한국 노인에서 인지기능 감소와 관련된 요인 김대현

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Received: May 27, 2015 Revised: June 11, 2015 Accepted: June 13, 2015.

Corresponding author: DaeHyun Kim

Department of Family Medicine, Keimyung University College of Medicine, 56 Dalsung-ro, Jung-gu, Daegu 700-712, Korea Tel: +82-53-250-7607, Fax: +82-53-250-7071, E-mail: [email protected]

The study was performed by using the Korean Longitudinal Study on Aging (KLoSA) data from Labor Institute of Korea.

This is an open access article distributed under the term s of the Creative Com m ons Attribution Non-Com m ercial License (http://creativecom m ons.org/ licenses/by-nc/4.0) which perm its unrestricted non-com m ercial use, distribution, and reproduction in any m edium , provided the original work is properly cited.

한국 노인에서 인지기능 감소와 관련된 요인

김대현

¹

, 이재혁

¹

, Hedenori Arai

²

, 김성희

³

1계명대학교 의과대학 가정의학교실, ²일본 국립장수의료연구센타, ³대구가톨릭대학교 의과대학 가정의학교실

Factors Related with Cognitive Frailty in Korean Elderly

DaeHyun Kim

¹

, JaeHyuck Lee

¹

, Hidenori Arai

²

, SungHee Kim

³

1

Department of Family Medicine, Keimyung University College of Medicine, Daegu, Korea,

²

National Center for Geriatrics and Gerontology, Obu, Aichi, Japan,

³

Department of Family Medicine, Catholic University of Daegu, School of Medicine, Daegu, Korea

Background: Cognitive impairment is important in clinical geriatrics as a mental frailty. The objective of this study was to investigate the factors related with cognitive impairment in Korean elderly.

Methods: We analyzed data from the Korean Longitudinal Study on Aging (KLoSA). A total of 4,165 Korean community-dwell- ing elderly (＞65 years, male/female 1,739/2,426) at the first wave (2006) of KLoSA were used for analysis. Cognitive function was assessed with the Mini-Mental State Examination Korean version (MMSE-K) through personal interviews by a trained interviewer with Computer Assisted Personal Interviewing (CAPI). Multiple logistic regression analysis was performed among participants to estimate the odd ratios (OR) and 95% confidence interval (CI) for MMSE score＜23.

These estimates were controlled for age, sex, education, MMSE score at baseline, alcohol consumption, current smoking, body mass index and disease history.

Results: 2,120 subjects (50.9%) were classified as cognitive impaired (MMSE score＜23). Age, sex, depression score (CESD-10), function (ADL, IADL), education, employment, income, smoking, drinking and BMI was significantly different between normal and impaired cognitive groups. Cognitive impairment ratio after covariates the female was 2.16 (1.63∼

2.86), age 70∼74, 75∼79, ≥80 were 3.51 (2.05∼5.99), 2.24 (1.55∼3.24), 1.87 (1.39∼2.52) low (elementary and no) education groups were 2.77 (1.99∼3.84) and 8.18 (5.66∼11.82) compare to more educated group (≥9 years).

Among health related factors, only ADL and IADL was significantly different after multivariates adjustment. Among social activities, number of meeting with friendly people volunteer group activity were significant factors.

Conclusion: Age, sex, depression score (CESD-10), fuction (ADL, IADL), education, ADL, IADL personal and group social activities were significantly related with cognitive decline in Korean elderly.

Key Words: Frailty, Cognitive frailty, Elderly

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Table 1. General characteristics of normal and impaired cognitive group

Variables

Total (n=4,165) Normal

2,045

MMSE impairment

2,120 P value

Age 70.89±4.9 75.04±6.8 ＜0.001*

Sex Male 1,163 (66.8) 577 (33.2) ＜0.001

^†

MMSE-K 26.74±1.7 16.29±6.5 ＜0.001*

CESD-10 5.3±4.6 7.98±6.3 ＜0.001*

ADL 0.07±0.72 0.91±2.8 ＜0.001*

IADL 0.43±1.6 2.72±5.2 ＜0.001*

Socioeconomic factor

Education ＜Elementary 277 (18.6) 1,216 (81.4) ＜0.001

^†

Elementary 801 (55.2) 650 (44.8)

