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Association of resting energy expenditure and nutritional substrate oxidation with COPD stage and prediction indexes.
Kovarik, M, Najpaverova, S, Koblizek, V, Zadak, Z, Hronek, M
Respiratory medicine. 2020;:106174
Abstract
While increase in resting energy expenditure (REE) of COPD patients is generally accepted, there is a lack of information about nutritional substrates oxidation (NSO) in this specific population. The aim of this study was comparison of REE and NSO from indirect calorimetry between COPD patients and control subjects and to evaluate possible associations with the disease stage and prediction indexes. In this observational study, 50 consecutive outpatients with stable COPD (COPD group) were examined and compared with 25 volunteers without respiratory problems (control group). Body composition, REE and NSO were determined in all study participants. All COPD subjects underwent a comprehensive examination to determine COPD severity and prognostic scales. Measured REE values adjusted for body weight, fat-free mass (FFM), and body surface were approximately 10% higher in COPD patients than in the control group. Respiratory quotient (RQ) and non-protein RQ (nRQ) values were respectively 5% and 10% higher in the COPD group. Adjusted carbohydrate oxidation was almost two times higher in comparison with the control group. We found no differences in absolute values of lipid and protein oxidation between the groups. Correlation analysis proved a positive association of relatively expressed REE and oxidation of lipids, and a negative association of RQ, nRQ and oxidation of carbohydrates with the value of prediction indexes. In conclusion, our study demonstrated metabolic changes in COPD patients leading to increased values of REE and changes in NSO which were associated with the disease stage, and which can be applied for nutritional support in clinical practice.
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The physiologic effects of a new generation conducted electrical weapon on human volunteers at rest.
Ho, JD, Dawes, DM, Kunz, SN, Klein, LR, Driver, BE, DeVries, PA, Jones, GA, Stang, JL
Forensic science, medicine, and pathology. 2020;(3):406-414
Abstract
Axon Enterprise, Inc. (Axon) released its newest generation conducted electrical weapon (CEW), the T7, in October 2018. In order to compare the effects of this new CEW to prior generations, we used our previously described methodology to study the physiologic effects of CEWs on human volunteers at rest. This was a prospective, observational study of human subjects consisting of two parts. Part 1 was testing a single cartridge (2-probe) exposure. Subjects received a 10-s exposure from the T7 to the back with a 30 cm (12 in.) spread between the two probes. Part 2 was testing a simultaneous two-cartridge (4-probe) exposure. Subjects received a 10-s exposure from the T7 to the back with two cartridges with a 10 cm (4 in.) spread between each probe pair. The probe pairs were arranged cephalad to caudal such that the distance between the top probe of the first cartridge and the bottom probe of the second cartridge was 30 cm (12 in.). Vital signs were measured immediately before and after the exposure. Continuous spirometry was performed. ECG monitoring was performed immediately before and after the exposure. Venous pH, lactate, potassium, CK, catecholamines, and troponin were measured before and immediately after the exposure, at 1-h post-exposure, and again at 24 h. 11 subjects completed part 1 of the study. 9 subjects completed part 2 of the study. No subjects had a dysrhythmia or morphology change in the surface ECG. There were no statistical changes in vital signs pre- and post-exposure. While subjects did not have a statistical change in spirometry parameters pre-exposure to exposure except for a small drop in PETCO2, there was an increase in minute ventilation after the exposure that could have several explanations. A similar pattern was seen with prior generation weapons. No subject had elevated troponin levels. Other blood parameters including venous pH, lactate, potassium, CK, and catecholamines had changes similar to prior generation weapons. Comparison of the data for the single-cartridge exposures against the simultaneous two-cartridge exposures yielded no difference in vital signs, but the minute ventilation was higher for the two-cartridge exposures. The blood data, where there was a difference, was mixed. In our study, the physiologic effects of the Axon T7 are modest, consistent with the electrically-induced motor nerve-driven muscle contraction, and were similar to prior generation weapons.
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Resting Heart Rate and Long-term Outcomes Among the African American Population: Insights From the Jackson Heart Study.
Parikh, KS, Greiner, MA, Suzuki, T, DeVore, AD, Blackshear, C, Maher, JF, Curtis, LH, Hernandez, AF, O'Brien, EC, Mentz, RJ
JAMA cardiology. 2017;(2):172-180
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Abstract
IMPORTANCE Increased resting heart rate is associated with worse outcomes in studies of mostly white populations, but its significance is not well established in African Americans persons whose cardiac comorbidities and structural abnormalities differ. OBJECTIVE To study the prognostic utility of heart rate in a community-based African American cohort in the Jackson Heart Study. DESIGN, SETTING, AND PARTICIPANTS A total of 5261 participants in the Jackson Heart Study, a prospective, community-based study in Jackson, Mississippi, were evaluated. Baseline heart rate was assessed by quintiles and as a continuous variable. All participants with baseline heart rate documented by a 12-lead electrocardiogram without pacing or atrial fibrillation noted on their baseline Jackson Heart Study examination were included in the study. Follow-up began September 26, 2000, and was completed December 31, 2011. Data analysis was performed from July to October 2015. MAIN OUTCOMES AND MEASURES Unadjusted and adjusted associations between heart rate and all-cause mortality and heart failure hospitalization using Cox proportional hazards regression models. RESULTS Of the 5261 individuals included in the analysis, 1921 (36.5%) were men; median (25th-75th percentile) age was 55.7 (45.4-64.8) years. Median (25th-75th percentile) baseline heart rate was 63 beats per minute (bpm) (57-71 bpm). The highest heart rate quintile (73-118 bpm) had higher rates of diabetes (398 [37.4%]; P < .001) and hypertension (735 [69.1%]; P < .001), higher body mass index (median [IQR], 32.4 [28.1-38.3]; P < .001), less physical activity (0 hours per week, 561 [52.8%]; P < .001), and lower β-blocker use (73 [6.9%]; P < .001) compared with lower quintiles. Caffeine intake (from 80.7 to 85.5 mg/d; P = .57) and left ventricular ejection fraction (from 62% to 62.3%; P = .01) were similar between groups. As a continuous variable, elevated heart rate was associated with increased mortality and heart failure hospitalizations, with adjusted hazard ratios for every 5-bpm increase of 1.14 (95% CI, 1.10-1.19) and 1.10 (95% CI, 1.05-1.16), respectively. Similar patterns were observed in comparisons between the highest and lowest quintiles. CONCLUSIONS AND RELEVANCE Higher baseline heart rate was associated with increased mortality and heart failure hospitalizations among African American participants in the Jackson Heart Study. These findings are similar to those seen in white populations, but further study is needed to understand whether African American individuals benefit from interventions targeting heart rate reduction.
