Social participation reduces isolation among Japanese older people in urban area: A 3-year longitudinal study.

OBJECTIVES: Social isolation is a particular problem among older people and social participation may reduce future isolation. However, it is unclear which types of activities and which level of participation are effective. This study examines the relationship between social participation and isolation among Japanese older people by employing a 3-year longitudinal study. METHODS: A mail survey was sent to 3,518 community-dwelling older people in an urban area in 2014 (baseline: BL). We then conducted follow-up mail survey on respondents who were non-isolated at BL in 2017 (follow-up: FL), with isolation being defined as being in contact with others less than once a week. An analysis was carried out on 1,070 subjects (398 men and 672 women). Social participation is defined by participation in group activities (community, senior club, hobbies, sports, volunteering, politics, industry, and religion). A logistic regression analysis was conducted to determine the association between the types of social participation and the number of organization types at BL, and isolation at FL. RESULTS: At FL, 75 men (18.8%) and 59 women (8.8%) were considered to be isolated. Among the men, participation in a hobby group and sports group both significantly reduced the degree of isolation. Moreover, participation in two organizations and three or more organizations significantly lowered the risk of isolation when compared to non-participants. Among women, there were no significant associations among particular types of social activities and isolation. On the other hand, participation in one organization and three or more organizations significantly reduced their isolation when compared to non-participants. There was a significant linear trend between the number of types of organizations and isolation, regardless of gender. CONCLUSIONS: Participation in social activities reduces future isolation in older people. Encouraging participation in social activities could help reduce negative health outcomes associated with social isolation later in life.

Serum brain-derived neurotrophic factor level in elderly women depression: a community-based study.

OBJECTIVES: Serum levels of brain-derived neurotrophic factor (BDNF) have been shown to be lower in patients with major depressive disorder (MDD) than in healthy persons. Although several studies have examined the associations between serum BDNF levels and broader categories of depression identified by psychiatrists or depressive symptoms measured with depression scales among nonpatient populations, some of these studies did not consider possible confounders and included mostly young or middle-aged subjects and nonrepresentative control subjects, such as volunteers and patients' relatives. Therefore, it remains unclear that whether MDD, broader categories of depression, or depressive symptoms in the elderly are associated with BDNF. The present study examined these associations in a community sample and controlled for confounders. METHODS: The subjects were 538 women aged 78 to 88 years who had participated in a follow-up survey of a cohort and had scored 24 or more on the Mini-Mental State Examination. Two depression scales were administered, and, using the Structured Clinical Interview for DSM-IV, psychiatrists identified 53 persons having any mood disorder (AMD) - 8 with MDD and 45 with other types of depression according to the DSM-IV or its research criteria - and 106 healthy controls. RESULTS: Subjects with MDD had serum BDNF levels lower than did controls but subjects with AMD did not. The severity of depressive symptoms assessed with either of the 2 depression scales was negatively correlated with serum BDNF levels in all subjects and in subjects remaining after persons with MDD or AMD were excluded. These associations were significant after controlling for possible confounders. CONCLUSION: We have found an association between MDD and serum BDNF levels in old-old women, as has previously been found in younger patients. Although serum BDNF levels were not found to be associated with the broader category of depression, they were associated with depressive symptoms among subjects without clinical depression.

Reference values and age and sex differences in physical performance measures for community-dwelling older Japanese: a pooled analysis of six cohort studies.

OBJECTIVES: To determine age- and sex-specific reference values for six physical performance measures, i.e. hand-grip strength, one-legged stance, and gait speed and step length at both usual and maximum paces, and to investigate age and sex differences in these measures among community-dwelling older Japanese adults. METHODS: We conducted a pooled analysis of data from six cohort studies collected between 2002 and 2011 as part of the Tokyo Metropolitan Institute of Gerontology-Longitudinal Interdisciplinary Study on Aging. The pooled analysis included cross-sectional data from 4683 nondisabled, community-dwelling adults aged 65 years or older (2168 men, 2515 women; mean age: 74.0 years in men and 73.9 years in women). RESULTS: Unweighted simple mean (standard deviation) hand-grip strength, one-legged stance, usual gait speed, usual gait step length, maximum gait speed, and maximum gait step length were 31.7 (6.7) kg, 39.3 (23.0) s, 1.29 (0.25) m/s, 67.7 (10.0) cm, 1.94 (0.38) m/s, and 82.3 (11.6) cm, respectively, in men and 20.4 (5.0) kg, 36.8 (23.4) s, 1.25 (0.27) m/s, 60.8 (10.0) cm, 1.73 (0.36) m/s, and 69.7 (10.8) cm, respectively, in women. All physical performance measures showed significant decreasing trends with advancing age in both sexes (all P<0.001 for trend). We also constructed age- and sex-specific appraisal standards according to quintiles. With increasing age, the sex difference in hand-grip strength decreased significantly (P<0.001 for age and sex interaction). In contrast, sex differences significantly increased in all other measures (all P<0.05 for interactions) except step length at maximum pace. CONCLUSION: Our pooled analysis yielded inclusive age- and sex-specific reference values and appraisal standards for major physical performance measures in nondisabled, community-dwelling, older Japanese adults. The characteristics of age-related decline in physical performance measures differed between sexes.

