Lipid and lipoprotein profiles and prevalence of dyslipidemia in Mexican adolescents.

The objective of the study was to determine the prevalence of different forms of dyslipidemia in an urban population of Mexican adolescents. A cross-sectional study was conducted in 1846 students from 8 randomly selected public junior high schools in Mexico City. Anthropometry, blood pressure, and 12-hour fasting lipids and lipoproteins were measured. We studied 770 male and 1076 female adolescents (13.2 +/- 1 years). The most prevalent dyslipidemia was low high-density lipoprotein cholesterol (HDL-C) (<35 mg/dL) either combined with other abnormalities (17.5% for male and 12.9% for female subjects, P < .001) or isolated (13.5% and 9.6% for male and female subjects, respectively, P < .001). Obese subjects showed the highest prevalence of low HDL-C (47.2% for male and 34.4% for female subjects) and of high total cholesterol, low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) (19.4%, 27.8%, and 36.1%, respectively, for male subjects; 9.8%, 13.1%, and 24.6%, respectively, for female subjects). Multiple regression analysis showed that waist circumference was negatively associated with HDL-C and positively associated with LDL-C and TG levels, whereas Tanner stages were negatively associated but sex was positively associated with total cholesterol, LDL-C, and TG concentrations. As in Mexican adults, low HDL-C and high TG levels were the most prevalent dyslipidemias. Increased blood lipids over long periods suggest that, as adults, these adolescents will be facing a higher risk for atherosclerosis.

Modulation of aortic vascular reactivity by sex hormones in a male rat model of metabolic syndrome.

Modulation by sex hormones of aortic reactivity in rats with the metabolic syndrome (MS) was investigated. The following groups of weanling male Wistar rats were used: control rats (C) received regular tap water while MS rats received 30% sucrose in their drinking water; both had rodent chow for 24 weeks. These two groups were further subdivided into the following four groups: intact (Int), castrated (Cas), castrated plus testosterone (T) and castrated plus estradiol (E). Vascular response of thoracic aortic rings to norepinephrine (NE), acetylcholine (ACh), indomethacin (Indo) and nitro-l-arginine-methyl ester (L-NAME) was investigated. Blood pressure (BP) and serum nitrates and nitrites were measured. BP and serum nitrates and nitrites were modified by castration and treatments with either T or E. Vasoconstriction in Int MS and Cas MS+T aortas was larger than in C and Cas C+T, respectively. Vasodilation in Int MS and Cas MS+T was reduced in comparison with C and Cas C+T, Cas MS and Cas MS+E. Indomethacin decreased vasoconstriction in all groups (P<0.002) but Int C and Cas C+T remained significantly smaller than Int MS and Cas MS+T. l-NAME in NE-contracted vessels induced a significant increase in vasoconstriction, except in Cas C+E rats; the responses of Int MS and Cas MS+T were significantly larger than in Int C and Cas C+T. The results suggest endothelial dysfunction in Int MS and Cas MS+T and a protective effect resulting from castration and castration plus E in MS animals, indicating a sex hormone influence.

Abnormal HDL subclasses distribution in overweight children with insulin resistance or type 2 diabetes mellitus.

BACKGROUND: Small HDL particles have emerged as significant predictors of incident type 2 diabetes mellitus (T2DM) in adults with impaired glucose tolerance (IGT). However, no previous study has investigated HDL size in pediatric subjects with these clinical conditions. METHODS: We studied the HDL size distribution by native polyacrilamide gradient gel electrophoresis in 106 overweight children, 47 with T2DM, 43 with normal glucose tolerance (NGT), 16 with IGT, and 39 healthy weight controls. RESULTS: Diabetic children had significantly lower proportions of HDL2b and HDL2a, and higher proportions of HDL3b and HDL3c than the other 3 groups. Overweight subjects showed HDL size distributions similar to those of controls. However, insulin-resistant children had lower proportions of HDL2b, and HDL2a, and higher proportions of HDL3b when compared with the insulin-sensitive overweight subjects. Multiple linear regression analyses showed that homeostasis model assessment correlated inversely with HDL2b and HDL2a, and directly with HDL3b, while BMI was independently associated only with HDL3a. CONCLUSIONS: This study showed that HDL size distribution was shifted toward smaller particles in T2DM pediatric patients and in overweight children with insulin resistance, independent of their glucose tolerance status. Insulin resistance was the main factor associated with these HDL size abnormalities. This parameter could be useful as an early risk marker of incident diabetes and, probably, of coronary heart disease.

