Determinants of Quality of Life in Myasthenia Gravis Patients

Abstract

Background: Although approximately half of myasthenia gravis (MG) patents achieve remission, for the remaining group MG is often a life-long disease. Better understanding of the determinants of Quality of Life (QoL) in MG is needed to optimize treatment goals in chronic cases. Materials and Methods: We performed a single center cross-sectional study in 339 MG adult patients (64.9% women), with ocular or generalized disease. SF-36 and a structured questionnaire was administered, including information on previous and current MG severity, medications, comorbidities, education, occupation and BMI of the patient. Mean disease duration was 7.5 + 9.3 years. Current age was 51.6 + 18.3 years, 55% had Early-Onset (<50 years) MG. Results: There were no statistically significant differences in mean SF-36 subscores between women and men. Worse MGFA class was related to lower QoL in physical (PCS) and mental (MCS) subscore (p = 0.000 for both). Patients with MGFA I-II class had significantly better QoL in physical and mental subscores than patients with more severe MG (p < 0.005). Late-onset MG patients had worse QoL than EOMG in physical score domain PCS (p = 0.049). Overweight and obese patients had lower PCS (p = 0.002) and MCS (p = 0.038) than patients with normal BMI. University education was related to statistically higher PCS (p = 0.015) and MCS (p = 0.006). QoL in currently employed was better in PCS and MCS (p = 0.000), with white collar workers reporting higher PCS (p = 0.049) than the remaining group. Patients living with family evaluated their MCS (p = 0.015) better than living alone. Moderate physical activity (twice a week) improved PCS (p = 0.045). Conclusion: Our study confirmed that greater severity of symptoms, age, age of onset but also BMI, type of work, education status and physical activity affect QoL in MG.

Keywords: MGFA; SF-36; employment; myasthenia gravis; obesity; quality of life.

Figure 1

The influence of MGFA score on QoL assessment. *P < 0.05. In PCS there were significant differences between patients in remission and MGFA II or more, between MGFA I and III or more, MGFA II and III or more; in MCS significant differences were found between patients in remission and MGFA II and more.

Figure 2

QoL assessment in PCS and MCS domain depending on BMI grouped by gender; *P < 0.05. BMI, body mass index; BMI (N), BMI up to 25 kg/m².

Figure 3

QoL assessment in PCS and MCS domain depending on employment status; *P < 0.05.