Development of Hypertension in a Cohort of Cuban Adolescents
January 2015, Vol 17, No 1

INTRODUCTION Primary hypertension has its origins in childhood and is a risk factor for atherosclerosis; it is considered an important health problem because of its high prevalence worldwide.

OBJECTIVE Describe the development of hypertension during adolescence, including some factors that influence its persistence and progression in Cuban adolescents.

METHODS A cohort study was conducted in an intentional sample of 252 apparently healthy adolescents from the catchment area of the Héroes del Moncada Polyclinic in Plaza de la Revolución Municipality, Havana. They were assessed in two cross-sectional studies in 2004 and 2008. Mean age at first assessment was 13.2 years, 17.1 years at the second. Variables were weight, height, body mass index, waist circumference, blood pressure, smoking, family history of hypertension and birth weight. Correlation coefficients and growth curve analyses were applied to assess blood pressure persistence. Risk of developing prehypertension and hypertension was estimated in the second assessment, based on predictors identified in the 2004 cut. Forecasting models with these factors were developed using classification trees as analytical tools.

RESULTS Of the six adolescents categorized as hypertensive in the first assessment, five still showed blood pressure alterations after four years. The main factors related to hypertension in those aged 16–19 were blood pressure itself and a body mass index >90th percentile, followed by low birth weight and abdominal obesity. Prognostic models for predicting this condition at the end of adolescence demonstrated the importance of blood pressure alterations at age 12–15 years.

CONCLUSIONS High rates of persistence and progression of hypertension during adolescence highlights the need for systematic blood pressure screening at the primary health care level and adoption of primary prevention strategies beginning in childhood.

KEYWORDS Atherosclerosis, atherogenesis, high blood pressure, adolescence, hypertension, risk factors, Cuba

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Contextual and Individual Influences on Diabetes and Heart Disease in Havana Primary Care Catchment Areas
April 2013, Vol 15, No 2

INTRODUCTION A population health profile is a cumulative product of socioenvironmental and political factors that create the contexts in which health problems arise, as well as opportunities and barriers to addressing them. Research on context has focused on demonstrating its effects, direct or indirect, on health indicators, but has made few incursions into assessing its role as a mediator of other factors. While individual risk factors for chronic diseases are well known, the same cannot be said for the complex of contextual factors operating at various levels and over the lifespan.

OBJECTIVES Estimate relative influences by contextual versus individual factors as determinants of diabetes type 2 and heart disease.

METHODS A cross-sectional study was carried out in populations served by 12 family doctor-and-nurse practices in Havana, in 840 families selected by simple random sampling, 70 per practice. Principal components analysis was used, as well as contextual logistic regression models with a nested model strategy, whose fit was meant to estimate the relative contributions of contextual compared to individual risk factors for diabetes and heart disease. Context was described and analyzed at two levels: that of the family or household and that of the catchment area served by a family doctor-and-nurse practice (geographically defined as a neighborhood).

RESULTS For diabetes, the contextual effect of neighborhood was modified when household effect was removed; that is, the effect of neighborhood was indirect and mediated by household. Individual coefficients were practically invariant; the principal effect of household changed noticeably on removal of individual effects, while age maintained its effect without variation.

For heart disease, the effect of neighborhood was slightly modified when household effect was controlled for. Individual coefficients showed little change. There was an important direct effect of household on risk of heart disease. Age and high blood pressure coefficients hardly varied.

CONCLUSIONS We confirmed interactions between individual and contextual (neighborhood and household) factors, whose effects on individual health are not entirely mediated by individual factors. Research needs to pay more attention to context beyond its direct effect on individual risk factors.

KEYWORDS Risk factors, risk reduction, community, neighborhood, type 2 diabetes mellitus, heart disease, logistic models, Cuba

 

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Lipid Levels as Predictors of Silent Myocardial Ischemia in a Type 2 Diabetic Population in Havana
January 2012, Vol 14, No 1

INTRODUCTION Silent myocardial ischemia is frequent in type 2 diabetics, therefore, symptoms cannot be relied upon for diagnosis and followup in these patients. Various studies relate blood lipid levels to cardiovascular diseases, and several authors describe certain lipoproteins as independent predictors of ischemia.

