Age- and Gender-Specific Smoothed Waist Circumference Percentiles for Kuwaiti Adolescents

Objective: To ascertain abdominal obesity prevalence (waist circumference, WC) in adolescents and to develop smoothed WC percentile charts for Kuwaiti adolescents for public health use. Subjects and Methods: A cross-sectional study of 4,219 healthy Kuwaiti male and female secondary school students between the ages of 11–19 years was examined. Adolescents were drawn from all geographical regions of the country, as part of the Kuwait Nutrition Surveillance Program (KNSP). The KNSP consists of yearly data collections of variables, including weights, heights, and WCs and several sociodemographic variables. LMS regression was used to develop smoothed WC percentile curves. The final percentile curves presented are the result of smoothing three age-specific curves, termed lambda (L), mu (M), and sigma (S) for each gender. Results: Between 5.9 and 12.8% of females and 8.0–30.3% males had WC values ≧90th percentile. Moreover, the mean WC of males was consistently higher than those of females at each age and the percent of adolescents who exceed the 90th percentile increased with age in males, but not in females. Conclusion: Mean WC was higher in males than in females at every age. In most cases, two to three times greater percentages of males, compared to females, equaled or exceeded the 90th percentile, a value frequently associated with higher cardiovascular risk. These results indicate the urgent need to reduce abdominal obesity, an important indicator of the metabolic syndrome, in Kuwaiti adolescents.