International Waist Circumference Percentile Cutoffs for Central Obesity in Children and Adolescents Aged 6 to 18 Years.

CONTEXT: No universal waist circumference (WC) percentile cutoffs used have been proposed for screening central obesity in children and adolescents. OBJECTIVE: To develop international WC percentile cutoffs for children and adolescents with normal weight based on data from 8 countries in different global regions and to examine the relation with cardiovascular risk. DESIGN AND SETTING: We used pooled data on WC in 113,453 children and adolescents (males 50.2%) aged 4 to 20 years from 8 countries in different regions (Bulgaria, China, Iran, Korea, Malaysia, Poland, Seychelles, and Switzerland). We calculated WC percentile cutoffs in samples including or excluding children with obesity, overweight, or underweight. WC percentiles were generated using the general additive model for location, scale, and shape (GAMLSS). We also estimated the predictive power of the WC 90th percentile cutoffs to predict cardiovascular risk using receiver operator characteristics curve analysis based on data from 3 countries that had available data (China, Iran, and Korea). We also examined which WC percentiles linked with WC cutoffs for central obesity in adults (at age of 18 years). MAIN OUTCOME MEASURE: WC measured based on recommendation by the World Health Organization. RESULTS: We validated the performance of the age- and sex-specific 90th percentile WC cutoffs calculated in children and adolescents (6-18 years of age) with normal weight (excluding youth with obesity, overweight, or underweight) by linking the percentile with cardiovascular risk (area under the curve [AUC]: 0.69 for boys; 0.63 for girls). In addition, WC percentile among normal weight children linked relatively well with established WC cutoffs for central obesity in adults (eg, AUC in US adolescents: 0.71 for boys; 0.68 for girls). CONCLUSION: The international WC cutoffs developed in this study could be useful to screen central obesity in children and adolescents aged 6 to 18 years and allow direct comparison of WC distributions between populations and over time.

Comorbidities of COPD in Bulgarian Patients - Prevalence and Association with Severity and Inflammation.

BACKGROUND: wis a disease with constantly rising economic and social burden; it is associated with multiple comorbidities which contribute to the disease severity. AIM: To investigate the prevalence of co-morbidities in COPD patients and their association with the disease severity and CRP levels. PATIENTS AND METHODS: We conducted a retrospective study among 338 COPD patients (mean age 65.2±7.6 years) with assessment of comorbidities, spirometry measurements and serum levels of CRP. In 183 patients we found metabolic syndrome (MS) according to IDF criteria. RESULTS: We found prevalence of cardiovascular diseases (CVD) of 73.5% (hyper-tension 70.4%, CHF 47.4%, ishemic heart disease 37.5%, and cardiac arrhythmias 12.6%), with higher prevalence in patients with more severe disease. We found prevalence of type 2 diabetes of 21.1%, and 12.4% prevalence of bronchiectasis. In a subpopulation of the patients we found 48.1% prevalence of MS and the serum levels of CRP were significantly higher in patients with COPD and MS compared to those without the syndrome: 7.4 (3.14 - 11. 54) mg/ml vs 4.06 (2.64 - 6.93) mg/ml, p=0.006. CONCLUSION: The present study suggests high prevalence of CVD comorbidities in COPD patients and association with the disease severity. Metabolic syndrome is a common comorbidity and is associated with increased inflammatory response.

Waist circumference percentile curves for Bulgarian children and adolescents aged 6-18 years.

BACKGROUND: Waist circumference (WC) is a simple, easily available anthropometric measurement, giving relevant information about fat distribution and reflecting the degree of central adiposity in children. It appears to be the main risk factor for the progress of the metabolic syndrome. Our aim was to develop age- and sex-specific WC percentile curves for Bulgarian children/adolescents and to compare them with those from other countries. METHODS: A representative cross-sectional study of 3,810 healthy Bulgarian children/adolescents (2,052 males) aged 6-18 years, conducted in 2006/07. Body weight, height and WC were measured and body mass index (BMI) was calculated. Sex- and age-specific WC percentile curves were constructed using the LMS method. RESULTS: WC increased with age in both sexes (P<0.0001), with higher values in boys at every age and percentile point. This difference became significant from age 11 years onwards (P<0.05). The boys' values continued to increase steeply after this age, while in girls we found a constant continuing increase until the age of 15. Thereafter WC began to decrease and level off. The WC percentile values in Bulgarian children were lower than in US children, higher than in British and Turkish children, and similar to those of their Cypriot peers. CONCLUSIONS: For the first time, WC percentile curves were constructed for Bulgarian children/adolescents. A unique standardized method for WC measurement in children is needed for more acceptable international comparisons.