[Association between body mass index and blood pressure of Tibetan primary and secondary school students in Lhasa City in 2020].

OBJECTIVE

To analyze the relationship between body mass index(BMI) and blood pressure among Tibetan primary and secondary school students in Lhasa City.

METHODS

From August to October 2020, 1929 Tibetan students were selected from 12 primary and secondary schools in Lhasa City to conduct questionnaire surveys on demographic characteristics, smoking, drinking, living habits, and food consumption frequency, and physical examinations such as height, weight and blood pressure measurements. The association between BMI and blood pressure was analyzed with multivariate logistic regression model and linear regression model.

RESULTS

A total of 843 boys(43.70%)and 1086 girls(56.30%)were surveyed, with an average age of(14.25±2.71) years old.925 people(47.95%)were in urban areas and 1004 people(52.05%)were in rural areas. There were 726 people(37.64%)inprimary school students, 692 people(35.87%)in junior high school, 363 people(18.82%)in high school, and 148 people(7.67%)in vocational high school. There were 541 people(28.05%)who were emaciated, 183 people(9.49%)who were overweight, and 87 people(4.51%)who were obese. The wasting, overweight and obesity rates of Tibetan primary and secondary school students were 28.05%, 9.49% and 4.51%, respectively. The high blood pressure rate was 8.76%. The BMI value of the high blood pressure group of students was higher than that of the students in the normal blood pressure group, and the difference was statistically significant(t=4.63, P<0.05). The result of the multi-factor logistic regression model showed that among the study subjects, the risk of high blood pressure, high systolic blood pressure, and high diastolic blood pressure were 3.07 times higher than those of people with normal BMI(95% CI 1.71-5.51, P<0.01), 2.83 times(95% CI 1.38-5.81, P<0.01), 4.19 times(95% CI 2.11-8.32, P<0.01). The risk of high blood pressure in overweight people was 1.17 times that of people with normal BMI(95% CI 1.04-2.84, P=0.04). The result of the linear regression model showed that mild wasting(β=-2.41, 95% CI-3.95--0.87) and moderate to severe wasting(β=-4.71, 95% CI-6.19--3.23) was negatively correlated with systolic blood pressure, while overweight(β=2.56, 95% CI 0.88-4.24) and obesity(β=5.55, 95% CI 3.20-7.91) were positively correlated with systolic blood pressure, moderate to severe wasting(β=-2.46, 95% CI-3.88--1.04) was negatively correlated with diastolic blood pressure, and obesity(β=3.42, 95% CI 1.16-5.68) was positively correlated with diastolic blood pressure.

CONCLUSION

Obesity is positively correlated with blood pressure and high blood pressure among Tibetan primary and secondary school students.