Comparison of metformin versus rosiglitazone in patients with Acanthosis nigricans: a pilot study.

BACKGROUND: Acanthosis nigricans (AN) is a skin condition commonly present on the neck of obese subjects. Obesity is often accompanied by insulin resistance and/or hyperinsulinemia. Metformin and rosiglitazone are 2 pharmacologic agents useful in conditions characterized by insulin resistance. OBJECTIVE: The aim of our study was to compare the efficacy of metformin versus rosiglitazone on AN lesions of the neck as well as their effects on metabolic and anthropometric variables. METHODS: This 12-week randomized, open-label pilot study involved overweight or obese subjects with AN treat with either metformin (n=4) or rosiglitazone (n=3). RESULTS: Only the rosiglitazone group showed a significant reduction in insulin levels. No effect on the severity of AN was observed, but modest improvements of skin texture occurred in both treatment groups. CONCLUSIONS: Metformin and rosiglitazone were well-tolerated. Although efficacy on skin lesions was very modest, their use in acanthotic subjects might be useful during longer treatment periods.

Protective effect of Arthrospira maxima on fatty acid composition in fatty liver.

BACKGROUND: Arthrospira maxima has been widely used for nutritional purposes. Additionally, A. maxima has shown immunomodulator, antiviral, antioxidant, vasomotor and hypolipidemic effects in laboratory and animal studies. A. maxima prevents fatty liver induced by either carbon tetrachloride (CCl4) or fructose-rich diet; however, the liver lipid composition in these models is not clearly known yet. The aim of this study was to evaluate the effects of A. maxima on the liver lipid profile in CCl4-induced steatohepatitis. METHODS: A single sublethal, intraperitoneal dose of CCl4 was administered to male Wistar rats fed a diet with or without 5% A. maxima. Liver lipids: total lipids, triacylglycerols, total cholesterol, free fatty acids, and thiobarbituric acid reactive substances were assessed 24 and 48 h after injury with CCl4. Additionally, triacylglycerols, total cholesterol and aspartate aminotransferase were evaluated in blood. RESULTS: Forty eight hours after CCl4 treatment, rats fed a diet without A. maxima had serum aspartate aminotransferase and liver triacylglycerols values that were, respectively, 2.2 and 1.4 times higher than those of animals receiving 5% A. maxima in their diet. The same pattern was observed for liver free fatty acids and thiobarbituric acid reactive substances. The groups fed a diet with A. maxima and treated with CCl4 showed a higher saturated fatty acid liver content than the groups without A. maxima in their diet. The percentage of unsaturated fatty acids increased 48 h after CCl4 treatment, but its value was 0.5 times lower in the group receiving A. maxima than in the group fed without A. maxima. In the liver, all animals receiving A. maxima showed a trend towards a lower percentage of unsaturated fatty acids, despite the mentioned increase 48 h after CCl4 treatment. CONCLUSIONS: The results suggest that, in the fatty liver induced by CCl4, the hepatoprotective effect of A. maxima involves (a) an antioxidant mechanism and (b) a lower unsaturation of the liver fatty acids. The preventive effect of A. maxima on the liver lipid changes induced by CCl4 could be partially explained by its antioxidant action and the ability to increase the synthesis/release of nitric oxide, but not by its soluble dietary fiber.

Prevalence and interrelations of cardiovascular risk factors in urban and rural Mexican adolescents.

PURPOSE: To examine the prevalence of coronary risk factors in Mexican adolescents, and their relations to school type, gender, and residence in urban and rural areas. METHODS: A cross-sectional survey was conducted in 3121 junior high school students, aged 12 to 16 years, attending urban schools (eight public, n = 1850, two private, n = 480) and three rural public (n = 791) schools. Weight, height, waist circumference, blood pressure, and fasting glucose and lipid-lipoprotein levels were measured. Tobacco smoking and physical activity were also ascertained. The prevalence rates of cardiovascular risk factors were determined by gender and school type. RESULTS: Obesity, overweight, high blood pressure, cigarette smoking, and physical inactivity were higher for urban than rural adolescents. The prevalence of the low HDL-C level was exceedingly high in adolescents of three school types (> 30%) but particularly in male rural students (48.9%). Compared with rural students, high LDL-cholesterol was twice as high in private schoolchildren. The prevalence of impaired fasting glucose was .35% in the whole population and much higher in obese males (1.6%) and obese females (2.4%). CONCLUSIONS: Our findings highlight an epidemic of coronary risk factors mainly in adolescents living in the urban area, suggesting the importance of environmental factors.

