Physical activity, functional limitations, and disability in older adults

OBJECTIVES: To explore initially how low levels of physical activity influence lower body functional limitations in participants of the Longitudinal Study of Aging. Changes in functional limitations are used subsequently to predict transitions in the activities of daily living/instrumental activities of daily living (ADL/IADL) disability, thus investigating a potential pathway for how physical activity may delay the onset of ADL/IADL disability and, thus, prolong independent living. DESIGN: Analysis of a complex sample survey of US civilian, noninstitutionalized population aged 70 years and older in 1984, with repeated interviews in 1986, 1988, and 1990. SETTING AND PARTICIPANTS: Analyses concentrated on 5151 men and women targeted for interview at all four LSOA interviews. MEASUREMENTS: Characteristics used in analyses: gender, age, level of physical activity, comorbid conditions including the presence of hypertension, diabetes, arthritis, and atherosclerotic heart disease, levels of functional limitations, and ADL/IADL disability. RESULTS: Transitional models provide evidence that older adults who have varying levels of disability and who report at least a minimal level of physical activity experience a slower progression in functional limitations (OR = .45, P < .001 for severe vs less severe limitations). This low level of physical activity, through its influence on changes in functional limitations, is shown to slow the progression of ADL/IADL disability. CONCLUSIONS: Results from analyses provide supporting evidence that functional limitations can mediate the effect that physical activity has on ADL/IADL disability. These results contribute further to the increasing data that seem to suggest that physical activity can reduce the progression of disability in older adults.     

Self-efficacy mediates walking performance in older adults with knee osteoarthritis

BACKGROUND: Self-efficacy is a determinant of walking performance in older adults with knee osteoarthritis. We examined whether self-efficacy mediated the effect of age, psychosocial, impairment, and mechanical factors on walking performance. METHODS: Fifty-four participants with knee osteoarthritis completed the Six Minute Walk test and Arthritis Self-Efficacy Scale. Independent variables reflected age, psychosocial (depressive symptoms), impairment (pain, stiffness), and mechanical (strength, obesity) factors. RESULTS: Self-efficacy fully mediated the effect of age and impairments on walking. The effects of strength were only partially mediated by self-efficacy. Depressive symptoms and obesity were not mediated by self-efficacy. CONCLUSIONS: These findings are consistent with Social Cognitive Theory, according to which age may alter outcome expectations, and impairments like pain and stiffness provide negative physiological feedback to influence performance. Mechanical factors like strength and obesity may better represent a person's capabilities and interact with other variables to influence physical performance in older adults with knee osteoarthritis.     

Inflammatory biomarkers and physical function in older, obese adults with knee pain and self-reported osteoarthritis after intensive weight-loss therapy

OBJECTIVES: To describe the relationships between proinflammatory biomarkers and self-reported and performance-based physical function and to examine the effect of weight loss on these markers of inflammation.
DESIGN: Randomized, longitudinal, clinical study comparing subjects eating an energy-restricted diet and participating in exercise training with a control group.
SETTING: Community-base participants for the Physical Activity, Inflamation and Body Composition Trial.
PARTICIPANTS: Eighty-seven obese (body mass index (BMI) >30.0 kg/m²) adults aged 60 and older with knee pain and self-report of osteoarthritis.
MEASUREMENTS: Inflammatory biomarkers (interleukin 6 (IL-6), tumor necrosis factor alpha (TNFα), C-reactive protein, and soluble receptors for TNFα (sTNFR1 and sTNFR2)) and self-reported (Western Ontario and McMaster University Osteoarthritis Index questionnaire) and performance-based (6-minute walk distance and stair climb time) measures of physical function at baseline and 6 months.
RESULTS: Mean (standard error of the mean) weight loss was 8.7% (0.8%) in the intervention group, compared with 0.0% (0.7%) in the control group. sTNFR1 was significantly less in the intervention group than in the control group at 6 months. sTNFR1 and sTNFR2 predicted stair climb time at baseline. Change across the 6-month intervention for sTNFR2 was an independent predictor for change in 6-minute walk distance.
CONCLUSION: These results indicate that an intensive weight-loss intervention in older obese adults with knee pain can help improve inflammatory biomarkers and that changes in these concentrations showed associations with physical function.     

