Relationship between measures of balance and strength in middle-aged adults

The purpose of this study was to investigate the relationship between variables of static and dynamic postural control as well as between isometric and dynamic muscle strength. A single-group design was used. Thirty-two middle-aged healthy adults (mean age: 56 ± 4 years) performed measurements of static (unperturbed)/dynamic (perturbed) balance and of isometric (i.e., maximal isometric torque [MIT]; rate of torque development [RTD] of the plantar flexor)/dynamic (i.e., countermovement jump [CMJ] height and power) lower extremity muscle strength. No significant associations were observed between variables of static and dynamic postural control (r = +0.128-0.341, p > 0.05) and between measures of balance and strength (r = -0.189 to +0.316, p > 0.05). Significant positive correlations were detected between variables of isometric and dynamic strength ranging from r = +0.361 to +0.501 (p < 0.05). Further, simple regression analyses revealed that a 10% increase in the mean CMJ height (3.1 cm) was associated with 44.4 N·m and 118.4 N·m·s better MIT and RTD, respectively. The nonsignificant correlations between static and dynamic balance measures and between balance and strength variables imply that static and dynamic postural control and balance and strength are independent of each other and may have to be tested and trained complementarily.     

Inter-scorer reliability of sleep assessment using EEG and EOG recording system in comparison to polysomnography

Sleep and Biological Rhythms - There are increasing needs for self-applicable methods assessing sleep in clinical and non-clinical settings. This study aimed to investigate the inter-scorer...     

Habitual sleep initiation time and metabolic syndrome in middle-aged and elderly adults

This study aimed to examine the association between habitual types of sleep initiation time and metabolic syndrome. A total of 2674 participants aged 40 to 69 years (48.73% men, mean age 48.33 ± 7.18 years), who were free of cardiovascular disease or cancer and were not shift workers, participated in this population-based cross-sectional study embedded within the Korean Genome Epidemiology Study (KoGES). Based on at baseline and the last visit, the study participants were classified into four types of sleep initiation time: persistent late sleep (PLS), persistent usual sleep (PUS), persistent early sleep (PES), and non-persistent sleep (NPS) types. Metabolic syndrome was defined as having three or more of the following five criteria: abdominal obesity, impaired glucose intolerance, high blood pressure, high triglyceride, and low high-density lipoprotein-cholesterol. Among the 2674 study participants, the prevalence of metabolic syndrome was 865 (32.35%). To estimate the association between sleep initiation time and the risk of having metabolic syndrome, we constructed multivariable logistic regression models. After adjusting for covariates including sleep duration, the participants of the PLS type were 1.87 times more likely to have metabolic syndrome (odds ratio = 1.87, 95% confidence interval 1.07–3.27) than those of the PES type. In conclusion, in this population-based cross-sectional study, we observed that the PLS type of sleep initiation time had a significantly increased risk of metabolic syndrome as compared to the PES type, even after adjusting for covariates.

     

Root caries incidence and associated risk factors in middle-aged and older adults

Data from population-based longitudinal studies required to assess the incidence of root caries and associated risk factors are sparse in the literature. To this end, a group of 130 middle-aged and older adults were examined for root caries at baseline and at a follow-up visit between nine and 24 months (median: 16 months). Dental examinations were conducted by one examiner at a Tufts dental clinic using NIDR defined diagnostic criteria. Fifty percent of subjects in this study population developed one or more new root caries lesions over the follow-up period. Also, an annualised increment of 0.60 (SD: 0.72) decayed and filled surfaces per person was observed for the 45–59 year old group while the 70+ group showed an annualised increment of 1.38 (SD: 1.97) DFS in this study. Multivariate logistic regression analysis identified past root caries experience, high plaque score, and high number of teeth (>= 22) to be positively associated with new root caries (p < 0.05).     

Gender-related differences in susceptibility to oxidative stress in healthy middle-aged Serbian adults

Gender-related differences in the association between polymorphism of xenobiotic-metabolising enzymes or non-genetic biomarkers and susceptibility to oxidative stress was assessed in healthy middle-aged Serbian adults, by urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG/creatinine) and total antioxidant status in serum (TAOS). Females were more susceptible to oxidative stress. In both genders, positive predictor of the antioxidative protection was serum triglyceride, while BMI?<25?kg/m² was associated with oxidative stress. Susceptibility to oxidative stress in males was associated with GSTT1*null allele and increased serum iron, but in females, it was decreased serum bilirubin. Early identification of the risk factors could be important in the prevention of oxidative stress-related diseases.     

