Kominami Kazuyuki, Akino Masatoshi
Department of Rehabilitation, Sanseikai Kitano Hospital, 6-30, 1- chome, Kitano 1-jyo, Kiyota-ku, Sapporo, Hokkaido 004-0861, Japan.
Department of Internal Medicine, Sapporo Kiyota Hospital, 1-1, 1-chome, Shin-ei 1-jyo, Kiyota-ku, Sapporo, Hokkaido 004-0831, Japan.
Cardiol Res. 2024 Feb;15(1):29-36. doi: 10.14740/cr1597. Epub 2024 Feb 28.
The partial pressure of end-tidal oxygen (PETO) and end-tidal oxygen concentration (ETO) are among the indices that can be measured by exhaled gas analysis. Several observational studies have shown that skeletal muscle function is impaired in patients with cardiac disease; thus, the assessment of skeletal muscle function is important. Additionally, although it has recently been suggested that the difference in PETO from rest to the ventilatory anaerobic threshold (VAT) reflects oxygen availability in peripheral factors, primarily skeletal muscle, the evidence for this is not well established. Therefore, we hypothesized and investigated whether increased blood lactate (BLa) levels, resulting from decreased skeletal muscle and mitochondrial oxygen availability, and PETO dynamics during cardiopulmonary exercise testing (CPET) would be related.
All participants performed the symptomatic limited CPET, and their BLa levels were measured. The difference in PETO and ETO from rest to VAT determined by the V-slope method (ΔPETO and ΔETO) was calculated and compared with the increase in BLa due to exercise testing.
We recruited 22 healthy older participants (nine males; 69.4 ± 6.8 years) and 11 patients with cardiovascular risk (eight males; 73.0 ± 8.8 years). ΔPETO and ΔETO did not differ between the two groups (P = 0.355 and P = 0.369, respectively), showing no correlation between increase in BLa from rest to VAT, but were significantly correlated with an increase in BLa from rest to the end of exercise (ΔPETO, P = 0.030; ΔETO, P = 0.029). The correlation was particularly pronounced among those at cardiovascular risk (ΔPETO, P = 0.012; ΔETO, P = 0.011).
ΔPETO and ΔETO from rest to VAT during CPET may be useful as indices reflecting skeletal muscle oxygen utilization capacity.
呼气末氧分压（PETO）和呼气末氧浓度（ETO）是可通过呼气气体分析测量的指标。多项观察性研究表明，心脏病患者的骨骼肌功能受损；因此，评估骨骼肌功能很重要。此外，尽管最近有人提出，从静息状态到通气无氧阈（VAT）时PETO的差异反映了外周因素（主要是骨骼肌）中的氧供应情况，但这方面的证据并不充分。因此，我们进行了假设并研究了在心肺运动试验（CPET）期间，骨骼肌和线粒体氧供应减少导致的血乳酸（BLa）水平升高与PETO动态变化之间是否存在关联。
所有参与者均进行了症状限制的CPET，并测量了他们的BLa水平。计算通过V斜率法确定的从静息状态到VAT时PETO和ETO的差异（ΔPETO和ΔETO），并将其与运动试验导致的BLa升高进行比较。
我们招募了22名健康老年参与者（9名男性；69.4±6.8岁）和11名有心血管风险的患者（8名男性；73.0±8.8岁）。两组之间的ΔPETO和ΔETO无差异（分别为P = 0.355和P = 0.369），表明从静息状态到VAT时BLa的升高之间无相关性，但与从静息状态到运动结束时BLa的升高显著相关（ΔPETO，P = 0.030；ΔETO，P = 0.029）。这种相关性在有心血管风险的人群中尤为明显（ΔPETO，P = 0.012；ΔETO，P = 0.011）。
CPET期间从静息状态到VAT时的ΔPETO和ΔETO可能作为反映骨骼肌氧利用能力的指标。
