Overweight and obesity in adolescents in northwest Russia in 2007: Do international and Russian criteria produce different results?

Background: Overweight and obesity is an increasing public health problem worldwide. The latest studies suggest an increase in obesity among Russian adults during the 2000s. It is unknown if this increases occurred in adolescents, especially in the areas outside large cities. Furthermore, most of the Russian studies apply Russian criteria for defining overweight and obesity making it difficult to make meaningful comparisons with international data.
Aim: To assess the prevalence of overweight and obesity among adolescents in a rural district in Northwest Russia by using international and Russian criteria.

Methods: All 9-11^th grade students (mean age 15.6 years) from all schools in Velsk district were asked to participate. The sample included 428 boys and 604 girls (response rate 87%). Overweight+obersity and obesity were defined according to IOTF, WHO-2007 and Russian criteria. Differences between the estimates by Russian criteria and each of the international criteria were studied by McNemar tests.
Results: The estimated prevalence of overweight+obesity among boys was 10.8% (95%CI: 8.2-14.0), 12.4% (95%CI: 9.6-15.7) and 7.6% (95%CI: 5.5-10.5) by IOTF, WHO-2007 and Russian criteria, respectively. The corresponding estimates for girls were 7.7% (95%CI: 5.9-10.1), 8.9% (95%CI: 6.9-11.4) and 9.2% (95%CI: 7.1-11.7). The prevalence of obesity among boys was 2.5% (95%CI: 1.4-4.4), 6.1% (95%CI: 4.2-8.7) and 1.8% (95%CI: 0.9-3.5) by IOTF, WHO-2007 and Russian criteria, respectively. The corresponding estimates for girls were 1.6% (95%CI: 0.9-2.9), 3.7% (95%CI: 2.5-5.5) and 2.7% (95%CI: 1.7-4.3). Russian criteria significantly underestimated the prevalence of overweight+obesity compared to both international references (all p<0.001) in boys, but not in girls. They also underestimated the prevalence of obesity in boys compared to the WHO-2007 criteria (p<0,001).

Conclusions: The prevalence of overweight and obesity in rural Northwest Russia is much lower than in Europe. Russian criteria may underestimate the prevalence of overweight and obesity in boys, but not in girls.