Baseline balance and functional decline in older adults with knee pain: the Observational Arthritis Study in Seniors

OBJECTIVES: To examine the cross-sectional and longitudinal effect of baseline balance, independent of multiple covariates (sociodemographic variables, comorbidities), on self-reported disability and several measures of functional performance. DESIGN: Observational Arthritis Study in Seniors was a community-based longitudinal study. SETTING: Data collection was conducted at an exercise science research laboratory. PARTICIPANTS: A cohort of 245 women and 235 men, aged 65 and older, with self-reported knee pain. MEASUREMENTS: Measurements of balance, self-reported disability, functional performance, strength, sociodemographic characteristics, disease burden (including radiographic knee osteoarthritis (OA)), and functional limitations were obtained on participants at baseline and 30 months. The four outcome measures (self-reported disability, stair climb time, car time, preferred walking speed) were also collected at 15 months. RESULTS: In cross-sectional analyses, baseline balance was significantly associated with each of the four outcome measures before adjusting for baseline knee strength. After adjusting for knee strength, baseline balance remained significantly associated with all functional performance outcomes and self-reported disability. In longitudinal analyses, baseline balance had a significant effect on car-time performance, whereby individuals in the lowest quartile of baseline balance scores declined in a quadratic manner from baseline to Month 30. CONCLUSION: Baseline balance, independent of strength and various other covariates, is an important component of performance for transfer and ambulatory tasks and for self-reported disability. Balance was predictive of change in performance over time only in a task that presented a significant challenge to the lateral mobility/stability of participants. Balance was not predictive of decline in ambulatory performance-based tasks or in self-reported disability.     

Association of cognitive status with functional limitation and disability in older adults

BACKGROUND AND AIMS: Although cognitive status is known to be associated with physical function in older people, the role it plays in the disability process is not well established. This study aimed at determining whether cognitive ability predicts functional limitations, as well as disability, and whether it is associated with the rate of change in physical functions. METHODS: A community-based longitudinal study was conducted, involving 977 older persons aged 65 and older living in an urban community. Physical functions were assessed by tests scoring functional limitations (upper and lower body) and disability (activities of daily living). Cognitive function was evaluated using the Mini-Mental State Examination. Linear regression analyses with generalized estimating equations modeled the two physical function scores separately, as functions of cognitive status and time, in a one-year follow-up, controlling for sociodemographic and health-related characteristics. RESULTS: Cognitive status independently predicted functional limitations as well as disability in older people. In addition, the strength of the association of cognitive status with physical functions increased over time, as revealed by the significant interaction between cognitive ability and time. Cognitive status influenced the rate of change in disability scores, more among women and in those aged 75 or older. The relationship was unaffected by baseline physical functional status, but was significant only among those with no cognitive impairment at baseline. CONCLUSIONS: Cognitive status appears to be a useful indicator of the disablement process in older people. It may play an important role in the development of disability, implying that strategies for early intervention to prevent the progression of disability may need to take cognitive functions into account. The increasing strength of the relationship between cognitive and physical functions over time further attests to its value in monitoring functional change.     

Prevalence and correlates of functional disability in Chinese older adults

Aim:   This article examines the prevalence of functional disability as well as sociodemographic correlations among Chinese older adults based on the most recent China National Sample Survey on Disability in 2006.
Methods:   Functional disability was defined as lost motor function or limited movements and activities according to the International Classification of Function, Disability and Health, and physicians made the diagnosis of disability. Utilizing stratified, multiphase and cluster probability sampling design, a nationally representative sample of the non-institutionalized elderly Chinese population was studied. Factors associated with functional disability were determined using a logistic regression model.
Results:   The prevalence of functional disability was 8.1%. Major causes were vascular disease, osteoarthritis and accidents. In the non-institutionalized elders, increased age, rural residence, less education, lower income, unemployment, being unmarried, living in simple housing, and living with others or non-homeowners emerged as factors associated with functional disability in men and women.
Conclusion:   To face the challenge of the rising prevalence of functional disability, prevention strategies should focus on reducing the incidences of chronic disease and improving socioeconomic status of older adults.     

