Risk of cardiovascular disease according to blood pressure categories in an argentinian cohort.

BACKGROUND: Hypertension is a recognized strong risk factor for cardiovascular disease. However, no data was available in our country to quantify the relationship between blood pressure and cardiovascular event. OBJECTIVE: to quantify the risk of cardiovascular events according to blood pressure categories. METHODS: A prospective epidemiological study was conducted in 1526 inhabitants from Rauch City, (Buenos Aires, Argentina) between 1997 and 2012. Subjects were classified into one of these blood-pressure categories: 1-optimal, 2-normal, 3-high-normal, 4-grade 1 hypertension, 5-grade 2 hypertension and 6-grade 3 hypertension. The first CVD event, including unstable angina pectoris, fatal and non-fatal myocardial infarction, myocardial revascularization, and fatal or non-fatal stroke, was defined as the primary endpoint. Multivariable Cox proportional-hazards regression models were used to estimate the relative risk (HR) of CVD according to base-line blood-pressure categories. RESULTS: In 2012, 1124 individuals (73.7% of the baseline sample), 719 women and 405 men (in 1997, aged 45±16 and 46±16 respectively) or their relatives in case of death, could be surveyed again in order to obtain information concerning incident CVD events. Cardiovascular event rates and HR values increased in a stepwise manner across the blood pressure categories (p for trend across categories <0.001 in both sex); however, in subjects aged ≥55 years a j-curve phenomenon was observed, showing the lowest incidence in the high-normal category. In all categories CVD events rates were higher for men. CONCLUSION: This study quantified relationships between BP and CVD starting from high-normal blood pressure in Argentina.

Blood pressure response to a community-based program and long-term cardiovascular outcome.

BACKGROUND: The significance in terms of the cardiovascular outcome of different patterns of blood pressure (BP) response to community-based activities has not been previously studied. The aim of our study was to evaluate the relationship between changes of BP observed during a community-based program and long-term rate of cardiovascular disease (CVD) events. METHODS: A program focused on the prevention of CVDs was implemented in a small city in Argentina over a 6-year period (1997-2003). The program was evaluated using a cohort of 1,526 randomly selected individuals. The population's mean systolic BP (SBP) decreased approximately 5mm Hg, but BP changes were heterogeneous. Eight years after the intervention had stopped, 1,124 individuals of the cohort were surveyed to evaluate incident CVD events. The sample was divided into 3 SBP change categories during the intervention: decrease (< -5mm Hg), no change (-5 to 5mm Hg) and increase (> 5mm Hg). Cox models were used to estimate the hazard ratio (HR) of CVD events for each category adjusted for age, sex, and baseline BP. RESULTS: At the end of the intervention, individuals who had increased their SBP showed an adjusted HR for CVD that was double those whose SBP levels decreased or did not change. An inverse relationship between baseline SBP and ΔSBP was observed: individuals with an increase in BP during the intervention had lower SBP at the beginning of the study. CONCLUSIONS: BP increase during the community-based program was an independent predictor of CVD events.

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.

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.