[Association of various measurements of obesity and the prevalence of hypertension]

Anthropometric measures of central adiposity are highly concordant with predictors of cardiovascular disease risk in HIV patients

Background

Body fat redistribution and metabolic abnormalities found in HIV patients receiving highly active antiretroviral therapy (HAART) contribute to an atherogenic profile, increasing cardiovascular disease risk.

Objective

We aimed to evaluate adiposity measures/indexes and propose cutoffs associated with predictors of cardiovascular disease risk in HIV patients on HAART.

Design

To evaluate cardiovascular disease risk in this cross-sectional study, we conducted electrocardiogram exams and stress electrocardiography, measured the ankle brachial index and blood pressure arterial hypertension, conducted lipid biochemical tests, and measured blood glucose. We measured circumferences [waist (WC), hip, thigh, calf, neck, trunk] and skinfold thicknesses (biceps, triceps, subscapular, suprailiac), conducted bioelectrical impedance analysis (BIA), and calculated indexes [body mass index, waist-to-hip ratio, waist-to-thigh ratio, waist-to-calf ratio, waist-to-height ratio (WHtR), trunk-to-arm ratio, body mass index corrected for body fat mass, Body Adiposity Index, conicity index, body shape index, fat mass (percentage), and phase angle]. For evaluating the performance of all adiposity measures/indexes, we used receiver operating characteristic (ROC) curves.

Results

Measures of central adiposity WC and WHtR showed the best performances-WC area under the curve (AUC) for men: 0.83 (95% CI: 0.78, 0.89; P < 0.05); WC AUC for women: 0.86 (95% CI: 0.81, 0.91; P < 0.05); WHtR AUC for men: 0.83 (95% CI: 0.78, 0.88; P < 0.05); and WHtR AUC for women: 0.85 (95% CI: 0.80, 0.91; P < 0.05). All adiposity measures/indexes presented different cutoffs from those proposed for the HIV seronegative population. The cutoffs for WC were 87.75 cm (sensitivity: 82.2%; specificity: 75.5%) for men and 90.5 cm (sensitivity: 84.0%; specificity: 73.0%) for women.

Conclusions

The measures/indexes of central adiposity presented excellent associations with predictors of cardiovascular disease risk, and the use of the cutoffs proposed in the present study aims to contribute to the early identification of increasing risk of cardiovascular diseases, enabling interventions. This trial was registered at the Brazilian clinical trials registry Registro brasileiro de ensaios clínicos (Rebec) as RBR-9rcxbq.

Comparing the Ability of Anthropometric Indicators in Identifying Metabolic Syndrome in HIV Patients

BACKGROUND

Highly active antiretroviral therapy (HAART) can cause side effects in HIV patients, as the metabolic syndrome. Early identification of risk for development of cardiovascular diseases using available reliable and practical methods is fundamental. On this basis, the aim of this study was to compare the effectiveness of anthropometric indicators to identify metabolic syndrome in HIV patients on HAART.

METHODS

It is a cross-sectional study. A number of 280 stable HIV patients were studied. It measured weight, height, waist circumference (WC), hip circumference (HP), thigh circumference (TC) and calculated body mass index (BMI), body adiposity index (BAI), waist to hip ratio (WHR) and waist to thigh ratio (WTR). There was also a performance of biochemical tests of lipid profile and fasting glucose. Systemic blood pressure was measured. The criteria proposed by the National Cholesterol Education Program III (NCEP-ATP III) to metabolic syndrome classification was used. Individuals were divided in groups with or without metabolic alterations and their anthropometric indicators were compared. Receiver operating characteristic (ROC) curves were designed for each anthropometric indicator using the metabolic syndrome classification to identify sensitivity and specificity.

RESULTS

WC was a good tool to identify each metabolic disorder separately: total cholesterol (only females, p<0.05), triglycerides (only males, p<0.001), HDL cholesterol (p<0.05), LDL cholesterol (p<005) and fasting glycemic (p<005). WC also showed the best performance to identify metabolic syndrome in both genders (areas under the curve (AUCs): 0.79 and 0.76 for male and female, respectively), while BAI proved to be an inadequate indicator (AUCs: 0.63 and 0.67 for males and females), respectively, in this population.