Bursting TENS increases walking endurance more than continuous TENS in middle-aged adults

The application of transcutaneous electrical nerve stimulation (TENS) can improve motor performance in both healthy individuals and those who present with clinically detectable sensory impairments. The purpose of our study was to compare the influence of continuous and intermittent TENS applied to the anterior thigh and tibialis anterior muscles on walking endurance and kinematics in healthy, middle-aged adults. Twenty-seven participants completed 4 trials of the 6-min walk test: Baseline, Continuous TENS (0.2 ms pulses at 50 Hz), Fast burst TENS (seven 0.15 ms pulses in 5 Hz bursts), and Slow burst TENS (seven 0.15 ms pulses in 0.5 Hz bursts). Linear mixed-effects models revealed that participants walked further (p ≤ 0.046) during all three TENS trials compared with Baseline (560 ± 76 m) and that they walked even further during both burst TENS trials (576 ± 83 m and 576 ± 83 m) compared with Continuous TENS (566 ± 79 m). Increases in walking speed were predicted by increases in stride length (p < 0.001) and stride frequency (p < 0.001) with toe-off angle being the only significant predictor (p ≤ 0.013) of both kinematic variables for the increase in walking speed. Bursting TENS was more effective than Continuous TENS at improving walking endurance in middle-aged, healthy adults.     

Relative reduced plasma zinc concentration in middle-aged but not elderly adults in Taiwan

Zinc is an essential micronutrient and its deficiency relates to many diseases like diabetes mellitus. Although zinc deficiency has become prevalent in many countries, this subject has not yet been studied in Taiwan. The present study was designed to investigate whether healthy elderly Taiwanese have reduced circulating zinc concentrations. Forty-three men and ninety women whose ages were >60 yr were recruited. Moreover, 31 middle-aged (30–40 yr) adults were also included in this study. The results showed that most of the elderly adults had normal plasma zinc values and suggested that they should not have any zinc deficiency. However, we also found that the middle-aged adults had relative hypozincemia, which might deserve further study.     

A dose-response investigation of the benefits of napping in healthy young,middle-aged and older adults

Older adults experience more fragmented sleep, greater daytime sleepiness and, nap more often than younger adults. Little research has investigated the effects of napping on waking function in older adults. In the present study, waking cognitive performance was examined in 10 young (mean age = 28 years), 10 middle-aged (mean age = 42 years) and 12 older adults (mean age = 61 years) following 60-min, 20-min and no nap conditions. It was expected that the older adults would need a longer nap to accrue benefits. Napping led to improvements for all age groups in subjective sleepiness, fatigue and accuracy on a serial addition/subtraction task. Waking electroencephalogram (EEG) confirmed that the participants were more physiologically alert following naps. There were no age differences in subjective reports or cognitive tasks; however, older adults had higher beta and gamma in the waking EEG, suggesting that they needed increased effort to maintain performance. Overall, older adults had smaller P2 amplitudes, reflecting their difficulty in inhibiting irrelevant stimuli, and delayed latencies and smaller amplitude P300s to novel stimuli, reflecting deficits in their frontal lobe functioning. Although older adults did garner benefits from napping, there was no evidence that they required longer naps to experience improvement.

     

Association between weekend catch-up sleep and the risk of depression among Korean middle-aged adults

Sleep and Biological Rhythms - Determining whether weekend catch-up sleep (CUS) is related to high risk of depression in the general middle-aged population in Korea. This study is a cross-sectional...     

Validity of six activity monitors in chronic obstructive pulmonary disease: a comparison with indirect calorimetry

Reduced physical activity is an important feature of Chronic Obstructive Pulmonary Disease (COPD). Various activity monitors are available but their validity is poorly established. The aim was to evaluate the validity of six monitors in patients with COPD. We hypothesized triaxial monitors to be more valid compared to uniaxial monitors. Thirty-nine patients (age 68±7 years, FEV(1) 54±18%predicted) performed a one-hour standardized activity protocol. Patients wore 6 monitors (Kenz Lifecorder (Kenz), Actiwatch, RT3, Actigraph GT3X (Actigraph), Dynaport MiniMod (MiniMod), and SenseWear Armband (SenseWear)) as well as a portable metabolic system (Oxycon Mobile). Validity was evaluated by correlation analysis between indirect calorimetry (VO(2)) and the monitor outputs: Metabolic Equivalent of Task [METs] (SenseWear, MiniMod), activity counts (Actiwatch), vector magnitude units (Actigraph, RT3) and arbitrary units (Kenz) over the whole protocol and slow versus fast walking. Minute-by-minute correlations were highest for the MiniMod (r?=?0.82), Actigraph (r?=?0.79), SenseWear (r?=?0.73) and RT3 (r?=?0.73). Over the whole protocol, the mean correlations were best for the SenseWear (r?=?0.76), Kenz (r?=?0.52), Actigraph (r?=?0.49) and MiniMod (r?=?0.45). The MiniMod (r?=?0.94) and Actigraph (r?=?0.88) performed better in detecting different walking speeds. The Dynaport MiniMod, Actigraph GT3X and SenseWear Armband (all triaxial monitors) are the most valid monitors during standardized physical activities. The Dynaport MiniMod and Actigraph GT3X discriminate best between different walking speeds.     

