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.

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.

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.

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.

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.

Effect of interproximal undercut on the dimensional accuracy of impression / 대한치과보철학회지

PURPOSE: This study evaluated the effect of loss of interproximal papilla, creating an undercut, on the accuracy of impression materials. MATERIALS AND METHODS: Two addition type silicone impression materials (Extrude(R) Wash, Imprint(TM) II Quick Step Light Body) and one alginate impression material (Cavex Impressional) were used to make impressions of a maxillary master model simulating clinical conditions with or without interproximal papilla. Stone was poured in the impressions and working casts were fabricated. A total of 6 groups with 6 working casts in each group were scanned using 3-dimensional optical scanner. The accuracy of the impressions was assessed by measuring the dimensional changes (DeltaI (%)) of 6 distances on working casts compared to a master model with a 3-dimensional digitizing and inspection software. The data were analyzed by two-way ANOVA (P<.05). RESULTS: Three of 6 distances showed statistically significant differences among the impression materials. Only 1 of 6 distances in alginate impression showed a statistically significant difference between casts with and without interproximal papilla (P=.047). CONCLUSION: The presence of undercut due to loss of interproximal papilla did not significantly influence the dimensional accuracy of addition type silicone and alginate impression materials.

Detorque values of abutment screws in a multiple implant-supported prosthesis / 대한치과보철학회지

PURPOSE: This study evaluated the detorque values of screws in a multiple implant-supported superstructure using stone casts made with 2 different impression techniques. MATERIAL AND METHODS: A fully edentulous mandibular master model and a metal framework directly connected to four implants (Branemark System(R); Nobel Biocare AB) with a passive fit to each other were fabricated. Six experimental stone casts (Group 1) were made with 6 non-splinted impressions on a master cast and another 6 experimental casts (Group 2) were made with 6 acrylic resin splinted impressions. The detorque values of screws (TorqTite(R) GoldAdapt Abutment Screw; Nobel Biocare AB) were measured twice after the metal framework was fastened onto each experimental stone cast with 20 Ncm torque. Detorque values were analyzed using the mixed model with the fixed effect of screw and reading and the random effect of model for the repeated measured data at a .05 level of significance. RESULTS: The mean detorque values were 7.9 Ncm (Group 1) and 8.1 Ncm (Group 2), and the mean of minimum detorque values were 6.1 Ncm (Group 1) and 6.5 Ncm (Group 2). No statistically significant differences between 2 groups were found and no statistically significant differences among 4 screws were found for detorque values. No statistically significant differences between 2 groups were also found for minimum detorque values. CONCLUSION: In a multiple external hexagon implant-supported prosthesis, no significant differences between 2 groups were found for detorque values and for minimum detorque values. There seems to be no significant differences in screw joint stability between 2 stone cast groups made with 2 different impression techniques.

The effects of polishing technique and brushing on the surface roughness of acrylic resin / 대한치과보철학회지

PURPOSE: This study evaluated the effect of polishing techniques on surface roughness of polymethyl methacrylate (PMMA), as well as the influence of light-cured surface glaze and subsequent brushing on surface roughness. MATERIALS AND METHODS: A total of 60 PMMA specimens (10x10x5 mm) were made and then divided into 6 groups of 10 each according to the polymerization methods (under pressure or atmosphere) and the surface polishing methods (mechanical or chemical polishing) including 2 control groups. The mechanical polishing was performed with the carbide denture bur, rubber points and then pumice and lathe wheel. The chemical polishing was performed by applying a light-cured surface glaze (Plaquit(R); Dreve-Dentamid GmbH). Accura 2000(R), a non-contact, non-destructive, optical 3-dimensional surface analysis system, was used to measure the surface roughness (Ra) and 3-dimensional images were acquired. The surface roughness was again measured after ultrasonic tooth brushing in order to evaluate the influence of brushing on the surface roughness. The statistical analysis was performed with Mann-Whitney test and t-test using a 95% level of confidence. RESULTS: The chemically polished group showed a statistically lower mean surface roughness in comparison to the mechanically polished group (P = .0045) and the specimens polymerized under the atmospheric pressure presented a more significant difference (P = .0138). After brushing, all of the groups, except the mechanically polished group, presented rougher surfaces and showed no statistically significant differences between groups. CONCLUSION: Although the surface roughness increased after brushing, the chemical polishing technique presented an improved surface condition in comparison to the mechanical polishing technique.

Factors Related to Mortality of Elderly Patients Admitted with Community-acquired Pneumonia

BACKGROUND: Community-acquired pneumonia is one of the main causes of hospitalization and death, especially in elderly patients. There have been many studies on prognosis for community-acquired pneumonia, but few in Korea. We sought to identify characteristics on admission predicting mortality in elderly patients hospitalized with community-acquired pneumonia and to compare mortality rates by PORT score with PORT study's ones. METHODS: We performed a retrospective study of 267 patients aged 65 years and over admitted with community- acquired pneumonia from January 2000 to December 2002. We reviewed demographic, clinical, laboratory, microbiological and radiologic data and identified independent factors associated with the mortality using logistic regression analysis. We classified patients into risk classes by PORT score and calculated the mortality rate. RESULTS: Among of 267 patients, 48 (18.0%) died. We identified six independent predictors of mortality; male (OR, 2,496; 95% CI, 1,012~6,153), lung cancer (OR, 3,409; 95% CI, 1,302~8,920), general weakness (OR, 5.218; 95% CI, 2,140~12,718), unable to walk (OR, 9,232; 95% CI, 2,228~38,257), BUN > or =30 mg/dL (OR, 3,327; 95% CI, 1.072~10.327), albumin <3 g/dL (OR, 3,219; 95% CI, 1,351~7,670) and pleural effusion (OR, 3.135; 95% CI, 1,052~9,342). Mortality rates of risk class II-V by PORT score were 6.7%, 9.5%, 30.4% and 34.4%, respectively. CONCLUSION: There were factors that were associated with mortality in elderly patients hospitalized with community-acquired pneumonia.