Ethanolic extract of Spirulina maxima alters the vasomotor reactivity of aortic rings from obese rats.

BACKGROUND: Aortic rings with endothelium excised from fructose-fed obese rats develop more tension in response to phenylephrine and relax less in response to carbachol than corresponding rings from lean rats. This altered vascular reactivity is prevented when Spirulina maxima is added to the fructose-rich diet. In the present study the effects of a raw ethanolic extract of Spirulina maxima on the vasomotor responses of aorta rings from sucrose-fed obese hypertensive rats were analyzed. METHODS: The experiments were performed on aorta rings from sucrose-fed obese male rats. For each experiment, a pair of rings from the same aorta (one with intact endothelium, the other without a functional endothelium) was used. In this study we analyzed, in vitro, the effects of the ethanolic extract of Spirulina maxima on the reactivity of the aortic rings to phenylephrine and to carbachol. RESULTS: On rings with endothelium, the extract produced the following effects: a) a concentration-dependent (0.06-1.0 mg/mL) decrease of the contractile response to phenylephrine; b) a rightward shift and a decrease in maximal developed tension, of the concentration-response curve to phenylephrine; c) a concentration-dependent relaxation of phenylephrine-precontracted rings. These effects persisted in the presence of indomethacin but were prevented by L-NAME. The extract had no effect on the concentration-response curve of phenylephrine-precontracted rings to carbachol. On endothelium-denuded rings the extract caused a significant rightward shift of the concentration response curve to phenylephrine without any effect on maximal tension development. CONCLUSIONS: These results suggest that, in rings from obese rats, the extract, in addition to increasing the synthesis/release of NO, also inhibits the synthesis/release of a cyclooxygenase-dependent vasoconstrictor metabolite of arachidonic acid, which is increased in obesity.

High insulin levels and increased low-density lipoprotein oxidizability in pediatric patients with systemic lupus erythematosus.

OBJECTIVE: To examine low-density lipoprotein (LDL) size, LDL susceptibility to oxidation, and plasma insulin levels in children with systemic lupus erythematosus (SLE). METHODS: Fifty-nine SLE patients and 59 healthy, age-matched control subjects were studied. LDL size was determined by gradient gel electrophoresis. LDL oxidizability was assessed by lag time for conjugated diene formation during copper incubation. Plasma levels of fasting insulin, glucose, lipids, lipoproteins, apolipoproteins B and A-I, and fatty acids were also measured. RESULTS: Compared with control subjects, SLE patients showed significantly higher plasma insulin levels and increased susceptibility of LDLs to oxidation. Patients with active disease were more likely than patients with inactive disease or control subjects to have the following lipid characteristics: small, dense LDL subclass, elevated total cholesterol levels, elevated LDL cholesterol levels, elevated triglyceride levels, and low levels of high-density lipoprotein cholesterol (HDL-C). Statistically significant direct correlations were observed between disease activity and triglyceride levels and between disease activity and lag time, whereas significant inverse correlations were found between disease activity and HDL-C levels and between disease activity and LDL size. Prednisone dosage explained only 15.6% of the variance in insulin levels. CONCLUSION: SLE patients have higher plasma insulin levels and increased LDL oxidizability compared with healthy control subjects. These abnormalities may contribute to the accelerated atherosclerosis observed in patients with SLE.

Apolipoprotein E polymorphism is related to plasma lipids and apolipoproteins in Mexican adolescents.

