Do differences in waist circumference modify the relationships among body mass index, insulin resistance, and related cardiometabolic risk factors in apparently healthy women?

OBJECTIVE: The aims of the study were to (1) compare the cardiometabolic risk profile between insulin-resistant and non-insulin-resistant women within similar body mass indexes (BMIs) and waist circumference (WC) groupings and (2) test the hypothesis that measurements of BMI are not inferior to WC in identifying insulin resistance. METHODS: The sample consisted of 899 women without known cardiovascular disease or diabetes. BMI was used to divide participants in normal (<25.0 kg/m(2)), overweight (≥25-29.9 kg/m(2)), and obese (≥30.0 kg/m(2)) subgroups, and waist circumference ≥88 cm was used to identify women with or without abdominal obesity. The 25% of the population with highest fasting insulin concentrations was classified as insulin resistant. BMI, WC, blood pressure, and fasting plasma glucose, insulin, triglyceride, and high-density lipoprotein cholesterol concentrations were compared using analysis of covariance (ANCOVA). The relationships between obesity and insulin resistance were analyzed using univariate, multivariate, and logistic regression. RESULTS: Triglyceride and glucose concentrations were higher and high-density lipoprotein cholesterol concentrations lower in the insulin-resistant group in each BMI category, as was the case when comparing by abdominal obesity. In the univariate analysis, correlations between obesity and the individual cardiometabolic risk factor were significant but weak. In multivariate analysis including both indices, only body mass independently predicted insulin resistance. CONCLUSION: Insulin-resistant women were at greater cardiometabolic risk, irrespective of adiposity category. Obesity contributed to a modest variability in insulin resistance, and abdominal obesity does not add to the ability of BMI to predict insulin resistance.

Comparison of the abilities of the plasma triglyceride/high-density lipoprotein cholesterol ratio and the metabolic syndrome to identify insulin resistance.

This study compares the ability of an elevated triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio, using sex-specific cut-points, to identify insulin-resistant individuals within a population without known cardiac disease or diabetes with that obtained using the diagnostic criteria of the metabolic syndrome (MetS). Measurements were made of waist circumference (WC), systolic and diastolic blood pressure, fasting plasma glucose, fasting plasma insulin (FPI), plasma TG and plasma HDL-C concentrations in 1102 women and 464 men. These data were used to classify subjects as being insulin resistant (FPI concentration in the upper quartile) and having the MetS or an elevated TG/HDL-C ratio (>2.5 and >3.5 for women and men, respectively). The sensitivity and specificity with which the two indices identified insulin-resistant subjects were similar (43% and 81% for TG/HDL-C ratio and 45% and 82% for MetS), as the number of individuals was found with either an elevated TG/HDL-C ratio (n = 386) or the MetS (n = 384). Eighty-one per cent of the individuals were identified concordantly. Cardio-metabolic risk profiles in 'low-risk' individuals identified by a low TG/HDL-C ratio were comparable to those who did not have the MetS, and this was also the case when comparing 'high-risk' groups identified by having the MetS or an elevated TG/HDL-C ratio. These findings suggest that TG/HDL-C concentration ratio is as adequate as MetS diagnosis to identify insulin-resistant subjects.

Relation among the plasma triglyceride/high-density lipoprotein cholesterol concentration ratio, insulin resistance, and associated cardio-metabolic risk factors in men and women.

Results of recent studies using the ratio of plasma triglyceride (TG) to high-density lipoprotein (HDL) cholesterol concentration to identify insulin-resistant patients at increased cardiometabolic risk have emphasized that the cut point used for this purpose will vary with race. Because TG and HDL cholesterol concentrations vary with gender, this analysis was initiated to define gender-specific plasma TG/HDL cholesterol concentration ratios that best identified high-risk subjects among women (n = 1,102) and men (n = 464) of primarily European ancestry. Insulin resistance was defined as the 25% of the population with the highest values for fasting plasma insulin concentration and homeostasis model assessment of insulin resistance. Using TG/HDL concentration ratios >2.5 in women and >3.5 in men identified subgroups of men and women that were comparable in terms of insulin resistance and associated cardiometabolic risk, with significantly higher values for fasting plasma insulin, homeostasis model assessment of insulin resistance, blood pressure, body mass index, waist circumference, and glucose and TG concentrations and lower HDL cholesterol concentrations than in women and men below these cut points. The sensitivity and specificity of these gender-specific cut points to identify insulin-resistant subjects were about 40% and about 80%, respectively. In conclusion, the plasma TG/HDL cholesterol concentration ratio that identifies patients who are insulin resistant and at significantly greater cardiometabolic risk varies between men and women.

