Predictive Properties of the Hyperventilation Provocation Test for the Diagnosis of the Hyperventilation Syndrome

In a first stage, the investigators will analyze in a prospective way a training cohort of HPTest datas from 74 subjects, involving 37 subjects with complaints and a Nijmegen questionnaire score of ≥23/64 (HVS+) matched on gender, age, height, weight and BMI category with 37 healthy controls without complaints and a Nijmegen questionnaire score of <23/64 (HVS-)(16).

All data will have to be collected by the same equipment and by the same operators in the pulmonology department of the CHU-St Pierre-Brussels between June 2018 and October 2021.

To rule out confounding respiratory pathology, each participant will have completed spirometry and methacholine testing, that will have a result within expected normal values.

For both cohorts, kinetics of the PETCO2 recorded during each of the 3 phases of the HPTest (adaptation, hyperventilation and recovery) will be mathematically modeled by an curvilinear model with the parameters (A, A', a and a') noted from the kinetic equation (TAU) : TAU [PETCO2(t)〖=A+a(1-exp〗^((b-t)/c))]. For any observed differences in parameters between groups, the Area Under Curves will be estimated at the cut-off that offers the best Sensitivity and Specificity. False negative and false positive rates will be estimated.

The probability of a type I error is set at 5%.