Abstract Validity of waist-to-height ratio as a screening tool for type 2 diabetes risk in non-Hispanic Whites, non-Hispanic Blacks, and Mexican American Adult Women, from the ages 20-65 years of age. Background: A prominent screening measure for type 2 diabetes is a simple measure of waist circumference. Waist circumference is an aggregate measurement of the actual amount of total and abdominal fat accumulation and is a crucial correlate of the complexities found among obese and overweight patients. However, waist circumference does not take into consideration the frame of an individual. Hence, recent epidemiologic data have suggested the use of height adjusted waist circumference (waist-to-height ratio). The use of waist-to-height ratio in screening for type 2 diabetes is poorly understood. Aims: The aim of this study is to determine racial/ethnic differences in the association of the independent variables waist-to-height ratio and waist circumference, with type 2 diabetes in non-Hispanic Whites, non-Hispanic Blacks, and Mexican American adult women, ages 20-65 years old. Methods: Data from the NHANES 2007-2008 surveys were used. Race/ethnic specific odds ratios from univariate and multivariate logistic regression models were to estimate the associations of waist-to-height ratio and waist circumference with type 2 diabetes. In the multivariate models, adjustments were made for age and alcohol use. Results: In the univariate models, WC was associated with 1.06, 1.07 and 1.04 increased odds of type 2 diabetes in Mexican Americans, non-Hispanic Whites and non-Hispanic Blacks, respectively. The corresponding values waist-to-height ratio were 2.85, 3.20 and 1.88, respectively. On adjusting for confounders, WC was associated with 1.07, 1.05, and 1.05 increased odds of type 2 diabetes in Mexican Americans, non-Hispanic Whites and non-Hispanic Blacks, respectively. WHtR was associated with 2.95, 2.38, and 2.37 increased odds of type 2 diabetes in Mexican Americans, non-Hispanic Whites and non-Hispanic Blacks, respectively. Conclusion: This study indicates that WHtR may be a powerful anthropometric predictor of risk for type 2 diabetes for Mexican American, non-Hispanic White and non-Hispanic Black American women ages 20-65.The literature on WHtR as a screening tool for type 2 diabetes in American women is lacking. This study is one of the first to examine the association between WHtR across varying races of American women. Future researchers should explore populations of women and men in the US with more races represented.

BACKGROUND: Type 2 diabetes and cardiovascular disease (CVD) are among the leading causes of death in the United States. The Metabolic Syndrome, which comprises a cluster of cardiometabolic risk factors, puts individuals at increased risk for these diseases. It is therefore important that people with Metabolic Syndrome, at high risk for CVD and type 2 diabetes, are identified and treated. Since it may not often be practical to obtain the laboratory measures necessary for diagnosing the Metabolic Syndrome, simple anthropometric measures are a useful way of quickly identifying individuals at increased risk for the Metabolic Syndrome. OBJECTIVE: The purpose of this thesis is to evaluate the utility of three of the most commonly used anthropometric measures – Body Mass Index (BMI), Waist Circumference (WC), and Waist-to-Height Ratio (WC) – for classifying individuals with and without the Metabolic Syndrome and its component risk factors in the United States. Using Receiver Operating Characteristic (ROC) curve analysis and Area Under the Curve (AUC) statistics, this thesis will assess the utility of each body measurement and compare it to BMI. METHODS: A large, multi-ethnic, nationally representative sample from the National Health and Nutrition Examination Survey (NHANES) 2007-2010 was used for this analysis. The study sample was restricted to adults aged 20-65 with complete information on height, weight, waist circumference, blood pressure, HDL cholesterol, fasting glucose, and triglycerides (n=3,769). In order to compare the utility of different anthropometric measures for classification, weighted ROC curves were constructed for each anthropometric measure-outcome combination and AUC statistics were compared. AUC statistics were calculated by approximating the definite integral of the ROC curves with the trapezoidal rule. Variances for AUC statistics and differences in AUC statistics were estimated with jackknife repeated replication. Analyses were completed for the entire sample and separately for non-Hispanic whites, non-Hispanic blacks, and Mexican Americans. RESULTS: For the entire sample, WC (AUC=0.752) did a better job than BMI (AUC=0.728) at classifying individuals with and without the Metabolic Syndrome (p CONCLUSION: Waist circumference should be considered, especially over BMI, for risk stratification in clinical settings and research. Further research should attempt to identify optimum waist circumference cut points for use in the US population.

