C-reactive protein levels and their relationship with metabolic syndrome and insulin resistance in Mexican adolescents.

OBJECTIVE: To investigate the relationship of high sensitive C-reactive protein (hs-CRP) with metabolic syndrome components and insulin resistance in Mexican adolescents. METHODS: 325 adolescents, 182 girls and 143 boys, aged 12-16 years were studied. Standardized clinical measurements and plasma lipids, glucose, insulin and hs-CRP were determined. For metabolic syndrome (MS), the NCEP-ATP III definition was used. RESULTS: MS prevalence was 13%. The most frequent MS components were low HDL-C (50%), high triglycerides (35%), and high waist circumference (28%). hs-CRP median and 75th percentile values for all children were 0.42 and 0.97 mg/dl, respectively. The highest values of hs-CRP were found in children who had MS, p <0.007. hs-CRP was positively correlated with waist circumference, triglycerides, and negatively with HDL-C, p <0.01, and positively with insulin, p <0.001. In stepwise multiple regression analysis, body mass index and HOMA-IR accounted for 10.4% and 12.7% of hs-CRP levels, respectively. CONCLUSIONS: Body mass index and insulin resistance have an independent effect on high hs-CRP levels, and explain a large part of hs-CRP concentrations in adolescents. Central adipose tissue might induce an inflammatory state that could be identified from adolescence.

Ethnicity and lipoprotein(a) polymorphism in Native Mexican populations.

BACKGROUND: Lp(a) is a lipoparticle of unknown function mainly present in primates and humans. It consists of a low-density lipoprotein and apo(a), a polymorphic glycoprotein. Apo(a) shares sequence homology and fibrin binding with plasminogen, inhibiting its fibrinolytic properties. Lp(a) is considered a link between atherosclerosis and thrombosis. Marked inter-ethnic differences in Lp(a) concentration related to the genetic polymorphism of apo(a) have been reported in several populations. AIM: The study examined the structural and functional features of Lp(a) in three Native Mexican populations (Mayos, Mazahuas and Mayas) and in Mestizo subjects. METHODS: We determined the plasma concentration of Lp(a) by immunonephelometry, apo(a) isoforms by Western blot, Lp(a) fibrin binding by immuno-enzymatic assay and short tandem repeat (STR) polymorphic marker genetic analysis by capillary electrophoresis. RESULTS: Mestizos presented the less skewed distribution and the highest median Lp(a) concentration (13.25 mg dL(-1)) relative to Mazahuas (8.2 mg dL(-1)), Mayas (8.25 mg dL(-1)) and Mayos (6.5 mg dL(-1)). Phenotype distribution was different in Mayas and Mazahuas as compared with the Mestizo group. The higher Lp(a) fibrin-binding capacity was found in the Maya population. There was an inverse relationship between the size of apo(a) polymorphs and both Lp(a) levels and Lp(a) fibrin binding. CONCLUSION: There is evidence of significative differences in Lp(a) plasma concentration and phenotype distribution in the Native Mexican and the Mestizo group.

Functional approach to investigate Lp(a) in ischaemic heart and cerebral diseases.

BACKGROUND: Lp(a), a major cardiovascular risk factor, contains a specific apolipoprotein, apo(a), which by virtue of structural homology with plasminogen inhibits the formation of plasmin, the fibrinolytic enzyme. A number of clinical reports support the role of Lp(a) as a cardiovascular or cerebral risk factor, and experimental data suggest that it may contribute to atherothrombosis by inhibiting fibrinolysis. DESIGN: A well-characterized model of a fibrin surface and an apo(a)-specific monoclonal antibody were used to develop a functional approach to detect pathogenic Lp(a). The assay is based on the competitive binding of Lp(a) and plasminogen for fibrin, and quantifies fibrin-bound Lp(a). High Lp(a) binding to fibrin is correlated with decreased plasmin formation. In a transversal case-control study we studied 248 individuals: 105 had a history of ischaemic cardiopathy (IC), 52 had cerebro-vascular disease (CVD) of thrombotic origin, and 91 were controls. RESULTS: The remarkably high apo(a) fibrin-binding in CVD (0.268 +/- 0.15 nmol L-1) compared with IC (0.155 +/- 0.12 nmol L-1) suggests the existence of peculiar and poorly understood differences in pro- or anti-thrombotic mechanisms in either cerebral and/or coronary arteries. CONCLUSIONS: Our results demonstrated that Lp(a) fibrin-binding and small Apo(a) isoforms are associated with athero-thrombotic disease.

