Circulating angiotensin-(1-7) is decreased in patients with isolated nocturnal hypertension

Isolated nocturnal hypertension (INHT), defined as nighttime elevated blood pressure (BP) with normal daytime BP assessed by ambulatory BP monitoring, is associated with higher cardiovascular morbidity and mortality. We hypothesized that an alteration in the circulating renin-angiotensin system (RAS) contributes to INHT development. We examined circulating levels of angiotensin (Ang) (1-7) and Ang II and ACE2 activity in 26 patients that met the INHT criteria, out of 50 that were referred for BP evaluation (62% women, 45 ± 16 years old). Those with INHT were older, had a higher BMI, lower circulating Ang-(1-7) (P = 0.002) and Ang II levels (P = 0.02) and no change in ACE2 activity compared to those normotensives. Nighttime DBP was significantly correlated with Ang-(1-7) and Ang II levels. Logistic regression showed significant association in Ang-(1-7) and Ang II levels with INHT. Our study reveals differences in circulating RAS in individuals with INHT.

[Prevalence, knowledge and control of arterial hypertension in vulnerable neighborhoods of Argentina: A Cross-sectional Study]

INTRODUCTION

Hypertension (HTN) represents the primary individual risk factor, contributing significantly to the global burden of cardiovascular diseases (CVD). In our country, epidemiological research has highlighted substantial variations in the prevalence of these risk factors across different populations. However, there is a lack of epidemiological studies assessing exclusive cardiovascular risk factors within vulnerable neighborhoods characterized by extremely limited economic resources, sociocultural challenges, and inadequate healthcare access.

METHODS

A multicenter cross-sectional observational study was conducted among individuals residing in economically deprived and marginalized communities, including informal settlements and underprivileged neighborhoods. Simple random sampling of households was employed. Blood pressure measurements, anthropometric assessments, and epidemiological, economic, and sociocultural questionnaires were administered. Results encompass prevalence rates, awareness levels, and blood pressure control across diverse regions. Logistic regression was utilized to identify independent variables influencing primary outcomes.

RESULTS

A total of 989 participants were analyzed. The overall prevalence of hypertension was 48.2%. About 82% had a body mass index (BMI) >25. Approximately 45.3% had less than 6 years of formal education. Independent association was established between education levels below 6 years and higher hypertension prevalence. Among hypertensive individuals, 44% were unaware of their condition, with only 17.2% achieving control, correlated with having health insurance and a higher educational background. Merely 24% were receiving combined therapy.

CONCLUSION

The prevalence of hypertension within vulnerable neighborhoods is alarmingly high, surpassing rates in other social strata. Knowledge, treatment, and control levels of hypertension are suboptimal, comparable to other populations. Inadequate use of combination therapy was observed. This study underscores the urgent need for targeted interventions addressing cardiovascular risk factors in poor areas to mitigate the burden of CVD.

Uncontrolled and masked uncontrolled blood pressure in treated pregnant women with chronic hypertension and risk for preeclampsia/eclampsia

To analyze the relationship between the level of BP achieved with treatment and the risk for development of preeclampsia/eclampsia (PE), we conducted a historical cohort study on 149 consecutive pregnant women with treated chronic hypertension, evaluated between January 1, 2016, and November 31, 2022. According to office BP readings and ambulatory blood pressure monitoring (ABPM) performed after 20 weeks of gestation, the cohort was classified in controlled hypertension, white-coat uncontrolled hypertension, masked uncontrolled hypertension and sustained hypertension. Risks for the development of PE were estimated using logistic regression. One hundred and twenty-four pregnant women with a control BP evaluation were included in this analysis. The rates of PE were 19.4%, 27.3%, 44.8% and 47.1% for controlled, white-coat uncontrolled, masked uncontrolled and sustained uncontrolled hypertension, respectively. Compared with women with controlled hypertension, the relative risk for PE increased markedly in women with sustained uncontrolled (OR 3.69, 95% CI, 1.19-11.45) and masked uncontrolled (OR 3.38, 95% CI, 1.30-11.45) hypertension, but not in those with white-coat uncontrolled (OR 1.56 95% CI, 0.36-6.70); adjustment for covariates did not modify the results. Each mmHg higher of systolic and diastolic daytime ABPM increased the relative risk for PE ~4% and ~5%, respectively. Each mmHg higher of systolic and diastolic nocturnal BP increased the risk ~5% and ~6%, respectively. When these risks were adjusted for ABPM values in opposite periods of the day, only nocturnal ABPM remained as a significant predictor. In conclusion, masked uncontrolled hypertension implies a substantial risk for the development of PE, comparable to those of sustained uncontrolled. The presence of nocturnal hypertension seems important.

Hypertension arising after 20 weeks of gestation: gestational hypertension or masked chronic hypertension?

