Seok Bum Lee

A nationwide survey on the prevalence of dementia and mild cognitive impairment in South Korea.

We investigated the prevalence of dementia and mild cognitive impairment (MCI) and the factors associate with risk of dementia from a representative nationwide sample of Korean elders. 8,199 randomly-sampled Koreans aged 65 years or older were invited to participate in the Phase I screening assessment using Mini-Mental State Examination by door-to-door home visit, and 6,141 subjects (response rate = 74.9%) responded. Among them, 2,336 subjects were invited to participate in the Phase II diagnostic assessment for dementia and MCI, and 1,673 subjects responded (response rate = 71.6%). Diagnostic assessments were administered using the Korean version of the Consortium to Establish a Registry for Alzheimers Disease Assessment Packet (CERAD-K) Clinical Assessment Battery. The CERAD-K Neuropsychological Assessment Battery was used for diagnosing MCI. Age-, gender-, education-, and urbanicity-standardized prevalence of dementia was estimated to be 8.1% (95% CI = 6.9-9.2) for overall dementia and 24.1% (95% CI = 21.0-27.2) for MCI. Alzheimers disease (AD) was the most prevalent type (5.7%) followed by vascular dementia (2.0%). Amnestic subtype (20.1%) was much more prevalent than nonamnestic subtype in MCI (4.0%). Older age, being male, lower education level, illiteracy, smoking, and histories of head trauma or depression were associated with increased dementia risk, and alcohol use and moderately intense exercise were associated with decreased dementia risk. We expect numbers of dementia patients to double every 20 years until 2050 in Korea and expect AD to account for progressively more dementia cases in the future.

Predictive validity and diagnostic stability of mild cognitive impairment subtypes

Mild cognitive impairment (MCI) is subclassified into four subtypes by the presence of impairment in the memory domain (amnestic vs nonamnestic) and the number of impaired cognitive domains (single vs multiple). However, predictive validity for outcomes of these criteria and the diagnostic stability of the subtypes are questionable.

Subclinical hypothyroidism (SCH) is not associated with metabolic derangement, cognitive impairment, depression or poor quality of life (QoL) in elderly subjects.

The objective of this study was to examine the relationship between SCH and metabolic and neuropsychiatric derangements in Korean elderly subjects. Nine hundred and eighteen euthyroid and SCH subjects aged 65 years and older were enrolled in the present study. We compared anthropometric (age, sex, blood pressure, body mass index=BMI, body fat contents=BF, waist circumference=WC and hip circumference=HC), laboratory (glucose and lipid profile, renal and liver functions, and C-reactive protein=CRP levels), and neuropsychiatric (neuropsychological function, mood, and QoL) parameters of SCH subjects with those of euthyroid subjects. Associated metabolic disorders of the subjects were also compared between the euthyroid and SCH groups. We could not observe any differences between the SCH group and the euthyroid group with regards to metabolic parameters as well as neuropsychiatric parameters. These findings may suggest that SCH does not appear to be associated with metabolic and neuropsychiatric derangement in elderly subjects.

Standardization of the Korean Version of the Geriatric Depression Scale: Reliability, Validity, and Factor Structure

Objective We developed a Revised Korean version of the Geriatric Depression Scale (GDS-KR) and examined its reliability, validity, and factor structures. We also estimated its optimal cutoff scores for major depressive disorder (MDD) and minor depressive disorder (MnDD) stratified by age and education. Methods The GDS-KR was administered to 888 subjects (61 MDD patients, 45 MnDD patients, and 782 normal elders). Its internal consistency and test-retest reliability were examined. Its concurrent validity was evaluated using Pearson correlation coefficients with the Korean version of the Center for Epidemiologic Studies Depression Scale (CES-D-K) and Hamilton Depression Rating Scale (HAM-D). The mean GDS-KR scores of the MDD patients, MnDD patients and normal elders were compared to evaluate its discriminant validity. To evaluate its construct validity, a principal component analysis with varimax rotation was performed. Receiver operator characteristic (ROC) curve analyses were performed to evaluate its diagnostic ability. Results Chronbachs coefficient alpha for the GDS-KR was 0.90 and the test-retest reliability was 0.91 (p<0.01). The Pearson correlation coefficients of the GDS-KR scores with the CES-D-K and HAM-D scores were 0.63 (p<0.01) and 0.56 (p<0.01), respectively. The GDS-KR consisted of 5 factors. The optimal cut-off scores of the GDS-KR were 16/17 for MDD only and 15/16 for both MDD and MnDD. The optimal cutoff scores of the GDS-KR were higher in the less educated and younger subjects. The diagnostic accuracy for MDD of the GDS-KR was higher than that of the CES-D. Conclusion The GDS-KR was found to be a reliable and valid questionnaire for screening MDD and MnDD in late life.

