Author Archives: Paul Older

There was an attempt to hack our we bsite by a ROBOT

Dear all

On August 4th a ROBOT attempt to hack our website was detected and the site was immediately shut down. This means that some of our members would have received the abstract that was currently being sent out whilst others would not.

All the abstracts from August 4th to August 14th are on the website under the heading ‘Abstracts’ on the top menu bar. I am not sending them out but our normal service has now been re-established and you will start to receive abstracts again.

My regards and apologies

Paul Older

Feasibility and Validity of the 6-Minute Cycling Test in Childhood Cancer Patients.

Wypyrsczyk L; Johannes Gutenberg-University Mainz,  Germany
Kuhn M; Dreismickenbecker E; Neu MA; et al

Pediatric Hematology & Oncology. 43(5):227-240, 2026 Aug.
Headings by Dr Older

Background The 6-min cycling test (6MCT), a submaximal endurance test, has not yet
been applied in pediatric oncology. This study evaluates its feasibility
and validity in 71 childhood cancer patients (9.6 +/- 4.0 years).
Methods For validation, 46 patients additionally underwent cardiopulmonary exercise
testing (CPET). Performance in the 6MCT (total revolutions) was correlated
with peak oxygen uptake (VO2peak) and peak work rate (WRpeak) using
Spearman’s correlation. Linear regressions assessed the predictive value
of VO2peak and WRpeak on 6MCT performance. Sixty-six participants (93%)
successfully completed the 6MCT, averaging 550 +/- 129 revolutions.
Results Revolutions correlated moderately with VO2peak (rho = 0.46, p = 0.001) and
strongly with WRpeak (rho = 0.64, p < 0.001). VO2peak significantly
predicted 6MCT performance (p = 0.001, R2 = 0.214), whereas WRpeak
explained more variance (p < 0.001, R2 = 0.488).
Conclusions The results demonstrate that the 6MCT is a feasible, valid endurance assessment in this
population, offering a promising alternative when gold standard testing is
not available.

Time for proper physiological assessment: the role of cardiopulmonary exercise testing in helping step-up therapy in difficult-to-treat and severe asthma. [Review]

Floriani AF; S. Valentino Hospital, Montebelluna, Italy.
Menzella F

Expert Review of Respiratory Medicine. 20(8):963-974, 2026 Aug.

INTRODUCTION: Persistent exertional dyspnea remains a major unmet need in
patients with difficult-to-treat and severe asthma, even in the era of
optimized inhaled therapy and biologics. Resting lung function and
inflammatory biomarkers often fail to explain exercise intolerance,
leading to empirical step-up therapy without clear physiological
justification.

AREAS COVERED: This review discusses the role of cardiopulmonary exercise
testing (CPET) in the evaluation of exertional dyspnea in
difficult-to-treat and severe asthma, within the treatable traits
framework. The review focuses on the main CPET-derived physiological
patterns, including ventilatory limitation, dynamic hyperinflation,
ventilatory inefficiency, dysfunctional breathing, deconditioning,
cardiovascular limitation, exercise-induced laryngeal obstruction, and
normal exercise physiology. It also examines how CPET may influence
step-up decisions, support trait-directed interventions, and inform
pharmacoeconomic considerations. A pragmatic clinical framework for
selective integration of CPET into severe asthma assessment is proposed.

EXPERT OPINION: CPET may represent a valuable physiological adjunct in
selected patients with difficult-to-treat or severe asthma and persistent
exertional dyspnea insufficiently explained by resting assessments. Its
integration into the assessment pathway may help contextualize symptoms,
distinguish asthma-driven exercise limitation from non-inflammatory or
non-asthmatic causes of dyspnea, and support more mechanism-based
management. However, current evidence supports CPET primarily as a tool
for physiological phenotyping and trait reclassification rather than as a
prospectively validated guide to treatment escalation, biologic
stewardship, or long-term outcome improvement.

Type 2 Diabetes and Cognitive Dysfunction: Cardiorespiratory Fitness and Physical Activity Matters.

Rojas Vega S; German Sport University Cologne, Germany,
Solera-Herrera A; Vafa R; Acero-Moreno D; et al

Journal of Diabetes Research. 2026(1):e1311227, 2026.