The objectives of this study were 1-to evaluate the prevalence of masked chronic hypertension in pregnant women classified as gestational hypertension 2-to compare the risks of developing preeclampsia in true gestational hypertension vs those women classified as having gestational hypertension but who had had masked hypertension in the first half of pregnancy. We conducted a cohort study in consecutive high-risk pregnancies who were evaluated before 20 weeks of gestation. Women who developed gestational hypertension (normotension in the office before 20 weeks of gestation and office BP ≥ 140/90 mmHg and/or antihypertensive treatment in the second half of gestation) were divided, according to an ABPM performed before 20 weeks of pregnancy, in two subgroups: subgroup 1-if their ABPM was normal, and subgroup 2-if they had masked chronic hypertension. Risks for preeclampsia (PE) were estimated and compared with normotensive women. Before 20 weeks of gestation, 227 women were evaluated (age 32 ± 6 years, median gestation age 15 weeks); 67 had chronic hypertension (29.5%). Of the remaining 160, 39 developed gestational hypertension (16 in subgroup 1 and 23 insubgroup 2. Compared with normotensive pregnant women, subgroup 1 of women with gestational hypertension did not increase the risk of developing PE (OR = 0.76, 95% CI = 0.16-6.65). Conversely, subgroup 2 of gestational hypertension increased the risk of PE more than 4 times (0R = 4.47 CI = 1.16-12.63). Risk estimation did not change substantially after the adjustment for multiple possible confounders. In conclusion, the59% of women initially diagnosed as gestational hypertensive according to current recommendations had masked chronic hypertension and a very high risk of developing PE.

Ambulatory Blood Pressure Monitoring for Diagnosis and Management of Hypertension in Pregnant Women

Hypertension disorders during pregnancy has a wide range of severities, from a mild clinical condition to a life-threatening one. Currently, office BP is still the main method for the diagnosis of hypertension during pregnancy. Despite of the limitation these measurements, in clinical practice office BP of 140/90 mmHg cut point is used to simplify diagnosis and treatment decisions. The out-of-office BP evaluations are it comes to discarding white-coat hypertension with little utility in practice to rule out masked hypertension and nocturnal hypertension. In this revision, we analyzed the current evidence of the role of ABPM in diagnosing and managing pregnant women. ABPM has a defined role in the evaluation of BP levels in pregnant women, being appropriate performing an ABPM to classification of HDP before 20 weeks of gestation and second ABMP performed between 20-30 weeks of gestation to detected of women with a high risk of development of PE. Furthermore, we propose to, discarding white-coat hypertension and detecting masked chronic hypertension in pregnant women with office BP > 125/75 mmHg. Finally, in women who had PE, a third ABPM in the post-partum period could identify those with higher long-term cardiovascular risk related with masked hypertension.

Masked hypertension and neonatal outcome in high-risk pregnancies

We previously showed that masked hypertension is a frequent finding in high-risk pregnancies and a strong predictor of preeclampsia/eclampsia. However, neonatal consequences of masked hypertension have not been deeply analyzed. Consequently, the aim of this study was to determine if masked hypertension is a risk factor for poor neonatal outcome. We evaluated a cohort of 588 high-risk pregnant women (29 ± 7 years old with 27 ± 6 weeks of gestation at blood pressure evaluation); 22.1%, 8.5%, 2.9%, and 2.6% had history of hypertension, diabetes, collagen diseases and chronic renal disease, respectively. According to the data of office and ambulatory blood pressures monitoring, women was classified as normotension (61.7%), white-coat hypertension (5.4%), masked hypertension (21.6%) and sustained hypertension (11.2%) respectively. Compared to normotension, all neonatal outcomes were worst in women with masked hypertension; neonates had lower mean birth weight (2577 (842) vs. 3079 (688) g, P < 0.001), higher prevalence of very low (12.1% vs 2.0%, P = .002) and extremely low birth weight (4.3% vs 0%, P < 0.001), and low one-minute APGAR score (7.8% vs 1.8%, P < 0.001). Furthermore, 14.2% needed admission to neonatal intensive care unit (NICE) (P = 0.001). Compared with normotension the risk for poor the combined neonatal outcome (admission to NICE plus still born) was significantly higher in masked hypertension (adjusted OR 2.58 95% CI 1.23-5.40) but not in white-coat hypertension (adjusted OR 0.41 95% CI 0.05-3.12). In conclusion, in high-risk pregnancies, masked hypertension was a strong and independent predictor for poor neonatal outcomes.

Hypertension, a linchpin between environmental noise exposure and the development of cardiovascular disease?