Previous studies in the Mexican population have failed to show an effect of apolipoprotein E (APOE) polymorphism on the lipid profile. The purpose of the present study was to determine the frequencies of APOE phenotypes, and their influence on lipid and apolipoprotein levels in a random sample of Mexican adolescents living in Mexico City. APOE polymorphism, fasting insulin levels, lipid levels, and apolipoprotein levels were determined in 420 adolescents. We found a high frequency of APOE*3 subjects (89.5%) and a low frequency of APOE*2 (3.0%) and APOE*4 (7.5%) subjects. The APOE*4 subjects (including APOE 4,3 and APOE 4,4) showed the highest concentrations of total cholesterol, low-density lipoprotein cholesterol, and apoB and the lowest high-density lipoprotein cholesterol levels, whereas carriers of the APOE*2 allele (APOE 3,2 and APOE 2,2) had the lowest values for total and low-density lipoprotein cholesterol and the highest concentrations of high-density lipoprotein cholesterol. No significant differences in triglyceride and insulin levels among subjects with different APOE polymorphisms were observed. Unlike previous studies in the Mexican population, our results show that lipid and lipoprotein levels are under the influence of APOE polymorphism. As in whites, APOE*4 may be a cardiovascular risk factor in the Mexican population.

Estrogen effect on heart rate variability in hypertensive postmenopausal women.

UNLABELLED: Healthy postmenopausal women and hypertensive patients show an imbalance in the modulation of autonomic nervous control of the cardiovascular system, which may increase the cardiovascular risk. OBJECTIVE: To examine the heart rate variability (HRV) response to estrogen replacement therapy (ERT) and its association with changes in metabolic variables in hypertensive postmenopausal women. METHODS: A double-blind, placebo-controlled clinical trial was conducted in 30 hypertensive postmenopausal women receiving 180 mg/day of verapamil. The experimental group (n=16) received 0.625 mg OD of natural conjugated estrogens during 4 months, while control group (n=14) received a placebo. Lipids, lipoproteins, apolipoproteins, glucose and insulin were measured at 0, 2 and 4 months. HRV was determined in time and frequency domains using a 24-h Holter before and after ERT. RESULTS: Significant higher values of spectral and non-spectral parameters of HRV, associated with a lower LF/HF ratio, were found at the end of 4 months of ERT. Multiple regression analysis revealed that estrogen treatment itself and changes in total cholesterol, LDL-cholesterol, glucose and waist circumference, contributed to the changes observed in indexes reflecting parasympathetic activity in time and frequency domains. CONCLUSIONS: We conclude that ERT partially improves HRV favoring increased parasympathetic drive, and that part of the effect may be mediated by changes in metabolic variables.

Apolipoprotein(a) phenotypes and lipoprotein(a) in type 1 diabetes mellitus patients and their first-degree relatives.

UNLABELLED: The coronary artery disease is associated with more than threefold-increased risk in diabetes mellitus. Lipoprotein(a) and apo(a), a specific protein of this lipoprotein are risk factors for atherosclerosis. However, the association of apo(a) size with the lipoprotein(a) levels in patients with type 1 diabetes mellitus still controversial. OBJECTIVE: We investigated the apo(a) polymorphism and its association with lipoprotein(a) levels in children with type 1 diabetes mellitus and their non diabetic first-degree relatives. METHODS: This cross-sectional study included 25 type 1 diabetic patients aged 1 to 17 years, one non-diabetic sibling of each patient and both parents. Glucose, lipids, lipoproteins, apoAI, apoB, lipoprotein(a) plasma concentration as well as apo(a) phenotypes were determined. RESULTS: Median plasma lipoprotein(a) concentrations were 8.3, 8.2, 4.2, and 9.3 mg/dL in type 1 diabetes mellitus, siblings, fathers and mothers respectively (p ns). The prevalence of plasma lipoprotein(a) excess (> 30 mg/dL) was not significantly higher in type 1 diabetes mellitus patients than in their non diabetic siblings, or in their parents. Lipoprotein(a) levels and apo(a) distribution were similar in all groups (p ns) and those of parents correlated directly with the lipoprotein(a) and phenotypes of their offspring. CONCLUSIONS: Lipoprotein(a) levels and apo(a) size were similar in type 1 diabetes mellitus cases and their first degree relatives and the associations between them were similar too, suggesting that Lp(a) does not appear to explain increased risk of atherosclerosis in patients with this disease.