BACKGROUND: Diabetes is associated with an increased risk of cognitive
dysfunction. We are aimed at examining cognitive performance in people
with Type 2 diabetes mellitus (T2DM) and their correlation with physical
activity (PA)/fitness level and mood.

METHODS: A cross-sectional study involving 47 individuals with T2DM, 30
diabetes-free individuals (controls): ages of 40-65 years and without
dementia. Subjects were evaluated using a neuropsychological test battery
that included Stroop, VLMT, CORSI, TMT and neuropsychiatric scales. The
Global Physical Activity Questionnaire (GPAQ) was assessed. Physical
fitness was evaluated using a maximal cardiopulmonary exercise testing
(CPX).

RESULTS: Compared with controls, people with T2DM had lower
cardiorespiratory fitness (CRF) and more frequent cognitive performance
below 1 SD of the normative value. Those individuals with T2DM, who
displayed low fitness, showed significantly poorer cognitive inhibition
(Stroop, p < 0.001), processing speed (TMT-A, p < 0.001), cognitive
flexibility (TMT-B, p < 0.001), visuospatial memory (CORSI, p < 0.001) and
memory consolidation (VLMT, p < 0.001). Higher ventilatory and metabolic
CRF markers and higher PA levels correlated significantly with higher
cognitive performance. None of the neuropsychological or psychiatric
background variables correlated significantly with any of the cognitive
scales.

CONCLUSIONS: Individual CRF markers and PA levels correlated positively
with cognitive performance in people with T2DM and in nondiabetic
individuals. However, individuals with T2DM showed at least two to three
times more frequent cognitive performances more than 1 SD below norm as
compared with controls. Among people with T2DM, those with low aerobic
fitness/PA levels showed significantly lower cognitive performance,
especially in the attention-concentration, executive functioning, episodic
memory and visuospatial processing domains.

Chronic thromboembolism phenotypes after acute pulmonary embolism: identification with the SEARCH algorithm.

Morris TA; University of California San Diego, La Jolla, CA, USA
Dakaeva K; Alotaibi M; McGuire WC; et al

European Respiratory Journal. 68(2), 2026 Aug.

BACKGROUND: Chronic dyspnoea and exercise impairment are common after
acute pulmonary embolism (PE) but poorly characterised. We performed a
prospective observational study to validate an algorithm to diagnose
discrete post-PE outcomes, including chronic thromboembolism phenotypes.

METHODS: Six pulmonologists independently reviewed records from 150
consecutive patients >=3 months after acute PE who had undergone a
stepwise diagnostic algorithm (SEARCH), which incorporates Symptom
screening, cardiopulmonary Exercise testing, pulmonary Arterial perfusion
scans, Resting echocardiography, Confirmatory imaging, and Haemodynamic
measurements by rest and exercise right heart catheterisation (RHC).
Clinical data were reviewed after the first post-PE evaluation and then 6
months later.

RESULTS: Symptomatic recovery was most common and occurred in 66.2% of
patients during the final evaluation. Dyspnoea without discernible
physiological defects occurred in 2.1% and dyspnoea from alternative
diagnoses in 19.7%. Chronic thromboembolism phenotypes were diagnosed in
12.0% of patients. Chronic thromboembolism with ventilatory inefficiency
and/or small stroke volume augmentation during exercise was seen in 6.3%:
2.1% without pulmonary hypertension on RHC and 4.2% in whom RHC was not
performed. Chronic thromboembolic pulmonary hypertension and chronic
thromboembolism with exercise-induced pulmonary hypertension occurred in
2.1% and 3.5%, respectively. Krippendorff’s alpha among the readers was
0.984 (95% CI 0.9663-0.9960), signifying very high diagnostic reliability.
No patient developed chronic thromboembolism between the first and final
evaluations.

CONCLUSIONS: Dyspnoea from chronic thromboembolism is common after acute
PE, most of which is not associated with pulmonary hypertension. The
SEARCH protocol reliably identifies chronic thromboembolism phenotypes
after acute embolism. Validation of the SEARCH algorithm offers clinicians
a straightforward method to diagnose post-PE conditions that are rarely
distinguished clinically. Improved categorisation and definition of
post-PE conditions will enhance clinical follow-up and allow more precise
end-point adjudication in clinical trials of acute PE treatment.

