Fuzhong Li

Tai Chi and Postural Stability in Patients with Parkinson's Disease

BACKGROUND Patients with Parkinsons disease have substantially impaired balance, leading to diminished functional ability and an increased risk of falling. Although exercise is routinely encouraged by health care providers, few programs have been proven effective. METHODS We conducted a randomized, controlled trial to determine whether a tailored tai chi program could improve postural control in patients with idiopathic Parkinsons disease. We randomly assigned 195 patients with stage 1 to 4 disease on the Hoehn and Yahr staging scale (which ranges from 1 to 5, with higher stages indicating more severe disease) to one of three groups: tai chi, resistance training, or stretching. The patients participated in 60-minute exercise sessions twice weekly for 24 weeks. The primary outcomes were changes from baseline in the limits-of-stability test (maximum excursion and directional control; range, 0 to 100%). Secondary outcomes included measures of gait and strength, scores on functional-reach and timed up-and-go tests, motor scores on the Unified Parkinsons Disease Rating Scale, and number of falls. RESULTS The tai chi group performed consistently better than the resistance-training and stretching groups in maximum excursion (between-group difference in the change from baseline, 5.55 percentage points; 95% confidence interval [CI], 1.12 to 9.97; and 11.98 percentage points; 95% CI, 7.21 to 16.74, respectively) and in directional control (10.45 percentage points; 95% CI, 3.89 to 17.00; and 11.38 percentage points; 95% CI, 5.50 to 17.27, respectively). The tai chi group also performed better than the stretching group in all secondary outcomes and outperformed the resistance-training group in stride length and functional reach. Tai chi lowered the incidence of falls as compared with stretching but not as compared with resistance training. The effects of tai chi training were maintained at 3 months after the intervention. No serious adverse events were observed. CONCLUSIONS Tai chi training appears to reduce balance impairments in patients with mild-to-moderate Parkinsons disease, with additional benefits of improved functional capacity and reduced falls. (Funded by the National Institute of Neurological Disorders and Stroke; ClinicalTrials.gov number, NCT00611481.).

Multilevel modelling of built environment characteristics related to neighbourhood walking activity in older adults

Objective: To examine the relation between built environment factors (representing several dimensions of urban form of neighbourhoods) and walking activity at both the neighbourhood level and the resident level, in an older adult sample. Design, setting, participants: A cross sectional, multilevel design with neighbourhoods as the primary sampling unit and senior residents as the secondary unit. Five hundred and seventy seven residents (mean age = 74 years, SD = 6.3 years) participated in the survey, which was conducted among 56 city defined neighbourhoods in Portland, Oregon, USA. Neighbourhood level variables were constructed using geographical information systems. Resident level variables consisted of a mix of self reports and geocoded data on the built environment. Main outcome measure: Self reported neighbourhood walking. Main results: A positive relation was found between built environment factors (density of places of employment, household density, green and open spaces for recreation, number of street intersections) and walking activity at the neighbourhood level. At the resident level, perceptions of safety for walking and number of nearby recreational facilities were positively related to high levels of walking activity. A significant interaction was observed between number of street intersections and perceptions of safety from traffic. Conclusions: Certain neighbourhood built environment characteristics related to urban form were positively associated with walking activity in the neighbourhoods of senior residents. Public health promotion of walking activity/urban mobility and the design of interventions need to consider the contribution of neighbourhood level built environment influences.

The influence of peers on young adult substance use.

Data collected from 294 young adults, ages 19 to 25, and both a same- and an opposite-gender best friend or mate across 3 annual assessments were analyzed to examine the similarity to and influence of the peer on the young adults substance use. The authors found similarity across time between both peers and the young adult in cigarette use, alcohol use, binge drinking, and, in most cases, marijuana use. In prospective analyses, peer use predicted young adult cigarette use, binge drinking, and problem use by the young adults. Results were generally consistent across gender and for both same- and opposite-gender peers. Findings emphasize peer influence contribution to young adult substance use and suggest the design of interventions that involve both young adults and their peers.