≥Middle 967 (79.2) 254 (20.8)

Employment Yes 458 (67.9) 217 (32.1) ＜0.001

^†

No 1,587 (45.5) 1,903 (54.5)

Income (10,000 won) ≥100 222 (46.1) 260 (53.9) ＜0.001

^†

30∼99 305 (57.9) 222 (42.1)

＜30 313 (75.8) 100 (24.2)

Health related factor

Smoking Current 380 (60.0) 253 (40.0) ＜0.001

^†

Past/none 1,665 (47.2) 1,866 (52.8)

Drinking Current 703 (61.6) 439 (38.4) ＜0.001

^†

Past/none 1,342 (44.4) 1,681 (55.6)

Health status

BMI 23.45±8.3 22.45±3.5 ＜0.001*

Hypertension Yes 805 (48.9) 841 (51.1) 0.849

^†

No 1,240 (49.1) 2,120 (50.9)

Diabetes Yes 318 (47.0) 359 (53.0) 0.24

^†

No 1,727 (49.5) 1,760 (50.5)

Values were presented as mean±SD or n (%). MMSE: mini-mental status examination, CESD: center for epidemiologic studies short depression scale, ADL: activities of daily living, IADL: instrumental activities of daily living. *Analyzed by t-test.

^†

Analyzed by chi-square

INTRODUCTION

Approximately 35.6 million people worldwide (estimated in 2010) and 600 thousand Koreans suffer from dementia (estimated in 2012), with the prevalence among the elderly nearly doubling every five years, from approximately 1.5 percent among 60∼69 year olds to 40 percent among 80∼89 year olds.^1,2) Research has suggested that cognitive decline and dementia are associated with many factors, including genetic factors, comorbidities, physical and social activities, diet and smoking.³⁾

Frailty is a losses of human functioning (physical, mental/cognitive, social) which increases the risk of adverse outcomes,⁴⁾ and cognitive impairment is important aspect of

mental frailty.^5,6) Compare to physical and cognitive factors, social factors were not studied and included in the assessment of frailty. It has been proposed that social factors, including social network ratings, leisure time physical activity, inactivity and physical/ social activity influence to cognitive function through the epigenetic and disease morbidity. Re- search on the physical and social activity show to prevent cognitive decline and dementia.⁷⁾

The objective of the study was to investigate the factors associated with cognitive frailty in Korean elderly.

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Table 2. Cognitive impairment ratios according to socioeconomic factors

Variables Model 1 Model 2 Model 3

Sex Women 3.52 (3.09∼4.01) 1.78 (1.52∼2.07) 2.16 (1.63∼2.86)

Men 1 1 1

P value ＜0.001 ＜0.001 ＜0.001

Age ≥80 7.64 (6.14∼9.50) 5.27 (4.11∼6.75) 3.51 (2.05∼5.99)

75∼79 3.00 (2.52∼3.58) 2.38 (1.95∼2.90) 2.24 (1.55∼3.24) 70∼74 1.76 (1.51∼2.06) 1.71 (1.43∼2.04) 1.87 (1.39∼2.52)

65∼69 1 1 1

P value ＜0.001 ＜0.001 ＜0.001

Education (y) 0 16.71 (13.82∼20.21) 9.56 (7.78∼11.75) 8.18 (5.66∼11.82)

6 3.08 (2.60∼3.67) 2.47 (2.05∼2.96) 2.77 (1.99∼3.84)

≥6 1 1 1

P value ＜0.001 ＜0.001 ＜0.001

Work No 3.03 (2.66∼3.40) 1.52 (1.23∼1.86) 1.28 (0.96∼1.70)

Yes 1 1 1

P value ＜0.001 ＜0.001 0.088

Living with spouse No 3.03 (2.66∼3.40) 1.08 (0.91∼1.29) 1.12 (0.80∼1.57)

Yes 1 1 1

P value ＜0.001 0.36 0.518

Residential district Urban 1.58 (1.36∼1.83) 1.15 (0.96∼1.38) 1.10 (1.03∼1.91)