Oral health status and self-reported functional dependence in community-dwelling older adults

OBJECTIVES: To assess the strength of association between graded groups of oral health status and self‐reported functional dependence in community‐dwelling older adults. DESIGN: Population‐based cross‐sectional study. SETTING: National Health and Nutritional Examination Survey (NHANES) 1999 to 2004. PARTICIPANTS: Three thousand eight hundred fifty‐six participants aged 60 and older (mean age 71.2) without missing values in the examined correlates. MEASUREMENTS: Oral health status was evaluated according to edentulism, severity of periodontal disease, and recommendation of periodontal care and compared with that of healthy controls. Self‐reported functional dependence was assessed according to 19 questions in five domains: activities of daily living (ADLs), instrumental activities of daily living (IADLs), leisure and social activities (LSAs), lower extremity mobility (LEM), and general physical activities (GPAs). RESULTS: After controlling for demographic and dental variables, health‐related behaviors, C‐reactive protein, and comorbidities, edentulism was significantly associated with disability in IADLs (odds ratio (OR)=1.58), LSAs (OR=1.63), LEM (OR=1.31), and GPAs (OR=1.45) compared with healthy controls. Likewise, severe periodontitis was associated with disability in IADLs (OR=1.58), LSAs (OR=1.70), and LEM (OR=1.63). The trends toward disability in IADLs, LSAs, LEM, and GPAs were statistically significant across increasing severity of oral health problems. CONCLUSION: Poor oral health, specifically edentulism and severe periodontitis, is associated with multiple domains of late‐life disability, but a causal relationship cannot be established based on current study design.     

Prospective study of self-reported pain, radiographic osteoarthritis, sarcopenia progression, and falls risk in community-dwelling older adults

Objective

To examine the potential role of self‐reported joint pain, stiffness, and dysfunction, and radiographic osteoarthritis (ROA), in sarcopenia progression and falls risk in older adults.

Methods

Seven hundred nine older adults (50% women, mean ± SD age 62 ± 7 years) were examined at baseline and followup (mean ± SD 2.6 ± 0.4 years). ROA was assessed using the Altman atlas, and pain at 7 anatomic sites was self‐reported. Dual x‐ray absorptiometry assessed leg lean mass, dynamometry assessed knee extension and whole leg strength, leg muscle quality (LMQ) was calculated as whole leg strength relative to leg lean mass, and the Physiological Profile Assessment assessed falls risk.

Results

In women only, baseline knee pain predicted a greater decline in knee extension strength, whole leg strength, and LMQ, and a greater increase in falls risk. Severe knee pain, stiffness, and dysfunction predicted greater declines in knee extension strength and increases in falls risk (all P < 0.05). Hip pain also predicted a greater decline in knee extension strength (?1.53 kg; 95% confidence interval [95% CI] ?2.95, ?0.11). No associations were observed between pain and sarcopenia indicators in men. Somewhat surprisingly, higher baseline total knee ROA score predicted a greater increase in mean leg lean mass (0.05 kg; 95% CI 0.02, 0.08) in both sexes. A path analysis demonstrated that knee ROA may contribute to declines in LMQ in women, through increases in pain, stiffness, and dysfunction.

Conclusion

Knee and hip pain may directly contribute to the progression of sarcopenia and increased falls risk in older women.