Association of visceral fat with coronary risk factors in a population-based sample of postmenopausal women.

OBJECTIVE: To investigate in a population-based random sample of postmenopausal women the adjusted association of visceral adipose tissue (VAT) with coronary risk factors. DESIGN: Cross-sectional population-based random sample study. SUBJECTS: Ninety-eight postmenopausal women (age 50-65 y). MEASUREMENTS: Visceral and subcutaneous fat areas by computer axial tomography, anthropometry, lipid profile, fasting glucose and insulin, diet, physical activity, smoking status and alcohol intake. RESULTS: Compared to women with low VAT, women with high VAT (>117.8 cm(2)) had a less favorable metabolic profile with significantly higher fasting glucose (120+/-50 vs 98+/-39), insulin (7.9+/-10 vs 5+/-8), triglycerides (172+/-69 vs 127+/-72), apolipoprotein B (119+/-24 vs 98+/-32) and significantly lower HDL-C (38+/-10 vs 46+/-14) values in the whole sample (n=98). A similar profile was found in women without diabetes and hypertension (n=39). In multiple regression models, VAT explained a portion of the variance of TG (6.2%) in the entire sample and of total cholesterol (12.4%), LDL-C (15.8%), triglycerides (16.3%), apolipoprotein B (11.6%), and fasting glucose (28.4%) in the group of non-diabetic or hypertensive women. Our VAT cut-off point of 117.8 cm(2) corresponded to a waist circumference of 84 cm. CONCLUSION: Our results in a random population-based sample of postmenopausal women confirm the association of VAT with most coronary risk factors. These associations persisted after adjusting for diet, physical activity, smoking status and alcohol intake.

LDL size and susceptibility to oxidation in experimental nephrosis.

The aim of this study was to investigate the relationship between endothelial dysfunction and low density lipoprotein (LDL) size and susceptibility to oxidation in nephrotic rats with or without deficiency of vitamin E and selenium. Four groups of male Wistar rats were studied: control (C), vitamin E and selenium deficient control (DefC), nephrotic (NS), and vitamin E and selenium deficient NS (DefNS). Nephrotic syndrome was induced by puromycin aminonucleoside. The molar ratio of vitamin E/LDL-cholesterol was significantly lower in DefNS, DefC rats, and NS vs. C rats. In comparison with control animals, vasodilation and LDL oxidability were significantly lower in nephrotic animals. LDL size was similar in all groups. Abnormal endothelial function in response to acetylcholine and carbachol was observed in NS animals compared to control rats. Relaxation response was inversely associated with an increase in LDL susceptibility to oxidation and with a lower molar ratio of vitamin E/LDL-c. LDL oxidability and LDL-c were the only variables independently associated with vasodilation. These results suggest that endothelial dysfunction of NS may be a consequence of the increased LDL susceptibility to oxidation, secondary to antioxidant deficiency.

Differential effects of obesity with and without hyperinsulinemia on plasma lipoprotein(a) concentrations in men.

To determine the association of in vivo concentrations of insulin, obesity, and gender with lipoprotein(a) [Lp(a)] levels, we used a cross-sectional population-based survey of a multistage random sample of the Mexico City adult population. We studied 423 normoglycemic, normotensive subjects from an original sample of 825, comprised of 239 men and 189 women with a mean age of 38.6 years (range, 17 to 90). All subjects were divided into 8 groups according to body mass index, fasting insulin, and gender. Lp(a) concentrations (mg/dL) were similar in obese women with and without high insulin levels (19.9 v 18.6), but hyperinsulinemic obese men had significantly lower Lp(a) levels than normoinsulinemic obese men (7.9 v 29.4). In addition, the proportion of obese men with Lp(a) concentrations of > or = 30 mg/dL was significantly higher in the normoinsulinemic than in the hyperinsulinemic (29.2% v 0.0%). The frequency distribution of Lp(a) levels was shifted to a lower range in hyperinsulinemic men compared with normoinsulinemic men. Our results show that in men, hyperinsulinemic obesity is associated with low Lp(a) levels, while obesity with normoinsulinemia is related to increased Lp(a) concentration. These observations were not found in women. These findings may explain the conflicting results reported by several studies.