City 1.19 (1.03∼1.38) 1.22 (1.03∼1.46) 1.27 (0.89∼1.81)

Metropolitan 1 1 1

P value ＜0.001 0.064 0.099

Income (10,000 won) ≥0, ＜30 3.67 (2.75∼4.89) 1.50 (1.08∼2.10) 1.36 (0.95∼1.93)

≥30, ＜100 1.60 (1.25∼2.06) 1.15 (0.83∼1.60) 1.05 (0.75∼1.48)

≥100 1 1 1

P value ＜0.001 0.04 0.140

Model 1: raw, Model 2: adjusted for age, sex, education, Model 3: adjusted for age, sex, education, Income, CESD-10, ADL, IADL.

MATERIALS AND METHODS

1. Participants

Data for this survey were collected from the Korean Longitudinal Study on Aging (KLoSA). In this project, the normal aging process has been assessed over time using de- tailed questionnaires, socioeconomic factors, frailty related factors (activities of daily living (ADL), instrumental ADL (IADL), grip strength, depression score) and medical history. Partici- pants in the KLoSA included randomly selected age- and sex-stratified individuals from Korea. The first wave of the KLoSA was conducted in 2006 and comprised 10,254 participants (4,460) men, 5,794 women; age range, 40∼79 years). Details of the KLoSA study have been reported else- where.⁸⁾

Exclusion criteria were as follows: (1) those who were

＜65 years (n=6,099), as cognitive function tested by the

Mini-Mental State Examination (MMSE); and (3) those who did not complete either the MMSE assessments or the self- reported questionnaire (n=721). A total of 4,165 Korean community-dwelling elderly (＞65 years, male/female 1,739/

2,426) who had been between 65 and 79 years in the first wave of the KLoSA were available for analysis.

2. Assessment of cognitive function

Cognitive function was assessed by the Korean version of the MMSE-K through interviews with a trained interviewer with Computer Assisted Personal Interview (CAPI). The MMSE is widely used as a brief screening test for dementia, and scores range from 0 to 30 points, which was validated in Korean.⁹⁾ The MMSE includes questions on orientation of time and place, registration, attention and calculation, recall, language and visual construction. We used cutoff scores of

＜23, which is traditionally used to represent ‘suggestive

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Table 3. Cognitive impairment ratios according to health related factors

Variables Model 1 Model 2 Model 3

Alcohol No 2.01 (1.75∼2.31) 1.05 (0.87∼1.26) 1.05 (0.72∼1.52)

Yes 1 1 1

P value ＜0.001 0.633 0.813

Smoking Yes 1.68 (1.42∼2.00) 1.01 (0.81∼1.26) 0.83 (0.60∼1.17)

No 1 1 1

P value ＜0.001 0.931 0.287

Exercise (≥1/week)

No 3.20 (2.78∼3.67) 1.68 (1.43∼1.97) 1.31 (0.97∼1.76)

Yes 1 1 1

P value ＜0.001 ＜0.001 0.077

Obesity degree Underweight 2.24 (1.74∼2.88) 1.23 (0.92∼1.66) 0.90 (0.53∼1.54) Normal 1.46 (1.14∼1.87) 1.21 (1.04∼1.42) 0.94 (0.71∼1.24)

Obese 1 1 1

P value ＜0.001 0.039 0.875

Depression (CESD-10)

Yes 2.44 (2.15∼2.77) 1.64 (1.42∼1.90) 1.22 (0.93∼1.58)

No 1 1 1

P value ＜0.001 ＜0.001 0.147

ADL Dependent 7.65 (5.66∼1034) 6.82 (4.75∼9.80) 3.03 (1.11∼8.29)

Independent 1 1 1

P value ＜0.001 ＜0.001 0.022

IADL Dependant 3.71 (3.17∼4.34) 2.82 (2.33∼3.41) 1.54 (1.06∼2.24)

Independent 1 1 1

P value ＜0.001 ＜0.001 0.023

Admission in proceeding year

Yes 1.534 (1.29∼1.84) 1.52 (1.23∼1.87) 1.13 (0.78∼1.65)