Mechanisms of dyspnoea and exercise intolerance in smokers with preserved ratio impaired spirometry.

Scussel A; Hospital de Clinicas de Porto Alegre, Brazil
Rodrigues NG; Santos AZ; Trombin LCB; et al

European Journal of Applied Physiology. 126(8):4567-4579, 2026 Aug.

PURPOSE: Smokers with preserved ratio impaired spirometry (PRISm) present
reduced forced expiratory volume in the first second (FEV1 < 80%
predicted) but preserved FEV1/forced vital capacity (FVC) >= 0.7. Although
they do not meet diagnostic criteria for chronic obstructive pulmonary
disease (COPD), they often report respiratory symptoms and exercise
intolerance. We aimed to compare sensory and physiological responses to
exercise between smokers with PRISm and matched healthy controls. Patients
with mild-to-moderate COPD were included as a reference group.

METHODS: In this cross-sectional study, smokers (> 10 pack-years) from a
specialized outpatient clinic were evaluated. Thirteen participants (11
females; 62.4 +/- 7.7 years) with PRISm and 13 age- and sex-matched
patients with mild-to-moderate COPD (FEV1/FVC < 0.7; FEV1 > 50% predicted)
underwent incremental cardiopulmonary exercise testing on a cycle
ergometer. Data from healthy nonsmoking controls were obtained from
previous studies.

RESULTS: PRISm and COPD groups had similarly reduced FEV1 (~ 72%
predicted) compared to controls (97% predicted), whereas FVC was lower in
PRISm (73% predicted) than in COPD and controls (~ 95% predicted). Both
patient groups showed higher ventilation, reduced ventilatory reserve, and
greater dyspnoea at a given submaximal workload versus controls. Increased
tidal volume/inspiratory capacity ratios were also observed, contributing
to greater dyspnoea for a given ventilation and lower peak work rate (42
+/- 16 vs. 68 +/- 11 vs. 94 +/- 17% predicted, respectively; all P <
0.05).

CONCLUSION: Smokers with PRISm exhibit increased dyspnoea and reduced
exercise tolerance compared to healthy controls, largely driven by
excessive ventilatory demand and reduced ventilatory capacity during
submaximal exercise.

 

The utility of the T wave peak to T wave end interval to Q-T end interval ratio as a dynamic indicator of cardiac sympathetic activity: a preliminary study

Saito S; Faculty of Medicine,Hokkaido University, Sapporo,  Japan.
Temma T
;  Watanabe M   Kadosaka T; et al

Heart Vessels Aug 5th 2026
Headings added by Dr Older

Background Excessive cardiac sympathetic nerve activity significantly contributes to chronic heart failure (CHF) and lethal arrhythmias. However, reliable dynamic markers to assess sympathetic modulation are lacking in clinical practice. The T wave peak to T wave end interval (TpTe) to Q-T end interval ratio (TpTe/QTe) has been suggested as a surrogate marker for transmural dispersion of repolarization (TDR). We hypothesized that the TpTe/QTe reflects cardiac sympathetic nerve activity based on anatomical differences in the distribution and activation of cardiac sympathetic nerves.
Methods 12-lead Electrocardiograms (ECGs) were analyzed retrospectively in two cohorts without structural heart disease: (1) Exercise study; ECGs from patients who underwent treadmill or cardiopulmonary exercise testing between 2013 and 2023 were analyzed at baseline and 1-min post-maximal exercise. (2) β-stimulator infusion study; ECGs from patients who underwent catheter ablation (CA) of premature ventricular contractions (PVCs) or paroxysmal supraventricular tachycardias (PSVT) between 2017 and 2022 were analyzed at baseline and post-isoproterenol (ISO) infusion.
Results In the exercise study, 45 patients (35.6% female, median age: 51) showed significant changes in the TpTe/QTe (interquartile range [IQR]: 0.20-0.30) from baseline to 1-min post-maximal exercise. In the β-Stimulator infusion study, 55 patients (63.6% female, median age: 55) had significant TpTe/QTe changes (0.19-0.33) from baseline to post-ISO infusion. The TpTe/QTe exhibited the largest change among the ECG parameters in both groups, regardless of sex, with no correlation to the left ventricular wall thickness.
Conclusions The TpTe/QTe may serve as a valuable dynamic indicator of cardiac sympathoexcitaion in patients without organic heart disease.