A population-based study of attention deficit/hyperactivity disorder symptoms and associated impairment in middle-aged adults

Attention deficit/hyperactivity disorder (ADHD) is the most prevalent childhood psychiatric condition. It frequently persists into adulthood and can have serious health and other adverse consequences. The majority of previous adult ADHD studies have focused on young adults so that relatively little is known about ADHD symptoms and their effects in mid and late life. In addition, effects of subclinical levels of attention deficit and hyperactivity have not been studied in detail. In this study we investigated ADHD symptoms and related impairment in a large population-based sample of middle-aged Australian adults (n = 2091; 47% male). Applying the WHO adult ADHD Self Report Screener (ASRS) we observed that 6.2% of participants had scores that were previously associated with ADHD diagnosis. No significant gender difference in the distribution of ASRS scores was observed. Multiple regression analyses indicated strong positive correlations between symptoms of ADHD and depression/anxiety and significant negative associations (p<0.01) with employment, financial stress, relationship quality, health and well-being measures in this age group. Importantly, associations were highly significant even when few ADHD symptoms were reported. Compared to the hyperactivity component, the inattention trait was particularly strongly associated and remained significant after controlling for depression/anxiety symptoms. Our study confirms previous findings and significantly adds to existing literature especially for an age-group that has not been well-studied. Our results suggest that ADHD symptoms continue to be associated with ill-health and functional impairment in mid-life and are, therefore, likely to be a major, previously unrecognized source of late-life morbidity with associated social and economic costs. Thus, there is a compelling need for better understanding and development of age-appropriate approaches to the diagnosis and treatment of ADHD in mid- to late-life.     

A comparison of deoxynivalenol intake and urinary deoxynivalenol in UK adults

The relationship between deoxynivalenol (DON) intake and first morning urinary DON was examined in UK adults to validate the latter as a biomarker of human exposure. DON was assessed in first morning samples collected during a period of normal diet, a wheat-restriction intervention diet, and partial wheat-restriction intervention in which bread was allowed. During the partial intervention duplicate bread portions were collected for DON analysis. During the normal diet, partial intervention and full intervention, urinary DON was detected in 198/210 (geometric mean 10.1?ng DON mg^?1 creatinine, 95% confidence interval (CI) 8.6–11.6?ng mg^?1; range nd–70.7?ng mg^?1), in 94/98 (5.9?ng mg^?1, 95% CI 4.8–7.0?ng mg^?1; range nd–28.4?ng mg^?1), and 17/40 (0.5?ng mg^?1, 95% CI 0.3–0.7?ng mg^?1; range nd–3.3?ng mg^?1) volunteers, respectively. A strong correlation between DON intake and the urinary biomarker was observed (p <0.001, adjusted r²?=?0.83) in models adjusting for age, sex and body mass index. These data demonstrate a quantitative correlation between DON exposure and urinary DON, and serve to validate the use of urinary DON as an exposure biomarker.     

Characterizing upper limb muscle volume and strength in older adults: a comparison with young adults

Aging is associated with the loss of muscle volume (MV) and force leading to difficulties with activities of daily living. However, the relationship between upper limb MV and joint strength has not been characterized for older adults. Quantifying this relationship may help our understanding of the functional declines of the upper limb that older adults experience. Our objective was to assess the relationship between upper limb MV and maximal isometric joint moment-generating capacity (IJM) in a single cohort of healthy older adults (age ≥ 65 years) for 6 major functional groups (32 muscles). MV was determined from MRI for 18 participants (75.1±4.3 years). IJM at the shoulder (abduction/adduction), elbow (flexion/extension), and wrist (flexion/extension) was measured. MV and IJM measurements were compared to previous reports for young adults (28.6±4.5 years). On average older adults had 16.5% less total upper limb MV compared to young adults. Additionally, older adult wrist extensors composed a significantly increased percentage of upper limb MV. Older adult IJM was reduced across all joints, with significant differences for shoulder abductors (p<0.0001), adductors (p=0.01), and wrist flexors (p<0.0001). Young adults were strongest at the shoulder, which was not the case for older adults. In older adults, 40.6% of the variation in IJM was accounted for by MV changes (p≤0.027), compared to 81.0% in young adults. We conclude that for older adults, MV and IJM are, on average, reduced but the significant linear relationship between MV and IJM is maintained. These results suggest that older adult MV and IJM cannot be simply scaled from young adults.     

