a1 Department of Kinesiology, University of Windsor, 401 Sunset Avenue, Windsor, ON N9B 3P4, Canada
a2 Faculty of Nursing, University of Windsor, Windsor, ON, Canada
a3 Faculty of Education, University of Windsor, Windsor, ON, Canada
Objective The purpose was to examine the associations among body weight status, blood pressure and daily Na intake among grade 7 students from south-western Ontario, Canada.
Design Cross-sectional. Data were collected using the Food Behaviour Questionnaire, including a 24 h diet recall. Measured height and weight were used to determine BMI. Blood pressure was taken manually using mercury sphygmomanometers.
Setting Twenty-six schools in south-western Ontario, Canada.
Subjects Grade 7 students (n 1068).
Results Body weight status indicated 1 % were underweight, 56 % normal weight, 23 % overweight and 20 % were obese. Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) were 108·3 (sd 10·3) mmHg and 66·0 (sd 7·5) mmHg, respectively, and mean Na intake was 2799 (sd 1539) mg/d. Bivariate analyses suggested that SBP (P < 0·001) and DBP (P < 0·001) were significantly different by body weight status, yet no associations were observed for Na. Adjusted for gender, ethnicity and under-reporting, participants were more likely to be overweight/obese if they had higher SBP (v. lower: OR = 1·06, 95 % CI 1·05, 1·08, P < 0·001), higher DBP (v. lower: OR = 1·02, 95 % CI 1·00, 1·04, P = 0·043) and higher intakes of Na (3rd v. 1st quartile: OR = 1·72, 95 % CI 1·14, 2·59, P = 0·009; 4th v. 1st quartile: OR = 2·88, 95 % CI, 1·76, 4·73, P < 0·001).
Conclusions High intakes of Na, coupled with high SBP and DBP, were associated with overweight and obesity status among the grade 7 sample from south-western Ontario, Canada.
(Received July 19 2012)
(Revised January 10 2013)
(Accepted January 22 2013)
(Online publication March 04 2013)