CONCLUSIONS

The central adiposity measure (WC) had the best performance to identify metabolic syndrome, and it is a convenient, cheap and reliable tool that can be used in clinical practice routinely to prevent cardiovascular complications in HIV patients.

Consumo de bebida alcoólica, fatores socioeconômicos e excesso de peso: um estudo transversal no sul do Brasil

O objetivo do estudo foi investigar o consumo de álcool e verificar sua associação com escolaridade, renda e excesso de peso em uma amostra de mulheres. Trata-se de um estudo transversal com 317 mulheres. Aplicou-se um questionário padronizado e pré-codificado para determinar a quantidade, a frequência e o tipo de bebida alcoólica consumida. As mulheres foram classificadas em dois grandes grupos, conforme a quantidade de bebida consumida. O primeiro grupo "Consumo de Álcool", formado por duas subcategorias: (1) mulheres que bebiam no mínimo 10g/dia de etanol; (2) mulheres que referiram não consumir 10g/dia de etanol e as que beberam em algum período da vida ou previamente, mas que o deixaram de fazer. O segundo grupo, "Contato com Álcool", foi composto por três subcategorias: (1) bebedoras (mulheres que bebiam no mínimo 10g/dia de etanol), (2) ex-bebedoras (já beberam regularmente, mas deixaram de consumir a bebida) e (3) não bebedoras. Das investigadas, 30% eram bebedoras e 36,6% se declararam ex-bebedoras. Tinham sobrepeso 39,4% das participantes e 34,3% eram obesas. As investigadas com maior grau de instrução consumiam maior quantidade de álcool, quando comparadas às mulheres com menor escolaridade (analfabetas) que consumam menos (p = 0,010).

Muscular static strength test performance: comparison between normotensive and hypertensive workers

OBJECTIVE

The aim of the study was to compare static muscular strength test performance between hypertensive and normotensive workers, considering the hypothesis that hypertensive individuals have lower strength than normotensive individuals.

METHODS

The participants consisted of 354 workers (246 men and 108 women) who underwent height, body mass, waist circumference, systolic and diastolic blood pressure (BP) measurements, as well as right and left handgrip, and scapular and lumbar strength tests. Assessments were performed during three days in all three shifts, with workers from a candy and sweets factory located in Rio Claro, SP, Brazil. BP measurements were performed with a 10-minute interval, with the subject in the sitting position. Before the strength tests were performed, the workers were familiarized with the equipment; the highest value was recorded after two attempts at each test.

RESULTS

The results showed significant differences between hypertensive and normotensive individuals for age, body mass, body mass index, and waist circumference greater for hypertensive individuals. Regarding static muscle strength tests performance, the hypertensive individuals did not differ significantly from normotensive individuals; however, this difference was observed when groups divided by body mass index (BMI) were compared. The obesity group had strength values above those of the normal weight/overweight group among normotensive individuals, but this was not observed among the hypertensive individuals. As for the intragender comparison, there were no significant differences for the strength tests.

CONCLUSION

Normotensive and hypertensive workers showed no significant differences in the performance of static muscular strength tests; however, body mass and gender seem to affect the association between muscle strength and blood pressure.

Indices of body fat distribution for assessment of lipodysthrophy in people living with HIV/AIDS

BACKGROUND

Metabolic and morphological changes associated with excessive abdominal fat, after the introduction of Antiretroviral Therapy, increase the risk of cardiovascular disease in people living with HIV/AIDS(PLWHA). Accurate methods for body composition analysis are expensive and the use of anthropometric indices is an alternative. However the investigations about this subject in PLWHA are rare, making this research very important for clinical purpose and to advance scientific knowledge. The aim of this study is to correlate results of anthropometric indices of evaluation of body fat distribution with the results obtained by Dual-energy X-Ray Absorptiometry(DEXA), in people living with HIV/AIDS.