Environmental noise exposure has been considered one of the most common hazards worldwide, especially in the workplace environment, and could produce a variety of health issues. Some epidemiological evidence supports the association between occupational noise exposition and a high risk for hypertension and cardiovascular diseases. Wang et al. has conducted an observational cross-sectional study using occupational data of 4746 workers, 32.4% were exposed to high occupational noise. These exposed individuals had a moderate increase in the risk for hypertension (adjusted odds ratio [OR], 1.30; 95% confidence interval [CI], 1.05-1.62). The subgroup analyses showed that the relationship between noise and hypertension prevalence was stronger in young participants (OR, 1.70; 95% CI, 1.21-2.40). Noise exposure activates the sympathetic and endocrine systems producing an increase in blood pressure and the changes in other biological risk factors. Moreover, a recently published study showed that oxidative stress and DNA damage were significantly higher in subjects exposed to noise. Emotional stress reactions and unconscious physiological stress could also be potential mechanisms for hypertension. Finally, physiological stress caused by noise exposure may also increase indulgence in unhealthy behaviors, such as smoking and alcohol consumption, and indirectly result in an increased risk of hypertension and cardiovascular diseases. Previously published studies showed relationships between environmental noise exposure (including road traffic, railway, and aircraft noises) and the development of hypertension and cardiovascular diseases. Thus, the study by Wang et al. emphasizes the importance of environmental control in the prevention of cardiovascular diseases, not only in the workplace but also outside it.

Plasmatic renin-angiotensin system in normotensive and hypertensive patients hospitalized with COVID-19

Background

Besides its counterbalancing role of the renin-angiotensin system (RAS), angiotensin-converting enzyme (ACE) 2 is the receptor for the type 2 coronavirus that causes severe acute respiratory syndrome, the etiological agent of COVID-19. COVID-19 is associated with increased plasmatic ACE2 levels, although conflicting results have been reported regarding angiotensin (Ang) II and Ang-(1−7) levels. We investigated plasmatic ACE2 protein levels and enzymatic activity and Ang II and Ang-(1−7) levels in normotensive and hypertensive patients hospitalized with COVID-19 compared to healthy subjects.

Methods

Ang II and Ang-(1−7), and ACE2 activity and protein levels were measured in 93 adults (58 % (n = 54) normotensive and 42 % (n = 39) hypertensive) hospitalized with COVID-19. Healthy, normotensive (n = 33) and hypertensive (n = 7) outpatient adults comprised the control group.

Results

COVID-19 patients displayed higher ACE2 enzymatic activity and protein levels than healthy subjects. Within the COVID-19 group, ACE2 activity and protein levels were not different between normotensive and hypertensive-treated patients, not even between COVID-19 hypertensive patients under RAS blockade treatment and those treated with other antihypertensive medications. Ang II and Ang-(1−7) levels significantly decreased in COVID-19 patients. When COVID-19 patients under RAS blockade treatment were excluded from the analysis, ACE2 activity and protein levels remained higher and Ang II and Ang-(1−7) levels lower in COVID-19 patients compared to healthy people.

Conclusions

Our results support the involvement of RAS in COVID-19, even when patients under RAS blockade treatment were excluded. The increased circulating ACE2 suggest higher ACE2 expression and shedding.

Timing of convalescent plasma administration and 28-day mortality in COVID-19 pneumonia

This is a multicenter cohort study including consecutive, hospitalized patients ≥18 years, with moderate to severe COVID-19, carried out to evaluate the relationship between the timing of convalescent plasma administration and 28-day mortality. Data were prospectively collected between May 14, 2020 and October 31, 2020. Patients were grouped according to the timing of administration of convalescent plasma as <3 days, between 3 and 7 days, and >7 days. The main outcome variable was 28-day mortality. Independent predictors of mortality were identified by logistic regression. Of 4719 patients receiving convalescent plasma, 3036 (64.3%) were in the general ward, 1171 (24.8%) in the intensive care unit (ICU), and 512 (10.8%) in the ICU on mechanical ventilation. Convalescent plasma was administered to 3113 (66%) patients within the first 3 days of hospital admission, to 1380 (29.2%) between 3 and 7 days, and to 226 after 7 days; 28-day mortality was, respectively, 18.1%, 30.4% and 38.9% (p<0.001). In the regression model, convalescent plasma administration within the first 3 days of admission was associated with reduced 28-day mortality, compared with the administration after 7 days (OR 0.40, 95% CI 0.30 to 0.53). Early convalescent plasma administration was associated to a significant decreased mortality in patients in the general ward (OR 0.45, 95% CI 0.29 to 0.69) and in the ICU (OR 0.35, 95% CI 0.19 to 0.64), but not in those requiring mechanical ventilation (OR 0.52, 95% CI 0.27 to 1.01). In conclusion, this study suggests that early administration of convalescent plasma to patients with COVID-19 pneumonia is critical to obtain therapeutic benefit.