Cognitive deficits are associated with frontal and temporal lobe white matter lesions in middle-aged adults living in the community

Background

The association between brain white matter lesions and cognitive impairment in old age is well established. However, little is known about this association in midlife. As this information will inform policy for early preventative healthcare initiatives, we investigated non-periventricular frontal, temporal, parietal and occipital lobe white matter hyperintensities (WMH) in relation to cognitive function in 428 (232 women) community-dwelling adults aged 44 to 48 years.

Results

Frontal white matter lesions were significantly associated with greater intraindividual RT variability in women, while temporal WMH were associated with face recognition deficits in men. Parietal and occipital lobe lesions were unrelated to cognitive performance. These findings did not differ when education and a range of health variables, including vascular risk factors, were taken into account.

Conclusion

Gender differences in WMH-cognition associations are discussed, and we conclude that small vessel disease is present in midlife and has functional consequences which are generally not recognized. Preventative strategies should, therefore, begin early in life.     

Testosterone prevents but not reverses anhedonia in middle-aged males and lacks an effect on stress vulnerability in young adults

Middle-aged male rats are more vulnerable than young adult ones to develop anhedonia when exposed to chronic mild stress (CMS). Clinical studies support the idea that in aged subjects the low testosterone (T) levels are related with their higher stress vulnerability and that this hormone possesses antidepressant-like actions. In this study we evaluated the role of gonadal hormones--mainly T--on the depressive-like behavior of middle-aged and young adult male rats submitted to CMS. In middle-aged rats we analyzed the effect of T restitution (at the levels of young adult animals) given 3 weeks before (experiment 1) or 3 weeks after (experiment 2) anhedonia development (indicated by a reduction in sucrose solution intake). T restitution before CMS effectively prevented anhedonia but failed to reverse it once installed. In young adult rats we studied if orchidectomy increased stress vulnerability and found that it failed to modify sucrose intake. These results indicate a stress-dependent differential effect of T in middle-aged rats an age differential role of gonadal hormones on the vulnerability to develop anhedonia. The results suggest that T is a resilience factor in middle-aged but not in young adult males.     

Comparing in-lab full polysomnography for diagnosing sleep apnea in children to home sleep apnea tests (HSAT) with an online video attending technician

Sleep and Biological Rhythms - The main study aim was to compare the validity of children sleep apnea data obtained from standard polysomnography (PSG) to a home sleep apnea test (HSAT) accompanied...     

Longitudinal impact of physical activity on lipid profiles in middle-aged adults: the Atherosclerosis Risk in Communities Study

Evidence exists that increased levels of physical activity decrease the population burden of cardiovascular disease (CVD). Although risk factors for CVD, including plasma lipids and lipoproteins, have been associated with physical activity, studies including a sizeable number of minority participants are lacking. Our purpose was to interrogate the longitudinal effect of physical activity on plasma lipids and lipoproteins in the African American and white participants of the Atherosclerosis Risk in Communities (ARIC) Study. Nine years of follow-up data on 8,764 individuals aged 45–64 years at baseline were used in linear mixed-effects models to estimate the association between increases in baseline physical activity on mean change in HDL, LDL, total cholesterol, and triglyceride levels. Increases in the level of activity were associated with increases in HDL in all strata and decreases in triglycerides among white participants. Physical activity was associated with LDL in all women, while the association with total cholesterol was limited to African American women. This study is one of the few to investigate the effect of physical activity on lipids and lipoproteins in a race- and sex-specific manner. Overall our results highlight the importance of physical activity on plasma lipid profiles and provide evidence for novel differential associations.     

Spider monkey home ranges: A comparison of radio telemetry and direct observation

The ranging patterns of two male and five female spider monkeys (Ateles geoffroyi) were studied with the use of radio telemetry in Santa Rosa National Park, Costa Rica. The average size of a spider monkey home range was 62.4 hectares; however, range size varied with sex, and, for females, with the presence of a dependent infant. The probability of encountering a radio-collared spider monkey in a three-hour search using radio telemetry (0.91) was much greater than using a visual search (0.20), and telemetric data resulted in a larger estimate of mean home range size than did observational data, when all subjects were compared. However, the difference appeared to be owing to the presence of male ranges in the telemetric, but not the observational, data. When the size of home ranges derived from radio-tracking data for adult females was compared to size of ranges for adult females derived from observations, the results were not significantly different. Adult males had larger home ranges than adult females, thus lending support to the hypothesis that males have adapted to the dispersion of females by occupying a large home range that overlaps the ranges of several adult females. The smallest home ranges were occupied by low-weight females with dependent infants, perhaps reflecting social and energetic constraints.