A Longitudinal Study of Neurocognition in Dementia with Lewy Bodies Compared to Alzheimer`s Disease

Introduction: There are relatively few longitudinal studies on the differences in cognitive decline between Alzheimer’s disease (AD) and dementia with Lewy bodies (DLB), and the majority of existing studies have suboptimal designs. Aim: We investigated the differences in cognitive decline in AD compared to DLB over 4 years and cognitive domain predictors of progression. Methods: In a longitudinal study, 266 patients with first-time diagnosis of mild dementia were included and followed annually. The patients were tested annually with neuropsychological tests and screening instruments [MMSE (Mini-Mental Status Examination), Clinical Dementia Rating (CDR), the second edition of California Verbal Learning Test (CVLT-II), Trail Making Test A & B (TMT A & B), Stroop test, Controlled Oral Word Associations Test (COWAT) animal naming, Boston Naming Test, Visual Object and Space Perception Battery (VOSP) Cubes and Silhouettes]. Longitudinal analyses were performed with linear mixed effects (LME) models and Cox regression. Both specific neuropsychological tests and cognitive domains were analyzed. Results: This study sample comprised 119 AD and 67 DLB patients. In TMT A, the DLB patients had a faster decline over 4 years than patients with AD (p = 0.013). No other longitudinal differences in specific neuropsychological tests were found. Higher executive domain scores at baseline were associated with a longer time to reach severe dementia (CDR = 3) or death for the total sample (p = 0.032). High or low visuospatial function at baseline was not found to be associated with cognitive decline (MMSE) or progression of dementia severity (CDR) over time. Conclusion: Over 4 years, patients with DLB had a faster decline in TMT A than patients with AD, but this should be interpreted cautiously. Beyond this, there was little support for faster decline in DLB patients neuropsychologically than in AD patients.publishedVersio

The relationship between workload and exercise-induced cardiac troponin elevations is influenced by non-obstructive coronary atherosclerosis

The relationship between exercise-induced troponin elevation and non-obstructive coronary artery disease (CAD) is unclear. This observational study assessed non-obstructive CAD's impact on exercise-induced cardiac Troponin I (cTnI) elevation in middle-aged recreational athletes. cTnI levels of 40 well-trained recreational athletes (73% males, 50 ± 9 years old) were assessed by a high-sensitive cTnI assay 24 h before, and at 3 and 24 h following two high-intensity exercises of different durations; a cardiopulmonary exercise test (CPET), and a 91-km mountain bike race. Workload was measured with power meters. Coronary computed tomography angiography was used to determine the presence or absence of non-obstructive (<50% obstruction) CAD. A total of 15 individuals had non-obstructive CAD (Atherosclerotic group), whereas 25 had no atherosclerosis (normal). There were higher post-exercise cTnI levels following the race compared with CPET, both at 3 h (77.0 (35.3–112.4) ng/L vs. 11.6 (6.4–22.5) ng/L, p < 0.001) and at 24 h (14.7 (6.7–16.3) vs. 5.0 (2.6–8.9) ng/L, p < 0.001). Absolute cTnI values did not differ among groups. Still, the association of cTnI response to power output was significantly stronger in the CAD versus Normal group both at 3 h post-exercise (Rho = 0.80, p < 0.001 vs. Rho = −0.20, p = 0.33) and 24-h post-exercise (Rho = 0.87, p < 0.001 vs. Rho = −0.13, p = 0.55). Exercise-induced cTnI elevation was strongly correlated with exercise workload in middle-aged athletes with non-obstructive CAD but not in individuals without CAD. This finding suggests that CAD influences the relationship between exercise workload and the cTnI response even without coronary artery obstruction.publishedVersio

Occult obstructive coronary artery disease is associated with prolonged cardiac troponin elevation following strenuous exercise