METHODS

The sample was of 67 PLWHA(39 male and 28 female), aged 43.6±7.9 years. Body mass index, conicity index, waist/hip ratio, waist/height ratio and waist/thigh were calculated. Separated by sex, each index/ratio was plotted in a scatter chart with linear regression fit and their respective Pearson correlation coefficients. Analyses were performed using Prism statistical program and significance was set at 5%.

RESULTS

The waist/height ratio presented the highest correlation coefficient, for both male (r=0.80, p<0.001) and female (r=0.87, p <001), while the lowest were in the waist/thigh also for both: male group (r=0.58, p<0.001) and female group (r=0.03, p=0.86). The other indices also showed significant positive correlation with DEXA.

CONCLUSION

Anthropometric indices, especially waist/height ratio may be a good alternative way to be used for evaluating the distribution of fat in the abdominal region of adults living with HIV/ADIS.

Prevalência de hipertensão arterialem crianças e adolescentes obesos

Há um incremento na carga de doenças crônicas que afetam a população mundial e, da mesma forma, uma significativa parcela da população brasileira. Figuram nesse contexto a hipertensão arterial e a obesidade, inclusive entre indivíduos de baixa faixa etária. Diante disso, este estudo objetivou investigar a prevalência de hipertensão arterial em crianças e adolescentes obesos, na tentativa de verificar sua manifestação conforme gênero e idade. Para tanto, foram avaliados 129 indivíduos obesos na faixa etária de 7 a 14 anos, de ambos os gêneros. A avaliação consistiu em medidas antropométricas e mensuração da pressão arterial. Posteriormente, as informações foram analisadas estatisticamente com auxílio do programa BioEstat 3.0, que indicou prevalência de hipertensão arterial em ambos os gêneros (masculino = 15,8% e feminino = 26,4%) sem diferirem estatisticamente entre si. Nos diferentes grupos etários, a doença também se manifestou, com destaque para os indivíduos de 13 e 14 anos (52,4%), os quais diferiram estatisticamente dos demais grupos etários. Com isso, concluiu-se que a hipertensão arterial se fez presente de forma marcante na população investigada, indicando que a obesidade pode interferir na elevação da pressão arterial de crianças e adolescentes.

Fatores associados a excesso de peso e concentração de gordura abdominal em adultos na cidade de Salvador, Bahia, Brasil

O objetivo foi identificar os fatores associados ao excesso de peso e concentração de gordura abdominal em adultos de ambos os sexos. Um estudo transversal envolvendo amostra representativa de 570 adultos de Salvador, Bahia, Brasil. A regressão de Poisson foi utilizada na análise, adotando-se o índice de massa corporal (IMC) e a circunferência da cintura como variáveis dependentes. Para as mulheres, a inadequação do IMC e da circunferência da cintura ocorreu com o aumento da idade e entre as que faziam dieta no momento do estudo, a história familiar de obesidade associou-se apenas com o IMC elevado. Para os homens, o IMC elevou-se na faixa etária de 30 a 39 e 50 a 59 anos. A circunferência da cintura elevou-se com a realização de três ou menos refeições-dia, com a hipertensão arterial, uso de bebida alcoólica e diminuiu entre mulatos e negros. Tanto IMC quanto circunferência da cintura elevaram-se com a historia familiar de infarto. Portanto são distintos os fatores que se associam ao excesso de peso e da gordura abdominal em homens e mulheres. Mas muitos deles podem ser modificados com a adoção do estilo de vida saudável.

Waist circumference cut-off values to predict the incidence of hypertension: an estimation from a Brazilian population-based cohort

BACKGROUND AND AIMS

Central obesity is a key component in the definition of the metabolic syndrome, but the cut-off values proposed to define abnormal values vary among different guidelines and are mostly based on cross-sectional studies. In this study, we identify the best cut-off values for waist circumference (WC) associated with the incidence of hypertension.