     

Predicting poor functional outcome in community-dwelling older adults with knee pain: prognostic value of generic indicators

BACKGROUND: In longitudinal studies across a range of regional musculoskeletal pain syndromes, certain prognostic factors consistently emerge. They are "generic" in the sense that they appear to apply regardless of the particular anatomical site or underlying cause of the pain. OBJECTIVE: To investigate the value of generic indicators of poor functional outcome for knee pain and osteoarthritis in the community. METHODS: We conducted a population-based cohort study of adults aged >or=50 years with knee pain as part of the Clinical Assessment Study (Knee) (CAS(K)). At baseline, participants completed a postal questionnaire and attended a research clinic where they completed a further questionnaire and underwent structured physical examination and x rays. The 18-month follow-up was via a self-completed questionnaire. Risk ratios were calculated using Cox regression with a fixed time period assigned to each participant. RESULTS: In total, 60% of participants experienced a poor outcome at 18 months. Twelve univariate associations were associated with poor outcome, with four variables remaining in the multivariate model (older age, being overweight or obese, having possible or probable anxiety, and more severe pain).Using a simple unweighted additive risk score (1 point each for age >or=60 years, body mass index >or=25 kg/m(2), possible or probable anxiety, Chronic Pain Grade II-IV), 90% of participants with all four generic indicators were correctly classified. CONCLUSIONS: This study has demonstrated that generic prognostic indicators can be used to determine the prognosis of older people in the community with knee pain.     

Longitudinal study of the relationship between physical activity and knee pain and functional limitation in community-dwelling older adults

AimsTo describe the associations between interindividual (between-person) and intraindividual (within-person) variability in physical activity (PA) and knee pain and functional limitation among older adults. We also investigated the potential bidirectional association of between-person and within-person variability in knee pain and functional limitation with PA.MethodParticipants (N = 1064; 51% women; mean age 63 ± 7.4 years) were measured at baseline, 2.5, and 5 years. PA was measured using pedometers. Knee pain and functional limitation were assessed using the WOMAC scale. A two-part hurdle model, with adjustment for confounders, estimated the association of between-person and within-person variability in PA with knee pain/functional limitation (as the outcome). Linear mixed effect regression models described the association of between-person and within-person variability in knee pain and functional limitation with PA (as the outcome).ResultsBetween-person effects showed that participants with a higher 5-year average PA had lower average WOMAC scores (β= –1.17, 95% CI: –1.82, –0.51). Within-person effects showed that at time-points when participants had a higher PA level than average, they also had lower WOMAC scores (β= –0.85, 95% CI: –1.36, –0.35). Conversely, both between-person (β= –15.6, 95% CI: –22.5, –8.8) and within-person increase (β= –7.4, 95% CI: –13.5, –1.4) in WOMAC scores were associated with lower PA.ConclusionThese findings suggest that PA and knee pain/dysfunctional contribute to the development of one another. Pain can lead to changes in inter- and intraindividual PA levels, but the reverse is also possible – changes in PA results in changes in inter- and intraindividual pain/dysfunctional levels.     

Association of flat feet with knee pain and cartilage damage in older adults

Objective

To assess the cross‐sectional relation of planus foot morphology to ipsilateral knee pain and compartment‐specific knee cartilage damage in older adults.

Methods

In the Framingham Studies, we adapted the Staheli Arch Index (SAI) to quantify standing foot morphology from pedobarographic recordings. We inquired about knee pain and read 1.5 T magnetic resonance image (MRI) scans using the Whole‐Organ MRI Score. Logistic regression compared the odds of knee pain among the most planus feet to the odds among all other feet, and estimated odds within categories of increasing SAI. Similar methods estimated the odds of cartilage damage in each knee compartment. Generalized estimating equations adjusted for age, sex, body mass index, and nonindependent observations.