Influence of the apolipoprotein E polymorphism on plasma lipoproteins in a Mexican population.

The influence of apolipoprotein E (APOE) genotypes on plasma lipid levels was determined in 278 Mexican individuals. The most frequent genotype was E3/3 (80.5%) followed by E3/4 (12.5%), E2/3 (5.0%), E2/4 (1.4%), and E4/4 (0.3%). Our data are similar to those previously described for Mexican-American and American Indian populations, which show the highest frequency worldwide of the APOE*3 and the E3/3 genotype. Compared to female carriers of the E3/3 genotype, women with the E3/4 genotype presented increased low-density lipoprotein cholesterol (117 +/- 28.0 mg/dL vs. 134.0 +/- 31.7 mg/dL, p < 0.05), and total cholesterol (179.4 +/- 33.4 mg/dL vs. 197.5 +/- 35.4 mg/dL, p < 0.01). Also, we detected increased high-density lipoprotein concentrations in women with the E2/3 genotype (53.7 +/- 19.5 mg/dL) when compared to women with the E3/3 genotype (45.2 +/- 12.0 mg/dL) (p < 0.032). Our data suggest that genetic variation at the APOE locus in the Mexican population is a genetic factor that influences plasma lipid levels. This effect was observed only in the female population. Additional studies attempting to correlate APOE polymorphism with plasma lipid profile in a large number of individuals would be helpful in establishing the true significance of this polymorphism in the Mexican population.

[Efficacy and safety of immediate-release niacin in patients with ischemic cardiopathy. Experience of the Instituto Nacional de Cardiología "Ignacio Chávez"]. / Eficacia y seguridad de la niacina de liberación inmediata en pacientes con cardiopatía isquémica. Experiencia del Instituto Nacional de Cardiología "Ignacio Chávez".

UNLABELLED: Primary and secondary prevention trials have demonstrated that niacin improves the lipid profile and reduces coronary morbidity and mortality. OBJECTIVE: To investigate the safety and efficacy of niacin in daily doses of 1.5 and 3.0 g in patients with ischemic heart disease and dyslipidemia. PATIENTS AND METHODS: Sixty one male and female patients, aged 30 to 70 years were included. Thirty two patients were later excluded; 18 for adverse events and 14 for causes not related to niacin. RESULTS: In the 29 patients that finished the study, niacin in a dose-dependent manner, significantly reduced the levels of total cholesterol, LDL-cholesterol, triglycerides, apoB and LDL-C/HDL-C ratio, and significantly increased HDL-Cholesterol concentrations; a decrease in lipoprotein(a) was observed with both dosages, but the change was significant only with the 3.0 g/day. In 11 patients (38%) lipids and lipoproteins reached ideal concentrations. In 15 patients (52%) C-LDL/C-HDL was lower than or equal to 3.5 at the end of the study. CONCLUSIONS: Our results suggest that niacin is well tolerated by 62% of the patients. Niacin is a safe, effective and a low cost alternative in the treatment of patients with ischemic heart disease and dyslipidemia.

Effect of the new diagnostic criteria for diabetes in the Mexico City study.