Tai Chi and Self-Rated Quality of Sleep and Daytime Sleepiness in Older Adults: A Randomized Controlled Trial

Objectives: To determine the effectiveness of tai chi on self‐rated sleep quality and daytime sleepiness in older adults reporting moderate sleep complaints.

Built Environment, Adiposity, and Physical Activity in Adults Aged 50–75

BACKGROUND Few studies have investigated the built environment and its association with health-especially excess adiposity-and physical activity in the immediate pre-Baby Boom/early-Baby Boom generations, soon to be the dominant demographic in the U.S. The purpose of this study was to examine this relationship. METHODS This study used a cross-sectional, multilevel design with neighborhoods as the primary sampling unit (PSU). Residents (N=1221; aged 50-75) were recruited from 120 neighborhoods in Portland OR. The independent variables at the PSU level involved GIS-derived measures of land-use mix, distribution of fast-food outlets, street connectivity, access to public transportation, and green and open spaces. Dependent variables included resident-level measures of excess adiposity (BMI>or=25), three walking activities, and physical activity. Data were collected in 2006-2007 and analyzed in 2007. RESULTS Each unit (i.e., 10%) increase in land-use mix was associated with a 25% reduction in the prevalence of overweight/obesity. However, a 1-SD increase in the density of fast-food outlets was associated with a 7% increase in overweight/obesity. Higher mixed-use land was positively associated with all three types of walking activities and the meeting of physical activity recommendations. Neighborhoods with high street connectivity, high density of public transit stations, and green and open spaces were related in varying degrees to walking and the meeting of physical activity recommendations. The analyses adjusted for neighborhood- and resident-level sociodemographic characteristics. CONCLUSIONS Findings suggest the need for public health and city planning officials to address modifiable neighborhood-level, built-environment characteristics to create more livable residential communities aimed at both addressing factors that may influence unhealthy eating and promoting active, healthy lifestyles in this rapidly growing population.

Tai Chi: improving functional balance and predicting subsequent falls in older persons.

PURPOSE To determine whether improved functional balance through a Tai Chi intervention is related to subsequent reductions in falls among elderly persons. METHODS Two hundred fifty-six healthy, physically inactive older adults aged 70-92 (mean age +/- SD = 77.48 +/- 4.95), recruited from a local health system in Portland, OR, participated in a 6-month randomized controlled trial, with allocation to Tai Chi or exercise stretching control, followed by a 6-month postintervention follow-up. Functional balance measures included Berg balance scale, dynamic gait index, and functional reach, assessed during the 6-month intervention period (baseline, 3-month, and 6-month intervention endpoint) and again at the 6-month postintervention follow-up. Fall counts were recorded during the 6-month postintervention follow-up period. Data were analyzed through intention-to-treat analysis of variance and logistic regression procedures. RESULTS Tai Chi participants who showed improvements in measures of functional balance at the intervention endpoint significantly reduced their risk of falls during the 6-month postintervention period, compared with those in the control condition (odds ratio (OR), 0.27, 95% confidence interval (CI), 0.07-0.96 for Berg balance scale; OR, 0.27, 95% CI, 0.09-0.87 for dynamic gait index; OR, 0.20, 95% CI, 0.05-0.82 for functional reach). CONCLUSIONS Improved functional balance through Tai Chi training is associated with subsequent reductions in fall frequency in older persons.