Nocturnal hypertension and risk of developing early-onset preeclampsia in high-risk pregnancies

To test the hypothesis that nocturnal hypertension identifies risk for early-onset preeclampsia/eclampsia (PE), we conducted an historical cohort study of consecutive high-risk pregnancies between 1st January 2016 and 31st March 2020. Office blood pressure (BP) measurements and ambulatory blood pressure monitoring (ABPM) were performed. The cohort was divided into patients without PE or with early- or late-onset PE (<34 and ≥34 weeks of gestation, respectively). The relative risks of office and ABPM hypertension for the development of late- or early-onset PE were estimated with multinomial logistic regression using no PE as a reference category. Four hundred and seventy-seven women (mean age 30 ± 7 years, with 23 ± 7 weeks of gestation at the time of the BP measurements) were analyzed; 113 (23.7%) developed PE, 69 (14.5%) developed late-onset PE, 44 (9.2%) developed early-onset PE. Office and ambulatory BP increased between the groups, and women who developed early-onset PE had significantly higher office and ambulatory BP values than those with late-onset PE or without PE. Hypertension prevalence increased across groups, with the highest values in early-onset PE. Nocturnal hypertension was the most prevalent finding and was highly prevalent in women who developed early-onset PE (88.6%); only 1.6% of women without nocturnal hypertension developed early-onset PE. Additionally, nocturnal hypertension was a stronger predictor for early-onset PE than for late-onset PE (adjusted OR, 5.26 95%CI 1.67-16.60) vs. 2.06, 95%CI 1.26-4.55, respectively). In conclusion, nocturnal hypertension was the most frequent BP abnormality and a significant predictor of early-onset PE in high-risk pregnancies.

May Measurement Month 2019: an analysis of blood pressure screening results from Argentina

The Argentinean Society of Hypertension, in agreement with the May Measurement Month (MMM) initiative of the International Society of Hypertension, implemented for the third consecutive year a hypertension screening campaign. A volunteer cross-sectional survey was carried out in public spaces and health centres during the month of May 2019 across 33 cities in Argentina. Hypertension was defined as systolic blood pressure (BP) ≥140 mmHg and/or diastolic BP ≥90 mmHg based on the mean of the second and third BP measurements, or in those on treatment for high BP. A total of 94 523 individuals (53.9 ± 17.8 years old, 55 231women and 39 292 men), were evaluated. The age and sex standardized mean BP was 124.7/77.2 mmHg. Among participants, 34.7% were overweight (25-29.9 m/kg²) and 28.7% had obesity (≥30 m/kg²). Individuals identified as being overweight had BP 3/2 mmHg higher and individuals with obesity 6/4 mmHg higher than those with normal weight. The prevalence of hypertension was 52.5%. Although 81.1% were aware and 77.7% were on antihypertensive treatment, only 46.0% of all individuals with hypertension had their BP controlled. Moreover, 19.8% of those not on any antihypertensive medication were found with raised BP. The low level of control of hypertension generates the critical need for the development of community-based prevention strategies reinforcing strategies to increase the awareness and control of hypertension.

Adherence to antihypertensive drug treatment in Argentina: A multicenter study

Adherence to antihypertensive medication is an important challenge that doctors often face in the treatment of hypertension. Good adherence is crucial to prevent cardiovascular complications. In consequence, the present study aimed at determining the prevalence of adherence to antihypertensive treatment and identifying associated clinical variables. A multicenter cross-sectional study was conducted in 12 cities of Argentina. A systematic sampling was performed in order to select patients with hypertension and under pharmacological treatment for at least 6 months. Physicians took three BP measurements, and the level of adherence was assessed using the self-administered Morisky questionnaire (MMAS-8). Participants were classified into three levels of adherence: high adherence-MMAS score of 8; medium adherence-MMAS scores of 6 to <8; and low adherence-MMAS scores of <6. A total of 1111 individuals (62 ± 12 years old, women 49.4%) were included in the present analysis; 159 (14.3%), 329 (29.6%) and 623 (56.1%) patients had low, medium, and high adherence, respectively. The prevalence of controlled hypertension increased only in high adherent patients: 42.8%, 42.2%, and 64.5% for low, medium, and high adherence groups, respectively. Similarly, systolic BP was lower only in the high adherence group. High educational level (OR 3.47, 95% CI 2.68-4.49) and diuretic treatment (OR 0.64, 95% CI 0.47-0.88) were independent predictors of high adherence. In conclusion, more than a half of treated hypertensive patients had a high level of adherence. These patients had lower BP values and higher control levels. A high educational level predicts high adherence.

Evaluation of ventricular-arterial coupling by impedance cardiography in healthy volunteers

BACKGROUND

The interplay between cardiac function and the arterial system is currently defined as ventricular-arterial coupling (VAC) and it is an expression of global cardiovascular efficiency. VAC involves a variety of complex interactions between the heart and the vasculature. A basic index of VAC is the ratio of effective arterial elastance (Ea)/ end-systolic elastance (Ees). While this is often done with echocardiography, obtaining Ea/Ees using impedance cardiography is feasible, although this possibility has not been explored so far.

OBJECTIVE

The aim of this study was to compare the Ea/Ees values obtained using echocardiography and impedance cardiography.