OBJECTIVE: To assess the effect of the new American Diabetes Association (ADA) diagnostic criteria for diabetes in the Mexico City survey. METHODS: The data available from the Mexico City study were included. This cross-sectional survey was conducted from January 1991 to March 1992 and involved 805 adults (20 years of age or older; mean age, 41 years). Survey procedures and results were previously published. Of the residents with diabetes, 74.2% had a previous diagnosis, and 25.8% were diagnosed on the basis of fasting plasma glucose (FPG) levels obtained during the survey. For the current report, these data were reanalyzed on the basis of the new ADA diagnostic criteria. RESULTS: The prevalence of newly diagnosed diabetes with use of the old and the new criteria was 23.1% versus 32.3% in men (P = 0.31) and 27.5% versus 36.3% in women (P = 0.32), respectively. The crude prevalence rate of diabetes increased from 8.7% to 9.3% (P = 0.42), and the age-adjusted rate increased from 10.6% to 11.2% for women (P = 0.64) and from 6.0% to 6.5% for men (P = 0.49). The prevalence of impaired FPG was 4.8%. Those patients with impaired FPG or newly diagnosed diabetes with FPG levels between 126 and 140 mg/dL had a more atherogenic risk profile than did those with normal carbohydrate metabolism. CONCLUSION: On the basis of the 1990 population census in Mexico City, the new ADA criteria will add 28,331 patients with diabetes (6.9%) to an already insufficient medical system. For those patients with impaired FPG or newly diagnosed diabetes on the basis of the new criteria, management should be focused on the control of the diverse and highly prevalent coronary risk factors.

[Lipoprotein(a) and lipids in chronic renal insufficiency and kidney transplant]. / Lipoproteína(a) y lípidos en insuficiencia renal crónica y en trasplante renal.

OBJECTIVE: To establish the prevalence of lipid and lipoprotein (a) abnormalities in patients under hemodialysis or who underwent renal transplantation. METHODS: Forty dialyzed patients, 64 transplanted and a comparison group of 77 subjects of the general population paired by gender and age were studied. RESULTS: The most prevalent disorder in the hemodialysis was hypoalfalipoproteinemia followed by Lp(a) excess while the least common disorder was hypercholesterolemia. The transplanted patients had the lowest prevalence of Lp(a) excess and a higher proportion of hypercholesterolemia when compared to hemodialysis patients but similar to that of controls. CONCLUSION: Our results confirmed some previous findings observations of others but differed in that hypoalfalipoproteinemia and not hypertriglyceridemia was the predominant abnormality in the hemodialysis patients.

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

BACKGROUND: It has been found that lipoprotein(a)[Lp(a)] is an independent risk factor for coronary heart disease. Studies on the influence of metabolic control on plasma 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 beginning 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 sessions. 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, LDL-cholesterol, and triglycerides also declined significantly (p < 0.001), and HDL-C increased (p < 0.05). In contrast, no significant changes in plasma Lp(a) concentrations 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 analysis 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 aged between 20 and 90 years, selected by multistage cluster sampling. HBP was diagnosed by previous history if systolic blood pressure was > or = 140 mmHg and/or diastolic blood pressure > or = 90 mmHg. The measurements taken included body mass index, waist-to-hip ratio, systolic and diastolic blood pressure, levels of insulin, glucose, trigylycerides, total cholesterol, high and low density lipoprotein cholesterol, and lipoprotein(a). RESULTS: Prevalence adjusted by age for HBP was 19.4%, for ISH, 4.7%, and for DH, 4.1%. Age had an important influence on HBP and ISH with a 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 factors must be studied thoroughly because they constitute different clinical entities.

Lipoprotein(a) and cardiovascular risk in adult Mexicans.

A cross-epidemiologic study concerning cardiovascular risk factors in a random sample population of Mexico City was carried out in 1991 and 1992. Lipoprotein(a) (Lp(a)) levels in 404 men and 311 women aged 20-90 years were determined by enzyme-linked immunoassay on fasting plasma. Men and women showed similar age-adjusted Lp(a) values. For the whole population the median Lp(a) was 6.9 mg/dL and the prevalence of high Lp(a) (> 30 mg/dL) was 14%. Small positive correlations between Lp(a) and plasma cholesterol (rs = 0.16) and low density lipoprotein cholesterol (LDL-C) (rs = 0.21), and a negative one with insulin (rs = -0.13) were found. In a multiple regression analysis, insulin and LDL-C were the variables that best explained the variation of Lp(a) in our sample. Our data show that Lp(a) in our population is similar to that found in other populations. An association of Lp(a) with myocardial infarction was observed (high Lp(a) was seen in 33% of atherosclerotic individuals versus 14% in healthy subjects) but did not reach statistical significance.