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Individual Patterns in Blood-Borne Indicators of Fatigue-Trait or Chance.
Julian, R, Meyer, T, Fullagar, HH, Skorski, S, Pfeiffer, M, Kellmann, M, Ferrauti, A, Hecksteden, A
Journal of strength and conditioning research. 2017;(3):608-619
Abstract
Julian, R, Meyer, T, Fullagar, HHK, Skorski, S, Pfeiffer, M, Kellmann, M, Ferrauti, A, and Hecksteden, A. Individual patterns in blood-borne indicators of fatigue-trait or chance. J Strength Cond Res 31(3): 608-619, 2017-Blood-borne markers of fatigue such as creatine kinase (CK) and urea (U) are widely used to fine-tune training recommendations. However, predictive accuracy is low. A possible explanation for this dissatisfactory characteristic is the propensity of athletes to react to different patterns of fatigue indicators (e.g., predominantly muscular [CK] or metabolic [U]). The aim of the present trial was to explore this hypothesis by using repetitive fatigue-recovery cycles. A total of 22 elite junior swimmers and triathletes (18 ± 3 years) were monitored for 9 weeks throughout 2 training phases (low-intensity, high-volume [LIHV] and high-intensity, low-volume [HILV] phases). Blood samples were collected each Monday (recovered) and Friday (fatigued) morning. From measured values of CK, U, free-testosterone (FT), and cortisol (C) as determined in the rested and fatigued state, respectively, Monday-Friday differences (Δ) were calculated and classified by magnitude before calculation of ratios (ΔCK/ΔU and ΔFT/ΔC). Coefficient of variation (CV) was calculated as group-based estimates of reproducibility. Linear mixed modeling was used to differentiate inter- and intraindividual variability. Consistency of patterns was analyzed by comparing with threshold values (<0.9 or >1.1 for all weeks). Reproducibility was very low for fatigue-induced changes (CV ≥ 100%) with interindividual variation accounting for 45-60% of overall variability. Case-wise analysis indicated consistent ΔCK/ΔU patterns for 7 individuals in LIHV and 7 in HILV; 5 responded consistently throughout. For ΔFT/ΔC the number of consistent patterns was 2 in LIHV and 3 in HILV. These findings highlight the potential value of an individualized and multivariate approach in the assessment of fatigue.
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Resting heart rate as predictor for left ventricular dysfunction and heart failure: MESA (Multi-Ethnic Study of Atherosclerosis).
Opdahl, A, Ambale Venkatesh, B, Fernandes, VRS, Wu, CO, Nasir, K, Choi, EY, Almeida, ALC, Rosen, B, Carvalho, B, Edvardsen, T, et al
Journal of the American College of Cardiology. 2014;(12):1182-1189
Abstract
OBJECTIVES The objective of this study was to investigate the relationship between baseline resting heart rate and incidence of heart failure (HF) and global and regional left ventricular (LV) dysfunction. BACKGROUND The association of resting heart rate to HF and LV function has not been well described in an asymptomatic multi-ethnic population. METHODS Resting heart rate was measured in participants in the MESA (Multi-Ethnic Study of Atherosclerosis) trial at inclusion. Incident HF was registered (n = 176) during follow-up (median 7 years) in those who underwent cardiac magnetic resonance imaging (n = 5,000). Changes in ejection fraction (ΔEF) and peak circumferential strain (Δεcc) were measured as markers of developing global and regional LV dysfunction in 1,056 participants imaged at baseline and 5 years later. Time to HF (Cox model) and Δεcc and ΔEF (multiple linear regression models) were adjusted for demographics, traditional cardiovascular risk factors, calcium score, LV end-diastolic volume, and mass in addition to resting heart rate. RESULTS Cox analysis demonstrated that for 1 beat/min increase in resting heart rate, there was a 4% greater adjusted relative risk for incident HF (hazard ratio: 1.04; 95% CI: 1.02 to 1.06; p < 0.001). Adjusted multiple regression models demonstrated that resting heart rate was positively associated with deteriorating εcc and decrease in EF, even when all coronary heart disease events were excluded from the model. CONCLUSIONS Elevated resting heart rate was associated with increased risk for incident HF in asymptomatic participants in the MESA trial. Higher heart rate was related to development of regional and global LV dysfunction independent of subclinical atherosclerosis and coronary heart disease. (Multi-Ethnic Study of Atherosclerosis [MESA]; NCT00005487).