APPROACH

Two independent operators estimated Ea/Ees in 91 (41  ±  14 years old, women 51%) untreated apparently healthy individuals using (1) Doppler echocardiography with the single-beat method developed by Chen et al (2001 J. Am. Coll. Cardiol. 38 2028-34); and (2) data provided by impedance cardiography. The differences between Ea/Ees values were compared and correlation between both methods was estimated.

MAIN RESULTS

Although Ea and Ees values calculated by impedance cardiography were lower than those estimated by echocardiography (-0.201  ±  0.457 mmHg ml^-1 and  -0.193  ±  0.413 mmHg ml^-1), Ea/Ees ratio values were similar. Thus, there was no significant difference between the mean values of Ea/Ees estimated by impedance cardiography or echocardiography (Ea/Ees impedance cardiography  -  Ea/Ees echocardiography  =  -0.015  ±  0.096, p   =  0.150). Ea/Ees values calculated by both methods were highly correlated (r  =  0.85, p   <  0.001), as well as the pre-ejection and left ventricular ejection time (r  =  0.83 and r  =  0.91, respectively).

SIGNIFICANCE

In healthy individuals, estimation of Ea/Ees by impedance cardiography yielded similar values to those obtained using echocardiography.

Hypertension control in Argentina, in the middle of a long road

In Argentina, cardiovascular diseases are the leading cause of death and represent 1/3 of total mortality. In 2017, hypertension prevalence for inhabitants ≥18 years old was 36.3%, and its level of knowledge and control (<140/90 mm Hg) were 61% and 24%, respectively. Furthermore, 56% of people treated with antihypertensive drugs do not reach therapeutic goal. In addition to this, prevalence of other risk factors, such as sedentary lifestyle, overweight-obesity, high blood glucose/diabetes, and high cholesterol, has worsened in the last 5 years. The governmental initiative "Less Salt More Life" intends to reduce salt consumption in the entire population and promoted a National Law, which establishes the progressive salt reduction in processed foods. This initiative is probably related to the reduction of salt use after cooking or sitting at the table, observed in the Risk Factors National Survey. Furthermore, previously published studies showed, in relatively small samples from Argentina, that populational blood pressure can be decreased and hypertension control can be improved using community-based or multicomponent intervention programs. However, no specific designed national effort for hypertension control is now officially applied. In consequence, we believe that, in order to increase hypertension control, the effort should not focus on developing new strategies, but on quickly implementing and maintaining those local multicomponent interventions that have already proven to be effective.

Nocturnal but not Diurnal Hypertension Is Associated to Insulin Resistance Markers in Subjects With Normal or Mildly Elevated Office Blood Pressure

OBJECTIVE

The aim was to evaluate the relationships among insulin resistance markers and nocturnal and diurnal hypertension in normotensive or mildly untreated hypertensive adults.

METHODS

The study was performed in both female and male adults referred to the Cardiometabolic Unit of the Hospital San Martín, La Plata, Argentina, in order to perform an ambulatory blood pressure measurement (ABPM) for the evaluation of a possible hypertensive disorder. The population was stratified according to their ABPM in: 1-presence or absence of diurnal hypertension and 2-presence or absence of nocturnal hypertension; both conditions were analyzed separately. Fasting plasma insulin (FPI), homeostasis model assessment of insulin resistance (HOMA-IR), and triglycerides (TG)/high-density lipoprotein cholesterol (HDL-C) ratio were used as surrogate markers of insulin resistance and compared among subjects with vs. without diurnal or nocturnal hypertension.

RESULTS

One hundred and five patients, 55 women, 47 (11) years old, and 50 men, 44 (16) years old, were included. Diurnal and nocturnal hypertension were found in 60% and 64% of the sample, respectively. There were no significant differences among the levels of insulin resistance markers between individuals with or without diurnal hypertension. In contrast, individuals with nocturnal hypertension were more insulin resistant irrespectively of whether they were evaluated using FPI (P = 0.016), HOMA-IR (P = 0.019), or TG/HDL-C ratio (P = 0.011); FPI differences remained significant after adjustment for sex, age, and obesity indicators (P = 0.032).

CONCLUSIONS

Nocturnal but not diurnal hypertension was related to higher levels of 3 insulin resistance markers in normotensive and untreated mildly hypertensive adults; this relationship seems partially independent of obesity.

Comparison of two surrogate estimates of insulin resistance to predict cardiovascular disease in apparently healthy individuals

BACKGROUND AND AIMS

Insulin resistance is associated with a cluster of abnormalities that increase cardiovascular disease (CVD). Several indices have been proposed to identify individuals who are insulin resistant, and thereby at increased CVD risk. The aim of this study was to compare the abilities of 3 indices to accomplish that goal: 1) plasma triglyceride × glucose index (TG × G); 2) plasma triglyceride/high-density lipoprotein cholesterol ratio (TG/HDL-C); and 3) Metabolic Syndrome (MetS).