Results

Among 1,903 participants (56% women, mean ± SD age 65 ± 9 years), 22% of knees were painful most days. Cartilage damage was identified in 45% of medial tibiofemoral (TF), 27% of lateral TF, 58% of medial patellofemoral (PF), and 42% of lateral PF compartments. Compared with other feet, the most planus feet had 1.3 times (95% confidence interval [95% CI] 1.1–1.6) the odds of knee pain (P = 0.009), and 1.4 times (95% CI 1.1–1.8) the odds of medial TF cartilage damage (P = 0.002). Odds of pain (P for linear trend = 0.05) and medial TF cartilage damage (P for linear trend = 0.001) increased linearly across categories of increasing SAI. There was no association between foot morphology and cartilage damage in other knee compartments.

Conclusion

Planus foot morphology is associated with frequent knee pain and medial TF cartilage damage in older adults.     

Factors related to sleep disturbance in older adults experiencing knee pain or knee pain with radiographic evidence of knee osteoarthritis

OBJECTIVES: To describe the types and frequencies of sleep complaints and the biopsychosocial factors associated with sleep disturbance in a large community sample of older adults experiencing knee pain or knee pain with radiographic evidence of knee osteoarthritis (OA). DESIGN: Baseline analyses of an observational prospective study. SETTING AND PARTICIPANTS: Participants were 429 men and women aged 65 years and older experiencing knee pain or knee pain with radiographic evidence of OA enrolled in the Observational Arthritis Study in Seniors (OASIS). MEASUREMENTS: Demographic variables (age, gender, ethnicity, education), health (X-rays of knee rated for OA severity, medical conditions, medication use, smoking status, body mass index, self-rated health), physical functioning (self-rated physical functioning, physical performance), knee pain, and psychosocial functioning (social support, depression) were measured. RESULTS: Problems with sleep onset, sleep maintenance, and early morning awakenings occurred at least weekly among 31%, 81%, and 51% of participants, respectively. Bivariate correlates of greater sleep disturbance in those with OA were less education, cardiovascular disease, more arthritic joints, poorer self-rated health, poorer physical functioning, poorer physical performance, knee pain, depression, and less social support. In regression analyses, each set of variables representing the domains of health, physical functioning, pain, and psychosocial functioning contributed to the prediction of sleep disturbance beyond the demographic set. Finally, in a simultaneous model, white race (trend, P = .06), poorer self-rated health, poorer physical functioning, and depressive symptoms were predictive of sleep disturbance. CONCLUSIONS: Sleep disturbance is common in older adults experiencing knee pain or knee pain with radiographic evidence of OA and is best understood through the consideration of demographic, physical health, physical functioning, pain, and psychosocial variables. Interventions that take into account the multidetermined nature of sleep disturbance in knee pain or knee OA are most likely to be successful.     

Quality of life and self-reported disability in patients with knee osteoarthritis

Abstract

Objectives Osteoarthritis (OA) is the most common degenerative joint disorder and a major public health problem throughout the world. The aims of this study are to assess quality of life (QoL) in patients with knee OA using the generic instrument Short Form-36 (SF-36) and to determine its relationships with conventional clinical measures and self-reported disability.

Methods Patients with knee OA (n = 112) with median age of 60 (45–76) years and 40 sex- and age-matched healthy controls were included in the study. Age, sex, body mass index (BMI), symptom duration, and Kellgren–Lawrence scores were recorded. QoL, disability, and pain were assessed using the SF-36, the Western Ontario and McMaster (WOMAC) index, the Lequesne index, and a visual analog scale (VAS) in patients. Also, QoL was assessed using the SF-36 in controls.

Results Patients with knee OA had lower scores in all subgroups of SF-36 compared with controls. In patients, the SF-36 physical function (PF) and pain areas significantly correlated with effusion, VAS pain, and Lequesne and WOMAC subgroup scores (p < 0.05). The pain area of QoL did not show correlation with comorbidity with knee OA. We found that SF-36 and WOMAC pain scores were more severe in female patients.

Conclusions Patients with knee OA had significantly poorer QoL compared with healthy controls. SF-36 is related to the clinical status and functional ability of patients with OA and can be used as a sensitive health status measure for clinical evaluation. Also WOMAC can be used as a sensitive measure for disability of patients with knee OA.