Efecto del extracto de nopal sobre lípidos y lipoproteínas en hipercolesterolemia moderada / The effect of prickly pear cactus extracts on lipids and lipoproteins in moderate hypercholesterolemia

Estudios epidemiológicos han encontrado asociación entre el consumo de dietas altas en fibra y la disminución en el riesgo para enfermedad car-diovascular. El extracto aislado de nopal (Opuntia fuliginosa) disminuye notablemente el colesterol de LDL en roedores alimentados con dietas altas en colesterol. Conocer la eficacia y seguridad de ese producto en humanos con hipercolestero-lemia moderada constituyó el objetivo de este estudio. El diseño fue aleatorio, doble ciego y controlado con placebo; para ello se analizaron 18 pacientes no diabéticos con colesterol total entre 200 y 300 mg/dL. Después de un periodo de dieta fase I, nueve pacientes recibieron extracto de nopal (3 g tid) y nueve, placebo. En el grupo con extracto existió tendencia a disminución en el colesterol de LDL (-8 por ciento) y triglicéridos (-10 por ciento), y aumento en el colesterol de HDL (+7 por ciento) y apolipoproteína A-I (+4 por ciento); estas diferencias no alcanzaron significado estadístico, a diferencia de las disminuciones de colesterol total (-6 por ciento, p < 0.05), apolipoproteína B (-11 por ciento, p < 0.05) y glucosa (-12 por ciento, p < 0.05). Estos resultados sugieren que la administración de 9 g/día de extracto aislado de nopal mejora el perfil lipídico de pacientes con hipercolesterolemia moderada, pero posiblemente se necesitan mayores dosis para observar un beneficio clínico.

Eficacia y seguridad de la niacina de liberación inmediata en pacientes con cardiopatía isquémica: experiencia del Instituto Nacional de Cardiología Ignacio Chávez / Immediate release niacin in the treatment of ischemic heart disease

Los estudios de prevención primaria y secundaria han demostrado que la niacina mejora el perfil de lípidos y reduce la morbimortalidad coronaria. Objetivo: Investigar la eficacia y seguridad de la niacina en dosis de 1.5 y 3.0 g al día en pacientes con cardiopatía isquémica y dislipidemia. Material y métodos: Se incluyeron 61 pacientes de ambos sexos y con edades de 30 a 70 años. Se eliminaron 32 pacientes: 18 por reacciones adversas y 14 por motivos no relacionados con el fármaco. Resultados: En los 29 pacientes que terminaron el estudio, la niacina produjo reducciones significativas, dependientes de dosis, en las concentraciones de colesterol total, C-LDL, triglicéridos, apolipoproteína B y la relación C-LDL/CHDL y aumentó de manera significativa el nivel de C-HDL. La lipoproteína(a) disminuyó con ambas dosis, pero sólo alcanzó significado estadístico con la dosis de 3.0 g. En once pacientes (38 por ciento), las variables del perfil lipoproteico alcanzaron los valores ideales, y en 15 pacientes (52 por ciento), la relación C-LDL/C-HDL fue menor o igual a 3.5 al final del tratamiento. Conclusiones: Los resultados indican que la niacina es tolerada por el 62 por ciento de los pacientes; por tanto, constituye una alternativa terapéutica efectiva y de bajo costo.

Improved metabolic control does not change plasma lipoproteina(a) levels in adolescents with type 1 diabetes mellitus

Background. It has been found that lipoprotein(a)[Lp(a) levels in Type 1 diabetics have reported conflicting results. The aim of this study was to investigate Lp(a) levels in carefully selected adolescents with Type 1 diabetes mellitus before and after improved metabolic control achieved during a 2-week Juvenile Diabetes Training Camp. Methods. Patients with conditions that affect plasma Lp(a) concentrations were not included. Metabolic variables were determined at the begining and at the end of the camp. Diet was designed to supply 40-60 Kcal/Kg/day. Physical exercise was performed in two 60 minute daily session. Intermediate action insulin was given twice daily, and rapid acting insulin was also administered to some patients. Results. On the last day of the camp, fructosamine declined from 430-362.7 mg/dL (p<0.001), mean levels of total cholesterol, and triglycerides also declineds significantly (p<0.001), and HDL-C increased (p0.05). In contrast, no significant changes in plasma Lp(a) cocentrations were observed. Conclusions. The findings of this study in this relatively large group of well-defined adolescents with Type 1 diabetes mellitus suggest that improved metabolic control does not reduce plasma Lp(a) levels