METHODS AND RESULTS

In a population sample of 723 individuals (486 women and 237 men, 50 ± 16 and 51 ± 16 years old, respectively), baseline demographic and metabolic variables known to increase CVD risk and incident CVD were compared among individuals defined as high vs. low risk by: TG × G; TG/HDL-C; or MetS. CVD risk profiles appeared comparable in high risk subjects, irrespective of criteria. Crude incidence of CVD events was increased in high risk subjects: 12.2 vs. 5.3% subjects/10 years, p = 0.005 defined by TG/HDL-C; 13.4 vs. 5.3% subjects/10 years, p = 0.002 defined by TG × G; and 13.4% vs. 4.5% of subjects/10 years, p < 0.001 in subjects with the MetS. The area under the ROC curves to predict CVD were similar, 0.66 vs. 0.67 for TG/HDL-C and TG × G, respectively. However, when adjusted by age, sex and multiple covariates, hazard ratios for incident CVD were significantly increased in high risk patients classified by either TG/HDL-C ratio (2.18, p = 0.021) or MetS (1.93, p = 0.037), but not by TG × G index (1.72, p = 0.087).

CONCLUSION

Although the 3 indices identify CVD risk comparably, the TG × G index seems somewhat less effective at predicting CVD.

Use of the triglyceride/high-density lipoprotein cholesterol ratio to identify cardiometabolic risk: impact of obesity?

There is evidence that the plasma concentration ratio of triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C) identifies insulin resistance and increased cardiometabolic risk and outcome in apparently healthy individuals. Since use of the TG/HDL-C ratio to accomplish this task in persons over a wide range of adiposity has not been studied, the ability of previously defined sex-specific TG/HDL-C cut-points to identify increased cardiometabolic risk was evaluated in apparently healthy normal weight, overweight, and obese individuals. Data were analyzed from a population-based study of apparently healthy men (n=416) and women (n=893), subdivided into categories by body mass index (BMI, kg/m2): normal weight (BMI 20.0–24.9), overweight (BMI 25.0–29.9) and obese (BMI 30.0–34.9). The adiposity groups were further stratified on the basis of their TG/HDL-C ratio into groups defined as being either at ‘high risk’ versus ‘low risk’ of cardiometabolic disease. Multiple cardiometabolic risk factors were compared between these subgroups, as was their degree of insulin resistance assessed by fasting plasma insulin concentration and homeostasis model assessment of insulin resistance. The proportion of high-risk individuals varied with BMI category, ranging from 14% (normal weight) to 36% (obese). However, within each BMI category high-risk individuals had a significantly more adverse cardiometabolic risk profile. Finally, the adjusted OR of being insulin resistant was significantly greater in those with a high TG/HDL-C ratio in the normal (3.02), overweight (2.86), and obese (2.51) groups. Thus, irrespective of differences in BMI, the TG/HDL-C ratio identified apparently healthy persons with a more adverse cardiometabolic risk profile associated with an increased prevalence of insulin resistance.

Insulin resistance: The linchpin between prediabetes and cardiovascular disease

The aim of this study was to test the hypothesis that cardiovascular disease occurs to the greatest extent in persons with prediabetes mellitus who are also insulin resistant. In 2003, 664 non-diabetic women (n = 457) and men (n = 207), aged 52 ± 16 and 53 ± 15 years, were surveyed during a programme for cardiovascular disease prevention. Fasting plasma glucose concentrations defined participants as having normal fasting plasma glucose (fasting plasma glucose <5.6 mmol/L) or prediabetes mellitus (fasting plasma glucose ⩾ 5.6 and <7.0 mmol/L). The tertile of prediabetes mellitus subjects with the highest fasting plasma insulin concentration was classified as insulin resistant. Baseline cardiovascular disease risk factors were accentuated in prediabetes mellitus versus normal fasting glucose, particularly in prediabetes mellitus/insulin resistant. In 2012, 86% of the sample were surveyed again, and the crude incidence for cardiovascular disease was higher in subjects with prediabetes mellitus versus normal fasting glucose (13.7 vs 6.0/100 persons/10 years; age- and sex-adjusted hazard ratio = 1.88, p = 0.052). In prediabetes mellitus, the crude incidences were 22.9 versus 9.6/100 persons/10 years in insulin resistant versus non-insulin resistant persons (age- and sex-adjusted hazard ratio = 2.36, p = 0.040). In conclusion, cardiovascular disease risk was accentuated in prediabetes mellitus/insulin resistant individuals, with a relative risk approximately twice as high compared to prediabetes mellitus/non-insulin resistant subjects.

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.

Should the first blood pressure reading be discarded?

