Exercise, ageing and the lung.

This review provides a pulmonary-focused description of the age-associated changes in the integrative physiology of exercise, including how declining lung function plays a role in promoting multimorbidity in the elderly through limitation of physical function. We outline the ageing of physiological systems supporting endurance activity: 1) coupling of muscle metabolism to mechanical power output; 2) gas transport between muscle capillary and mitochondria; 3) matching of muscle blood flow to its requirement; 4) oxygen and carbon dioxide carrying capacity of the blood; 5) cardiac output; 6) pulmonary vascular function; 7) pulmonary oxygen transport; 8) control of ventilation; and 9) pulmonary mechanics and respiratory muscle function. Deterioration in function occurs in many of these systems in healthy ageing. Between the ages of 25 and 80 years pulmonary function and aerobic capacity each decline by ∼40%. While the predominant factor limiting exercise in the elderly likely resides within the function of the muscles of ambulation, muscle function is (at least partially) rescued by exercise training. The age-associated decline in pulmonary function, however, is not recovered by training. Thus, loss in pulmonary function may lead to ventilatory limitation in exercise in the active elderly, limiting the ability to accrue the health benefits of physical activity into senescence.

Comparison of performance status with peak oxygen consumption in operable patients with non-small-cell lung cancer.

BACKGROUND AND OBJECTIVE: In this era of increasing options for treatment of 'surgical' lung cancer patients, preoperative physiologic assessment of accurate patient selection is becoming more important. The variability in an objective measure of cardiorespiratory fitness (peak oxygen consumption (VO2peak )) across performance in operable non-small-cell lung cancer (NSCLC) patients enrolled in the Cancer and Leukemia Group B trial was compared. METHODS: Using a cross-sectional design, 392 NSCLC patients underwent an incremental cardiopulmonary cycling exercise test to symptom limitation with expired gas analysis to determine VO2peak . Performance status (PS) was assessed using the Eastern Cooperative Oncology Group (ECOG) tool. RESULTS: There was a significant decrease in VO2peak across increasing ECOG categories (P < 0.0001). However, there was a large range in VO2peak for any given ECOG category with overlap between categories (ECOG 0: 5.0-31.5 mL/kg/min; ECOG 1: 4.3-24.8 mL/kg/min; ECOG 2: 8.9-21.9 mL/kg/min; ECOG 3; 3.3-11.7 mL/kg/min). CONCLUSIONS: PS scoring systems do not provide a sensitive measure of functional status. Objective measures such as VO2peak may be a useful in the clinical management of oncology patients.

Noninvasive assessment of normality of VD/VT in clinical cardiopulmonary exercise testing utilizing incremental cycle ergometry.

Dead space to tidal volume ratio (V(D)/V(T)), a measure of pulmonary gas exchange efficiency, cannot be accurately calculated without arterial blood sampling. We sought to determine, in patients presenting for diagnostic cardiopulmonary exercise tests, whether there are ranges of the ratio of exhaled ventilation to carbon dioxide output (V(E)/VCO(2)) measured at the lactate threshold that are highly predictive of normality or abnormality of exercise V(D)/V(T) (below or above 0.3) and whether other demographic or physiologic variables aid in this prediction. We reviewed 691 incremental cycle ergometer cardiopulmonary exercise tests featuring breath-by-breath gas exchange measurement and serial arterial blood sampling that were performed for patients with a range of disorders. When V(E)/VCO(2) at the lactate threshold was ≤28, 96 % of subjects had normal V(D)/V(T). For V(E)/VCO(2) 29-32, V(D)/V(T) was normal in 83 % of cases. V(E)/VCO(2) of 33-38 provided no useful information; V(D)/V(T) was normal and abnormal in 50 % of cases each. When V(E)/VCO(2) was ≥39, V(D)/V(T) was abnormal in 87 % of cases. For V(E)/VCO(2) ≥ 39, when FEV(1)/VC was <70 %, V(D)/V(T) was abnormal in 95 % of cases. End-tidal PCO(2) was of no help in distinguishing V(D)/V(T) normality in any V(E)/VCO(2) range. Our results reveal that certain values of V(E)/VCO(2) at LT (V (E)/VCO(2) ≤ 28 and V(E)/VCO(2) ≥ 39), but not others (V(E)/VCO(2) 29-32 and especially V(E)/VCO(2) of 33-38), can be helpful in determining normality of V(D)/V(T) during exercise in patients presenting for cardiopulmonary exercise testing.

Identification of Patients With COPD in a Cardiac Rehabilitation Setting: THE COnCuR STUDY.

PURPOSE: To examine the feasibility of screening for chronic obstructive pulmonary disease (COPD) in an outpatient cardiac rehabilitation (CR) setting and to evaluate the detection rate of COPD using a targeted screening protocol. METHODS: A total of 95 patients (62.5 ± 10.0 yr; men, n = 77), >40-yr old with a history of smoking were included in the study sample. Each participant answered the 5-item Canadian Lung Health Test (CLHT) questionnaire assessing symptoms such as coughing, phlegm, wheezing, shortness of breath, and frequent colds. Endorsing ≥1 item was indicative of potential COPD and warranted pulmonary function testing (PFT) and/or spirometry to diagnose or rule out COPD. RESULTS: The CLHT questionnaire identified 44 patients at risk for COPD, with an average of 1.9 ± 1.2 items endorsed. Of the patients who underwent PFT, 6 new cases of mild COPD were diagnosed, resulting in a true positive rate with CLHT screening of 19% and a false-positive rate of 81%. CONCLUSIONS: Implementing the CLHT to patients referred to CR correctly identified COPD in <20% of cases. Using the CLHT to screen for COPD prior to starting CR may not be optimal, due to disparities between true- and false-positive rates.

The relationship between vestibular function and topographical memory in older adults.

Research during the past two decades has demonstrated an important role of the vestibular system in topographical orientation and memory and the network of neural structures associated with them. Almost all of the supporting data have come from animal or human clinical studies, however. The purpose of the present study was to investigate the link between vestibular function and topographical memory in normal elderly humans. Twenty-five participants aged 70 to 85 years who scored from mildly impaired to normal on the Montreal Cognitive Assessment (MoCA) received three topographical memory tests: the Camden Topographical Recognition Memory Test (CTMRT), a computerized topographical mental rotation test (TMRT), and a virtual pond maze (VPM). They also received six vestibular or oculomotor tests: optokinetic nystagmus (OKN), visual pursuit (VP), actively generated vestibulo-ocular reflex (VOR), the sensory orientation test (SOT) for posture, and two measures of rotational memory (error in degrees, or RM°, and correct directional recognition, or RM→). The only significant bivariate correlations were among the three vestibular measures primarily assessing horizontal canal function (VOR, RM°, and RM→). A multiple regression analysis showed significant relationships between vestibular and demographic predictors and both the TMRT (R = 0.78) and VPM (R = 0.66) measures. The significant relationship between the vestibular and topographical memory measures supports the theory that vestibular loss may contribute to topographical memory impairment in the elderly.