Psychomotor speed and functional brain MRI 2 years after completing a physical activity treatment.
ABSTRACT: Short-term adherence to physical activity (PA) in older adults improves psychomotor processing abilities and is associated with greater brain activation. It is not known whether these associations are also significant for longer-term adherence to moderate-intensity activities.We measured the cross-sectional association of regular walking with brain activation while performing the digit symbol substitution test (DSST). Participants of the lifestyle interventions and independence for elders-pilot study were examined 2 years after completing a 1-year treatment, consisting of either PA or education in successful aging (SA). Data were obtained from 20 PA participants who reported having remained active for 2 years after the end of the treatment and from 10 SA participants who reported having remained sedentary during the same period (mean age: 81.5 and 80.8 years). Complete brain activation and behavioral data were available for 17 PA and 10 SA participants.Two years after the formal intervention had ended, the PA group engaged in more minutes of moderate activity and had significantly greater DSST score and higher brain activation within regions important for processing speed (left dorsolateral prefrontal, posterior parietal, and anterior cingulate cortices). Associations were independent of self-reported health, blood pressure, cognition, medication records, gray matter atrophy, and white matter hyperintensities.Persistent engagement in PA may have beneficial effects on psychomotor processing speed and brain activation, even for moderate levels and even when started late in life. Future studies are warranted to assess whether these beneficial effects are explained by delayed neuronal degeneration and/or new neurogenesis.
Project description:Psychomotor slowing is common in children with sickle cell disease (SCD), but little is known about its severity in adults. We conducted a cross-sectional study to quantify psychomotor speed, measured with the digit symbol substitution test (DSST), in relationship with disease severity in adults with SCD attending an outpatient clinic (n = 88, age 36.3 years). Genotype was used to group patients in "severe" (homozygous for hemoglobin S or compound heterozygous with ?0 thalassemia) or "moderate" groups (compound heterozygous for HbS, with either HbC or ?+ thalassemia). Analyses were repeated after exclusion of patients with a history of stroke (n = 11). Mild impairment in processing speed was detectable in both the "severe" and the "moderate" group (30% and 9%, respectively; age-adjusted P = .14). Compared with the "moderate" group, those in the "severe" group had significantly lower standardized DSST scores (P = .004), independent of adjustment for factors that differed between the groups: hemoglobin, ferritin, hydroxyurea use, blood pressure parameters, and stroke history. Results were similar after excluding patients with stroke. Psychomotor slowing in SCD differs in relationship to genotype; this difference appears unrelated to history of stroke or severity of anemia and other risk factors examined cross-sectionally. Although less prevalent, mild cognitive impairment was also detectable in patients with a less severe genotype. Longitudinal studies of SCD should include all diseases genotypes and examine factors that would reduce the risk of slow processing speed and perhaps more general cognitive impairment in each subgroup.
Project description:OBJECTIVE:Psychomotor slowing is a common cognitive complication in type 1 diabetes (T1D), but its neuroanatomical correlates and risk factors are unclear. In nondiabetic adults, smaller gray matter volume (GMV) and presence of white matter hyperintensities are associated with psychomotor slowing. We hypothesize that smaller GMV in prefronto-parietal regions explains T1D-related psychomotor slowing. We also inspect the contribution of microvascular disease and hyperglycemia. METHODS:GMV, white matter hyperintensities (WMH), and glucose levels were measured concurrently with a test of psychomotor speed (Digit Symbol Substitution Test [DSST]) in 95 adults with childhood-onset T1D (mean age/duration = 49/41 years) and 135 similarly aged non-T1D adults. Linear regression models tested associations between DSST and regional GMV, controlling for T1D, sex, and education; a bootstrapping method tested whether regional GMV explained between-group differences in DSST. For the T1D cohort, voxel-based and a priori regions-of-interest methods further tested associations between GMV and DSST, adjusting for WMH, hyperglycemia, and age. RESULTS:Bilateral putamen, but no other regions examined, significantly attenuated DSST differences between the cohorts (bootstrapped unstandardized indirect effects: -3.49, -3.26; 95% confidence interval = -5.49 to -1.80, -5.29 to -1.44, left and right putamen, respectively). Among T1D, DSST was positively associated with GMV of bilateral putamen and left thalamus. Neither WMH, hyperglycemia, age, nor other factors substantially modified these relationships. CONCLUSIONS:For middle-aged adults with T1D and cerebral microvascular disease, GMV of basal ganglia may play a critical role in regulating psychomotor speed, as measured via DSST. Studies to quantify the impact of basal ganglia atrophy concurrent with WMH progression on psychomotor slowing are warranted.