We evaluated the consequences of excluding the first of three blood pressure (BP) readings in different settings: a random population sample (POS, n=1525), a general practice office (GPO, n=942) and a specialized hypertension center (SHC, n=462). Differences between systolic and diastolic BP (SBP and DBP) estimates obtained including and excluding the first reading were compared and their correlation with ambulatory BP monitoring (ABPM) was estimated. The samples were divided into quartiles according to the difference between the third and the first SBP (3-1ΔSBP). SBP decreased through sequential readings, 3-1ΔSBP was -5.5 ± 9.7 mm Hg (P<0.001), -5.1 ± 10.4 mm Hg (P<0.001) and -6.1 ± 9.3 mm Hg (P<0.001) for POS, GPO and SHC, respectively. However, individuals included in the top quartile of 3-1ΔSBP showed their highest values on the third reading. The mean SBP estimate was significantly higher excluding the first reading (P<0.001), but the differences among both approaches were small (1.5-1.6 mm g). Moreover, the correlation between SBP values including and excluding the first reading and daytime ABPM were comparable (r = 0.69 and 0.68, respectively). Similar results were observed for DBP. In conclusion, our study does not support the notion of discarding the first BP measurement and suggests that it should be measured repeatedly, regardless the first value.

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.

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.

Identifying cardiovascular disease risk and outcome: use of the plasma triglyceride/high-density lipoprotein cholesterol concentration ratio versus metabolic syndrome criteria

BACKGROUND

Metabolic syndrome (MetS) has been shown to predict both risk and CVD events. We have identified sex-specific values for the triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio associated with an unfavourable cardio-metabolic risk profile, but it is not known whether it also predicts CVD outcome.

METHODS

To quantify risk for CVD outcomes associated with a high TG/HDL-C ratio and to compare this risk with that predicted using MetS, a population longitudinal prospective observational study was performed in Rauch City, Buenos Aires, Argentina. In 2003 surveys were performed on a population random sample of 926 inhabitants. In 2012, 527 women and 269 men were surveyed again in search of new CVD events. The first CVD event was the primary endpoint. Relative risks for CVD events between individuals above and below the TG/HDL-C cut-points, and with or without MetS, were estimated using Cox proportional hazard.

MAIN OUTCOME

The first CVD event was the primary endpoint. Relative risks for CVD events between individuals above and below the TG/HDL-C cut-points, and with or without MetS, were estimated using Cox proportional hazard.

RESULTS

The number of subjects deemed at 'high' CVD risk on the basis of an elevated TG/HDL-C ratio (30%) or having the MetS (35%) was relatively comparable. The unadjusted hazard risk was significantly increased when comparing 'high' versus 'low' risk groups no matter which criteria was used, although it was somewhat higher in those with the MetS (HR = 3.17, 95% CI:1.79-5.60 vs. 2.16, 95% CI:1.24-3.75). However, this difference essentially disappeared when adjusted for sex and age (HR = 2.09, 95% CI:1.18-3.72 vs. 2.01, 95% CI:1.14-3.50 for MetS and TG/HDL-C respectively).

CONCLUSIONS

An elevated TG/HDL-C ratio appears to be just as effective as the MetS diagnosis in predicting the development of CVD.

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.

Alanine-aminotransferase: an early marker for insulin resistance?

In a population-based sample, after excluding alcohol consumption, hepatotoxic drugs and hepatitis B and C infected, we investigated if alanine-aminotransferase (ALT) was associated with metabolic syndrome and insulin resistance, and if this association was caused by non-alcoholic fatty liver disease (NAFLD). The sample (432 female and 119 male) was divided into two ALT thresholds corresponding to the 50th and 75th percentiles (P) (female > or = 15 and > or = 19 U/L; male > or = 17 and > or = 23 U/I, respectively). Blood pressure, body mass index, waist circumference, cholesterol, HDL cholesterol (HDLc), triglyceride (TG), TG/HDLc ratio, glycemia and homeostasis model assessment of insulin resistance (HOMA-IR) were compared between those above and below each ALT threshold. Female placed above the 50th P of ALT had higher levels of TG/HDLc ratio (p=0.029), glycemia (p=0.028), and homeostasis model assessment of insulin resistance, (p=0.045), and above the 75th P had higher SBP (p=0.036), DBP (p=0.018), TG (p=0.024), TG/HDLc ratio (p=0.028), glycemia (p=0.004) and HOMA-IR (p=0.0014). Male placed above the 50th P of ALT had higher BMI (p=0.017) and TG/HDLc ratio (p=0.048), and above the 75th P had lower values of HDLc (p=0.042). Only 16.5% of women and 14.5% of men, above the 75th P of ALT, showed an increase in liver brightness in the echography. This work shows in woman an early association of ALT with TG/HDLc ratio and HOMA-IR. Since the last two are independent predictors of cardiovascular risk, attention should be drawn to ALT values near the upper limit of the normal range even in the absence of NAFLD and obesity.

