Influence of waist circumference on blood pressure status in non-obese adolescents

Objectives To check whether excess in abdominal adiposity and metabolic factors were associated with blood pressure abnormalities in non-obese adolescents. Methods We randomly selected 1100 adolescent students, aged 12-18 years, from schools and classrooms in the city of Constantine, Algeria. Among them 179 were overweight and 51 were obese (IOTF criteria). Waist circumference (WC) was considered high if >74 cm in boys and 75 cm in girls (mean of WC of all population studied). Hypertension (HBP) and prehypertension (preHBP) were defined by the NHBPEP's 2004 criteria. Results The prevalence of HBP/preHBP were 13.0%/12.4% with no difference between boys and girls. The percentages of HBP/preHBP patients were 15.6%/15.6% in overweight adolescents, 5.9%/31.4% in obese adolescents and 12.9%/10.6% in adolescents with normal body weight (p < 0.0001). In obese adolescents, the prevalence of HBP was higher among boys than girls (36% vs. 27%, p = 0.002). In normal and overweight adolescents, the prevalence of HBP and preHBP was similar in boys and girls (11.9% vs. 11.0% and 14.7% vs. 12.1%); the association of WC (high vs. not high) with HBP was found in boys (16.1% vs. 8.8%, p = 0.009) but not in girls (12.1% vs. 10.2%), and with preHBP in girls (15.5% vs. 8.0%, p = 0.029) but not in boys (16.2% vs. 13.6%). Waist circumference [OR: 1.04 (1.03-1.06); p < 0.0001] and HOMA index [OR: 1.65 (1.13-2.39); p = 0.009] were associated with an increased risk of HBP. Conclusion In non-obese adolescents, a high WC, defined by values over the mean WC observed in our population, is associated with a higher risk of HBP in boys.