Gait Speed and Processing Speed as Clinical Markers for Geriatric Health Outcomes.

OBJECTIVE: This study investigates the independent and combined potential of slowed gait speed and slowed processing speed as predictors of adverse health outcomes. The role of depressive symptoms in these associations is also investigated. METHODS: In the prospective cohort study, using the Longitudinal Aging Study Amsterdam database, three study samples for each outcome variable were defined: persistent cognitive decline (PCD; N = 1,271, 13 years of follow-up), falls (N = 1,282, 6 years of follow-up), and mortality (N = 1,559, age 74.9 ± 5.8, 21 years of follow-up). At baseline, gait speed (6-m walk with a turn at 3 m), processing speed (coding task), depressive symptoms (Center for Epidemiologic Studies Depression Scale), and basic demographic data were assessed. Also, time to PCD, falls, and mortality were assessed. Cox (for PCD and mortality) and stratified Cox (for falls) regression models were used. RESULTS: Slowed processing speed predicted PCD (HR: 7.8; 95% CI: 3.3-18.8), slowed gait speed predicted falls (HR: 1.3; 95% CI: 1.0-1.5), and both measures predicted mortality (gait speed HR: 2.1; 95% CI: 1.6-2.6; processing speed HR: 1.9; 95% CI: 1.6-2.4). Each association remained significant after adjusting for the other slowing symptom. Slowed processing speed only predicted falls in the presence of slowed gait (interaction). A slowing sum score that combines both slowing symptoms predicted all three outcomes. The associations were not influenced by depressive symptoms. CONCLUSION: Slowing of thought is as relevant as slowing of movement to predict adverse health outcomes, because they seem to represent separate underlying pathologies.

A 13-year prospective cohort study on the effects of aging and frailty on the depression-pain relationship in older adults.

OBJECTIVES: The primary aim of the study is to investigate the effect of age and aging on the association between pain and depression over 13 years. We hypothesized that (1) this association would become stronger with age and frailty and that (2) this association is mainly driven by somatic and psychological factors. METHODS: Data were derived from the Longitudinal Aging Study Amsterdam, a prospective population-based cohort study with four follow-up measurements over 13 years, consisting of 1528 respondents (mean age 67.9 ± 8.1). Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale; pain was measured with an adapted version of the Nottingham Health Profile. Follow-up time and age were used as proxy variables for aging and gait speed as frailty marker. Cognition, mastery and neuroticism were measured using the mini mental state examination, the Pearlin Mastery Scale and the Dutch Personality Questionnaire respectively. RESULTS: Linear mixed models showed that pain and depressive symptoms were associated over the 13-year follow-up: b = 0.095, p < 0.001. Neither aging nor frailty changed this association. Measured somatic and psychological characteristics explained 40% of the covariance between pain and depressive symptoms over time. DISCUSSION: When dealing with people suffering from pain and depression, interventions should be similar for all aged people, encompassing both somatic and psychological factors, irrespective of age or frailty status.

Cognitive functioning and the natural course of depressive symptoms in late life.

OBJECTIVES: To investigate whether specific domains of cognitive functioning predict the natural course of depressive symptoms in older people. DESIGN AND PARTICIPANTS: Using the nationally representative, population-based cohort of the Longitudinal Aging Study Amsterdam, 281 participants with clinically relevant depressive symptoms (Center for Epidemiological Studies Depression Scale ≥16) aged 55 years and older were followed longitudinally during a period of 6 years. MEASUREMENTS: Using a maximum of 14 successive Center for Epidemiological Studies Depression Scale observations, three clinical course types of depressive symptoms were defined. At baseline, general cognitive functioning was assessed using the Mini-Mental State Exam, memory performance (immediate recall and retention) by means of the auditory verbal learning test, and processing speed by means of a timed coding task. RESULTS: Remission, fluctuating course, and chronic course were seen in 22%, 50%, and 28%, respectively. In univariate analyses, a slowed processing speed was associated with a chronic course of depressive symptoms, as compared with remission (mean: 21.5, SD: 6.6, versus mean: 24.6, SD: 6.8, t = 2.78, df = 139, p < 0.001). Using multivariate regression techniques, this association remained significant after correcting for potential confounders and a number of risk factors for vascular brain damage (odds ratio: 1.08, 95% confidence interval: 1.01-1.14). Neither global cognitive functioning nor memory performance was associated with any course type of depressive symptoms. CONCLUSION: We found an independent association of a slowed processing speed with a poor natural course of depressive symptoms in older people. In clinical practice, when dealing with an older depressed person with comorbid cognitive decline, processing speed might be a more useful tool than the Mini-Mental State Exam in predicting the prognosis.

