Reference values for cardiopulmonary exercise testing in healthy adults: a systematic review

Abstract

Reference values (RV) for cardiopulmonary exercise testing (CPET) provide the comparative basis for answering important questions concerning the normality of exercise response in patients and significantly impacts the clinical decision-making process. The aim of this study is to systematically review the literature on RV for CPET in healthy adults. A secondary aim is to make appropriate recommendations for the practical use of RV for CPET. Systematic searches of MEDLINE, EMBASE and PEDro databases up to March 2014 were performed. In the last 30 years, 35 studies with CPET RV were published. There is no single set of ideal RV; characteristics of each population are too diverse to pool the data in a single equation. Therefore, each exercise laboratory must select appropriate sets of RV that best reflect the characteristics of the population/patient tested, and equipment and methodology utilized.

Keywords::

• cardiopulmonary exercise testing
• exercise physiology
• healthy adults
• maximal oxygen consumption
• reference values

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• There is no single set of ideal reference values (RV); the population characteristics of each population are too diverse to pool the data in a single equation.

• Each exercise laboratory must select appropriate set of RV that best reflect the characteristics of the population/patient tested, and equipment and methodology utilized.

• Normal RV provide the comparative basis for answering important questions concerning the normality of exercise responses in patients and can significantly impact the clinical decision-making process.

• Maximal oxygen uptake is dependent on age, sex and anthropometric properties, and can be affected by training status.

• Peak workload decreased with age, and males systematically scored higher than females.

• Peak heart rate decreased with age, with some small differences between males and females.

• There is a small variety in population in which norms are established; Caucasian, Japanese and Scandinavian populations were most frequently studies, whereby Caucasian white men were by far the most measured. Data from other populations from Asia, Middle-East, Africa and South America are needed.

• RV may change over time and should be regularly updated/validated.

• Standardization of the methodology to generate RV, reporting of cardiopulmonary exercise testing parameters, reporting on specific software and hardware settings of the equipment and data harmonization are necessary to facilitate interpretation and optimize clinical application of cardiopulmonary exercise testing.