Prevalence of high blood pressure and associated coronary risk factors in an adult population of Mexico city

Background. Several studies have addressed arterial hypertension prevalence in Mexico. However, few include an anlysis of other types of hypertension and their associated risk factors. The present work describes the prevalence of high blood pressure (HBP), isolated systolic hypertension (ISH) and diastolic hypertension (DH) and their association to certain risk factors of cardiovascular disease in an adult population of Mexico City. Methods. A cross-sectional study was performed on 825 subjects age between 20 and 90 years, selected by multistage cluster sampling. HBP was diagnosed by previous history if systolic blood pressure was =140 mmHg and/or diastolic blood pressure =90 mmHg. The measurements taken included body mass index, waist-to-hip ratio, systolic and diastolic blood pressure, levels of insulin, glucose, triglycerides, total cholesterol, high and low density hipoprotein cholesterol, and lipoprotein(a). Results. Prevalence adjusted by age for HBP was 19.4 percent, for ISH, 4.7 percent, and for DH, 4.1 percent. Age had an important influence on HBP and ISH with highly significant X²t. The profile of metabolic variables was modified according to sex and type of hypertension. Thus, in DH, metabolic variables were more affected than in other types of hypertension. Conclusions. Results in HBP prevalence in the present study were lower than in other surveys performed in Mexico. It must be noted, however, that much care should be taken to choose the strategy of subject selection, since results of the prevalence of a disease depend on it to a great extent. The ISH and DH and their association to risk factor must be studied thoroughly because they constitute different clinical entities

Lipoproteína(a) y lípidos en insuficiencia renal crónica y en trasplante renal / Lipoprotein(a) and lipid abnormalities in chronic renal insufficiency and renal transplantation

Objetivo. Establecer la prevalencia de las anormalidades de lípidos y lipoproteína(a) en pacientes tratados con hemodiálisis y en trasplantados. Métodos. Se estudiaron 40 dializados, 64 trasplantados y un grupo de comparación de 77 sujetos de población abierta pareados por edad y género. Resultados. En el grupo de hemodiálisis la atención más prevalente fue la hipoalfalipoproteinemia seguida de exceso de Lp(a) y la de menor frecuencia fue la hipercolesterolemia. Contrariamente, los trasplantados tuvieron la prevalancia más baja de exceso de Lp(a), y una proporción de hipercolesterolemia más alta que la de pacientes hemodializados y semenjantes a los controles. Conclusión. Nuestros resultados confirman algunas observaciones de otros pero en nuestro estudio fue la hipoalfalipoproteinemia y no la hipertrigliceridemia la anormalidad predominante en los pacientes hemodializados

Lipoprotein(a) levels in children and adolescents with diabetes

Objetivo. Determinar los niveles de lipoproteina(a) en niños y adolescentes con IDDM y evaluar su relación con los niveles de Lp(a) de sus familiares en primer grado. Diseño y métodos. En un estudio tranversal se incluyeron 141 pacientes con IDDM (58 masculino y 83 femeninos) con edades promedio de 12.2 ñ 2.8 y 12.6 ñ 3.1 años, respectivamente. Se excluyeron los pacientes con microalbumina, hepatopatía tiroidea, los que padecían alguna infección, descompensación aguda o que hubieran sido sometidos a tratamiento quirúrgicos en los tres meses previos al estudio. Se les realizó historia clínica con examan físico y se determinaron química sanguínea, hemoglobina glucosilada, microalbuminuria y perfil de lípidos que incluyó colesterol total, triglicéridos, C-HDL, Apo A-l, Apo B y Lp(a). Cuando fue posible se estudiaron los padres y hermanos no diabéticos de los casos. Resultados. Los promedios de las concentraciones plasmáticas de colesterol total, C-HDL y apo A-l fueron significativamente mayores en los pacientes masculinos en comparación con sus hermanos no diabéticos. Los valores promedio de Lp(a) y la prevalencia de exceso de Lp(a) fueron similares en pacientes diabéticos, sus hermanos sanos y sus padres. No se encontró correlación entre HbA y las concentraciones de Lp(a), pero sí se observó una correlación entre Lp(a) de los padres con la de sus hijos diabéticos y sanos. Conclusión. La diabetes mellitus parece no modificar los niveles de Lp(a). Estos datos consistentes con la hipótesis de que los niveles plasmáticos de Lp(a) están regulados genéticamente