Prevalence of Dementia and Its Subtypes in an Elderly Urban Korean Population: Results from the Korean Longitudinal Study on Health and Aging (KLoSHA)

Background/Aims: We estimated the prevalence of dementia and its major subtypes in an elderly urban Korean population. Methods: A study population of 1,118 Korean elders was randomly sampled from the residents aged 65 years or older living in Seongnam, Korea. Standardized face-to-face interviews, and neurological and physical examinations were conducted on 714 respondents. Dementia was diagnosed according to the DSM-IV diagnostic criteria, and its subtypes were determined according to the criteria of the NINCDS-ADRDA, the NINDS-AIREN, and the consensus guideline proposed by McKeith et al. [Neurology 1996;47:1113–1124]. Results: The estimated age- and gender-standardized prevalences were 6.3% for dementia (95% CI = 4.5–8.1), 4.8% for Alzheimer’s disease (AD; 95% CI = 3.3–6.4), 1.0% for vascular dementia (VD; 95% CI = 0.3–1.8), and 0.4% for dementia with Lewy bodies (DLB; 95% CI = 0.0–0.9). The prevalence of AD consistently increased with age, whereas that of VD peaked at age 75–79 years and decreased thereafter. Of the dementia patients, 72.0% were in the very mild or mild stages of the disease. Conclusions: The prevalence of dementia in a typical urban area of Korea was estimated to be 6.3%, and AD was the most prevalent subtype. DLB was less prevalent than VD among these community-dwelling Korean elders.

Association Between Comorbid Depression and Osteoarthritis Symptom Severity in Patients with Knee Osteoarthritis

BACKGROUND We sought to investigate the reported association between depression and severity of knee osteoarthritis symptoms stratified by radiographic severity of osteoarthritis and to quantify the contribution made by depression to symptom severity. METHODS Six hundred and sixty elderly Koreans (sixty-five years or older) were evaluated for radiographic severity of knee osteoarthritis on the basis of the Kellgren-Lawrence grading system and also for symptom severity on the basis of the Western Ontario and McMaster Universities Osteoarthritis Index scales. Patient interviews and a questionnaire that made use of a geriatric depression scale were conducted for the purpose of assessing depressive disorders. Regression analyses were performed to assess the relative contributions by radiographic severity and depression severity to Western Ontario and McMaster Universities Osteoarthritis Index scores and to explore any associations between radiographic severity and the presence of a depressive disorder with regard to the risk of symptomatic knee osteoarthritis. Symptomatic knee osteoarthritis was defined as a Western Ontario and McMaster Universities Osteoarthritis Index score of ≥39. RESULTS The presence of a depressive disorder was found to be associated with an increased risk of symptomatic knee osteoarthritis (odds ratio = 5.87 [95% confidence interval, 3.01 to 11.44]). However, the influence of the presence of a depressive disorder was limited to subjects with a radiographic severity of minimal to moderate (Kellgren-Lawrence grade 0 to 3). The presence of a depressive disorder was not associated with the risk of symptomatic knee osteoarthritis in subjects with severe osteoarthritis (Kellgren-Lawrence grade 4). CONCLUSIONS This study indicates that the assessment and management of coexisting depression should be integrated with the assessment and management of knee osteoarthritis, particularly when radiographic changes of osteoarthritis in the knee joint are not severe.

A nationwide survey on the prevalence and risk factors of late life depression in South Korea

OBJECTIVE This study aimed to estimate prevalence rates and risk factors of LLD among a large nationwide sample of Korean elders in South Korea. METHOD Of 8199 randomly sampled Koreans aged 65 years or more, 6018 participated (response rate=73.4%). Using the Korean version of the short form Geriatric Depression Scale (SGDS-K), we classified individual scoring 8 or 9 as having possible depression and those scoring ≥ 10 as having probable depression. RESULTS The age-, gender-, education-, and urbanicity-standardized prevalences were 10.1% (95% CI=9.3-10.8) for possible depression, 17.8% (95% CI=16.8-8.7) for probable depression, and 27.8% (95% CI=26.7-29.0) for overall depression. Poverty, living alone, low education, illiteracy, smoking, history of head trauma, and low Mini Mental Status Examination score were associated with greater risk of depression, while mild alcohol use and moderate to heavy exercise were associated with lower risk of depression. However gender difference in the risk of depression was not found. CONCLUSION LLD is decidedly common in South Korea. It was associated with various sociodemographic and clinical factors, some of which are amendable through policy actions. This study was limited by use of the SGDS-K rather than a standardized clinical interview.