METHODS AND RESULTS

Participants for this prospectively planned cohort study were 589 individuals who were free of hypertension and selected at random from the community of Porto Alegre, Brazil. Hypertension was defined by a blood pressure measurement >or= 140/90 mmHg or the use of blood pressure lowering drugs. A logistic regression model established the association between WC and the incidence of hypertension. A receiver operating characteristics (ROC) curve analysis was used to select the best WC cut-off point to predict the incidence of hypertension. During a mean follow-up of 5.5+/-0.9 years, 127 subjects developed hypertension. The hazard ratios for the development of hypertension, adjusted for age, baseline systolic blood pressure, alcohol consumption, gender and scholarship were 1.02 (95% CI; 1.00-1.04; P=0.02) for WC. The best cut-off WC values to predict hypertension were 87 cm in men and 80 cm in women, with an area under the curve of 0.56 (95% CI; 0.47-0.64; P=0.17) and 0.70 (95% CI; 0.63-0.77; P<0.001), respectively.

CONCLUSION

Excess visceral adiposity is a major risk factor for hypertension in individuals living in communities in Brazil, and this risk begins at lower values of WC that those recommended by some guidelines.

Índice de massa corporal, circunferência da cintura e dobra cutânea triciptal na predição de alterações lipídicas em crianças com 11 anos de idade

OBJETIVO: Analisar a capacidade preditiva do índice de massa corporal (IMC), da circunferência da cintura (Ccin) e da dobra cutânea triciptal (TR) no diagnóstico de alterações lipídicas e sugerir pontos de corte para tais medidas na identificação da doença em crianças. METODOLOGIA: Avaliou-se o IMC, a Ccin, a TR e os níveis lipídicos de 374 escolares (11,25 ± 0,28 anos) da rede de ensino da cidade de Santa Maria, RS. A análise estatística foi realizada por meio da curva ROC (IC95%), da sensibilidade, da especificidade e dos valores preditivos. RESULTADOS: As variáveis antropométricas apresentaram capacidade diagnóstica apenas para TG no sexo feminino, CT e LCL-C no sexo masculino. CONCLUSÃO: Conclui-se que o IMC correspondente a 19,3 kg/m² é um valor diagnóstico para alterações no TG, no sexo feminino, e para CT e LDL-C, no sexo masculino. As concentrações elevadas de CT e LDL-C, no sexo masculino, também podem ser diagnosticadas a partir de valores superiores a 65,7 cm para Ccin e 21 mm para TR.

Distúrbios metabólicos e adiposidade em uma população rural

O objetivo deste estudo transversal foi investigar a prevalência de sobrepeso e adiposidade central (AC) e suas relações com alterações no metabolismo de lipídeos, glicose e níveis pressóricos em uma amostra de 287 indivíduos adultos residentes em uma comunidade rural do Estado de Minas Gerais. Foram realizadas comparações de médias dos indicadores metabólicos: lipoproteínas, glicose e níveis pressóricos, segundo categorias de sobrepeso e AC, usando análise de variância e teste de Tukey. A prevalência de sobrepeso foi de 24,8% (37,4% no sexo feminino; 11,5% no sexo masculino). A AC esteve presente em 28,1% das pessoas (50,3% no sexo feminino; 4,3% no sexo masculino). Indivíduos com AC apresentaram maiores valores médios de pressão arterial (HA), colesterol total, LDL, triglicérides e glicemia de jejum; e menores valores médios de HDL. Foram verificadas associações entre AC e HA, dislipidemia e hiperglicemia. Associações significativas entre sobrepeso e HA, dislipidemia e hiperglicemia também foram evidenciadas. Esses resultados confirmam o potencial efeito das alterações na composição corporal, principalmente em nível central, sobre o metabolismo lipídico e de glicose, e também sobre o aumento dos níveis pressóricos em populações da área rural.