No 1 1 1

P value ＜0.001 ＜0.001 0.523

HTN Yes 0.99 (0.87∼1.12) 1.04 (0.89∼1.20) 0.87 (0.66∼1.15)

No 1 1 1

P value 0.84 0.64 0.325

Diabetes Yes 0.90 (0.77∼1.06) 1.28 (1.06∼1.56) 1.05 (0.72∼1.52)

No 1 1 1

P value 0.224 0.012 0.813

cognitive impairment’.¹⁰⁾

3. Social factors assessments

Socioeconomic status were assessed in the aspects of pop- ulation, family, education (＜9, 10∼12 or ＞13 years of school), income (yes or no), employment (yes or no), mar- riage, religion,

Health behaviors were assessed with subjective health.

smoking status (current, past, none), exercise and drinking.

Chronic disease history of heart disease, hypertension, diabetes, cancer, lung disease, liver, stroke, mental disease, ar- thritis, prostate disease were collected with personal Interview.

4. Statistical analysis

All statistical analyses were conducted using statistical analysis system software version 20.0 (SPSS Institute, Cary, NC, USA). General characteristic were compared by t-test for continuous variables, and X2 test for nominal variables.

Odd ratios for cognitive decline were analyzed by multiple logistic regression, compare to normal cognitive non-decline.

The covariates were age (year, continuous), sex, education (＜9, 10∼12, ＞13 years), employment, CESD-10, IADL, weight loss. (Model 1=crude: Model 2=adjusted by age, sex, education: Model 3=age, sex, education, employment, CESD-10, IADL, weight loss). All reported P values are two-sided, and a P value o 0.05 was considered significant.

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Table 4. Cognitive impairment ratio according to social activities

Variables Model 1 Model 2 Model 3

Number of meeting friendly people

≤1~2/month 0.97 (0.84∼1.12) 0.76 (0.64∼0.91) 1.16 (0.85∼1.60) 1~3/week 0.93 (0.80∼1.08) 0.93 (0.77∼1.11) 1.56 (1.11∼2.21)

≥4/week 1 1 1

P value 0.660 0.007 0.034

Religious No 1.25 (1.09∼1.45) 1.23 (1.03∼1.46) 1.27 (0.92∼1.77)

Yes 1 1 1

P value 0.002 0.022 0.149

Social club No 1.91 (1.69∼2.16) 1.27 (1.10∼1.47) 1.03 (0.79∼1.35)

Yes 1 1 1

P value ＜0.001 0.001 0.803

Leisure No 1.92 (1.34∼2.74) 1.22 (0.81∼1.85) 1.26 (0.60∼2.65)

Yes 1 1 1

P value ＜0.001 0.338 0.054

Alumni No 5.15 (3.97∼6.68) 1.38 (1.03∼1.86) 1.06 (0.69∼1.62)

Yes 1 1 1

P value ＜0.001 0.031 0.798

Volunteer No 27.1 (6.59∼111.4) 14.59 (3.36∼63.4) 16.89 (3.53∼80.74)

Yes 1 1 1

P value ＜0.001 ＜0.001 ＜0.001

Model 1: raw, Model 2: adjusted for age, sex, education, Model 3: adjusted for age, sex, education, Income, CESD-10, ADL, IADL.

RESULTS

Baseline characteristics of 4,165 Korean community-dwelling elderly (＞65 years, male/female 1,739/2,426) ware analyzed (Table 1). 2,120 subjects (50.9%) were classified as cognitive impaired(MMSE score ＜23). Between normal and impaired cognitive group, age, sex, depression score (CESD- 10), daily fuction (ADL, IADL), education, employment, income was significantly different. Among health related factors, smoking, drinking and BMI was significantly different between normal and impaired cognitive groups.

Table 2 show that cognitive impairment ratio according to socioeconomic factors after covariates (age, sex, education, employment, CESD-10, IADL, weight loss) were controlled.

The multivariate-adjusted odd ratios (ORs) (95% CIs) for the female was 2.16 (1.63∼2.86), for age 70∼74, 75∼79,

≥80 were 3.51 (2.05∼5.99), 2.24 (1.55∼3.24), 1.87 (1.39∼

2.52) compare to 65∼69 years old group. In education, cognitive impairment ratio of elementary graduates and no education groups were 2.77 (1.99∼3.84) and 8.18 (5.66∼

11.82) compare to more educated group (≥9 years).

