The journals of gerontology. Series A, Biological sciences and medical sciences最新文献

Background: This study aims to evaluate the effectiveness of computerized cognitive training (CCT) on white matter (WM) neuroplasticity and neuropsychological performance.

Methods: A total of 128 community older adults (64.36 ± 6.14 years) were recruited and randomly assigned to the intervention or control group. Participants in the intervention group received a home-based, multidomain, and adaptive CCT for 30 minutes, 2 days per week for 1 year. Neuropsychological assessments, diffusion magnetic resonance imaging (MRI), and T1-weighted structural MRI were performed at the pre- and post-intervention visits.

Results: Eighty-one of 128 participants (41 in the intervention group and 40 in the control group) completed the 1-year intervention, and 61 of them (27 in the intervention group and 34 in the control group) underwent MRI scans twice. After excluding attrition bias, a significant time-by-group interaction on the Stroop Color-Word Test (SCWT; F = 51.85, p < .001) was found, showing improvement in the intervention group and a decline in the control group. At the brain level, the intervention group exhibited increased axial diffusivity in the left posterior thalamic radiation, and this increase was significantly correlated with reduced SCWT reaction time (r = ‒0.42, p = .029). No significant time-by-group interactions were found for gray matter volume.

Conclusions: Our findings suggest that conducting multidomain adaptive CCT is an effective and feasible method to counteract cognitive decline in older adults, with WM neuroplasticity underpinning cognitive improvements. This study contributes to the understanding of the neural basis for the beneficial effect of CCT for older adults.

Background: The associations of high and low testosterone with all-cause and cardiovascular disease (CVD) mortality risk in men are conflicting. Our objective was to examine associations of total testosterone, free testosterone, bioavailable testosterone, and sex hormone-binding globulin (SHBG) with all-cause and CVD mortality in older Chinese men.

Methods: Total testosterone and SHBG were assayed, and free testosterone and bioavailable testosterone were calculated using Vermeulen formula. Cox proportional hazards regression was used to assess the associations with risks of all-cause and CVD mortality, giving hazard ratios (HRs) and 95% confidence intervals (CIs).

Results: Of 3 948 men aged 50+ years, 949 deaths (312 CVD) occurred during an average 10.5-year follow-up. After multivariable adjustments, the highest, versus the third, quartile of total testosterone and free testosterone were associated with higher all-cause mortality risk (1.17 [0.97-1.41] and 1.45 [1.20-1.74], respectively), whereas free testosterone was associated with higher CVD mortality risk (1.88 [1.33-2.66]). Similar positive associations were found for bioavailable testosterone and all-cause mortality risk (1.27 [1.05-1.54]). Lower SHBG (quartile 1 vs quartile 3) was associated with higher all-cause and CVD mortality risk (1.25 [1.04-1.52] and 1.28 [1.08-1.52], respectively). Consistent associations were observed in relatively healthy men and men excluded death during the first year.

Conclusions: Higher total testosterone, free testosterone, and bioavailable testosterone were associated with higher all-cause mortality in older men, higher free testosterone was associated with higher CVD mortality whilst lower SHBG was associated with higher all-cause and CVD mortality. Clarification and confirmation of causality require further mechanistic studies.

Background: The D3-creatine (D3-Cr) dilution method is of emerging interest for estimating total-body skeletal muscle mass. This review explores the association of muscle mass estimated via D3-Cr with various clinical outcomes and provides a summary of the literature comparing D3-Cr with other body composition techniques.

Methods: A literature search was conducted on PubMed/MEDLINE and Web of Science for studies using D3-Cr to measure muscle in adult populations (ie, ≥18 years old) from inception until September 2023.

Results: Out of the 23 included studies, 15 investigated the correlation between D3-Cr and clinical outcomes. More consistent associations were reported for mortality (100%, n = 2), mobility disability (100%; n = 5), falls and fractures (100%; n = 3), physical performance (63.3%; n = 11), muscle strength (44.4%; n = 9), and muscle composition (33.3%; n = 3). However, conflicting findings were also reported for such correlations. Among the 23 studies, 14 compared D3-Cr-estimated muscle with other body composition techniques, including magnetic resonance imaging (MRI) as a reference method. Strong and positive correlations were found between D3-Cr and MRI. Nonetheless, variations in muscle measurements were noted, with differences in D3-Cr values ranging from 0.62 kg lower to 13.47 kg higher compared to MRI.