Optimal uric acid threshold to identify insulin resistance in healthy women.

BACKGROUND: Identifying insulin-resistant (IR) individuals is an issue of particular interest in the assessment of cardiometabolic risk, but there is no simple way to accomplish this task. Our aims were to determine the relationship between uric acid and insulin resistance and to define the optimal uric acid cutoff to identify insulin resistance in women. METHODS: A population-based sample of 588 women without cardiovascular diseases, diabetes, or low glomerular filtration rate (GFR) was divided according to uric acid tertiles. Systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting glucose, low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), TG/HDL-C ratio, insulin [fasting plasma insulin (FPI)], and homeostasis model assessment of insulin resistance (HOMA-IR) were compared between the mentioned tertiles. Receiver operating characteristic (ROC) curves were constructed to determinate the optimal cutoff of uric acid and identify IR individuals defined by the top tertile of FPI and HOMA-IR. The same variables were compared using the top tertile of uric acid and the maximum Youden index as cutoffs. The P values were adjusted by age, GFR, and body mass index (BMI) using analysis of covariance (ANCOVA). RESULTS: FPI, HOMA-IR, and all of the cardiometabolic risk factors increased through uric acid tertiles. Both cutoffs of uric acid, estimated by the top tertile and by ROC, were identical (4.0 mg/dL). FPI, HOMA-IR, SBP, DBP, TG, TG/HDL-C ratio, and fasting glucose were higher, whereas HDL-C was lower in women who had uric acid levels >4.0 mg/dL. All of the differences remained significant after the adjustment by age and GFR. CONCLUSION: In healthy women, uric acid levels >4.0 mg/dL were associated with all the markers of IR.

Prevalencia de tabaquismo y factores de riesgo cardiovascular en el casco urbano de una localidad rural de la Provincia de Buenos Aires / Smoking habit prevalence and cardiovascular risk factors in a town located in a rural area of the Buenos Aires province, Argentina

Objetivo: determinar prevalencia de tabaquismo en población general y en individuos con alto riesgo cardiovascular.Métodos: Se realizó una encuesta de tabaquismo y factores de riesgo cardiovascular en una muestra poblacional aleatoria (≥ 15 años) de San Andrés de Giles, Bs As. Seconsideró fumadores actuales a quienes habían fumado más de 100 cigarrillos y fumaban actualmente y ex fumadores a quienes habían fumado más de 100 cigarrillos y abandonado. Analizamos: instrucción, vivienda, ingresos, actividad física, consumo de alcohol, hipertensión, diabetes, obesidad, dislipemia, sindrome metabólico, antecedentes de infarto, angina de pecho y accidente cerebrovascular. Resultados: Fueron encuestados 1091 mujeres (40.8±0.5 años) y 500 varones (40.4±0.8 años). La prevalencia ajustada por edad de fumadores actuales fue 32.8 en varones(IC95% 28.7-36.9) y 25.4 en mujeres (IC95% 22.9-28.0). En el grupo 15-24 años 41.8% de los varones y 31.5% de las mujeres eran fumadores actuales. Del total de fumadores actuales, habían pensado dejar 56.0% y fijarían fecha en 30 días 29.0%. No hubo diferencias en la prevalencia según el nivel de educación (p=0.699). La prevalencia defumadores actuales fue mayor en aquellos sin vivienda propia (p<0.001), en quienes consumían alcohol (p<0.001) y en quienes no realizaban actividad física (p=0.003). Eran fumadores actuales 24.5% de los hipertensos, 15.4% de los diabéticos, 25.0% de los obesos, 22.9% de los dislipémicos, 20.9% de los con síndrome metabólico y 27.1% de los con enfermedad cardiovascular.Conclusiones: El tabaquismo estuvo fuertemente asociado a la falta de actividad física y al consumo de alcohol y una alta proporción de sujetos con alto riesgo cardiovascular continúan fumando.

