Waist circumference cut-off points to identify major cardiovascular events and incident diabetes in Latin America: findings from the prospective Urban rural epidemiology study Colombia

Background

Abdominal obesity (AO) indirectly represents visceral adiposity and can be assessed by waist circumference (WC) measurement. In Latin America, cut-off points for the diagnosis of AO are based on Asian population data. We aim to establish the WC cut-off points to predict major cardiovascular events (MACE) and incident diabetes.

Methods

We analyzed data from the cohort PURE study in Colombia. WC cut-off points were defined according to the maximum Youden index. Multivariate logistic regression was used to obtain associations between WC and MACE, diabetes, and cumulative incidence of outcomes visualized using Kaplan-Meier curves.

Results

After a mean follow-up of 12 years, 6,580 individuals with a mean age of 50.7 ± 9.7 years were included; 64.2% were women, and 53.5% were from rural areas. The mean WC was 85.2 ± 11.6 cm and 88.3 ± 11.1 cm in women and men, respectively. There were 635 cases of the MACE composite plus incident diabetes (5.25 events per 1,000 person-years). Using a cut-off value of 88.85 cm in men (sensitivity = 0.565) and 85.65 cm in women (sensitivity = 0.558) resulted in the highest value for the prediction of the main outcome. These values were associated with a 1.76 and 1.41-fold increased risk of presenting the composite outcome in men and women, respectively.

Conclusions

We defined WC cut-off points of 89 cm in men and 86 cm in women to identify the elevated risk of MACE and incident diabetes. Therefore, we suggest using these values in cardiovascular risk assessment in Latin America.

Latin American Consensus on the management of hypertension in the patient with diabetes and the metabolic syndrome

: The prevalence of hypertension, type 2 diabetes mellitus (DM2) and the metabolic syndrome continues to increase in Latin America, while the rates of diagnosis, treatment and control of these disorders remain low. The frequency of the risk factors that constitute the metabolic syndrome and are associated with an increased risk of cardiovascular disease has not diminished since the publication of the previous consensus. This document discusses the socioeconomic, demographic, environmental and cultural characteristics of most associated Latin American countries and partially explains the lack of better results in improving clinical and public health actions that allow high morbidity and mortality rates caused by cardiovascular diseases and DM2 to be reduced through programs aligned with the so-called precision medicine, which should be predictive, preventive, personalized and participatory. The Consensus ratifies the diagnostic criteria expressed in the previous consensus to define hypertension and DM2 but, for the metabolic syndrome, and in the absence of evidence, the recommendation is to implement a cohort study that determines the abdominal perimeter value associated with hard outcomes, such as DM2 and CVD. Meanwhile, we recommend modifying the criterion to more than 94 cm in men and more than 84 cm in women according to WHO recommendations. We also recommend the carrying out of a study that identifies the situation of hypertension and DM2 in people of African ancestry who, in Latin America, exceed 75 million and whose epidemiology does not include solid studies. With respect to the proposed therapeutic targets, we recommended maintaining those defined in the previous consensus, but insisting that early pharmacological management of prediabetes with metformin should be introduced, as should the treatment of diabetic hypertensive patients with a combination therapy of two fixed-dose antihypertensive drugs and management with statins. To increase adherence, the use of different drugs combined in a single pill (polypill) is recommended. The simplification of the therapeutic regimen is accompanied by greater control of cardiovascular risk factors, both in primary and secondary prevention, and has been shown to be cost-effective. The consensus recommends the use of the currently available polypill combining an angiotensin-converting enzyme inhibitor, a statin and aspirin for secondary cardiovascular prevention and in patients with a high cardiovascular risk, such as hypertension patients with DM2.

Atherogenic Dyslipidemia in Latin America: Prevalence, causes and treatment: Expert's position paper made by The Latin American Academy for the Study of Lipids (ALALIP) Endorsed by the Inter-American Society of Cardiology (IASC), the South American Society of Cardiology (SSC), the Pan-American College of Endothelium (PACE), and the International Atherosclerosis Society (IAS)

This is an executive summary made by a group of experts named Latin American Academy for the study of Lipids (ALALIP). In the current clinical guidelines, atherogenic dyslipidemia (AD) is a poorly recognized entity. Due to the frequent lipid alterations associated with AD in Latin America (LA), we organized a group of experts named (ALALIP) to generate a document in order to analyze their prevalence and to offer practical recommendations.

