# Assessment of sub-maximal aerobic capacity in North African patients with chronic hepatitis B: a pilot case-control study

## TL;DR

This study found that non-cirrhotic chronic hepatitis B patients have reduced aerobic capacity and accelerated aging of their cardiorespiratory and muscular systems compared to healthy individuals.

## Contribution

This is the first pilot study to assess sub-maximal aerobic capacity in non-cirrhotic chronic hepatitis B patients using a 6-min walk test and novel composite metrics.

## Key findings

- CHB patients walked 61 meters less in the 6-min walk test compared to controls.
- CHB patients showed 11-year accelerated aging of cardiorespiratory and muscular systems.
- 23% of CHB patients had chronotropic insufficiency versus 3.57% in controls.

## Abstract

Studies assessing sub-maximal aerobic capacity in non-cirrhotic chronic hepatitis B (CHB) patients are scarce. This study aimed to evaluate sub-maximal aerobic capacity in CHB patients compared to apparently healthy participants (control-group).

A 6-min walk test was performed. The 6-min walk distance (6MWD) was recorded, along with heart-rate, oxygen hemoglobin saturation (SpO
2), blood pressure, and dyspnea (

ie
; visual analogue scale) at rest (
Rest) and at the end (
End) of the test. Additionally, 6-min walk work (6MWW), “6MWD × body mass index (BMI), “6MWD × SpO
2End”, and “estimated cardiorespiratory and muscular chain age” were calculated. Signs of physical intolerance were determined including abnormal 6MWD (

ie
; 6MWD < lower limit of normal), chronotropic insufficiency (

ie
; heart-rate
End < 60% of maximal predicted heart-rate), high dyspnea (

ie
; dyspnea
End > 5), and desaturation (

ie
; drop in SpO
2 > 5 points).

Compared to the control-group (n=28), the CHB-group (n=26) exhibited significantly lower 6MWD by 61 meters (13%), lower 6MWW by 5266 m.kg, lower “6MWD × BMI” by 1498 m.kg/m
2, lower “6MWD × SpO
2End” by 5650%, and lower heart-rate
End by 26 bpm (12% predicted). The CHB-group included higher percentages of participants with chronotropic insufficiency (23.08% vs. 3.57% in the CG) and abnormal 6MWD (34.61% vs. 3.57% in the CG). CHB accelerated the aging of the “cardiorespiratory and muscular chain” by 11 years.

Non-cirrhotic CHB may contribute to reduced submaximal aerobic capacity and acceleration of “cardiorespiratory and muscular chain” aging. A regular physical activity program could be a valuable intervention to mitigate these effects.