Objetive: To determine the prevalence of the tobacco smoking habit in the general population and in individuals with high cardiovascular risk. Methods: A population-based cross-sectional survey took place in a random sample ofthe inhabitants aged 15 years and more at San Andres de Giles, Buenos Aires, Argentina. People who had smoked at least 100 cigarettes in their life and still smoked were defined as current smokers, while people that had smoked at least 100 cigarettes but had quitsmoking were considered former smokers. We evaluated: 1-education level, 2-access to housing, 3-self perception of income, 4-regular physical activity, 5-alcohol consumption, 6-hypertension, 7-diabetes, 8-obesity, 9-dyslipidemia, 10-metabolic syndrome (NCEPATPIII criteria), 11-history of myocardial infarction, angina and stroke.Results: The sample included 1091 women (40.8 ± 0.5 years) and 500 males (40.4 ± 0.8 years). The prevalence of current smokers was 32.8 in men (CI 95% 28.7-36.9) and 25.4 inwomen (CI95% 22.9-28.0). In the age group that included people between the ages 15 to 24 years, 41.8% of men and 31.5% of women were current smokers. 56.0% of the current smokers had thought about quitting and 29.0% were willing to fix a date within the next 30days. There were no significant differences according to education level (p=0.699). Alcohol consumption (p<0.001) and lack of regular physical activity (p=0.003) were associatedwith a high prevalence of current smokers. 24.5% participants were hypertensives, 15.4% diabetics, 25.0% obeses and 22.9% dyslipidaemics; 20.9% had metabolic syndrome and27.1% of those with cardiovascular disease, were current smokers.Conclusion: There were strong relationships between smoking, alcohol consumption and lack of physical activity. A high proportion of subjects with high cardiovascular risk were current smokers.

Relationships among insulin resistance, obesity, diagnosis of the metabolic syndrome and cardio-metabolic risk.

The aim of this study is to test the hypotheses that: 1) diagnosing the metabolic syndrome does not effectively identify insulin-resistant (IR) individuals; and 2) waist circumference (WC) is no better than body mass index (BMI) in predicting insulin resistance or the components of the metabolic syndrome (MetS). Measurements of BMI, WC, blood pressure, and fasting plasma glucose, insulin (FPI), triglycerides (TG), and HDL-cholesterol (HDL-C) concentrations were made in 1,300 adults, without known cardiovascular disease (CVD) or drug treatment of hypertension or diabetes. Receiver operating characteristic curves were used to determine the ability of the MetS, and its components, to identify IR individuals. In addition, comparisons were made of CVD risk factors following division of the population into quartiles of FPI concentrations, and univariate and multiple regression analysis used to compare the ability of WC, BMI, and FPI as predictors of MetS components. The MetS was no more effective in identifying IR individuals than several individual components (sensitivity~40%), and IR individuals not identified were at significantly increased CVD risk. FPI concentration was the best predictor of an abnormal glucose, TG, and HDL-C, whereas the adiposity indices were better predictors of abnormal blood pressure. The relationship between BMI and WC with the MetS and its components seemed comparable.

Glomerular filtration rate, cardiovascular risk factors and insulin resistance.

The aim of this paper was to study the estimated glomerular filtration rate (eGFR), its changes with age, and its association with systolic blood pressure (SBP) and diastolic BP (DBP), indicators of obesity, dyslipemia, insulin resistance and inflammation on a random population sample. BP, weight, size and waist circumference (WC) were recorded at home. Fasting morning blood samples were analysed. The eGFR was calculated with MDRD (eGFR-MDRD), Cockroft-Gault (eGFR-CG) adjusted to 1.73 m2 and reciprocal of serum creatinine (100/serum cretinine). A total of 1016 individuals, 722 females (41.97 +/- 0.66 years old) and 294 males (42.06 +/- 0.99 years old), completed the laboratory tests. The mean of 100/Scr was 115.13 +/- 0.60 (dl/mg), the mean eGFR-CG was 98.48 +/- 0.82 ml/min/1.73 m2; the mean eGFR-MDRD was 85.15 +/- 0.58 ml/min/1.73 m2. The eGFR-MDRD decreased with age and with the number of risk factors in both sexes. The eGFR-MDRD < 60 ml/min/1.73 m2 adjusted prevalence was 6.2 per 100 inhabitants (CI 95%, 4.7-7.7), 3.6 (CI 95%, 1.5-5.7) in males and 8.6 (CI 95%, 6.6-10.6) in females. The bivariate analysis showed that the eGFR-MDRD correlates inversely with age, SBP, DBP WC, BMI, serum glucose, serum total cholesterol, LDL cholesterol, serum triglycerides, serum uric acid and, in males, with C-reactive-protein. There was no correlation with either insulinemia or HOMA. The mean eGFR value, its association with cardiovascular risk factors and the prevalence of eGFR < 60 ml/min/1.73 m2 found in a rural population of Argentina are similar to those found in other parts of the world.