Plasma heat shock protein 72 as a biomarker of sarcopenia in elderly people.

Sarcopenia is a geriatric syndrome in which there is a decrease of muscle mass and strength with aging. In age-related loss of muscle strength, there are numerous observations supporting the assertion that neural factors mediate muscle strength. A possible contributing cause may be that aging changes systemic extracellular heat shock protein (eHsp)72 activity. The present study was designed to assess the plasma levels of eHsp72 in elderly people and to investigate its potential interaction with components of sarcopenia. A total of 665 men and women participated in an official medical health examination and an integrated health examination, including psychological and physical fitness tests. Blood samples were assayed for levels of plasma Hsp72, serum C-reactive protein, interleukin 6, tumor necrosis factor α, and regular biomedical parameters. We found that higher Hsp72 in plasma is associated with lower muscle mass, weaker grip strength, and slower walking speed, and may be a potential biomarker of sarcopenia in elderly people. This finding was supported by other results in the present study: (1) older age and shrinking body and lower hemoglobin levels, all of which characterize sarcopenia, were related to higher eHsp72 tertiles and (2) the ORs of the highest tertile of eHsp72 for the lowest tertiles of muscle mass, grip strength, and walking speed were 2.7, 2.6, and 1.8, respectively. These ORs were independent of age, sex, and the incidence of related diseases. Our results would reveal that eHsp72 in plasma is linked to sarcopenia factors and is a potential biomarker or predictor of sarcopenia.

Effects of exercise and amino acid supplementation on body composition and physical function in community-dwelling elderly Japanese sarcopenic women: a randomized controlled trial.

OBJECTIVES: To evaluate the effectiveness of exercise and amino acid supplementation in enhancing muscle mass and strength in community-dwelling elderly sarcopenic women. DESIGN: Randomized controlled trial. SETTING: Urban community in Tokyo, Japan. PARTICIPANTS: One hundred fifty-five women aged 75 and older were defined as sarcopenic and randomly assigned to one of four groups: exercise and amino acid supplementation (exercise + AAS; n = 38), exercise (n = 39), amino acid supplementation (AAS; n = 39), or health education (HE; n = 39). INTERVENTION: The exercise group attended a 60-minute comprehensive training program twice a week, and the AAS group ingested 3 g of a leucine-rich essential amino acid mixture twice a day for 3 months. MEASUREMENTS: Body composition was determined using bioelectrical impedance analysis. Data from interviews and functional fitness parameters such as muscle strength and walking ability were collected at baseline and after the 3-month intervention. RESULTS: A significant group × time interaction was seen in leg muscle mass (P = .007), usual walking speed (P = .007), and knee extension strength (P = .017). The within-group analysis showed that walking speed significantly increased in all three intervention groups, leg muscle mass in the exercise + AAS and exercise groups, and knee extension strength only in the exercise + AAS group (9.3% increase, P = .01). The odds ratio for leg muscle mass and knee extension strength improvement was more than four times as great in the exercise + AAS group (odds ratio = 4.89, 95% confidence interval = 1.89-11.27) as in the HE group. CONCLUSION: The data suggest that exercise and AAS together may be effective in enhancing not only muscle strength, but also combined variables of muscle mass and walking speed and of muscle mass and strength in sarcopenic women.

Body composition prediction equations based on bioelectrical impedance and anthropometric variables for Japanese obese women.

The tetrapolar bioelectrical impedance (BI) technique has been proposed as a convenient, valid approach to estimate body composition in normal, healthy adults. However, the validity of the BI technique for obese individuals is undetermined. The purpose of this study was to determine the validity of body composition estimated from the BI method when compared to underwater weighing with correction for residual volume, and to develop a convenient, useful equation that would sufficiently predict body composition of Japanese obese women. The order of assessing body composition was randomized for each subject. The subjects were 75 moderately or mildly obese women with a body fat content of 25.1-60.1%, aged 18-68 years. Among 12 independent variables which were arbitrarily selected as possible predictors of hydrodensitometrically determined body density (Db), BM Z/S2 was the best predictor (r = 0.803, n = 53), where BM = body mass (kg), Z = impedance (ohms), and S = stature (cm). When chronological age was added in a multiple regression analysis, Db was derived with higher accuracy (r = 0.878) with an SEE of 0.0064 g/cm3 . The linear multiple regression equation constructed for predicting the Db was, for instance, Db = 1.1171 - 0.0535BM Z/S2 - 0.0003 Age - 0.0005T, where T = triceps skinfold thickness (mm). Three equations developed in the present study were then cross-validated in a different sample (n = 22) of obese women. The results indicated that the above equation had the lowest SEE (0.0070 g/cm3 ). We suggest that body composition of Japanese obese women can be predicted with relatively high accuracy by a combination of BM Z/S2 with age and the triceps skinfold thickness. © 1992 Wiley-Liss, Inc.