Correlations between body mass index and body diathesis indicators among medical students

Objective To analyze correlations between body mass index (BMI) and body diathesis indicators among medical students.Methods According to the requirements in "National Criteria for Physical Health of Chinese Students",height,weight,vital capacity,50-meter running,standing long jump,sit-and-reach test,sit-ups,pull-ups,and visual acuity were measured among 3 997 medical students in a medical college between March and June 2015.Correlations between BMI and these indicators were analyzed with Pearson method.Results Among the students,the mean BMI was 21.79 ±1.84 kg/m² and 87.57% of the BMI values were within the normal range; the proportion of overweight was 10.84%.Compared to those of overweight and obese students of same gender,the male students with normal BMI showed significantly higher vital capacity weight index (61.4±12.73 mL/kg),standing long jump distance (2.27±0.22 m),sit-and-reach distance (11.24±7.04 cm),and number of pull-ups (6.36±4.16 times)(P<0.05 for all); the female students with normal BMI had significantly higher vital capacity weight index (53.08+14.1mL/kg,P<0.05),standing long jump distance (1.68±0.17 m)and sit-and-reach distance (13.12±6.76 cm)(both P<0.01 in comparison with those of low weight or overweight).Better mean visual acuities were observed among the male students (4.68±0.25 and 4.68±0.27 for left and right eye)and the female students (4.68±0.24 and 4.67±0.27 for left and right eye) with normal BMI than among the students with low weight or overweight (P<0.01 for all).BMI was positively correlated with 50-meter running time in the female students (r=0.049,P<0.01)and reversely correlated with standing long jump distance,sit-and-reach distance,number of pull-ups,number of sit-ups,and visual acuity in both male and female students (P<0.05 for all).Conclusion High BMI values may be associated with poor physical health among medical students.