Conclusions: D3-Cr-estimated muscle mass may be a valuable predictor of clinical outcomes showing consistent associations with falls and fractures, mobility disability, and mortality. However, less consistent associations were found with muscle strength and composition, and physical performance. Although a strong correlation exists between D3-Cr-estimated muscle mass and MRI measurements, under- or overestimation may occur.

Background: Pain is associated with reports of restricted physical activity (PA), yet the association between musculoskeletal pain characteristics and objectively measured PA quantities and patterns in late life is not well understood.

Methods: A total of 553 adults (mean age 75.8 ± 8.4 years, 54.4% women) in the Baltimore Longitudinal Study of Aging (BLSA) completed a health interview and subsequent 7-day wrist-worn ActiGraph assessment in the free-living environment between 2015 and 2020. Pain characteristics, including pain presence in 6x sites (ie, shoulders, hands/wrists, low back, hip, knees, and feet), pain laterality in each site, and pain distribution were assessed. PA metrics were summarized into total daily activity counts (TAC), activity fragmentation, active minutes/day, and diurnal patterns of activity. Linear regression models and mixed-effects models examined the association between pain characteristics and PA outcomes, adjusted for demographics and comorbidities.

Results: Unilateral knee pain was associated with 184 070 fewer TAC (p = .039) and 36.2 fewer active minutes/day (p = .032) compared to those without knee pain. Older adults with shoulder pain or hand/wrist pain had more active minutes compared to those without pain (p < .05 for all). For diurnal patterns of activity, participants with knee pain had fewer activity counts during the afternoon (12:00 pm to 5:59 pm). Analyses stratified by sex showed that these associations were only significant among women.

Conclusions: Our study highlights the importance of assessing pain laterality in addition to pain presence and suggests that pain interferes with multiple aspects of daily activity. Longitudinal studies are needed to assess the temporality of these findings.

The age-related decline in muscle mitochondrial energetics contributes to the loss of mobility in older adults. Women experience a higher prevalence of mobility impairment compared to men, but it is unknown whether sex-specific differences in muscle energetics underlie this disparity. In the Study of Muscle, Mobility and Aging (SOMMA), muscle energetics were characterized using in vivo phosphorus-31 magnetic resonance spectroscopy and high-resolution respirometry of vastus lateralis biopsies in 773 participants (56.4% women, age 70-94 years). A Short Physical Performance Battery (SPPB) score ≤8 was used to define lower-extremity mobility impairment. Muscle mitochondrial energetics were lower in women compared to men (eg, Maximal Complex I&II OXPHOS: Women = 55.06 ± 15.95; Men = 65.80 ± 19.74; p < .001) and in individuals with mobility impairment compared to those without (eg, Maximal Complex I&II OXPHOS in women: SPPB ≥ 9 = 56.59 ± 16.22; SPPB ≤ 8 = 47.37 ± 11.85; p < .001). Muscle energetics were negatively associated with age only in men (eg, Maximal ETS capacity: R = -0.15, p = .02; age/sex interaction, p = .04), resulting in muscle energetics measures that were significantly lower in women than men in the 70-79 age group but not the 80+ age group. Similarly, the odds of mobility impairment were greater in women than men only in the 70-79 age group (70-79 age group, odds ratio [OR]age-adjusted = 1.78, 95% confidence interval [CI] = 1.03, 3.08, p = .038; 80+ age group, ORage-adjusted = 1.05, 95% CI = 0.52, 2.15, p = .89). Accounting for muscle energetics attenuated up to 75% of the greater odds of mobility impairment in women. Women had lower muscle mitochondrial energetics compared to men, which largely explain their greater odds of lower-extremity mobility impairment.