Depression in Vascular Dementia Is Quantitatively and Qualitatively Different from Depression in Alzheimer's Disease

Background/Aims: To compare the prevalence and characteristics of depression in vascular dementia (VaD) and Alzheimer’s disease (AD) after adjusting for dementia severity and gender. Methods: One hundred and eight pairs of VaD and AD patients matched for dementia severity and gender were assessed. Results: Major depressive disorder (MDD) was more prevalent in the VaD group than in the AD group (20.4% in VaD, 10.2% in AD, p = 0.04, Cochran-Mantel-Haenszel, CMH, test) regardless of the dementia severity and gender. The odds ratio for developing MDD in the VaD group versus the AD group was estimated to be 2.20 (95% confidence interval = 1.02–4.74). Neurovegetative symptoms such as ‘felt tired and weak all the time’ (30.6% in VaD, 13.9% in AD, p = 0.003, CMH test) and ‘changed weight without trying’ (16.7% in VaD, 6.5% in AD, p = 0.02, CMH test) were more prevalent in the VaD group than in the AD group. Conclusion: Depression in VaD was quantitatively and qualitatively different from that in AD regardless of the severity of dementia and gender; depression was more prevalent, severer and more retarded and vegetative in VaD than in AD.

Prevalence of major depressive disorder and minor depressive disorder in an elderly Korean population: Results from the Korean Longitudinal Study on Health and Aging (KLoSHA)

OBJECTIVE We investigated the prevalence, risk factors and impact of major depressive disorder (MDD) and minor depressive disorder (MnDD) in a randomly selected community-dwelling Korean elderly population. METHOD This study was conducted as a part of the Korean Longitudinal Study on Health and Aging (KLoSHA). A study population of 1118 Korean elders was randomly sampled from residents of Seongnam, Korea aged 65 years or older. Standardized face-to-face interviews and neurological and physical examinations were conducted on 714 respondents using the Korean version of Mini International Neuropsychiatric Interview. MDD was diagnosed according to the DSM-IV criteria, and MnDD according to research criteria proposed in Appendix B of the DSM-IV criteria. RESULTS Age-, gender- and education-standardized prevalence rates in Korean elders aged 65 years or older were estimated as 5.37% (95% CI=3.72-7.03) for MDD, 5.52% (95% CI=3.84-7.19) for MnDD, and 10.89% (95% CI=8.60-13.17) for overall late-life depression (LLD). A prior MDD episode (OR=3.07, 95% CI=1.38-6.82 in MDD, OR=3.44, 95% CI=1.49-7.94 in MnDD), female gender (OR=3.55, 95% CI=1.53-8.24 in MDD, OR=2.68, 95% CI=1.19-6.04 in MnDD) and history of stroke or TIA (OR=3.45, 95% CI=1.62-7.35 in MDD, OR=2.95, 95% CI=1.34-6.52 in MnDD) were associated with the risks of both MDD and MnDD. Lack of formal education (OR=2.75, 95% CI=1.30-5.85) and low income (OR=2.83, 95% CI=1.02-7.88) were associated with the risk of MDD only. Quality of life (QOL) of the MDD and MnDD patients was worse than that of non-depressed elders (P<0.001, ANOVA). CONCLUSION MnDD was as prevalent as MDD in Korean elders and impacted QOL as MDD did. MnDD patients may increase in the future with accelerated population aging and westernization of lifestyle in Korea.

Relationship between lower urinary tract symptoms and metabolic syndrome in a community-based elderly population.

OBJECTIVES Evidence has shown that a relationship exists between lower urinary tract symptoms and the metabolic syndrome. We investigated the relationship between the metabolic syndrome and lower urinary tract symptoms in a community-based elderly population. METHODS We collected data from the Korean Longitudinal Study on Health and Aging. We selected a total of 348 male participants by random sampling. The selected patients were interviewed with a questionnaire that included the International Prostate Symptom Score (IPSS) and were evaluated with history, physical examination, blood tests, and transrectal ultrasonography. We divided the participant into two groups: the metabolic syndrome group, which met the metabolic syndrome criteria (n = 102, 74.3 +/- 8.1 years old) and the nonmetabolic syndrome group, which did not (n = 246, 74.9 +/- 8.1 years old). We compared the voiding symptoms, quality of life, and prostate volume between the two groups. RESULTS No significant differences were found in the mean IPSS or quality-of-life score between the metabolic and nonmetabolic syndrome groups. The total IPSS for the two groups was 11.1 +/- 8.2 and 12.3 +/- 8.8, respectively (P > .05), and the quality-of-life score was 2.1 +/- 1 and 52.4 +/- 1.6, respectively (P > .05). The percentage of patients with moderate to severe voiding symptoms (IPSS of 8 or greater) was not different between the metabolic and nonmetabolic groups (55% and 61%, respectively, P > .05). CONCLUSIONS No statistically significant differences were found in voiding symptoms between the metabolic and nonmetabolic groups. The results of our study showed that no relationship exists between lower urinary tract symptoms and metabolic syndrome in elderly Korean male patients.