No description available.

No description available.

Metabolic syndrome is a cluster of disorders including central obesity, hypertension, dyslipidemia, and hyperglycemia. Today's metabolic syndrome definitions identify central obesity by waist circumference (WC) measurements. A recent pilot study suggests that cut-points derived from a waist-to-height ratio (WHtR), or Index of Central Obesity (ICO), is a more accurate measurement of central obesity. This study compared the association between the metabolic syndrome components and central obese parameters (ICO and WC) among the white, black, and Hispanic adults in the United States. The subjects' data was obtained from the 2005-2006 National Health and Nutrition Examination Survey. ICO was highly correlated with metabolic syndrome components among white subjects and the least correlated in Hispanic subjects. Multivariate logistic regression analysis did not indicate that ICO was a better parameter for metabolic syndrome than WC. Other WHtR cut-points may be more sensitive in predicting metabolic syndrome components than the values used in this study.

Os objetivos do estudo foram correlacionar a razão entre a circunferência abdominal e altura (CA/A) e o índice de massa corpórea (IMC) com as variáveis cardiometabólicas e inflamatórias em escolares de seis a 10 anos; avaliar a frequência de sobrepeso/obesidade e alterações cardiometabólicas e comparar o desempenho dos referenciais de índice de massa corpórea (IMC) do Centers for Disease Control and Prevention 2000 (CDC) e Organização Mundial de Saúde 2007 (OMS) no diagnóstico de sobrepeso/obesidade e alterações cardiometabólicas. Métodos: estudo de corte transversal, que incluiu 175 crianças, provenientes do Centro de Referência para Tratamento da Criança e do Adolescente (CRTCA), em Campos, Rio de Janeiro. As crianças foram divididas segundo os escores z do CDC e OMS em: não obesas (z do IMC <1) e sobrepeso/obesidade (z do IMC > 1). As variáveis cardiometabólicas analisadas foram: pressão arterial sistólica (PAS) e diastólica (PAD), glicose, lipoproteínas de baixa e alta densidades (LDL e HDL, respectivamente), triglicerídeos (TG), HOMA-IR. Como variáveis inflamatórias, analisamos proteína C reativa ultra-sensível (PCR) e leucometria. Resultados: a média da CA/A do grupo sobrepeso/obesidade foi maior que a do não obeso (0,58 ± 0,007 e 0,45 ± 0,004, respectivamente, p< 0,0001). Houve correlação significativa da CA/A com os escores z do IMC (r = 0,88, p < 0,0001), PAS (r= 0,51, p<0,0001), PAD (r= 0,49, p<0,0001), HOMA-IR (r=0,83, p<0,0001), HDL (r = -0,28, p< 0,0002), TG (r= 0,26, p<0,0006), LDL (r= 0,25, p<0,0008) e PCR (r= 0,51, p<0,0001). Contudo, a CA/A não se correlacionou com glicemia nem leucócitos. A sensibilidade da CA/A se equivaleu à do IMC no diagnóstico das alterações cardiometabólicas. A sensibilidade mais elevada da CA/A foi para o diagnóstico de alteração da PAS (80,0 %), PAD (76,6%) e HOMA-IR (92,6%). O ponto de corte superior a 0,47 foi sensível para o diagnóstico de resistência insulínica, mas acima de 0,50, para os demais distúrbios cardiometabólicos. A frequência de sobrepeso/obesidade nos escolares foi igual a 49,7%. Com exceção de hipertrigliceridemia, todas as outras alterações cardiometabólicas foram mais