Background Sudden cardiac death among middle-aged recreational athletes is predominantly due to myocardial ischaemia. This study examined whether measuring cardiac troponin I and T (cTnI and cTnT) after strenuous exercise could identify occult obstructive coronary artery disease. Design Prospective observational study. Methods Subjects were recruited from 1002 asymptomatic recreational cyclists completing a 91-km mountain bike race (North Sea Race Endurance Exercise Study). No subject had known cardiovascular disease or took cardiovascular medication. Blood samples were collected within 24 h before and 3 h and 24 h after the race. Coronary computed tomography angiography was performed in 80 participants with the highest post-exercise cTnI and in 40 reference subjects with moderately elevated cTnI values. Results Study subjects (N = 120) were 45 (36–52) years old and 74% were male. There were similar demographics in the High-cTnI group and the Reference group. The cTn concentrations were highest at 3 h post-race: cTnI, 224 (125–304) ng/L; cTnT, 89 (55–124) ng/L. Nine subjects had obstructive coronary artery disease on coronary computed tomography angiography, eight of whom were High-cTnI responders. Two subjects had myocardial bridging, both High-cTnI responders. Troponin concentrations at 24 h post-race were higher in subjects with obstructive coronary artery disease than in the rest of the cohort (n = 109): cTnI, 151 (72–233) ng/L vs. 24 (19–82) ng/L, p = 0.005; cTnT, 39 (25–55) ng/L vs. 20 (14–31) ng/L, p = 0.002. The areas under the receiver operating characteristic curves for predicting obstructive coronary artery disease were 0.79, p = 0.005 (cTnI) and 0.82, p = 0.002 (cTnT). Conclusion In subjects with occult obstructive coronary artery disease there was a prolonged elevation of cTn following strenuous exercise.acceptedVersio

Duration of elevated heart rate Is an important predictor of exercise-induced troponin elevation

Background The precise mechanisms causing cardiac troponin (cTn) increase after exercise remain to be determined. The aim of this study was to investigate the impact of heart rate (HR) on exercise‐induced cTn increase by using sports watch data from a large bicycle competition. Methods and Results Participants were recruited from NEEDED (North Sea Race Endurance Exercise Study). All completed a 91‐km recreational mountain bike race (North Sea Race). Clinical status, ECG, blood pressure, and blood samples were obtained 24 hours before and 3 and 24 hours after the race. Participants (n=177) were, on average, 44 years old; 31 (18%) were women. Both cTnI and cTnT increased in all individuals, reaching the highest level (of the 3 time points assessed) at 3 hours after the race (P150 beats per minute was a significant predictor of both cTnI and cTnT, at both 3 and 24 hours after exercise. Neither mean HR nor mean HR in percentage of maximum HR was a significant predictor of the cTn response at 3 and 24 hours after exercise. Conclusions The duration of elevated HR is an important predictor of physiological exercise‐induced cTn elevation.publishedVersio

Endurance exercise training volume is not associated with progression of coronary artery calcification

Background Recent cross‐sectional studies have suggested a dose‐dependent relationship between lifelong exposure to physical activity and the burden of calcified coronary artery disease (CAD). No longitudinal studies have addressed this concern. Hypothesis Exercise volume is associated with progression of coronary artery calcium (CAC), defined as ≥10 units increase in CAC score. Methods Sixty‐one recreational athletes who were assessed by coronary computed tomography angiography (CCTA) as part of the NEEDED 2013/14 study were re‐assessed 4‐5 years later, in 2018. Results Subjects were 45.9 ± 9.6 years old at inclusion, and 46 (74%) were male. Between 2013 and 2018, the participants reported median 5 (range: 0‐20, 25th‐75th percentile: 4‐6) hours of high‐intensity exercise per week. None of the included subjects smoked during follow‐up. At inclusion, 21 (33%) participants had coronary artery calcifications. On follow‐up CCTA in 2018, 15 (25%) subjects had progressive coronary calcification (≥10 Agatston units increase in CAC). These subjects were older (53 ± 9 vs 44 ± 9 years old, P = .002) and had higher levels of low‐density lipoprotein at baseline (3.5 (2.9‐4.3) vs 2.9 (2.3‐3.5) mmol/L, P = .031) as compared to subjects with stable condition. No relationship was found between hours of endurance training per week and progression of coronary artery calcification. In multiple regression analysis, age and baseline CAC were the only significant predictors of progressive CAC. Conclusion No relationship between exercise training volume and the progression of coronary artery calcification was found in this longitudinal study of middle‐aged recreational athletes.publishedVersio