Project description:to examine whether psychomotor speed predicts individual and combined disorders in cognition, mobility and mood and if white matter hyperintensities explain these associations.longitudinal; Cardiovascular Health Study.5,888 participants (57.6% women, 15.7% black, 75.1 (5.5), mean years (SD)).psychomotor speed (Digit Symbol Substitution Test (DSST)) and small vessel disease (white matter hyperintensities (WMH)) were measured in 1992-94. Global cognition (Modified Mini-Mental State (3MS) examination), mobility (gait speed (GS)) and mood (Center for Epidemiologic Studies Depression (CES-D) scale) were measured annually over 5 years and classified as clinical, subclinical or no disorders based on established values (3MS: 80 and 85 points; GS: 0.6 and 1.0 m/s; CES-D: 10 and 5 points). Analyses were adjusted for demographics, baseline status, education, diabetes, hypertension, ankle-arm index.among those with no disorder in cognition, mobility and mood (N = 619) in 1992-94, being in the lowest DSST quartile compared to the highest was associated with nearly twice the odds of developing 1+ clinical or subclinical disorders (N = 413) during follow-up. Associations were stronger for incident clinical disorders in cognition (OR: 8.44, p < 0.01) or mobility (OR: 9.09, p < 0.05) than for mood (OR: 1.88, p < 0.10). Results were similar after adjustment for WMH.slower psychomotor speed may serve as a biomarker of risk of clinical disorders of cognition, mobility and mood. While in part attributable to vascular brain disease, other potentially modifiable contributors may be present. Further studying the causes of psychomotor slowing with ageing might provide novel insights into age-related brain disorders.
Project description:Being able to measure the acute effects of alcohol consumption on psychomotor functions in natural settings could be useful in injury prevention interventions. This study examined the feasibility and acceptability of collecting app-based measures of information processing, working memory, and gait stability during times of typical alcohol consumption among young adults.Ten young adults (aged 21-26) with hazardous drinking completed a baseline assessment and ecological momentary assessments (EMA) on 4 consecutive Fridays and Saturdays, every hour from 8 pm to 12 am. EMA assessed alcohol consumption and perceived intoxication, followed by a digit symbol substitution task (DSST), a visuospatial working memory task (VSWMT), and a 5-step tandem gait task (TGT). Exit interviews probed user experiences. Multilevel models explored relationships between estimated blood alcohol concentration (eBAC; mg/dL) and DSST and VSWMT performance.Participants completed 32% of EMA. Higher rates of noninitiation occurred later in the evening and over time. In multilevel models, higher eBAC was associated with lower DSST scores. Eight out of 10 individuals had at least 1 drinking occasion when they did not perceive any intoxication. Lower DSST scores would identify impairment in 45% of these occasions. Exit interviews indicated that adding real-time feedback on task performance could increase awareness of alcohol effects.Collecting app-based psychomotor performance data from young adults during drinking occasions is feasible and acceptable, but strategies to reduce barriers to task initiation are needed. Mobile DSST is sensitive to eBAC levels and could identify occasions when an individual may not perceive impairments.
Project description:To investigate whether greater cardiorespiratory fitness (CRF) is associated with better cognitive function 25 years later.We studied 2,747 participants in the community-based Coronary Artery Risk Development in Young Adults Study of black and white men and women aged 18 to 30 years at recruitment in 1985-1986 (baseline year 0). Symptom-limited maximal treadmill test durations at years 0 and 20 provided measures of CRF. Cognitive tests at year 25 measured verbal memory (Rey Auditory Verbal Learning Test [RAVLT]), psychomotor speed (Digit Symbol Substitution Test [DSST]), and executive function (Stroop Test).Per minute of baseline CRF, the RAVLT was 0.12 words recalled higher (standard error [SE] = 0.03, p < 0.0001), the DSST was 0.92 digits higher (SE = 0.13, p < 0.0001), and the Stroop Test score was 0.52 lower (better performance, SE = 0.11, p < 0.0001), after accounting for race, sex, age, education, and clinical center. Compared with the lowest quartile of CRF, each cognitive test was 21% to 34% of an SD better in the highest CRF quartile. Further adjustment for lifestyle and clinical measures attenuated coefficients for RAVLT and DSST slightly, while the coefficient predicting the Stroop Test lost more than half its value (p = 0.07). Analysis in the subset of 1,957 participants who also completed the year-20 treadmill test showed that 20-year change in CRF was positively associated only with DSST (p < 0.001).Better verbal memory and faster psychomotor speed at ages 43 to 55 years were clearly associated with better CRF 25 years earlier.
