RESUMO
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.
Assuntos
Dislipidemias/epidemiologia , Dislipidemias/metabolismo , Metabolismo dos Lipídeos , Lipoproteínas/metabolismo , Adolescente , Consumo de Bebidas Alcoólicas/sangue , Consumo de Bebidas Alcoólicas/metabolismo , Pressão Sanguínea/fisiologia , Índice de Massa Corporal , Criança , HDL-Colesterol/sangue , HDL-Colesterol/metabolismo , LDL-Colesterol/sangue , LDL-Colesterol/metabolismo , Estudos Transversais , Dislipidemias/fisiopatologia , Feminino , Humanos , Lipoproteínas/sangue , Masculino , México/epidemiologia , Prevalência , Fumar/sangue , Fumar/metabolismo , Triglicerídeos/sangue , Triglicerídeos/metabolismo , População UrbanaRESUMO
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.
Assuntos
Diabetes Mellitus Tipo 2/sangue , Resistência à Insulina , Lipoproteínas HDL/sangue , Lipoproteínas HDL/classificação , Obesidade/sangue , Adolescente , Glicemia , Criança , Colesterol/sangue , Feminino , Humanos , Masculino , Tamanho da PartículaRESUMO
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.
Assuntos
Acantose Nigricans/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Resistência à Insulina , Metformina/uso terapêutico , Tiazolidinedionas/uso terapêutico , Acantose Nigricans/sangue , Acantose Nigricans/patologia , Administração Oral , Adulto , Feminino , Humanos , Hipoglicemiantes/administração & dosagem , Insulina/sangue , Masculino , Metformina/administração & dosagem , Obesidade , Projetos Piloto , Rosiglitazona , Tiazolidinedionas/administração & dosagem , Resultado do TratamentoRESUMO
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.
Assuntos
Doenças Cardiovasculares/etiologia , Dislipidemias/epidemiologia , Hipertensão/epidemiologia , Adolescente , Criança , Estudos Transversais , Dislipidemias/complicações , Exercício Físico , Feminino , Inquéritos Epidemiológicos , Humanos , Hipertensão/complicações , Masculino , México/epidemiologia , Prevalência , Fatores de Risco , População Rural , Instituições Acadêmicas , Fatores Sexuais , Fumar/efeitos adversos , População UrbanaRESUMO
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.
Assuntos
Aorta Torácica/fisiopatologia , Produtos Biológicos/administração & dosagem , Cianobactérias/química , Suplementos Nutricionais , Obesidade/fisiopatologia , Vasoconstrição/efeitos dos fármacos , Administração Oral , Animais , Produtos Biológicos/química , Masculino , Obesidade/tratamento farmacológico , Técnicas de Cultura de Órgãos , Ratos , Ratos WistarRESUMO
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.
Assuntos
Arteriosclerose/sangue , Insulina/sangue , Lipoproteínas LDL/sangue , Lúpus Eritematoso Sistêmico/sangue , Adolescente , Jejum , Feminino , Humanos , Hiperinsulinismo/sangue , Hiperinsulinismo/epidemiologia , Hiperlipidemias/sangue , Hiperlipidemias/epidemiologia , Lúpus Eritematoso Sistêmico/epidemiologia , Masculino , Oxirredução , Estresse Oxidativo , Prevalência , Fatores de RiscoRESUMO
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.
Assuntos
Apolipoproteínas E/genética , Frequência do Gene , Genética Populacional , Lipoproteínas/genética , Polimorfismo Genético , Adolescente , Apolipoproteínas E/sangue , Doenças Cardiovasculares/genética , Criança , Estudos Transversais , Feminino , Humanos , Lipoproteínas/sangue , Masculino , México , Fatores de RiscoRESUMO
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.
Assuntos
Apolipoproteínas A/genética , Diabetes Mellitus Tipo 1/genética , Lipoproteína(a)/genética , Adulto , Criança , Saúde da Família , Feminino , Humanos , Masculino , FenótipoRESUMO
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.
Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Colesterol , Estudos de Coortes , Medicina Herbária , Hipercolesterolemia , Triglicerídeos/sangue , Cardiopatias , Análise de VariânciaRESUMO
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.