Echocardiographic assessment of myocardial efficiency predicts exercise performance

Cardiac function is a major determinant of cardiopulmonary fitness. This study aimed to determine if novel echocardiographic myocardial function and efficiency parameters at rest can predict exercise performance during different types of prolonged high-intensity endurance exercise. Echocardiography was performed before exercise in 40 healthy (75% males) 50.3 ± 9.1-year-old recreational athletes. Echocardiographic parameters at rest were compared with exercise performance assessed by power output during two different exercises: A lactate threshold and cardiopulmonary exercise test (La-CPET) and a 91-km mountain bike sport cycling race. The La-CPET had a median duration of 43 (40, 45) minutes and a mean power output of 2.9 ± 0.5 W/kg. The race had a median duration of 236 (214, 268) minutes and a mean power output of 2.1 ± 0.5 W/kg. There was moderate left ventricular (LV) dilatation in individuals with the highest performance. The myocardial efficiency parameter, global wasted work (GWW), was positively correlated with race duration (rho = 0.42, p = 0.008) and negatively correlated with mean power output during both the La-CPET (rho = −0.43, p = 0.007) and the race (rho = −0.44, p = 0.005). In multivariable models, including LV volumes, left GWW remained an independent predictor of race duration (beta = 0.40, p = 0.007) and of mean power output during the La-CPET (beta = −0.40, p = 0.006) and the race (beta = −0.43, p = 0.003). The novel echocardiographic myocardial efficiency parameter, GWW, measured at rest, is an independent predictor of prolonged high-intensity endurance exercise performance in healthy middle-aged athletes. These findings suggest that resting myocardial efficiency parameters may aid the identification of exercise-induced LV dilatation.publishedVersio

Low Recruitment in a Population of Brook Trout in a Norwegian Watershed—Is It Due to Dilution of the Water Chemistry?

Dilution of the water chemistry caused by reduced acidification has lately received increased attention, both in Europe and North America. There has also been a declining trend in the supply of sea salts. Several studies have predicted detrimental effects on aquatic life due to dilution. A population of brook trout living in River Hunnedal in southwestern Norway was studied for 14 years (2006–2019).Despite acceptable water chemistry with respect to pH and inorganic Al, limited reproduction was found. With median conductivity, Ca and Na of 7.1– 8.6 μScm−1, and 0.17–0.19 and 0.9–1.0 mgL−1, respectively, the water at the study sites was found to be extremely dilute. We detected a significant positive effect of Na on the densities of brook trout fry, while a less distinct effect of Ca was found. However, due to the correlation between Ca and Na we cannot conclude that Ca is unimportant. For all samplings without catch of fry (n = 13), Na was 0.86 ± 0.15 mgL−1, suggesting a critical limit for Na slightly below 1 mgL−1.We suggest that the reproduction of brook trout was restricted by the highly dilute water and the subsequent scarcity of essential ions. Acidification recovery . Water chemistry . Dilution . Calcium. Sodium. Mountain streams . Brook troutpublishedVersio

Low Recruitment in a Population of Brook Trout in a Norwegian Watershed—Is It Due to Dilution of the Water Chemistry?