frequentes no grupo sobrepeso/obesidade (aumento de PA, p<0,0001; glicemia de jejum alterada, p < 0,0048; aumento de LDL, p< 0,015 e redução do HDL, p<0,0001). O referencial da OMS 2007 reclassificou 11 crianças a mais como obesas que o CDC, que apresentaram médias de escores z de PAS (1,71 ± 1,54), PAD (2,64 ± 1,83) e HOMA-IR (1,84 ± 0,98) semelhantes às médias das obesas (PAS = 1,25 ± 2,04; PAD = 1,94 ± 1,19 e HOMA-IR = 2,09 ± 1,12), mas superiores às médias das classificadas como sobrepeso (PAS = 0,49 ± 1,34, p < 0,023; PAD = 1,45 ± 0,97, p < 0,04 e HOMA-IR = 1,24 ± 0,67, p < 0,04 ). Conclusões: a razão CA/A foi tão sensível quanto IMC da OMS 2007 no diagnóstico do risco cardiometabólico e inflamatório. O referencial da OMS 2007 foi o mais sensível não só para o rastreamento de sobrepeso/obesidade, como também para pressão arterial elevada e resistência insulínica, em escolares de seis a 10 anos / This study aims to correlate the waist-to-height ratio (WHtR) and the body mass index (BMI) with the cardiometabolic and inflammatory variables in 6-10 year-old school children; to evaluated the frequency of overweight/obesity and cardiometabolic disturbances, and to compare the 2000 Centers for Disease Control and Prevention (CDC) and 2007 World Health Organization (WHO) body mass index (BMI) references in the diagnosis of overweight/obesity and the cardiometabolic disturbances. Methods: a cross-sectional study which included 175 subjects, selected from the Reference Center for the Treatment of Children and Adolescents, in Campos, Rio de Janeiro. The subjects were classified according to the 2000 CDC and 2007 OMS BMI z scores as non obese (BMI < 1) and overweight/obese ones (BMI > 1). The analized cardiometabolic variables were systolic and diastolic blood pressure (SBP and DBP respectively), fasting glycemia, low and high density lipoproteins (LDL and HDL respectively), trigliceride (TG), homeostatic model assessment (HOMA-IR). As inflammatory markers we analized the ultra-sensitive Creactive protein (CRP) and the leucocyte count. Results: the WHtR mean of the overweight/obese group was higher than that of the non obese ones (0,58 ± 0,007 and 0,45 ± 0,004, respectively,p < 0,0001). There was correlation between the WHtR and BMI z score (r = 0,88, p < 0,0001), SBP (r = 0,51, p < 0,0001), DBP (r = 0,49, p < 0,0001), HOMA-IR (r = 0,83, p < 0,0001), HDL (r = -0,28, p < 0,0002, TG (r= 0,26, p < 0,0006), LDL (r = 0,25, p < 0,0008), and CRP (r = 0, 51, p < 0.0001). However, the WHtR was neither correlated with glycemia nor with the leucocyte count. The WHtR sensitivity was equivalent to that of the BMI in the diagnosis of all cardiometabolic variables. The highest WHtR sensitivity was to diagnose the SBP (80,0%), DBP (76,6%) and HOMA-IR (92,6%) alterations. The WHtR cut-off higher than 0,47 pointed out to insulin resistance diagnosis, but higher than 0,5, it did to the other metabolic disturbances. The frequency of overweight/obesity was 49,7% in these school children. Except for hypertriglyceridemia, all the remaining cardiometabolic disturbances were more frequent in the overweight/obese group. The 2007 WHO BMI reference reclassified 11 children more as obese than the 2000 CDC, who had means of SBP (1,71 ± 1,54) and DBP z scores (2,64 ± 1,83) and HOMA-IR (1,84 ± 0,98) similar to those of the obese ones (SBP = 1,25 ± 20,4; DBP = 1,94 ± 1,1 and HOMA-IR = 2,09 ± 1,12), but higher than those of the classified as overweight (SBP= 0,49 ± 1,34, p<0,023; DBP= 1,45 ± 0,97, p<0,04 and HOMA-IR= 1,24 ± 0,67, p<0,04). Conclusions: the WHtR was so sensitive as the 2007 WHO BMI z score in diagnosing the cardiometabolic and inflammatory risk. The 2007 WHO reference was the most sensitive not only to screen obesity, but also the high blood pressure and insulin resistance, in 6-10-year-old children

Os objetivos do estudo foram correlacionar a razão entre a circunferência abdominal e altura (CA/A) e o índice de massa corpórea (IMC) com as variáveis cardiometabólicas e inflamatórias em escolares de seis a 10 anos; avaliar a frequência de sobrepeso/obesidade e alterações cardiometabólicas e comparar o desempenho dos referenciais de índice de massa corpórea (IMC) do Centers for Disease Control and Prevention 2000 (CDC) e Organização Mundial de Saúde 2007 (OMS) no diagnóstico de sobrepeso/obesidade e alterações cardiometabólicas. Métodos: estudo de corte transversal, que incluiu 175 crianças, provenientes do Centro de Referência para Tratamento da Criança e do Adolescente (CRTCA), em Campos, Rio de Janeiro. As crianças foram divididas segundo os escores z do CDC e OMS em: não obesas (z do IMC <1) e sobrepeso/obesidade (z do IMC > 1). As variáveis cardiometabólicas analisadas foram: pressão arterial sistólica (PAS) e diastólica (PAD), glicose, lipoproteínas de baixa e alta densidades (LDL e HDL, respectivamente), triglicerídeos (TG), HOMA-IR. Como variáveis inflamatórias, analisamos proteína C reativa ultra-sensível (PCR) e leucometria. Resultados: a média da CA/A do grupo sobrepeso/obesidade foi maior que a do não obeso (0,58 ± 0,007 e 0,45 ± 0,004, respectivamente, p< 0,0001). Houve correlação significativa da CA/A com os escores z do IMC (r = 0,88, p < 0,0001), PAS (r= 0,51, p<0,0001), PAD (r= 0,49, p<0,0001), HOMA-IR (r=0,83, p<0,0001), HDL (r = -0,28, p< 0,0002), TG (r= 0,26, p<0,0006), LDL (r= 0,25, p<0,0008) e PCR (r= 0,51, p<0,0001). Contudo, a CA/A não se correlacionou com glicemia nem leucócitos. A sensibilidade da CA/A se equivaleu à do IMC no diagnóstico das alterações cardiometabólicas. A sensibilidade mais elevada da CA/A foi para o diagnóstico de alteração da PAS (80,0 %), PAD (76,6%) e HOMA-IR (92,6%). O ponto de corte superior a 0,47 foi sensível para o diagnóstico de resistência insulínica, mas acima de 0,50, para os demais distúrbios cardiometabólicos. A frequência de sobrepeso/obesidade nos escolares foi igual a 49,7%. Com exceção de hipertrigliceridemia, todas as outras alterações cardiometabólicas foram mais frequentes no grupo sobrepeso/obesidade (aumento de PA, p<0,0001; glicemia de jejum alterada, p < 0,0048; aumento de LDL, p< 0,015 e redução do HDL, p<0,0001). O referencial da OMS 2007 reclassificou 11 crianças a mais como obesas que o CDC, que apresentaram médias de escores z de PAS (1,71 ± 1,54), PAD (2,64 ± 1,83) e HOMA-IR (1,84 ± 0,98) semelhantes às médias das obesas (PAS = 1,25 ± 2,04; PAD = 1,94 ± 1,19 e HOMA-IR = 2,09 ± 1,12), mas superiores às médias das classificadas como sobrepeso (PAS = 0,49 ± 1,34, p < 0,023; PAD = 1,45 ± 0,97, p < 0,04 