METHODOLOGY

using the Delphi methodology, we conducted a comprehensive literature review with emphasis on those publications related to LA. Subsequently, we developed key questions for discussion. As a convention, those recommendations that had a 100% of acceptance were considered unanimous, those with >80% were consensual, and those with <80% were in disagreement.

RESULTS

a systematic analysis of national health surveys and regional cohort studies showed a consistently high prevalence of the lipid abnormalities that define AD: low levels of high-density lipoprotein cholesterol (HDL-C) range from 34.1% to 53.3% and elevated triglycerides (TG) range from 25.5% to 31.2%. These abnormalities could be related to high consumption of food with a high caloric density, cholesterol and trans fats, a sedentary lifestyle and perhaps epigenetic changes CONCLUSIONS: lipid abnormalities that define AD have a high prevalence in LA. The interaction between an unfavorable lifestyle, inheritance and epigenetic changes is probably their cause. It is important to design a global study of risk factors in LA to know its true prevalence in the region, its consequences and to derive from its treatment strategies.

Is myopia another clinical manifestation of insulin resistance?

Myopia is a multifactorial visual refraction disease, in which the light rays from distant objects are focused in front of retina, causing blurry vision. Myopic eyes are characterized by an increased corneal curvature and/or ocular axial length. The prevalence of myopia has increased in recent decades, a trend that cannot be attributed exclusively to genetic factors. Low and middle income countries have a higher burden of refractive error, which we propose could be a consequence of a shorter exposure time to a westernized lifestyle, a phenomenon that may also explain the rapid increase in cardiometabolic diseases, such as diabetes, among those populations. We suggest that interactions between genetic, epigenetic and a rapidly changing environment are also involved in myopia onset and progression. Furthermore, we discuss several possible mechanisms by which insulin resistance may promote abnormal ocular growth and myopia to support the hypothesis that insulin resistance and hyperinsulinemia are involved in its pathogenesis, providing a link between trends in myopia and those of cardiometabolic diseases. There is evidence that insulin have direct ocular growth promoting effects as well an indirect effect via the induction of insulin-like growth factors leading to decreases insulin-like growth factor-binding protein, also implicated in ocular growth.

The Role of Adiponectin in Cardiometabolic Diseases: Effects of Nutritional Interventions

Adiponectin is an adipocyte-derived hormone abundantly present in plasma that exerts its effects through the activation of 3 receptors. Its concentrations are negatively regulated by the accumulation of visceral fat, and clinical studies implicate hypoadiponectinemia in the pathogenesis of diabetes mellitus type 2, coronary artery disease, hypertension, and left ventricular hypertrophy. In contrast, high concentrations of adiponectin are associated with a decreased risk of coronary artery disease, with an improvement in the differentiation of preadipocytes into adipocytes, and with increased endothelial nitric oxide production. Therefore, adiponectin appears to be an important molecule involved in limiting the pathogenesis of obesity-linked disorders, and it may have potential benefits in the treatment and prevention of cardiovascular disease. Caloric restriction, moderate alcohol consumption, and consuming a Mediterranean diet increase adiponectin concentrations, and current evidence suggests a positive, dose-dependent relation between ω-3 (n-3) fatty acid intake and circulating concentrations of adiponectin. Recently, it was reported that the administration of aged garlic extract and a single food intervention with pistachios can increase adiponectin concentrations in individuals with metabolic syndrome. Moreover, the Mediterranean diet is associated with higher adiponectin concentrations. Additional studies are needed to evaluate the potential benefits of increasing adiponectin by nutritional interventions in the treatment and prevention of cardiometabolic diseases.

Assessment of human lymphocyte proliferation associated with metabolic syndrome

BACKGROUND

Metabolic syndrome (MetS), a cluster of various metabolic conditions, has become epidemic and causes increased morbidity and mortality.