[Accuracy of waist circumference and waist-to-hip ratio as predictors of dyslipidemia in a cross-sectional study among blood donors in Cuiabá, Mato Grosso State, Brazil]

This study evaluated the accuracy of anthropometric fat location indices (waist circumference and waist-to-hip ratio) as predictors of dyslipidemia, in addition to defining their respective cut-offs. The sample consisted of 416 healthy male blood donors from 20 to 58 years of age at the Blood Center in Cuiabá, capital of Mato Grosso State, Brazil. Serum lipids were determined through the enzymatic method. Data analysis through the ROC curve identified the best indicator and the cut-off with the largest statistically significant area under the ROC curve. The best cut-off points for waist-to-hip ratio and waist circumference were 0.90 and 85cm, respectively. The area under the ROC curve between waist circumference and high cholesterol/HDL relation included the 0.50 value, so waist circumference could not be considered a predictor of dyslipidemia. The best sensitivity and specificity were in the youngest group. Waist-to-hip ratio was a better predictor of dyslipidemia than waist circumference, although the latter showed better discriminating power to detect hypertriglyceridemia. The most accurate cut-off points were lower than those set by the World Health Organization.

Hipertensão, obesidade abdominal e baixa estatura: aspectos da transição nutricional em uma população favelada

OBJETIVO: Investigar, em mulheres de muito baixa renda, a prevalência e a associação entre a baixa estatura, o sobrepeso, a obesidade abdominal e a hipertensão arterial, discutindo os achados, segundo o processo de transição nutricional e a hipótese da programação fetal (hipótese Barker). MÉTODOS: Foram estudadas 223 mulheres de 18 a 65 anos, por meio dos seguintes indicadores: índice de massa corporal (kg/m²) >25 para sobrepeso + obesidade ou <18,5 para magreza; razão cintura-quadril > 0,8 para obesidade abdominal; pressão arterial sistólica e/ou diastólica >140/90mmHg para hipertensão; percentil 25 (1º quartil) para baixa estatura. RESULTADOS: A prevalência de sobrepeso + obesidade (35,9%) foi superior à de magreza (9,4%). A pressão diastólica associou-se com o índice de massa corporal (r=0,37; IC 95%: 0,01 <r² <0,26) e com a razão cintura-quadril (r=0,35; IC 95%: 0,01 <r² <0,25). Comparando-se os 1º e 4º quartis de estatura, encontraram-se os seguintes resultados, respectivamente, para a prevalência de hipertensão: 23,3% e 8,9% (odds ratio=3,08; p=0,03); para sobrepeso + obesidade: 41,7% e 35,7% (p=0,51); para o índice de massa corporal médio: 24,6 e 23,7 (p=0,27); para a média da razão cintura-quadril: 0,87 e 0,85 (p=0,04). CONCLUSÃO: A prevalência de sobrepeso/obesidade foi menor do que a de desnutrição. A baixa estatura, um indicador de desnutrição no início da vida, foi um importante fator de risco para a hipertensão arterial e para a obesidade abdominal. Apesar da miséria, a população parece estar passando pelo processo de transição nutricional. Os mecanismos resultantes da adaptação metabólica à desnutrição imposta no início da vida, parecem desempenhar importante papel na determinação desses achados.

Systemic hypertension, diabetes mellitus, and dyslipidemia in relation to body mass index: evaluation of a Brazilian population