OBJECTIVE Identify blood lipid levels that predict silent myocardial ischemia in a type 2 diabetic population in Havana.

METHODS From May 2005 through May 2009, assessment was done of 220 asymptomatic type 2 diabetics in ten polyclinics in Havana using laboratory tests and Single-Photon Emission-Computed Tomography, synchronized with electrocardiogram, known as gated SPECT (gSPECT). Coronary angiography was used for confirmation when gSPECT detected ischemia. Patients were classified into two groups: gSPECT positive and gSPECT negative. Descriptive statistics (mean and standard deviation) were calculated for all variables and mean comparison tests were conducted. Classification trees were developed relating lipid values to gSPECT results, identifying optimal cutoff points for their use as indicators of silent myocardial ischemia in the total study population and for each sex separately.

RESULTS GSPECT found silent myocardial ischemia in 29.1% of those examined, and 68.4% of angiograms found multivessel disease. gSPECT-positive diabetics had higher levels of total cholesterol, LDL, and triglycerides (p < 0.05). HDL levels were lower in this group (p < 0.05). Classification trees showed optimal cutoff points, indicators for silent ischemia, for: HDL ≤44 mg/dL, LDL >119.9 mg/dL, and triglycerides >107.2 mg/d; 80.4% of diabetics with these HDL and triglyceride values had ischemia. HDL was the most important normalized variable when the entire population was analyzed. Analysis by sex showed a greater percentage of silent ischemia in men (33.3%) than in women (24.8%). The most important normalized variables were LDL of >100.8 mg/dL for men and HDL of ≤44 mg/dL for women.

CONCLUSIONS A considerable percentage of the study population had silent myocardial ischemia. Type 2 diabetics with ischemia had higher levels of total cholesterol, LDL and triglycerides. HDL levels were significantly lower in these patients. The association of low HDL with high triglycerides was a strong indicator of myocardial ischemia in type 2 diabetics without clinical cardiovascular signs.

KEYWORDS Lipids, type 2 diabetes, silent myocardial ischemia, decision trees, diagnostic imaging, Single-Photon Emission-Computed Tomography, cardiac-gated SPECT, early detection, Cuba

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Albuminuria as a Marker of Kidney and Cardio-cerebral Vascular Damage. Isle of Youth Study (ISYS), Cuba
October 2010, Vol 12, No 4

INTRODUCTION The disease complex comprised of atherosclerosis, chronic kidney disease (CKD) and other associated chronic vascular diseases is the leading cause of mortality worldwide. Microalbuminuria is a marker for vascular damage in the heart, kidney and brain. This paper presents selected findings of the clinical-epidemiological Isle of Youth Study (ISYS) of markers for kidney and vascular damage from chronic vascular diseases and their common risk factors in total population, focusing on Phase 2 reassessment (in 2010) of Phase 1 (2004 to 2006) results.

OBJECTIVES (1) Update the prevalence of risk factors in the study population aged ≥20 years (adult population). (2) Confirm presence of microalbuminuria in at-risk adults diagnosed as presumptive positives in Phase I. (3) Evaluate association between microalbuminuria and selected risk factors.

METHODS Of 3779 adults positive for microalbuminuria in ISYS Phase 1, 73.1% were reevaluated. The risk-factor questionnaire was re-administered and blood pressure, weight and height were measured. Blood was tested for creatinine, glycemia, cholesterol and triglycerides. Glomerular filtration rate was calculated using the Modification of Diet in Renal Disease (MDRD) formula. Albuminuria was measured in urine using Micral-Test (Germany) and albumin/creatinine ratio (ACR) by nephelometry. This paper uses ACR as the reference for analyzing risk factor associations. Double-entry tables were developed to analyze association among microalbuminuria, risk factors and co-morbidities.