Lipoprotein(a) levels in children and adolescents with diabetes.

OBJECTIVE: To determine lipoprotein(a) in children and adolescents with IDDM and assess its relation with Lp(a) levels in their first degree relatives. RESEARCH DESIGN AND METHODS: In a cross-sectional study we included 141 IDDM patients, (58 male and 83 female) with mean ages 12.2 +/- 2.8 and 12.6 +/- 3.1 years, respectively. Patients with microalbuminuria, hepatopathy, thyroid dysfunction, infectious disease, acute decompensation or surgery three months prior to the study, were excluded. Clinical history, physical examination, blood chemistry, glycosilated hemoglobin, microalbuminuria and lipid profile including total cholesterol triglycerides, HDL-C, Apo A-I, Apo B and Lp(a) were determined. Parents and non-diabetic siblings were also studied when feasible. RESULTS: Mean plasma concentration of total cholesterol, HDL-C and Apo A-I were significantly higher in diabetic boys compared to their non-diabetic sibs. Mean Lp(a) plasma values and the prevalence of Lp(a) > 30 mg/dL were similar in the IDDM patients, their healthy sibs and parents. Hypercholesterolemia and hypertriglyceridemia were more frequent among the IDDM patients. No correlation was found between HbA1, and Lp(a) concentrations. However, a correlation was observed between Lp(a) plasma concentrations of parents and their diabetic and healthy offspring. CONCLUSION: Diabetes mellitus does not seem to affect Lp(a) levels. These data are consistent with a genetic regulation of Lp(a) plasma levels.

Clustering of metabolic disorders and hyperinsulinemia in Mexico City.

OBJECTIVE: To investigate the relationship between fasting insulin concentrations and several metabolic and anthropometric variables in the Mexico City population. DESIGN: Cross-sectional, randomized, stratified by age, sex and economically active and inactive. SUBJECTS: 700 healthy adults, older than 20 years, 396 males and 304 females. MEASUREMENTS: Body mass index, waist to hip ratio, systolic and diastolic blood pressure, insulin, glucose, triglycerides, total, HDL and LDL cholesterol and lipoprotein(a). RESULTS: Means for age were 39 +/- 13 years for men and 41 +/- 12 for women (p < 0.05). In males, the mean values of body mass index, waist-to-hip ratio, systolic and diastolic blood pressure, triglycerides, glucose and LDL-cholesterol : HDL-cholesterol increased significantly with higher insulin levels. A significant inverse tendency was observed for the mean concentrations of HDL-cholesterol and lipoprotein(a). Age, total cholesterol and LDL-cholesterol were not related to the insulin levels. A similar pattern was observed in women, significance, however, was only obtained for the body mass index, triglycerides, glucose, HDL-cholesterol and lipoprotein(a). Age-adjusted multiple regression analysis showed that insulin was directly and independently associated to triglyceride levels and inversely with lipoprotein(a) concentrations for both sexes, and with HDL-C, only in males. CONCLUSIONS: The prevalence of insulin resistance related metabolic disorders was high in a random sample of the Mexico City population. Increased cardiovascular risk factors associated with the insulin resistance syndrome were observed with higher insulin levels, and lipoprotein(a) was inversely and significantly related to insulin. Preventive strategies are urgently needed to avoid the already increased incidence of morbidity and mortality associated to atherosclerotic disease.

[Microalbuminuria and macrovascular risk factors in insulin-dependent diabetic children]. / Microalbuminuria y factores de riesgo macrovascular en niños diabéticos insulino-dependientes.

OBJECTIVE: To investigate the prevalence of microalbuminuria in children and teenagers with IDDM and its relationship with other variables. METHODS: We studied 160 IDDM children and teenagers with a mean age of 13 +/- 4 years from our endocrine department outpatient clinic. A complete medical history was obtained as well as a fasting blood sample for glycemia, glycosilated hemoglobin and lipid profile and a urine sample for microalbuminuria using laser immunonephelometry. RESULTS: 13 patients (8%) had microalbuminuria (20-200 micrograms/min) and 5 (3%) clinical proteinuria (> 200 micrograms/min). The abnormal excretion was more prevalent in females with the poorest metabolic control, the longest duration of diabetes, and the highest age (13-18 years). The presence of microalbuminuria or clinical proteinuria associated with a more atherogenic risk profile compared to patients with a normal urinary albumin excretion. CONCLUSIONS: There was a poor metabolic control in our IDDM population. In addition, our current findings in a population with a relatively short duration of their diabetes point out the need to improve an integral management strategy to prevent or delay the late complications associated with IDDM.