Background: Motoric cognitive risk syndrome (MCR) is a predementia condition that combines slow gait speed and subjective cognitive concerns (SCC). The SCC criterion is presently unstandardized, possibly limiting risk detection. We sought to (a) characterize SCC practices through MCR literature review; (b) investigate the ability of SCC in slow gait individuals in predicting the likelihood of cognitive impairment in a demographically diverse sample of community-dwelling, nondemented older adults.

Methods: First, we comprehensively reviewed the MCR literature, extracting information regarding SCC measures, items, sources, and cognitive domain. Next, Einstein Aging Study (EAS) participants (N = 278, Mage = 77.22 ± 4.74, %female = 67, Meducation = 15 ± 3.61, %non-Hispanic White = 46.3) completed gait, Clinical Dementia Rating Scale (CDR), and SCC assessment at baseline and annual follow-up (Mfollow-up = 3.5). Forty-two participants met slow gait criteria at baseline. Generalized linear mixed-effects models examined baseline SCC to predict cognitive impairment on CDR over follow-up.

Results: We reviewed all published MCR studies (N = 106) and documented ambiguity in SCC criteria, with a prevalent approach being use of a single self-reported memory item. In EAS, high SCC endorsement on a comprehensive, validated screen significantly affected the rate of cognitive impairment (CDR; βinteraction = 0.039, p = .018) in slow gait individuals.

Conclusions: An assessment approach that queries across numerous SCC domains was found to predict future decline in clinical dementia status in slow gait older adults. Current SCC practices in MCR, which tend to utilize a single-memory item, may not be the optimal approach. We discuss the implications of SCC criteria validation and standardization to enhance early dementia detection in MCR.

Background: Older adults have the highest rates of head injury and are at the greatest risk for subsequent dysfunction, yet research on subsequent physical decline is limited. We sought to examine cross-sectional and prospective associations of head injury with physical functioning and frailty among older adults.

Methods: A total of 5 598 Atherosclerosis Risk in Communities Study participants from Visit 5 (2011-13) underwent assessments of physical functioning (Short Physical Performance Battery [SPPB], comprised of gait speed, chair stands, and balance) and frailty (defined using established criteria) were followed through Visit 7 (2018-19). Head injury was self-reported or based on ICD-9 codes. Adjusted linear and multinomial logistic regression models were used to estimate associations. Prospective models incorporated inverse probability of attrition weights to account for death or attrition.

Results: Participants were a mean age of 75 years, 58% were women, 22% were Black, and 27% had a prior head injury. Compared to individuals without head injury, individuals with head injury had worse physical functioning (SPPB total score, β-coefficient = -0.22, 95% CI: -0.35 to -0.09) and were more likely to be pre-frail (OR = 1.19, 95% CI: 1.04 to 1.35) or frail (OR = 1.40, 95% CI: 1.08 to 1.80) compared to robust. Prospectively, head injury was associated with a 0.02 m/s greater decline (95% CI: -0.04 to -0.01) in gait speed over a median of 5 years. Among baseline robust individuals (n = 1 847), head injury was associated with increased odds of becoming pre-frail (OR = 1.32, 95% CI: 1.04 to 1.67) or frail (OR = 1.92, 95% CI: 1.05 to 3.51) compared to robust.

Conclusions: Older adults with prior head injury had worse physical functioning and greater frailty at baseline and were more likely to become frail and walk slower over time, compared to individuals without head injury.

Epigenetic age is an emerging marker of health that is highly predictive of disease and mortality risk. There is a lack of evidence on whether lifestyle changes are associated with changes in epigenetic aging. We used data from 1 041 participants in the Melbourne Collaborative Cohort Study with blood DNA methylation measures at baseline (1990-1994, mean age: 57.4 years) and follow-up (2003-2007, mean age: 68.8 years). The Alternative Healthy Eating Index-2010 (AHEI-2010), the Mediterranean Dietary Score, and the Dietary Inflammatory Index were used as measures of diet quality, and weight, waist circumference, and waist-to-hip ratio as measures of body size. Five age-adjusted epigenetic aging measures were considered: GrimAge, PhenoAge, PCGrimAge, PCPhenoAge, and DunedinPACE. Multivariable linear regression models including restricted cubic splines were used to assess the cross-sectional and longitudinal associations of body size and diet quality with epigenetic aging. Associations between weight and epigenetic aging cross-sectionally at both time points were positive and appeared greater for DunedinPACE (per SD: β ~0.24) than for GrimAge and PhenoAge (β ~0.10). The longitudinal associations with weight change were markedly nonlinear (U-shaped) with stable weight being associated with the lowest epigenetic aging at follow-up, except for DunedinPACE, for which only weight gain showed a positive association. We found negative, linear associations for AHEI-2010 both cross-sectionally and longitudinally. Other adiposity measures and dietary scores showed similar results. In middle-aged to older adults, declining diet quality and weight gain may increase epigenetic age, while the association for weight loss may require further investigation. Our study sheds light on the potential of weight management and dietary improvement in slowing aging processes.