RESULTS Most prevalent risks were hypertension, consumption of nonsteroidal anti-inflammatory drugs (NSAIDs), excess weight and hypertriglyceridemia. Microalbuminuria was confirmed in 18% of cases, using the same test. Elevated prevalence of microalbuminuria was positively associated with advancing age, male sex, underweight, smoking, NSAID use, dyslipidemia, hypertension, diabetes, heart disease and stroke.

CONCLUSIONS The at-risk cohort studied presented low levels of confirmation for positive microalbuminuria. Positive microalbuminuria stratified individuals at greatest risk, except for obesity.

KEYWORDS Chronic kidney disease, cardiovascular disease, risk factors, damage markers, albuminuria, microalbuminuria, Cuba

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Severe Maternal Morbidity in the Intensive Care Unit of a Havana Teaching Hospital,1998 to 2004
July 2008, Vol 10, No 3

Introduction In recent years, several reports have appeared in the international literature concerning evolution and prognosis for obstetric patients whose illnesses have led to admission to intensive care units (ICUs). The term severe maternal morbidity has been proposed to refer to life-threatening complications that occur during pregnancy, delivery or postpartum.

Objective Characterize severe maternal morbidity in obstetric patients admitted to the ICU of the Enrique Cabrera General Teaching Hospital in Havana from 1998 to 2004.

Methods From 1998 to 2004, we conducted a prospective, descriptive, and observational study of 312 patients admitted to the ICU of the Enrique Cabrera General Teaching Hospital in Havana, Cuba. Patients were included whose length of stay was >24 hours, and whose family members provided written informed consent. A data collection form was developed to record general characteristics, personal and family medical history, cause of ICU admission, diagnosis, obstetric condition at the onset of illness and at admission, pregnancy outcome, surgeries performed and patient’s ICU discharge status (survivor or non-survivor), the latter a dependent variable. An Excel database was compiled and processed using SPSS 13.0. Percentages were used to summarize qualitative variables. A Chi-square test was used for univariate analysis between these qualitative variables and patient discharge status; t-test was used for quantitative analyses.

Results Overall mortality in the cohort was 7.4% (23 patients), greater among women aged <20 years, those with a history of previous illnesses, and those subjected to several surgical interventions. Obstetric hemorrhage, pre-eclampsia/eclampsia, and postpartum sepsis were the most commonly diagnosed obstetric disorders. Non-obstetric disorders diagnosed included severe asthma, pneumonia and peritonitis. Amniotic fluid embolism, postpartum sepsis, early postpartum hemorrhage and pre-eclampsia/eclampsia were associated with the highest hospital case fatality rates in women with obstetric disorders; while acute chest syndrome, promyelocytic leukemia and pulmonary embolism were associated with the highest hospital case fatality rates among women with non-obstetric disorders.

Conclusions Our results concur with most of those published on severe maternal morbidity in ICUs, including a high incidence of hemorrhagic disorders, pre-eclampsia and postpartum sepsis. The number of patients with hematological disorders accounts for the difference between the results of our study and others concerning morbidity and mortality among this patient group. A significant correlation was observed between history of previous illnesses and patient discharge status. Prognosis was worse for patients subjected to several surgical interventions, which can be attributed to the higher risk of complications and the severity of the underlying illness.

Keywords Maternal mortality, maternal morbidity, intensive care, critical care, postpartum hemorrhage, pre-eclampsia, eclampsia, postpartum sepsis

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Prevalence of Obesity and its Association with Chronic Kidney Disease, Hypertension and Diabetes Mellitus. Isle of Youth Study (ISYS), Cuba
April 2008, Vol 10, No 2

Introduction Obesity is a social disease constituting a global pandemic. It is present in 90% of diabetic and 65% of hypertensive patients. It is associated with cardiometabolic syndrome and with damaging physiopathological mechanisms, particularly for the vascular system and the kidneys. On Cuba’s Isle of Youth, a community-based epidemiological study of chronic kidney disease (CKD), hypertension (HTN), diabetes mellitus (DM) and cardio-cerebral vascular disease was carried out in total population, including an examination of common risk factors.