Lipoprotein(a) and cardiovascular risk in adult Mexicans

De 1991 a 1992 se realizó un estudio epidemiológico transversal en una muestra aleatoria de la población adulta de la ciuda de México en la que se analizaron los factores de riesgo de enfermedad arterial coronaria (EAC). La concentración plasmática de lipoproteína(A) (Lp(a)) se midió por ELISA en 404 hombres y 311 mujeres de 20 a 90 años de edad. La mediana de Lp(a) fue de 6.9 mg/dL y la prevalencia de valores elevados (> 30 mg/dL) de 14 por ciento. El nivel de Lp(a) correlacionó positivamente con el de colesterol total (rs = 0.16) y con el colesterol de lipoproteína de baja densidad (C-LDL) (rs = 0.21), y en forma negativa con la insulina (rs = 0.13). La insulina y el C-LDL fueron las variables que mejoro explicaron las concentraciones de Lp(a) en la población. La distribución de Lp(a) en la ciudad de México es similar a la descrita para otras poblaciones y nuestros resultados sugieren, aunque sin alcanzar significancia estadística, que las cifras elevadas de Lp(a) pudieran estar asociadas con la EAC en nuestra población

Microalbuminuria y factores de riesgo macrovascular en niños diabéticos insulino-dependientes / Microalbuminuria and macrovascular risk factors in insulin-dependent diabetics

El objetivo del presente estudio fue investigar la frecuencia de microalbuminuria y su correlación con variables antropométricas y metabólicas que se asocian a riesgo cardiovascular en un grupo de niños y adolescentes diabéticas. Material y métodos. Se estudiaron 160 niños y adolescentes diabéticos insulinodependientes de nuestra consulta externo de endocrinología pediátrica, 73 del sexo masculino y 87 del femenino, con edad media de 13 ñ 4 años. Se les realizó una historia clínica y se tomaron deterinaciones de glucemia, hemoglobina glucosilada y perfil de lípidos. Se obtuvo una muestra de orina para determinación de microalbuminuria, por el método de inmunonefelometría de rayo láser. Se investigó la asociación de la microalbuminuria y en 5 (3 por ciento) se encontró proteinuria clínica. La prevalencia de microalbuminuria y proteinuria clínica fue más alta en pacientes con relativamente pocos años de duración de la diabetes, sugieren un panorama poco halagador. Debe insistirse en mejorar la atención integral del paciente del paciente diabético y diseñar estrategias para prevenir o retrasar el desarollo de complicaciones tardías en nuestro medio

High Blood pressure and cardiovascular risk factors in an adult population of Mexico City: characteristics of the studies population

The present report is a description of the characteristics of a studied population and of the methodology used in a study performed to investigate high blood pressure prevalence and cardiovascular risk factors among the adult population of Mexico City. A cross-sectional study was conducted from January 1991 to March 1992. Random samplings of multiple stages was used and 825 adult subjects were studied in Mexico City. The following measurements were registered: blood pressure, body mass index (BMI), waist-hip ratio (WHR), total cholesterol (TC), triglycerides (TG), high density lipoproteins (HDL-C) and low density lipoproteins (LDL-C), lipoprotein(a) (Lp(a)), glucose and insulin. Personal and family history of cardiovascular illness were investigated, as well as exposure to some risk factor such as smoking, alcohol consumption and sedentarism. The response rate was 86.6 percent. The prevalence of high blood pressure was 21.1 percent, and of non-insulin dependent diabetes mellitus was 8.7 percent. Frequency of dyslipidemia in the studied sample was 24.4 percent for high TG, 23.6 percent for low HDL-C, 23.6 percent for high LDL-C, 14.9 percent for Lp(a) excess (lp(a) > or = 30 mg/dl; overweight and obesity were more prevalent among women. The diversity of living conditions among the population of Mexico City was included in the sampling strategy design, not only to register the high blood pressure (HBP) frequency in each stratum but to identify other cardiovascular risk factors which could be decisive in the development of HBP. Regarding the features of the studied population, BMI did not reveal differences among men, but their TG levels were higher and HDL levels lower than those of other populations. In women, the results obtained for BMI, WHR, lipids and lipoproteins were also higher compared with the mean reported for other populations