PURPOSE

The aim of this study was to compare lymphocyte proliferation under two different stimuli, Concanavalin A (ConA) and insulin, in a group of patients with MetS (Group 1) and a healthy group (Group 2).

METHODS

Group 1 consisted of 53 patients who met the diagnostic criteria for MetS. Group 2 consisted of 63 patients without MetS. All individuals were evaluated for lipid profile and glycemia. Lymphocyte extraction and culture were performed for each subject and lymphocyte proliferation was assessed using the Alamar blue technique.

RESULTS

There was no gender difference between both groups, but in terms of age, there was a significant difference. The use of Con A at concentrations of 1 and 5 µg/mL induced a high lymphocyte proliferation in both groups. In contrast, when different concentrations of insulin were added, no significant changes in lymphocyte proliferation were observed. However, the proliferation of lymphocytes was significantly higher in Group 1 compared to Group 2 under insulin stimulus, which did not happen under ConA stimulation. Even after age and gender correction, this difference was maintained.

CONCLUSIONS

The increased lymphocyte proliferative response to insulin in patients with MetS found in this study suggests a role of the lymphocyte response to insulin in the pathophysiology of MetS. This response may be used as an immuno-biological marker for MetS, although further studies to evaluate its clinical usefulness need to be conducted.

The role of leptin/adiponectin ratio in metabolic syndrome and diabetes

The metabolic syndrome comprises a cluster of cardiometabolic risk factors, with insulin resistance and adiposity as its central features. Identifying individuals with metabolic syndrome is important due to its association with an increased risk of coronary heart disease and type 2 diabetes mellitus. Attention has focused on the visceral adipose tissue production of cytokines (adipokines) in metabolic syndrome and type 2 diabetes mellitus, as the levels of the anti-inflammatory adipokine adiponectin are decreased, while proinflammatory cytokines are elevated, creating a proinflammatory state associated with insulin resistance and endothelial dysfunction. In this review, we will give special attention to the role of the leptin/adiponectin ratio. We have previously demonstrated that in individuals with severe coronary artery disease, abdominal obesity was uniquely related to decreased plasma concentrations of adiponectin and increased leptin levels. Leptin/adiponectin imbalance was associated with increased waist circumference and a decreased vascular response to acetylcholine and increased vasoconstriction due to angiotensin II. Leptin and adiponectin have opposite effects on subclinical inflammation and insulin resistance. Leptin upregulates proinflammatory cytokines such as tumor necrosis factor-α and interleukin-6; these are associated with insulin resistance and type 2 diabetes mellitus. In contrast, adiponectin has anti-inflammatory properties and downregulates the expression and release of a number of proinflammatory immune mediators. Therefore, it appears that interactions between angiotensin II and leptin/adiponectin imbalance may be important mediators of the elevated risk of developing type 2 diabetes mellitus and cardiovascular diseases associated with abdominal obesity.

Maternal undernutrition and cardiometabolic disease: a Latin American perspective

The current epidemic of obesity and cardiometabolic diseases in developing countries is described as being driven by socioeconomic inequalities. These populations have a greater vulnerability to cardiometabolic diseases due to the discrepancy between the maternal undernutrition and its consequence, low-birth weight progeny, and the subsequent modern lifestyles which are associated with socioeconomic and environmental changes that modify dietary habits, discourage physical activity and encourage sedentary behaviors. Maternal undernutrition can generate epigenetic modifications, with potential long-term consequences. Throughout life, people are faced with the challenge of adapting to changes in their environment, such as excessive intake of high energy density foods and sedentary behavior. However, a mismatch between conditions experienced during fetal programming and current environmental conditions will make adaptation difficult for them, and will increase their susceptibility to obesity and cardiovascular diseases. It is important to conduct research in the Latin American context, in order to define the best strategies to prevent the epidemic of cardiometabolic diseases in the region.

Inflammation and hypertension: are there regional differences?