Among health related factors, only ADL and IADL was

significantly different after adjustment of multivariates (Model 3=age, sex, education, employment, Center for Epidemiologic Studies-Depression (CES-D-10), IADL, weight loss) (Table 3).

Among social activities, less (1~3/week) number of meeting with friendly people group have significantly higher multivariate-adjusted odd ratios (95% CIs) for 1.56 (1.11~2.21) compare to more (≥4/week) group, and odd ratios (95%

CIs) no volunteer activity group was 16.89 (3.53∼80.74) compare to activity group (Table 4).

DISCUSSION

Frailty is a dynamic state affecting an individual who ex- periences losses in one or more domains of human functioning (physical, mental, social) that are caused by the influence of a range of variables and which increases the risk of adverse outcomes. Physical, mental and social domain is contribute to increase frailty independently or interact toge- ther.¹⁰⁾ Among many frailty assessment scales some scales (ex. Fried, Indexes for prediction of falls and fractures, FRAIL, Korean Frailty Scale) have no social activities assessment item, and several (Edmonton, Groningen, Tilburg,

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Kihon Checklist) have social activities assessment item (s).^11-17) Between normal and impaired cognitive group, age, sex, depression score (CESD-10), daily function (ADL, IADL), education, employment, income smoking, drinking and BMI was significantly different.

Cognitive impairment ratio according to socioeconomic factors after adjusting covariates (age, sex, education, employment, CESD-10, IADL, weight loss) odd ratios (ORs) (95% CIs) for the sex (female) and age (older), education, ADL and IADL was significantly different.

Among social activities, less number of meeting with friendly people group and no volunteer activity group have significantly higher ratios for cognitive decline.

In The Korean Longitudinal Study on Aging (KLoSA) data, age, sex, depression score (CESD-10), function (ADL, IADL), education, ADL, IADL personal and group social activities were significantly related with cognitive decline. Fac- tors related with cognitive decline need to be clarified with prospective follow up data.

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▪ 국문요약 ▪

연구배경: 인지기능 장애는 치매를 정신적 쇠약 차원에서 임상 노인의학에서 중요한 요인이다. 우리나라 노인에서 인 지기능 장애와 관련된 요인을 알아보기 위하여 연구를 시행하였다.

방법: 2006년도 노동부의 고령화 연구패널조사(Korean Longitudinal Study on Aging, KLoSA) 자료 중 65세 이상 4,165명 을 분석하였다. 교육된 면접원이 컴퓨터가 시간과 계산의 정답 오답을 측정할 수 있도록 도와주는(CAPI) 설문 프로 그램으로 인지능력을 비롯한 사회경제적, 건강관련 자료를 측정하였다. 관련 요인을 독립 T 검증과 X

²

검증으로 알아보고, 공변량을 통제한 다변량 회귀분석으로 인지기능 장애의 우도비를 계산하였다.

결과: 중등도이상 인지기능 장애군(MMSE score＜23)은 50.9% (2,120/4,165)였다. 인지기능 장애군과 정상군에서 나이, 성별, 우울정도(CESD-10), 일상생활 기능(ADL, IADL), 교육, 고용, 수입, 흡연여부와 체질량지수의 유의한 차이가 있었다. 공변량 통제 후에 인지기능 감소의 우도비(95% 신뢰구간)는 여성이 2.16 (1.63∼2.86), 연령 70∼74군, 75∼

79군, ≥80군이 65∼69세군에 비해 각각 3.51 (2.05∼5.99), 2.24 (1.55∼3.24), 1.87 (1.39∼2.52), 저학력군과 무학력군 이 고학력군(≥9년)에 비해 2.77 (1.99∼3.84)과 8.18 (5.66∼11.82)이었다. 건강관련요인들은 공변량을 통제한후에 ADL과 IADL이 유의한 차이를 보였다. 사회적 활동은 개인적인 만남과 집단적 사회 활동중 자원봉사 모임만이 유 의한 요인이었다.