Glomerular filtration rate, cardiovascular risk factors and insulin resistance / Filtrado glomerular, riesgo cardiovascular y resistencia a la insulina

The aim of this paper was to study the estimated glomerular filtration rate (eGFR), its changes with age, and its association with systolic blood pressure (SBP) and diastolic BP (DBP), indicators of obesity, dyslipemia, insulin resistance and inflammation on a random population sample. BP, weight, size and waist circumference (WC) were recorded at home. Fasting morning blood samples were analysed. The eGFR was calculated with MDRD (eGFR-MDRD), Cockroft-Gault (eGFR-CG) adjusted to 1.73 m² and reciprocal of serum creatinine (100/serum cretinine). A total of 1016 individuals, 722 females (41.97 ± 0.66 years old) and 294 males (42.06 ± 0.99 years old), completed the laboratory tests. The mean of 100/Scr was 115.13 ± 0.60 (dl/mg), the mean eGFR-CG was 98.48 ± 0.82 ml/min/1.73 m²; the mean eGFR-MDRD was 85.15 ± 0.58 ml/min/1.73 m². The eGFR-MDRD decreased with age and with the number of risk factors in both sexes. The eGFR-MDRD < 60 ml/min/1.73 m² adjusted prevalence was 6.2 per 100 inhabitants (CI 95%, 4.7-7.7), 3.6 (CI 95%, 1.5-5.7) in males and 8.6 (CI 95%, 6.6-10.6) in females. The bivariate analysis showed that the eGFR-MDRD correlates inversely with age, SBP, DBP WC, BMI, serum glucose, serum total cholesterol, LDL cholesterol, serum triglycerides, serum uric acid and, in males, with C-reactive-protein. There was no correlation with either insulinemia or HOMA.The mean eGFR value, its association with cardiovascular risk factors and the prevalence of eGFR < 60 ml/min/1.73 m² found in a rural population of Argentina are similar to those found in other parts of the world.

El objetivo fue evaluar en una muestra poblacional aleatoria el filtrado glomerular estimado (FGe), sus cambios con la edad y su asociación con presión arterial sistólica (PAS) y diastólica (PAD), indicadores de obesidad, dislipemia, resistencia a la insulina e inflamación. En cada domicilio fueron medidos presión arterial, peso y talla y perímetro de la cintura (PC). Se analizaron muestras de sangre en ayunas y fue calculado el FGe usando las fórmulas de MDRD (FGe-MDRD) y Cockroft-Gault (FGe-CG) ajustado a 1.73 m², y la inversa de la creatinina sérica (100/CrS). Completaron el protocolo de laboratorio 1016 sujetos, 722 mujeres (41.97 ± 0.66 años) y 294 varones (42.06 ± 0.99 años). La media de 100/Crs fue 115.13 ± 0.60 (dl/mg), la del FGe-CG 98.48 ± 0.82 ml/min/1.73 m² y la del FGe-MDRD 85.15 ± 0.58 ml/min/1.73 m² (CI 95% 84.00-86.29). El FGe-MDRD disminuyó con la edad y con el número de factores de riesgo cardiovascular en ambos sexos. La prevalecencia ajustada de FGe-MDRD < 60 ml/min/1.73 m² fue 6.2 por 100 habitantes (CI 95%, 4.7-7.7); 3.6 (CI 95%, 1.5-5.7) en varones y 8.6 (CI 95%, 6.6- 10.6) en mujeres. El análisis bivariado mostró correlación inversa del FGe-MDRD con edad, PAS, PAD, PC, IMC, glucemia, colesterolemia total, colesterol-LDL, trigliceridemia, uricemia y, en varones, con la proteina-C-reactiva. No hubo correlación con insulinemia u HOMA. La media del FGe, su asociación con factores de riesgo cardiovascular y la prevalecencia de FGe < 60 ml/min/1.73 m² fueron similares a los hallados en otras partes del mundo.