OBJECTIVE: To determine the prevalence of systemic hypertension, diabetes mellitus, hypercholesterolemia, and hypertriglyceridemia in a Brazilian population in relation to body mass index. METHOD: Retrospective evaluation of 1213 adults (mean age: 45.2 ± 12.8; 80.6% females) divided into groups according to body mass index [normal (18.5 - 24.4 kg/m²); overweight (25 - 29.9 kg/m²); grade 1 obesity (30 - 34.9 kg/m²); grade 2 obesity (35 - 39.9 kg/m²), and grade 3 obesity (> 40 kg/m²)]. The prevalence of hypertension, diabetes mellitus, hypercholesterolemia, and hypertriglyceridemia were analyzed in each group. The severity of cardiovascular risk was determined. High-risk patients were considered those reporting 2 or more of the following factors: systemic hypertension, HDL < 35 mg/dL, total cholesterol > 240 mg/dL, triglycerides > 200 mg/dL when HDL < 35 mg/dL, and glycemia > 126 mg/dL. Moderate-risk patients were those reporting 2 or more of the following factors: systemic hypertension, HDL < 45, triglycerides > 200 mg/dL, and total cholesterol > 200 mg/dL. RESULTS: The prevalence of systemic hypertension, diabetes mellitus, hypertriglyceridemia, and low HDL-cholesterol levels increased along with weight, but the prevalence of hypercholesterolemia did not. The odds ratio adjusted for gender and age, according to grade of obesity compared with patients with normal weight were respectively 5.9, 8.6, and 14.8 for systemic hypertension, 3.8, 5.8, and 9.2 for diabetes mellitus and 1.2, 1.3, and 2.6 for hypertriglyceridemia. We also verified that body mass index was positively related to cardiovascular high risk (P < .001) CONCLUSION: In our population, cardiovascular risk increased along with body mass index.

Risk factors for cardiovascular disease in a Brazilian population-based cohort study

OBJECTIVE

Our aim was to investigate risk factors for cardiovascular disease (CVD) in a population-based Brazilian cohort.

DESIGN AND METHODS

A cohort study was conducted with 1091 individuals identified through multi-stage probability sampling in Porto Alegre, Brazil. Risk factors were investigated among demographic and anthropometric characteristics, including education, smoking habits, income, alcoholic beverage consumption, and blood pressure. A fatal or non-fatal episode of myocardial infarction, stroke, or heart failure, and cases of sudden death comprised the composite endpoint.

RESULTS

Vital status was determined in 982 (90.0%) of the participants of the original cohort after 6.0+/-1.7 years of follow-up. A total of 52 individuals presented a cardiovascular event. Male gender (hazard ratio (HR) 2.01, 95% CI 1.03-3.91), systolic blood pressure (mmHg) (HR 1.03, 95% CI 1.01-1.04) and alcohol consumption (g/day) (HR 1.001, 95% CI 1.00-1.003) were associated with the incidence of CVD after controlling for confounding. Body mass index (HR 1.05, 95% CI 0.99-1.11) and current or previous smoking (HR 1.65, 95% CI 0.83-3.26) showed a trend for a positive association.

CONCLUSIONS

We confirmed that male gender, systolic blood pressure, obesity and smoking are risk factors for cardiovascular disease in a Brazilian population. The positive association between alcohol consumption and incident CVD was unexpected and deserves replication.

Avaliação antropométrica e dietética de hipertensos atendidos em ambulatório de um hospital universitário

O objetivo deste trabalho foi avaliar o estado nutricional e o consumo de nutrientes de hipertensos, na faixa etária de 18 a 74 anos, atendidos ambulatorialmente no Hospital das Clínicas da Universidade Federal de Pernambuco. A amostra, escolhida ao acaso, foi composta por 156 indivíduos de ambos os sexos (51 homens e 105 mulheres). As análises mostraram uma elevada prevalência de pacientes (73,1%) com peso acima da média e entre eles a hipertensão se associou significativamente com a obesidade (Índice de Massa Corporal > 30 Kg/m²) e com o sobrepeso (Índice de Massa Corporal >25 e < 30 Kg/m²) mas não com a distribuição central de gordura. Em relação ao consumo de nutrientes, os achados desta pesquisa revelaram um baixo consumo energético, o qual não pode explicar a alta prevalência de sobrepeso e obesidade. De uma forma geral, exceto pelo cálcio, a ingestão média diária de nutrientes esteve adequada. No entanto, o consumo diário de sódio foi alto, 270 e 260 mEq para homens e mulheres, respectivamente.

