Evaluation of waist-to-height ratio as a predictor of cardio metabolic risk in 6 to 10 years 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). 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 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