Project description:<h4>Background</h4>The antihypertensive angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors (ACE-Is) have similar indications and mechanisms of action, but prior work suggests divergence in their effects on cognition.<h4>Methods</h4>Participants in the National Alzheimer's Coordinating Center database with a clinical diagnosis of dementia due to Alzheimer's disease (AD) using an ACE-I or an ARB at any visit were selected. The primary outcome was delayed recall memory on the Wechsler Memory Scale Revised - Logical Memory IIA. Other cognitive domains were explored, including attention and psychomotor processing speed (Trail Making Test [TMT]-A and Digit Symbol Substitution Test [DSST]), executive function (TMT-B), and language and semantic verbal fluency (Animal Naming, Vegetable Naming, and Boston Naming Tests). Random slopes mixed-effects models with inverse probability of treatment weighting were used, yielding rate ratios (RR) or regression coefficients (B), as appropriate to the distribution of the data. Apolipoprotein (APOE) ?4 status and blood-brain barrier (BBB) penetrance were investigated as effect modifiers.<h4>Results</h4>Among 1689 participants with AD, ARB use (n?=?578) was associated with 9.4% slower decline in delayed recall performance over a mean follow-up of 2.28?years compared with ACE-I use (n?=?1111) [RR?=?1.094, p?=?0.0327]; specifically, users of BBB-crossing ARBs (RR?=?1.25, p?=?0.002), BBB-crossing ACE-Is (RR?=?1.16, p?=?0.010), and non-BBB-crossing ARBs (RR?=?1.20, p?=?0.005) had better delayed recall performance over time compared with non-BBB-crossing ACE-I users. An interaction with APOE ?4 status (drug × APOE × time RR?=?1.196, p?=?0.033) emerged; ARBs were associated with better delayed recall scores over time than ACE-Is in non-carriers (RR?=?1.200, p?=?0.003), but not in carriers (RR?=?1.003, p?=?0.957). ARB use was also associated with better performance over time on the TMT-A (B =?2.023?s, p?=?0.0004) and the DSST (B?=?0.573 symbols, p?=?0.0485), and these differences were significant among APOE ?4 non-carriers (B?=?4.066?s, p?=?0.0004; and B?=?0.982 symbols, p?=?0.0230; respectively). Some differences were seen also in language and verbal fluency among APOE ?4 non-carriers.<h4>Conclusions</h4>Among APOE ?4 non-carriers with AD, ARB use was associated with greater preservation of memory and attention/psychomotor processing speed, particularly compared to ACE-Is that do not cross the blood-brain-barrier.
Project description:Previous data have demonstrated that administration of inflammatory cytokines or their inducers leads to altered basal ganglia function associated with reduced psychomotor speed. Decreased psychomotor speed, referred to clinically as psychomotor retardation, is a cardinal symptom of major depressive disorder (MDD) and has been associated with poor antidepressant treatment response. We therefore examined the association between plasma inflammatory markers and psychomotor speed in ninety-three un-medicated patients with MDD. Psychomotor speed was assessed by a range of neuropsychological tests from purely motor tasks (e.g. movement latency and finger tapping) to those that involved motor activity with increasing cognitive demand and cortical participation (e.g. Trails A and Digit Symbol Substitution Task (DSST)). Linear regression analyses were performed to determine the relationship of inflammatory markers and psychomotor task performance controlling for age, race, sex, education, body mass index, and severity of depression. MDD patients exhibited decreased psychomotor speed on all tasks relative to normative standards. Increased IL-6 was associated with decreased performance on simple and choice movement time tasks, whereas MCP-1 was associated with decreased performance on the finger tapping task and DSST. IL-10 was associated with increased performance on the DSST. In an exploratory principle component analysis including all psychomotor tasks, IL-6 was associated with the psychomotor speed factor. Taken together, the data indicate that a peripheral inflammatory profile including increased IL-6 and MCP-1 is consistently associated with psychomotor speed in MDD. These data are consistent with data demonstrating that inflammation can affect basal ganglia function, and indicate that psychomotor speed may be a viable outcome variable for anti-inflammatory therapies in depression and other neuropsychiatric disorders with increased inflammation.