[Childbirth and live newborns of adolescent and young adult mothers in the municipality of Feira de Santana, Bahia State, Brazil, 1998]

Data from the Brazilian Ministry of Health and the literature indicate that adolescents may be overrepresented in the prevalence of maternal morbidity and mortality and neonatal complications. This study focused on childbirth and live newborns among adolescent and young adult mothers in the municipality of Feira de Santana, Bahia, identifying risk factors for morbidity and mortality. A cross-sectional cohort study was conducted based on data from the Information System on Live Births (SINASC) in the municipality in 1998, totaling 5,279 live births among adolescent (10 to 19 years) and young adult mothers (20 to 24 years). Variables were age, schooling, prenatal care, gestational care, form of delivery, and birthweight. The authors measured the association between maternal age and the child's birthweight, while controlling potential confounders. Some 21.6% of live births were to adolescent mothers, 51.2% of whom had not finished primary school; there was an association between the 10 to 16-year age bracket and incomplete primary schooling, lack of prenatal care, and low and insufficient birthweight as compared to the other age brackets; there was also a high rate of underrecording in the SINASC. The results suggest the need for specific measures focusing on the reproductive health of adolescents in the municipality.

Erectile dysfunction is a marker for cardiovascular complications and psychological functioning in men with hypertension

The aim of this study was to investigate the incidence of cardiovascular complications in hypertensive patients with erectile dysfunction (ED). An anonymous questionnaire was mailed to 467 and received from 104 hypertensive male patients. Despite the low response rate of 22%, the following interesting findings could be observed: 70.6% of the patients who responded suffered from ED. The hypertensive patients with ED had significantly higher prevalence of cardiovascular complications (P < 0.05). The correlation between depression and low quality of life as well as between ED and low sexual satisfaction was also statistically significant (P = 0.05). ED in hypertensive patients can be considered as a marker for cardiovascular complications in this patient group.

Abdominal adiposity values associated with established body mass indexes in white, black and hispanic Americans. A study from the Third National Health and Nutrition Examination Survey

PURPOSE

To determine whether white, black and hispanic young (17-39y) and middle-aged (40-59y) adults, and elderly (60-90y) Americans have the same values of abdominal adiposity (estimated from waist circumference (WC) at the established levels of overweight (body mass index, BMI 25-29.9 kg/m2) and obesity (BMI > or = 30 kg/m2).

METHODS

Data (n=16,120) from the US Third National Health and Nutrition Survey were utilized. Age-adjusted linear regression analyses were used to estimate gender- and ethnic-specific WC values corresponding to overweight and obesity. Receiver operating characteristic (ROC) curves were also employed to determine the choices of WC values corresponding to the established BMI cut-off points. With ROC, gender- and ethnic-specific cut-off points producing the best combination of sensitivity and specificity were selected as optimal thresholds for WC values corresponding to the established BMI cut-off points.

RESULTS

WC values associated with the established BMI were lower in blacks and hispanics compared with whites. In men, the WC values that corresponded to overweight ranged from 89 to 106 cm, from 84 to 95 cm, and from 87 to 97 cm in whites, blacks and hispanics, respectively. The corresponding values for obesity ranged from 99 to 110 cm, from 96 to 107 cm, and from 97 to 108 cm. The WC values that corresponded to overweight in women ranged from 82 to 91 cm, from 81 in to 90 cm, and from 83 to 92 cm in whites, blacks and hispanics, respectively. The analogous values for obesity ranged from 94 to 101 cm, from 93 to 100cm, and from 94 to 101 cm.

CONCLUSIONS

The lack of higher WC values in blacks (particularly women) and hispanics at the same levels of BMI for whites challenges previously held assumptions regarding the role of abdominal adiposity in cardiovascular disease experienced by non-whites. Defining the anthropometric variables that satisfactorily describe reasons for ethnic differences in cardiovascular disease is one of the challenges for future research.

