopapillary neoplasm of the pancreas with liver metastasis initially misinterpreted as benign haemorrhagic cyst

Solid pseudopapillary neoplasm (SPN) of the pancreas is considered a low-malignant neoplasm with a good prognosis. However, 5% to 15% of patients with SPNs develop metastatic disease, most commonly in the liver. Metastatic hepatic malignancies that show pseudocystic features are rare. Here we describe the case of a middle-aged female with a cystic liver metastasis from SPN. To the best of our knowledge, SPN with a single cystic liver metastasis has not been described, although these tumours frequently undergo haemorrhagic-cystic degeneration. Thus, in these patients the marked cystic change could be misinterpreted as a benign lesion.