Background: The prognostic implication of cholesterol levels in older adults remains uncertain. This study aimed to examine the relationship between low-density-lipoprotein cholesterol (LDL-c) and mortality outcomes in older individuals.

Methods: This post hoc analysis examined the associations of LDL-c levels with mortality risks from all-cause, cardiovascular disease (CVD), cancer, and combined non-CVD/noncancer conditions in a cohort of individuals aged ≥65 years from the ASPirin in Reducing Events in the Elderly trial (NCT01038583). At baseline, participants had no diagnosed dementia, physical disability, or CVD, and were not taking lipid-lowering agents. Outcome analyses were performed using multivariable Cox models.

Results: We analyzed 12 334 participants (mean age: 75.2 years). Over a median 7-year follow-up, 1 250 died. Restricted cubic splines found a U-shaped relation for LDL-c and all-cause mortality, cancer mortality, and noncancer/non-CVE mortality (nadir: 3.3-3.4 mmol/L); the risk of CVD mortality was similar at LDL-c below 3.3 mmol/L and increased above 3.3 mmol/L. Similar trends were observed in analyses modeling LDL-c by quartiles. When modeling LDL-c as a continuous variable, the risk of all-cause mortality, cancer mortality, and noncancer/non-CVD mortality was decreased by 9%, 16%, and 18%, respectively, per 1-mmol/L higher LDL-c, and the risk of CVD mortality was increased by 19% per 1-mmol/L higher LDL-c. Reduced all-cause and non-CVD/noncancer mortality risks were only significant in males but not females (pinteraction < .05).

Conclusions: There were U-shaped relationships between LDL-c and all-cause mortality, cancer mortality, and noncancer/non-CVD mortality in healthy older adults. Higher LDL-c levels were associated with an increased risk of CVD mortality. Future studies are warranted to confirm our results.

Background: How magnetic resonance (MR) derived thigh muscle volume and deuterated creatine dilution derived muscle mass (D3Cr muscle mass) differentially relate to strength, fitness, and other functions in older adults-and whether associations vary by sex-is not known.

Methods: Men (N = 345) and women (N = 482) aged ≥70 years from the Study of Muscle, Mobility, and Aging completed leg extension strength (1-repetition max) and cardiopulmonary exercise testing to assess fitness (VO2peak). Correlations and adjusted regression models stratified by sex were used to assess the association between muscle size measures, study outcomes, and sex interactions.

Results: D3Cr muscle mass and MR thigh muscle volume were correlated (men: r = 0.62, women: r = 0.51, p < .001). Each standard deviation (SD) decrement in D3Cr muscle mass was associated with lower 1-repetition max strength (-14 kg men, -4 kg women, p < .001 for both; p-interaction = .003) and lower VO2peak (-79 mL/min men, -30 mL/min women, p < .001 for both, p-interaction: .016). Each SD decrement in MR thigh muscle volume was also associated with lower strength (-32 kg men, -20 kg women, p < .001 for both; p-interaction = .139) and lower VO2peak (-217 mL/min men, -111 mL/min women, p < .001 for both, p-interaction = .010). There were associations, though less consistent, between muscle size or mass with physical performance and function; associations varied by sex.

Conclusions: Less muscle-measured by either D3Cr muscle mass or MR thigh muscle volume-was associated with lower strength and fitness. Varied associations by sex and assessment method suggest consideration be given to which measurement to use in future studies.