Predictive values of waist circumference for dyslipidemia, type 2 diabetes and hypertension in overweight White, Black, and Hispanic American adults

Waist circumferences (WC) >/=102 cm for men and >/=88 cm for women have been proposed by an expert panel as cut-points for identifying increased risk for the development of obesity comorbidities for most adults. The aim of this investigation was to examine the predictive values of these WC cut-points for hypercholesterolemia, low concentration of high (HDL-C), and high concentration of low (LDL-C) density lipoprotein cholesterol, hypertriglyceridemia, type 2 diabetes, and hypertension in overweight American adults. Data from NHANES III were utilized for the analysis. Predictive abilities were determined by calculating sensitivity, specificity, positive (PV+) and negative (PV-) predictive values in overweight subjects with BMI 25-29.9 kg/m(2). Sensitivity of WC cut-point was stronger for high LDL-C compared to other risk factors with the highest values recorded in the 40-59 and 60-69 year age groups in men and women, respectively. PV+ of WC cut-points for dyslipidemia, type 2 diabetes, and hypertension were low in men compared to women. PV+ tended to increase with age, from 19-39, 40-59 to 60-90 year age groups in Whites, Blacks, and Hispanic men. In men, the highest PV+ were recorded for hypertriglyceridemia in the 60-90 years old groups, with values of 71.6%, 52.5%, and 43.3% in Whites, Blacks, and Hispanics, respectively. The CVD risk factor associated with the highest PV+ in women was diabetes with values of 97.2% in Whites and 88.9% in Blacks, and hypertriglyceridemia with a value of 93.8% in the 17-39 year age group in Hispanics. Among Black men 40-59 years of age, only 32% of a population of overweight hypertensives were detected by the WC cut-points, and among Black women, 40-59 years of age, only 54% were detected. Given the low sensitivity of these cut-points for detecting hypertension, one of the major co-morbidities of obesity, these cut-points failed to provide adequate evidence for the use of WC in determining or evaluating patients as to co-morbid states. We recommend further studies to determine a set of specific cut-points associated with increased risk of CVD in different population groups.

Predictive value of abdominal obesity cut-off points for hypertension in blacks from west African and Caribbean island nations

BACKGROUND

Waist circumferences (WC) >/=94 cm for men and >/=80 cm for women (action level I) and >/=102 cm for men and >/=88 cm for women (action level II) have been suggested as limits for health promotion purposes to alert the general public to the need for weight loss. In this analysis we examined the ability of the above cut-off points to correctly identify subjects with or without hypertension in Nigeria, Cameroon, Jamaica, St Lucia and Barbados. We also determined population- and gender-specific abdominal adiposity cut-off points for epidemiological identification of risk of hypertension.

METHODS

Waist measurement was made at the narrowest part of the torso as seen from the front or at midpoint between the bottom of the rib cage and 2 cm above the top of the iliac crest. Sensitivity and specificity of the established WC cut-off points for hypertension were compared across sites. With receiver operating characteristics (ROC), population- and gender-specific cut-off points associated with risk of hypertension were determined over the entire range of WC values.

RESULTS

Predictive abilities of the established WC cut-off points for hypertension were poor compared to the specific cut-off points estimated for each population. Different values of WC were associated with increased risk of hypertension in these populations. In men, WC cut-off points of 76, 81, 80, 83 and 87 cm provided the highest sensitivity for identifying hypertensives in Nigeria, Cameroon, Jamaica, St Lucia and Barbados, respectively. The analogous cut-off points in women were 72, 82, 85, 86 and 88 cm.

CONCLUSIONS

The waist cut-off points from this study represent values for epidemiological identification of risk of hypertension. For the purpose of health promotion, the decision on what cut-off points to use must be made by considering other additional factors including overall impact on health due to intervention (e.g. weight reduction) and potential burden on health services if a low cut-off point is employed. There is a need to develop abdominal adiposity cut-off points associated with increased risks for cardiovascular diseases in different societies, especially for those populations where the distribution of obesity and associated risk factors tends to be very different from those of the technologically advanced nations. International Journal of Obesity (2000) 24, 180-186