Objective Based on the Isle of Youth Study (ISYS) data, determine prevalence of obesity and overweight, and their association with CKD, HTN, DM, and shared risk factors for all these conditions in total population of the Isle of Youth, Cuba.

Methods Phase 1: Population diagnosis (November 2004-April 2006): 96.6% of the Isle of Youth’s total population (80,117) was studied, including all ages and both sexes. Information was offered to the public, and written informed consent obtained. Screening was conducted by participant questionnaire including risk factors, physical measurements (weight, height, blood pressure and body mass index), and a single first-morning urine sample to determine the presence of vascular-renal damage markers – proteinuria and hematuria (Combur 10 Test, Roche), and microalbuminuria (Micral Test, Roche). When results were positive, serum creatinine was determined and glomerular filtration rate (GFR) estimated with Modification of Diet in Renal Disease (MDRD) formula for adults and Schwartz formula for children <15 years. Data obtained were analyzed to determine association of participants’ nutritional status with prevalence of chronic kidney disease, hypertension and diabetes mellitus, as well as a set of common risk factors.

Results Population <20 years: Obesity prevalence 3.2%; positive urine markers in 56.9% of obese and 8.9% of non-obese participants; positive albuminuria in 38% of obese and 3% of non-obese. Obese participants were found to be hyperfiltrating. DM prevalence was 9.5% in obese and 1.1% in non-obese participants. Population ≥20 years: Overweight, 31.3%; obese, 13.4%. Positive markers in normal-weight, overweight and obese individuals were 18.3%, 21.2% and 32.7%, respectively; microalbuminuria values increased with weight. Obese individuals were found to be hyperfiltrating. HTN prevalence in normal-weight, overweight and obese individuals was 18.3%, 31.5%, and 51.0% respectively; DM rates were 2.8%, 5.2% y 11.3%, respectively.

Conclusion In Cuba, obesity poses significant risk for vascular and renal damage and should be the focus of increased prevention efforts.

Keywords Vascular diseases, chronic kidney disease, CKD, chronic kidney insufficiency, hypertension, diabetes mellitus, risk factors, obesity, overweight, body mass index, glomerular filtration rate

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Design & Methodology of the Isle of Youth Community-Based Epidemiological Study of CKD, Cardio-cerebral Vascular Disease, Hypertension, and Diabetes Mellitus (ISYS)
October 2007, Vol 9, No 1

The methodology is described in detail for the population-based Isle of Youth Study (ISYS) for epidemiological evaluation of CKD associated with cardio-cerebral vascular disease, arterial hypertension, diabetes mellitus, and other risk factors.

Background: Chronic kidney disease emerges as an important and growing global health problem associated with an increase in the incidence and prevalence of the above mentioned diseases.

ISYS Objectives: Ascertain CKD morbidity and its relation to chronic vascular diseases and other risk factors in whole population of Cuba’s Isle of Youth special municipality.

Method: 96.6% of the Isle of Youth’s total population (80,117 inhabitants) was studied, all ages and both sexes, November 15, 2004-April 30, 2006. The public was offered general information on the objectives and benefits of the study, and participants provided informed consent. Active screening was performed via personal interview questionnaire and urine sample to determine markers of kidney damage: proteinuria and hematuria (Combur-10-Test) and microalbuminuria (Micral-Test), according to a diagnostic algorithm. For those testing positive for any marker, serum creatinine was studied and glomerular filtration rate (GFR) calculated – in adults by Cockcroft-Gault and Modification of Diet in Renal Disease (MDRD) formulas and in children aged <15 years, by Schwartz – to stratify CKD by stages. Blood pressure, height, weight, and body mass index (BMI) were determined.

Expected Results: Prevalence of kidney damage markers in general population and risk groups; relationship in population between CKD and cardio-cerebral vascular disease, diabetes mellitus, hypertension, and other risk factors; comparison of Cockcroft-Gault and Modification of Diet in Renal Disease (MDRD) formulas for measuring the GFR and their application to studies involving mass population screenings; and stratification of CKD in population.

Conclusions: ISYS Phase I, active screening of markers for renal damage was concluded using the methodology described above; results are pending publication. (Abstract)

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