Hypertension is a chronic disease with global prevalence and incidence rapidly increasing in low and medium income countries. The surveillance of cardiovascular risk factors, such as hypertension, is a global health priority in order to estimate the burden and trends, to appropriately direct resources, and to measure the effect of interventions. We propose here that the adoption of Western lifestyles in low and middle incomes countries has dramatically increased the prevalence of abdominal obesity, which is the main source of proinflammatory cytokines, and that the vascular systemic inflammation produced by adipose tissue contributes to the development of hypertension. The concentration of proinflammatory cytokines is higher in the Latin American population than that reported in developed countries, suggesting a higher susceptibility to develop systemic low-degree inflammation at a given level of abdominal obesity. These particularities are important to be considered when planning resources for health care programs. Moreover, studying these singularities may provide a better understanding of the causes of the burden of cardiovascular risk factors and the remarkable variability in the prevalence of these medical conditions within and between countries.

Risk factors for preeclampsia in women from Colombia: a case-control study

BACKGROUND

Preeclampsia (PE) is a multi-causal disease characterized by the development of hypertension and proteinuria in the second half of pregnancy. Multiple risk factors have been associated with the development of PE. Moreover, it is known that these risk factors vary between populations from developed and developing countries. The aim of this study is to identify which risk factors are associated with the development of preeclampsia (PE) among Colombian women.

METHODS

A multi-centre case-control study was conducted between September 2006 and July 2009 in six Colombian cities. Cases included women with PE (n = 201); controls were aged-matched pregnant women (n = 201) without cardiovascular or endocrine diseases for a case-control ratio of 1:1. A complete medical chart, physical examination and biochemical analysis were completed before delivery. Multivariable logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI) of potential risk factors associated with PE.

RESULTS

The presence of factors present in the metabolic syndrome cluster such as body mass index >31 Kg/m2 (OR = 2.18; 1.14-4.14 95% CI), high-density lipoprotein <1.24 mmol/L (OR = 2.42; 1.53-3.84 95% CI), triglycerides >3.24 mmol/L (OR = 1.60; 1.04-2.48 95% CI) and glycemia >4.9 mmol/L (OR = 2.66; 1.47-4.81 95%CI) as well as being primigravidae (OR = 1.71; 1.07-2.73 95% CI) were associated with the development of PE, after adjusting for other variables.

CONCLUSION

Factors present in the cluster of metabolic syndrome and primigravidity were associated with a greater risk of PE among Colombian women. Understanding the role of this cluster of risk factors in the development of PE is of crucial importance to prevent PE and remains to be determined.

Angiogenic imbalance and plasma lipid alterations in women with preeclampsia from a developing country

BACKGROUND

An imbalance between anti-angiogenic factors (e.g. soluble vascular endothelial growth factor receptor-1 (s-FLT1) and soluble endoglin (s-Eng)) and pro-angiogenic factors (e.g. placental growth factor (PlGF)) as well as increased oxidized low-density lipoprotein (ox-LDL) concentrations have been associated with preeclampsia (PE). Risk factors associated with the development of PE, however, are known to be different between developed and developing countries. The aim of the study was to determine the levels of s-FLT1, s-Eng, PIGF, and ox-LDL in women with PE from a developing country.

METHODS

A multi-center case-control study was conducted. One hundred and forty three women with PE were matched by age and parity with 143 healthy pregnant women without cardiovascular or endocrine diseases. Before delivery, blood samples were taken and serum was stored until analysis.

RESULTS

Women with PE had lower concentrations of PIGF (p<0.0001) and higher concentrations of s-Eng (p=0.001) than healthy pregnant women. There were no differences between the groups regarding ox-LDL or s-FLT1. Women with early onset PE had higher s-FLT1 concentrations (p=0.0004) and lower PIGF concentrations (p<0.0001) than their healthy pregnant controls. Women with late onset PE had higher concentrations of s-Eng (p=0.005). Women with severe PE had higher concentrations of s-Eng (p=0.0008) and ox-LDL (p=0.01), and lower concentrations of PIGF (p<0.0001).