Keywords: Cardiac sympathetic nerve activity; Cardiac sympathoexcitation; T peak to T end interval; T peak to T end interval to Q-T end interval ratio; Ventricular sympathoexcitation.

N-Palmitoyl Glutamine Is a Candidate Mediator of Cardiorespiratory Fitness.

Robbins JM; Beth Israel Deaconess Medical Center, Boston, MA USA
Benson M; Verkerke ARP; Tiwari G; et al

Circulation. 153(1):47-58, 2026 Jan 06.

BACKGROUND: Cardiorespiratory fitness is an integrative measure of
cardiometabolic health and predictor of survival, yet little is known
about its molecular underpinnings. Small molecule metabolites and lipids
are increasingly recognized as exercise-stimulated signaling molecules and
candidate molecular transducers of cardiorespiratory fitness.

METHODS: We performed nontargeted liquid chromatography mass
spectrometry-based plasma metabolomics in 654 participants (mean age, 35
years; 55% women) from the HERITAGE Family Study (Health, Risk Factors,
Exercise Training, and Genetics) who had cardiorespiratory fitness
(maximal oxygen uptake [VO2max]) measured by cardiopulmonary exercise
testing and underwent 20 weeks of supervised endurance training.
Metabolite-VO2max relationships were assessed using linear regression and
tested for replication in FHS (Framingham Heart Study) participants who
also underwent cardiopulmonary exercise testing. Metabolite relationships
with incident all-cause mortality ascertained in JHS (Jackson Heart Study)
and MESA (Multi-Ethnic Study of Atherosclerosis) were tested using Cox
regression. Experimental studies of cellular respiration and mitochondrial
function were performed in C2C12 myotubes.

RESULTS: An unknown mass spectrometry peak (mass-to-charge, 385.3056;
retention time, 3.69 minutes) had the strongest, positive relationship
with VO2max (mLxkg-1min-1) after adjustment for age, sex, race, and lean
body mass (beta=1.29; false discovery rate q=5.3×10-6); was identified as
N-palmitoyl glutamine (N-pal-gln) using tandem mass spectrometry and
bioinformatics; and was confirmed with an authentic chemical standard. The
biological role of N-pal-gln has not been described previously. The
relationship of N-pal-gln with VO2max was validated in 408 participants
from the FHS (beta=1.2; P=3.8×10-5), and its levels increased after
exercise training (log fold change=0.22; q=5.3×10-12). N-pal-gln levels
were inversely associated with all-cause mortality in JHS and MESA (hazard
ratio, 0.91 and 0.65 [P=0.029 and P=0.028], respectively). Previous
studies have shown that structurally related biochemicals modulate energy
homeostasis; thus, we performed mitochondrial experiments. N-pal-gln
administration led to a dose-dependent increase in mitochondrial:nuclear
DNA ratio compared with control treated cells (15% and 20% increases at
6.5 nM and 26 nM N-pal-gln, respectively [P=0.04 and P=0.02]) and improved
bioenergetics (N-pal-gln at 26 nM increased the phosphate:oxygen ratio
across ADP concentrations from 0 to 100 mcM; ANOVA P=0.0027).

CONCLUSIONS: We identified a novel, lipidated amino acid, N-pal-gln, that
is positively associated with VO2max, increases after regular aerobic
exercise, and is inversely associated with incident mortality. N-pal-gln
stimulates mitochondrial biogenesis and efficiency, demonstrating its
potential role as an exercise-stimulated transducer of cardiorespiratory
fitness.

Single-O2 ligation of hemoglobin links aerobic and anaerobic metabolism. Source

Burchert HH; Medical Faculty, University of Basel, Basel, Switzerland.
Stringer WW; Dash RK

Journal of Applied Physiology. 141(2):401-416, 2026 Aug 01.

