Mediating effect of exercise on the relationship between body mass index and health-related quality of life

Abstract

Objective To evaluate the effect of exercise on the relationship between body mass index (BMI) and health-related quality of life (HRQOL). Methods A total of 1 114 participants were recruited from the Physical Examination Center of two hospitals. SF-36 was used to measure HRQOL, and the classification of sports level was done according to the subjective evaluation of participants. Results The total score of HRQOL, physical component summary and mental component summary were 76.26±16.10, 75.97±16.67 and 76.55±18.33 respectively.The results of correlation analysis were as following: the positive correlation between BMI and general health(r=0.109), vitality(r=0.116), social functioning(r=0.092), role emotional(r=0.122), mental health(r=0.145)were significant(P<0.01). The negative correlation between BMI and PF(r=-0.07, P=0.019)was significant.The mediation effects of exercise in was relationship between BMI and general health, vitality, mental health were significant, and the mediating effect were 5.84%, 9.14% and 6.58%. Conclusion This study demonstrates that mediation effects of the exercise are significant in some dimensions of HRQOL, but the direct influence of BMI on the HRQOL plays a leading role.And BMI is a protective factor under certain conditions. Key words: Body mass index; Exercise; Health-related quality of life; Mediating effect