Gait Speed and the Natural Course of Depressive Symptoms in Late Life; An Independent Association With Chronicity?

INTRODUCTION: Psychomotor slowing is a core feature of depression in late life, but its prognostic value with respect to course and chronicity is unclear. We investigated whether gait speed can predict chronicity of depressive symptoms. Furthermore, we tested whether (1) cognitive slowing and (risk factors for) vascular diseases, (2) a marker of chronic inflammation, and (3) specific somatic conditions could explain this association. METHODS: In the population-based Longitudinal Aging Study Amsterdam, 271 aged participants with clinically relevant depressive symptoms (Center for Epidemiologic Studies Depression Scale ≥16) were followed during a period of 6 years. With 14 successive Center for Epidemiologic Studies Depression Scale observations, 3 clinical course types of depressive symptoms were defined. RESULTS: Remission, fluctuating course, and chronic course of depressive symptoms were seen in 21%, 48%, and 30%, respectively. Slowed gait speed at baseline was associated with a chronic course of depressive symptoms using remission as the reference (odds ratio 0.56, 95% confidence interval 0.41-0.77). Processing speed and vascular risk factors explained this association only for 2%. Specific somatic comorbidity (number of chronic diseases, chronic obstructive pulmonary disease, osteoarthritis) or inflammation influenced the odds ratio. LIMITATION: Some variables were not measured with as much detail as would be possible in a clinical study setting. CONCLUSIONS: Slowed gait speed is a robust predictor of chronicity of depressive symptoms in late life, independent of somatic comorbidity and partly in concert with a slowed processing speed. Results suggest that slowed gait speed is an integral part of the depressive syndrome, probably a subtype associated with chronic course, independent of somatic comorbidity.

Do depressive symptoms and gait speed impairment predict each other's incidence? A 16-year prospective study in the community.

OBJECTIVES: To investigate whether gait speed predicts incident depressive symptoms and whether depressive symptoms predict incident gait speed impairment; to ascertain the presence of shared risk factors for these associations. DESIGN: The Longitudinal Aging Study Amsterdam, a prospective cohort study with five follow-up cycles over 16 years. SETTING: Population based. PARTICIPANTS: One thousand nine hundred twenty-eight respondents for incident depressive symptoms (mean age 68.9 ± 8.5) and 1,855 respondents for incident gait speed impairment (mean age 68.0 ± 8.2). MEASUREMENTS: Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale; gait speed was measured, back and forth, during a 3-m walk as quickly as possible, with a 180° turn. Multivariate analyses were performed for both sexes using Cox regression. RESULTS: Incident depressive symptoms occurred in 24% of respondents. In univariate analyses, gait speed at baseline predicted incident depressive symptoms in men and women; after adjustment for covariates, this association persisted in men only. Examining the reverse association, 34% of respondents developed gait speed impairment. Depressive symptoms at baseline were univariately associated with incident gait speed impairment in women but not in men; this association did not persist after adjustment. The bidirectional associations did not share the same explanatory variables. CONCLUSION: Gait speed predicts depressive symptoms in men. The geriatric giants of depressive symptoms and slowed gait speed in late life appear to result from different pathologies, both of which therefore require their own treatment strategies.