Oxygen (O2) binding and release by hemoglobin (Hb) are governed by
cooperative interactions among its four subunits. During incremental
workload exercise, femoral venous oxyhemoglobin (O2Hb) saturation exhibits
a reproducible, momentary increase at the gas exchange
threshold-coinciding with the inflection point of the in vivo O2
nonequilibrium curve (ONC). This suggests a transient shift in Hb’s
binding dynamics. We hypothesized that at this threshold, Hb tetramers
carrying <=1 bound O2 become predominant. In this state, the last bound O2
promotes further cooperative binding, but its release confers no
cooperative advantage for unloading, biasing toward O2 rebinding. Using
the O2 equilibrium curve models of Dash et al. (Eur J Appl Physiol 116:
97-113, 2016) and Adair, we computed the distribution of Hb’s O2 ligation
states across 12 pooled mean femoral venous blood samples from incremental
workload cardiopulmonary exercise testing of five healthy male
participants. At the gas exchange threshold-where the ONC inflects and
flattens-tetramers with <=1 O2 indeed dominated. This ligation-state
distribution is consistent with Perrella et al.’s (J Biol Chem 274:
2605-2608, 1999) cryogenic resolution of native human Hb, which shows that
carbon monoxide-ligated Hb tetramers peak at ~15%-20% saturation, matching
femoral venous ranges at the gas exchange threshold. Our results suggest
that, at sufficiently low O2Hb saturation, Hb may favor O2 rebinding over
cooperative unloading. We propose that glycolytic proton production and
other Bohr effectors may counter this predicted binding bias supporting
continued O2 unloading. If confirmed, this mechanism unifies long-standing
controversies in O2 transport physiology, framing the Hb-Bohr system as a
proportional-integral controller of tissue oxygenation. NEW & NOTEWORTHY
Anaerobic metabolism is usually viewed as a fallback when oxygen delivery
becomes insufficient. Our analysis suggests a different role: it may
preserve oxygen delivery by correcting a hemoglobin-binding bias that
emerges at low oxyhemoglobin saturation. When hemoglobin tetramers carry
one or no oxygen molecules, the remaining bound oxygen can promote
cooperative rebinding but not cooperative release. Glycolytic proton
production and other Bohr effectors may counter

Cardiopulmonary Exercise Testing Combined With Stress Echocardiography for the Evaluation of Myocardial Dysfunction in Patients at Risk for Coronary Insufficiency.

Schoffl I; Department of Pediatric Cardiology, Erlangen,Germany.
Trager E; Kessler L; Paech C;et al

Pediatric Exercise Science. 38(3):315-323, 2026 Aug 01.

PURPOSES: In pediatric cardiology, stress echocardiography is rarely used,
even though it is an established tool for investigating myocardial
dysfunction due to coronary insufficiency, a threat in children after
arterial switch operation (ASO) or Kawasaki disease (KD). This study
combines stress echocardiography with cardiopulmonary exercise testing in
this cohort.

METHOD: The participants in this study were recruited from a cohort of
patients after ASO or KD. An age- and sex-matched control group was
recruited from university students and school children from nearby
schools. All undertook a cardiopulmonary exercise testing either on a
tilt-recline cycle ergometer or on a treadmill with intermittent
echocardiography. The echocardiographic examination consisted of global
longitudinal strain measurements of the left ventricle as parameters of
left ventricular function. In addition to the standard cardiopulmonary
exercise parameters (peak oxygen consumption, peak heart rate, O2pulse,
oxygen uptake efficiency slope, VE/VCO2-slope, and others), the behavior
of the O2pulse before and after the end of exercise was evaluated.

RESULTS: Overall, 43 participants were recruited (20 ASO, mean age: 14.7
y, 8 females; 10 KD, mean age: 15.0 y, 3 females; 13 controls, mean age:
15.7 y, 5 females). The patients after ASO showed a significantly lower
peak cardiopulmonary function (VO2peak: 39.6 vs 45.9 mL/kg/min) than the
control group. When combined (KD and ASO patients), the first ventilatory
threshold as well as the decline of the O2pulse during recovery were
significantly lower than in the control group. There were no differences
with respect to the echocardiographic parameters.

CONCLUSION: The lower peak oxygen consumption observed in the ASO group
point to a lower cardiopulmonary function. The lower oxygen consumption at
first ventilatory threshold can be an indicator of poorer endurance. Even
though the ventricular function recorded using echocardiography showed no
significant decrease, the slower recovery of the O2pulse during recovery
could point to an impairment in cardiac output during exercise as the
O2pulse is a surrogate parameter of cardiac output at peak exercise