Dilution of the water chemistry caused by reduced acidification has lately received increased attention, both in Europe and North America. There has also been a declining trend in the supply of sea salts. Several studies have predicted detrimental effects on aquatic life due to dilution. A population of brook trout living in River Hunnedal in southwestern Norway was studied for 14 years (2006–2019).Despite acceptable water chemistry with respect to pH and inorganic Al, limited reproduction was found. With median conductivity, Ca and Na of 7.1– 8.6 μScm−1, and 0.17–0.19 and 0.9–1.0 mgL−1, respectively, the water at the study sites was found to be extremely dilute. We detected a significant positive effect of Na on the densities of brook trout fry, while a less distinct effect of Ca was found. However, due to the correlation between Ca and Na we cannot conclude that Ca is unimportant. For all samplings without catch of fry (n = 13), Na was 0.86 ± 0.15 mgL−1, suggesting a critical limit for Na slightly below 1 mgL−1.We suggest that the reproduction of brook trout was restricted by the highly dilute water and the subsequent scarcity of essential ions. Acidification recovery . Water chemistry . Dilution . Calcium. Sodium. Mountain streams . Brook trou

Stress in School. Some Empirical Hints on the Circadian Cortisol of Children in Outdoor and Indoor Classes

This prospective longitudinal survey compared the stress levels of students taught using an outdoor curriculum in a forest, with children in a normal school setting. We were especially interested in the effect outdoor teaching might have on the children’s normal diurnal cortisol rhythm. 48 children (mean age = 11.23; standard deviation (SD) = 0.46) were enrolled, with 37 in the intervention group (IG), and 11 in the control group (CG). The intervention consisted of one full school day per week in the forest over the school year. Stress levels were measured in cortisol with three samples of saliva per day. Furthermore, the data allowed for statistical control of physical activity (PA) values. For data analysis, we used a linear mixed-effects model (LMM) with random intercept and general correlation matrix for the within-unit residuals. The LMM yields that IG have expected greater decline of cortisol compared to CG; rate 0.069 μg/L vs. 0.0102 μg/L (log-units/2 h), p = 0.009. PA does not show a statistically significant interaction with cortisol (p = 0.857), despite being higher in the intervention group (p < 0.001). The main effect in our measures was that the IG had a steady decline of cortisol during the school day. This is in accordance with a healthy child’s diurnal rhythm, with a significant decline of cortisol from morning to noon. This effect is constant over the school year. The CG does not show this decline during either measurement day. Further research is needed to fully explain this interesting phenomenon.publishedVersio

Race duration and blood pressure are major predictors of exercise-induced cardiac troponin elevation

Background The underlying mechanisms of the exercise-induced increase in cardiac troponins (cTn) are poorly understood. The aim of this study was to identify independent determinants of exercise-induced cTn increase in a large cohort of healthy recreational athletes. Methods A total of 1002 recreational cyclists without known cardiovascular disease or medication, participating in a 91-km mountain bike race were included. Median age was 47 years and 78% were males. Blood samples were obtained 24 h prior to, and 3 and 24 h after the race. Results Cardiac TnI concentrations increased markedly from baseline [1.9 (1.6–3.0) ng/L] to 3 h after the race [52.1 (32.4–91.8) ng/L], declining at 24 h after the race [9.9 (6.0–20.0) ng/L]. Similarly, cTnT increased from baseline [3.0 (3.0–4.2) ng/L] to 3 h after the race [35.6 (24.4–54.4) ng/L], followed by a decline at 24 h after the race [10.0 (6.9–15.6) ng/L]. The 99th percentile was exceeded at 3 h after the race in 84% (n = 842) of subjects using the cTnI assay and in 92% (n = 925) of study subjects using the cTnT assay. Shorter race duration and higher systolic blood pressure (SBP) at baseline were highly significant (p < 0.001) independent predictors of exercise-induced cTn increase both in bivariate and multivariable analysis. The age, gender, body mass index, training experience and cardiovascular risk of participants were found to be less consistent predictors. Conclusion Systolic blood pressure and race duration were consistent predictors of the exercise-induced cTn increase. These variables likely reflect important mechanisms involved in the exercise-induced cTn elevation.acceptedVersio