CONCLUSIONS

Women with PE from a developing country demonstrated an angiogenic imbalance and an increased rate of LDL oxidation. Findings from this study support the theory that PE is a multifactorial disease, and understanding differences in these subpopulations may provide a better target to approach future therapies.

Epidemic of cardiometabolic diseases: a Latin American point of view

Poor early nutrition has varying effects on subsequent cardiometabolic disease (CMD) rates. Fetal and neonatal periods are critical for the development and growth of the systems involved in CMD. The increased rates of hypertension, metabolic syndrome, diabetes mellitus type 2, renal failure and heart failure observed nowadays in Latin America could be the result of the discrepancy between the nutritional environment during fetal and early life and the adult environment. This discrepancy causes a mismatch between the fetal programming of the subject and its adult circumstances created by the imposition of new life styles. The two largest international studies on cardiovascular risk factors for a first myocardial infarction (INTERHEART) and stroke (INTERSTROKE) demonstrated that in Latin America the factor with the highest attributable population risk was abdominal obesity. The conflict between the earlier programming and the later presence of abdominal obesity produced a higher sensitivity of this population to develop a state of low-degree inflammation, insulin resistance and the epidemic of CMD to lower levels of abdominal adiposity. The relative roles played by genetic and environmental factors and the interaction between the two are the still subjects of great debate. We have reviewed the relationship between maternal malnutrition, early growth restriction, epigenetic adaptations, and the later occurrence of abdominal obesity and CMD in Latin America.

Cardiovascular disease in Latin American women

Cardiovascular disease is a leading cause of death and disability in adults in Latin America. Women are more affected by these diseases than by all forms of cancer. Latin American countries have experienced rapid and uneven socioeconomic changes with a significant effect on lifestyle, demographic and health-related indicators. Differences in methodological approaches make it difficult to compare studies and health statistics across countries in the region. According to available statistics, female population in Latin American countries have lower mortality rate from coronary heart disease and higher mortality rate from cerebrovascular disease than North America. Current rates of obesity and type 2 diabetes are alarming in female in some countries. The high prevalence of risk factors forecasts an increase in cardiovascular disease for the coming decades in this region of the world. More systematic and sustained efforts for research, education, surveillance, prevention, early detection and affordable treatment are required across all Latin American countries to improve health conditions for adult population and particularly for women, who are more affected by obesity and diabetes. This article reviews the available information on cardiovascular disease and related risk factors in Latin American countries with a focus on female and to provide a brief description of selected multinational and national efforts to study and prevent this threat.

Hyperinsulinemia is a predictor of new cardiovascular events in Colombian patients with a first myocardial infarction

BACKGROUND

Acute Myocardial Infarction (AMI) is one of the main causes of mortality and disability in Colombia. The factors associated to a new event in surviving subjects to a first AMI in our population have not yet been fully identified.

METHODS

Two hundred and ninety five surviving subjects to a first AMI (58.8±12.6 years) were included in a prospective cohort study between 2000 and 2006. Lipid profile, glycemia and plasma insulin levels were measured. Deaths of cardiovascular origin, a new AMI, unstable angina, heart failure, stroke, new myocardial revascularization or angioplasty were considered new cardiovascular events.

RESULTS

The study included 61 (20.6%) women and 234 (79.4%) men. The mean follow up time was 50±30 months with a 38.9% incidence of new events. Fifty five patients (18.6%) were diabetic. Bi-varied analysis identified as risk factors for a new cardiovascular event the presence of: hypertension, anterior descending coronary artery stenosis, intrahospital cardiac failure, age over 55, low income, lack of education, Killip III-IV, heart rate over 76 bpm, pulse pressure over 80 mmHg, total cholesterol over 200 mg/dl and insulin over 10 IU/ml. After logistic regression analysis, the log values of insulin remained as the only significant predictor for new cardiovascular events.

CONCLUSIONS

Hyperinsulinism was the most important factor associated to the occurrence of new cardiovascular events in Colombian patients with AMI, which emphasizes the pivotal role of insulin resistance in the physiopathologic mechanisms of atherosclerosis, especially in undeveloped countries.