An Evaluation of the Effects of Tai Chi Exercise on Physical Function Among Older Persons: A Randomized Controlled Trial

This study was designed to determine whether a 6-month Tai Chi exercise program can improve self-reported physical functioning limitations among healthy, physically inactive older individuals. Ninety-four community residents ages 65 to 96 (M age = 72.8 years, SD = 5.1) volunteered to participate in the study. Participants were randomly assigned to either a 6-month experimental (Tai Chi) group (n = 49), which exercised twice per week for 60 min, or a wait-list control group (n = 45). A 6-item self-report physical functioning scale, assessing the extent of behavioral dysfunction caused by health problems, was used to evaluate change in physical functioning limitations as a result of Tai Chi intervention. Results indicated that compared to the control group, participants in the Tai Chi group experienced significant improvements in all aspects of physical functioning over the course of the 6-month intervention. Overall, the experimental group had 65% improvement across all 6 functional status measures ranging from daily activities such as walking and lifting to moderate-vigorous activities such as running. It was concluded that the 6-month Tai Chi exercise program was effective for improving functional status in healthy, physically inactive older adults. A self-paced and self-controlled activity such as Tai Chi has the potential to be an effective, low-cost means of improving functional status in older persons.

Built Environment and 1-Year Change in Weight and Waist Circumference in Middle-Aged and Older Adults Portland Neighborhood Environment and Health Study

This study examined neighborhood built environment characteristics (fast-food restaurant density, walkability) and individual eating-out and physical activity behaviors in relation to 1-year change in body weight among adults 50-75 years of age at baseline. The authors surveyed 1,145 residents recruited from 120 neighborhoods in Portland, Oregon. During the 1-year follow-up (2006-2007 to 2007-2008), mean weight increased by 1.72 kg (standard deviation, 4.3) and mean waist circumference increased by 1.76 cm (standard deviation, 5.6). Multilevel analyses revealed that neighborhoods with a high density of fast-food outlets were associated with increases of 1.40 kg in weight (P<0.05) and 2.04 cm in waist circumference (P<0.05) among residents who visited fast-food restaurants frequently. In contrast, high-walkability neighborhoods were associated with decreases of 1.2 kg in weight (P<0.05) and 1.57 cm in waist circumference (P<0.05) among residents who increased their levels of vigorous physical activity during the 1-year assessment period. Findings point to the negative influences of the availability of neighborhood fast-food outlets and individual unhealthy eating behaviors that jointly affect weight gain; however, better neighborhood walkability and increased levels of physical activity are likely to be associated with maintaining a healthy weight over time.

Self-Efficacy as a Mediator Between Fear of Falling and Functional Ability in the Elderly:

Objectives: This study examined falls self-efficacy and fear of falling to determine whether self-efficacy acts as a mediator between fear of falling and functional ability. Methods: Using the Survey of Activities and Fear of Falling in the Elderly as a fear-of-falling measure and the Activities-Specific Balance Confidence Scale for falls self-efficacy, structural relationships among fear of falling, self-efficacy, functional balance, and physical functioning outcomes were tested with older adults (N = 256, M age = 77.5). Results: Lower levels of fear of falling were significantly related to higher levels of falls self-efficacy, which was in turn associated with better functional outcomes. Moreover, falls self-efficacy mediated the effects of fear of falling on functional outcomes. Discussion: Results substantiate the hypothesized mediational role of falls self-efficacy in fear of falling and underscore the need to consider ways of enhancing falls self-efficacy in interventions aimed at reducing falls and fear of falling.

Replication of a Problem Behavior Model with American Indian, Hispanic, and Caucasian Youth:

The replicability of a model of family and peer influences on adolescent problem behavior was evaluated with samples of adolescent boys and girls from three ethnic groups: American Indians, Hispanics, and Caucasians. Participants were 1,450 seventh-grade students from 16 communities. The model included links between three aspects of family functioning (family conflict, positive family relations, and inadequate parental monitoring) and adolescents’ association with deviant peers. Those variables were hypothesized predictors of adolescents’ problem behavior (antisocial behavior, poor school performance, and frequency of substance use). The resulting cross-sectional model showed good consistency across the three ethnic groups for both genders, but some subgroup differences emerged in the magnitude of relations between monitoring and adolescents’ associations with deviant peers and between substance use and the problem behavior construct. With those qualifications, the model was applicable to Hispanic and Native American adolescents in the sample.