e HOMA-IR = 1,24 ± 0,67, p < 0,04 ). Conclusões: a razão CA/A foi tão sensível quanto IMC da OMS 2007 no diagnóstico do risco cardiometabólico e inflamatório. O referencial da OMS 2007 foi o mais sensível não só para o rastreamento de sobrepeso/obesidade, como também para pressão arterial elevada e resistência insulínica, em escolares de seis a 10 anos / This study aims to correlate the waist-to-height ratio (WHtR) and the body mass index (BMI) with the cardiometabolic and inflammatory variables in 6-10 year-old school children; to evaluated the frequency of overweight/obesity and cardiometabolic disturbances, and to compare the 2000 Centers for Disease Control and Prevention (CDC) and 2007 World Health Organization (WHO) body mass index (BMI) references in the diagnosis of overweight/obesity and the cardiometabolic disturbances. Methods: a cross-sectional study which included 175 subjects, selected from the Reference Center for the Treatment of Children and Adolescents, in Campos, Rio de Janeiro. The subjects were classified according to the 2000 CDC and 2007 OMS BMI z scores as non obese (BMI < 1) and overweight/obese ones (BMI > 1). The analized cardiometabolic variables were systolic and diastolic blood pressure (SBP and DBP respectively), fasting glycemia, low and high density lipoproteins (LDL and HDL respectively), trigliceride (TG), homeostatic model assessment (HOMA-IR). As inflammatory markers we analized the ultra-sensitive Creactive protein (CRP) and the leucocyte count. Results: the WHtR mean of the overweight/obese group was higher than that of the non obese ones (0,58 ± 0,007 and 0,45 ± 0,004, respectively,p < 0,0001). There was correlation between the WHtR and BMI z score (r = 0,88, p < 0,0001), SBP (r = 0,51, p < 0,0001), DBP (r = 0,49, p < 0,0001), HOMA-IR (r = 0,83, p < 0,0001), HDL (r = -0,28, p < 0,0002, TG (r= 0,26, p < 0,0006), LDL (r = 0,25, p < 0,0008), and CRP (r = 0, 51, p < 0.0001). However, the WHtR was neither correlated with glycemia nor with the leucocyte count. The WHtR sensitivity was equivalent to that of the BMI in the diagnosis of all cardiometabolic variables. The highest WHtR sensitivity was to diagnose the SBP (80,0%), DBP (76,6%) and HOMA-IR (92,6%) alterations. The WHtR cut-off higher than 0,47 pointed out to insulin resistance diagnosis, but higher than 0,5, it did to the other metabolic disturbances. The frequency of overweight/obesity was 49,7% in these school children. Except for hypertriglyceridemia, all the remaining cardiometabolic disturbances were more frequent in the overweight/obese group. The 2007 WHO BMI reference reclassified 11 children more as obese than the 2000 CDC, who had means of SBP (1,71 ± 1,54) and DBP z scores (2,64 ± 1,83) and HOMA-IR (1,84 ± 0,98) similar to those of the obese ones (SBP = 1,25 ± 20,4; DBP = 1,94 ± 1,1 and HOMA-IR = 2,09 ± 1,12), but higher than those of the classified as overweight (SBP= 0,49 ± 1,34, p<0,023; DBP= 1,45 ± 0,97, p<0,04 and HOMA-IR= 1,24 ± 0,67, p<0,04). Conclusions: the WHtR was so sensitive as the 2007 WHO BMI z score in diagnosing the cardiometabolic and inflammatory risk. The 2007 WHO reference was the most sensitive not only to screen obesity, but also the high blood pressure and insulin resistance, in 6-10-year-old children