Project description:Coupled with an aging society, the rising obesity prevalence is likely to increase the future burden of physical disability. We set out to determine whether obesity modified the effects of a physical activity (PA) intervention designed to prevent mobility disability in older adults. Older adults at risk for disability (N = 424, age range: 70-88 years) were randomized to a 12 month PA intervention involving moderate intensity aerobic, strength, balance, and flexibility exercise (150 min per week) or a successful aging (SA) intervention involving weekly educational workshops. Individuals were stratified by obesity using a BMI >or=30 (n = 179). Mobility function was assessed as usual walking speed over 400 m and scores on a short physical performance battery (SPPB), which includes short distance walking, balance tests, and chair rises. Over 12 months of supervised training, the attendance and total amount of walking time was similar between obese and nonobese subjects and no weight change was observed. Nonobese participants in the PA group had significant increases in 400-m walking speed (+1.5%), whereas their counterparts in the SA group declined (-4.3%). In contrast, obese individuals declined regardless of their assigned intervention group (PA: -3.1%; SA: -4.9%). SPPB scores, however, increased following PA in both obese (PA: +13.5%; SA: +2.5%) and nonobese older adults (PA: +18.6%; SA: +6.1%). A moderate intensity PA intervention improves physical function in older adults, but the positive benefits are attenuated with obesity.
Project description:Few cohort studies have examined longitudinal associations between age-related changes in cognition and physical performance. Further, whether these associations differ for men versus women or can be attributed to differences in physical activity (PA) is unknown.Participants were 2,876 initially well-functioning community-dwelling older adults (aged 70-79 years at baseline; 52% female; 39% black) studied over a 9-year period. Usual gait speed, self-reported PA, and two cognitive measures-Digit Symbol Substitution Test (DSST) and Mini-Modified Mental State examination (3MS)-were assessed years 0 (ie, baseline), 4, and 9.Early decline between years 0 and 4 in gait speed predicted later decline between years 4 and 9 in performance on the 3MS (? = 0.10, p = .004) and on the DSST (? = 0.16, p < .001). In contrast, the associations between early decline in cognition and later decline in gait speed were weaker and were non-significant after correcting for multiple comparisons (? = 0.08, p = .019 for 3MS and ? = .06, p = .051 for DSST). All associations were similar for women and men and were unaltered when accounting for PA levels.The results indicate declining gait speed as a precursor to declining cognitive functioning, and suggest a weaker reciprocal process among older women and men.
Project description:OBJECTIVES:To assess the utility of a long-term physical activity (PA) intervention for reducing resting pulse rate (RPR) in older persons. DESIGN:Community. SETTING:Lifestyle Interventions and Independence for Elders Study. PARTICIPANTS:Individuals aged 70 to 89 (N = 1,635, 67.2% women) were randomized to a moderate-intensity PA intervention (n = 818) or a health education-based successful aging (SA) intervention (n = 817). MEASUREMENTS:RPR was recorded at baseline and 6, 18, and 30 months. Longitudinal changes in RPR of intervention groups were compared using a mixed-effects analysis of covariance model for repeated-measure outcomes, generating least squares means with standard errors (SEs) or 95% confidence intervals (CIs). RESULTS:Mean duration of the study was 2.6 years (median 2.7 years, interquartile range 2.3-3.1 years). The average effect of the PA intervention on RPR over the course of the study period was statistically significant but clinically small (average intervention difference = 0.84 beats/min; 95% CI = 0.17-1.51; Paverage = .01), with the most pronounced effect observed at 18 months (PA, 66.5 beats/min (SE 0.32 beats/min); SA, 67.8 beats/min (SE 0.32 beats/min); difference = 1.37 beats/min, 95% CI = 0.48-2.26 beats/min). The relationship became somewhat weaker and was not statistically significant at 30 months. There were no significant differences between several prespecified subgroups. CONCLUSION:A long-term moderate-intensity PA program was associated with a small and clinically insignificant slowing of RPR in older persons. Whether PA can deliver a beneficial reduction in RPR requires further examination in older adults.