Cardiometabolic disease in latin america: the role of fetal programming in response to maternal malnutrition

Latin America is experiencing an epidemic of cardiovascular disease and type-2 diabetes mellitus. The rise in life-expectancy and increasingly rapid urbanization have resulted in a greater prevalence of overweight, obesity and metabolic syndrome. In Latin America, there is a high level of susceptibility to the development of insulin resistance and low-grade inflammation at relatively low levels of abdominal obesity. This susceptibility is associated with the adaptive response of the fetus to deficient fetal nutrition, which results in a loss of anatomical structures such as nephrons, cardiomyocytes and pancreatic beta cells. These adaptations may prove detrimental if food becomes abundant again after birth. In Latin America, the high prevalence of maternal and fetal malnutrition could mean that the resulting fetal adaptations may contribute to an increased risk of cardiometabolic disease. The socioeconomic differences that exist between developed and underdeveloped countries may be reflected in different biological adaptations, which could invalidate the diagnostic criteria and preventive and therapeutic approaches that have been recommended on the basis of research carried out in populations with different characteristics. Clinical studies are needed to evaluate the effectiveness of interventions recommended for preventing and aiding recovery from cardiometabolic disease in Latin America.

Are nutrition-induced epigenetic changes the link between socioeconomic pathology and cardiovascular diseases?

The prevalence of cardiovascular diseases (CVD) and diabetes mellitus type 2 (DM 2) is decreasing in developed countries despite the increase in the percentage of subjects with obesity and other well-recognized cardiovascular risk factors. In contrast, the recent transition of the economic model experienced by developing countries, characterized by the adoption of a Western lifestyle, that we have named "socioeconomic pathology," has led to an increase in the burden of CVD. It has been demonstrated that conventional cardiovascular risk factors in developed and developing countries are the same. Why then does the population of developing countries currently have a higher incidence of CVD than that of developed countries if they share the same risk factors? We have proposed the existence of a higher susceptibility to the development of systemic inflammation at low levels of abdominal obesity in the population of developing countries and the consequent endothelial dysfunction, insulin resistance, DM 2, and CVD. In contrast, an important percentage of obese people living in developed countries have a healthy phenotype and low risk of developing CVD and DM 2. Human epidemiologic studies and experimental dietary interventions in animal models have provided considerable evidence to suggest that nutritional imbalance and metabolic disturbances early in life may later have a persistent effect on an adult's health that may even be transmitted to the next generations. Epigenetic changes dependent on nutrition could be key in this evolutionary health behavior, acting as a buffering system, permitting the adaptation to environmental conditions by silencing or increasing the expression of certain genes.

Inter-relationships between body mass index, C-reactive protein and blood pressure in a Hispanic pediatric population

BACKGROUND

The link between inflammation, obesity, and cardiovascular disease (CVD) has been described in adult populations but few data are available with respect to children. The aim of this study was to describe the inter-relationships between adiposity, C-reactive protein (CRP) plasma concentrations, and blood pressure levels in a Hispanic pediatric population.

METHODS

We included 325 schoolchildren (mean age, 10.0 years) selected from the school population of Bucaramanga, Colombia. Blood pressure, lipid profile, glucose, and CRP plasma concentration were measured using standard procedures. Body mass index (BMI) was used for evaluating the children's nutritional condition. Correlation coefficients were calculated for all the variables using Spearman's test.

RESULTS

As expected, a positive correlation was found between BMI and systolic blood pressure (SBP) in both genders, and between CRP and SBP levels in boys. After a multivariate regression analysis, the association between adiposity and blood pressure remained significant, whereas the CRP concentrations were no longer associated with SBP.

CONCLUSIONS

The results obtained in our study of Hispanic school-age children show that adiposity is correlated with CRP concentrations and SBP values as has been earlier described in Caucasian populations. However, we failed to find a significant relationship between low-grade inflammation and SBP levels. Further studies are needed in order to explore alternative pathophysiological mechanisms linking obesity and high blood pressure in children and to define the impact of these associations on the cardiovascular risk of our pediatric population.