[Associated variables to hypertension in a region of Argentina]

We conducted a study in a random sample of 1523 inhabitants (15-75 years old) of Rauch city to determine risk factors prevalence to development hypertension and cardiovascular diseases. We measured blood pressure, weight, height, waist circumference, cholesterol and glucose levels, sodium excretion, and alcohol and tobacco consumption. We found a high prevalence of hypertension (43.20% in men and 28.50% in women), and obesity-overweight (54.81% in men and 44.65% in women), both of them augmented with aging. Only 4% of hypertensive subjects were being controlled and only 32% of them were aware of their condition. Men showed a marked increment of prevalence of hypertension and obesity-overweight between groups of 15-24 years and 25-34 years. Women had delayed and more gradual increments. In male and female respectively, the prevalence of hypercholesterolemia was 26.86 and 13.81, the prevalence of diabetes was 3.42 and 1.53, and the prevalence of tobacco consumption was 34.61 and 20.83. Higher BMI and waist circumference identified subjects with higher blood pressure up to 54 and 65 years, in men and women, respectively. Age and waist circumference in the whole group, and alcohol consumption in men, were independently correlated with blood pressure; sodium excretion had no correlation. High prevalence of hypertension and obesity-overweight and their association suggest that the most important primary prevention measure in this community should be to prevent obesity. Low levels of awareness indicate the need of ongoing detection programs, and low grade to control of hypertension could be modified with education programs for health providers.

Ion mobility spectrometry of hydrazine, monomethylhydrazine, and ammonia in air with 5-nonanone reagent gas

Hydrazine (HZ) and monomethylhydrazine (MMH) in air were monitored continuously using a hand-held ion mobility spectrometer equipped with membrane inlet, 63Ni ion source, acetone reagent gas, and ambient temperature drift tube. Response characteristics included detection limit, 6 ppb; linear range, 10-600 ppb; saturated response, >2 ppm; and stable response after 15-30 min. Ammonia interfered in hydrazines detection through a product ion with the same drift time as that for MMH and HZ. Acetone reagent gas was replaced with 5-nonanone to alter drift times of product ions and separate ammonia from MMH and HZ. Patterns in mobility spectra, ion identifications from mass spectra, and fragmentation cross-sections from collisional-induced dissociations suggest that drift times are governed by ion-cluster equilibria in the drift region of the mobility spectrometer. Practical aspects including calibration, stability, and reproducibility are reported from the use of a hand-held mobility spectrometer on the space shuttle Atlantis during mission STS-37.

Alpha lipoic acid: a novel treatment for depression

Insulin resistance has been associated with people diagnosed with depression. Conversely, it has also been documented that diabetics have an increased risk of depression. Evidence suggests that insulin activity plays a role in serotonergic activity by increasing the influx of tryptophan into the brain. This increased influx of tryptophan has been shown to result in an increase in serotonin synthesis. In accordance with the serotonin theory of depression, it may be possible to treat depression by increasing insulin activity. The antioxidant alpha lipoic acid has been shown to increase insulin sensitivity and is used to treat people with diabetes. Therefore, the nutrient alpha lipoic acid should be clinically tested as an adjunct treatment for depression.

A qualitative evaluation of an assisted self-help group for drug-addicted clients in a structured outpatient treatment setting

We conducted a qualitative evaluation of a semi-structured, client-led support group that addressed drug use recovery issues and was assisted by a psychological consultant. Seven regular group members and their counselors were interviewed about the effect of the assisted self-help group on drug use and the clients' quality of life, and these interviews were content analyzed. In addition, the psychological consultant made group process observations for each session of the first three months. Clients reported group strengths as: Feeling supported and understood, being able to speak freely without fear of staff reprisals, obtaining information/feedback, improved mood, and decreased drug use. With the provision of professional support and guidance, this group shows promise as an adjunct to standard outpatient drug abuse treatment by allowing for some degree of client independence and extending the scarce resource of professional counseling.

Ten-year blood pressure trends in nonhypertensive inhabitants of La Plata, Argentina

OBJECTIVES

To compare, according to blood pressure (BP) categories, 10-year trends in BP measurements in nonhypertensive subjects and the relative risk of developing hypertension.

DESIGN

Population study. BP was recorded as the average of two measures taken on a single occasion with a mercury sphygmomanometer and the auscultation method.

SETTING

Residents of La Plata, aged 15 to 64 years.

PARTICIPANTS

The study was based on randomly chosen individuals who, during a previous survey in 1985, were 15 to 64 years old and whose BP was below 140/90 mmHg. They were grouped according to sex and BP categories. Random age- and sex-stratified sampling of 151 men and 193 women was performed. Categories were high normal BP, optimal BP (as defined by the fifth report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure) and normal but not optimal BP defined as BP 120 to 129/80 to 84 mmHg.

RESULTS

BP increased in all categories; this increase was significant (P < 0.01) except for diastolic BP in women with high normal BP. BP increases were higher in optimal BP subjects and lower in high normal BP subjects (P < 0.01 for women and not significant for men). The relative risk of developing hypertension in high normal BP subjects was triple that in optimal BP subjects (P < 0.01).

CONCLUSIONS

Increases in BP observed in optimal BP subjects stress the importance of monitoring BP changes and recommending primary prevention in the whole population.