High blood pressure and cardiovascular risk factors in an adult population of Mexico City. Characteristics of the studied 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 factors such as smoking, alcohol consumption and sedentarism. The response rate was 86.6%. The prevalence of high blood pressure was 21.1%, and of non-insulin dependent diabetes mellitus was 8.7%. Frequency of dyslipidemia in the studied sample was 24.4% for high TG, 23.6% for low HDL-C, 23.6% for high LDL-C, 14.9% 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.

Cholesterol levels and prevalence of hypercholesterolemia in a Mexican adult population.

In Mexico, the incidence and prevalence of coronary heart disease (CHD) has increased over the past three decades and has become the leading cause of death in the country. Hypercholesterolemia is a major risk factor for coronary atherosclerosis and most developed countries currently have public health strategies that attempt to reduce the level of cholesterol. In order to determine the mean total cholesterol values and the prevalence of hypercholesterolemia, an epidemiologic survey was carried out in a representative national population sample that included men and women aged 1 to 98 years. In this report, we present the findings in all individuals older than 20 years (n = 33,558). Considering the country as a whole, the mean serum total cholesterol (TC) was 4.80 +/- 1.16 mmol/l, the prevalence of borderline hypercholesterolemia (TC between 5.17 and 6.20 mmol/l) was 22.8% and the prevalence of high risk hypercholesterolemia (TC > or = 6.20 mmol/l) was 10.6%. This cross sectional study demonstrated the existence of significant geographic differences in serum TC, with mean state values ranging from 4.43 +/- 1.05 mmol/l in the south to 5.48 +/- 1.36 mmol/l in the north. The prevalence of high risk hypercholesterolemia was as high as 24.8% in Baja California Norte and as low as 4.0% in the state of Guerrero. These large differences in mean TC values are probably diet related and reinforce the need to carry out prospective and intervention trials related to CHD and its risk factors.

[Lipid and lipoprotein levels in athletes in different sports disciplines]. / Concentraciones de lípidos y lipoproteínas en atletas de diferentes disciplinas deportivas.

The purpose of this study was to investigate the effects of long-term high level physical exertion on plasma lipids and lipoproteins. Ninety-one young athletes, 70 men and 21 women, who practiced sports such as running, swimming, rowing, boxing and soccer, were studied. The control group included 101 healthy subjects, 77 men and 24 women, with sedentary life style. The mean plasma levels of total cholesterol (TC) (p = 0.04), low-density lipoprotein cholesterol (LDL-C) (p = 0.04) and the atherogenic index (p = 0.01) were lower, and high-density lipoprotein cholesterol (HDL-C) (p < 0.005) significantly higher in male athletes than in controls. Mean plasma lipids and lipoproteins concentrations were not significantly different in sportswomen when compared with their controls. The prevalence of hypercholesterolemia, hypertriglyceridemia and low HDL-C levels, were lower in male and female athletes of the five sport disciplines than in sedentary controls; however, only hypercholesterolemia (p < 0.05) and the atherogenic index (p < 0.01) were statistically different. These results, consistent with data previously published, show that low plasma levels of TG and high levels of HDL-C characterizes the athletes who practice an aerobic physical activity; additionally, in male athletes we found that long-term exercise appears to reduce LDL-C plasma levels. This latter finding agree with most, but not all, studies in the literature. We conclude that athletes have a lipid profile that may be protective against the development of atherosclerosis.

The prevalence of NIDDM and associated coronary risk factors in Mexico City.

OBJECTIVE: To determine the prevalence of diabetes and associated coronary risk factors in the Mexico City population. RESEARCH DESIGN AND METHODS: A sample of 805 adults was selected from Mexico City. The participants, 20-90 years of age and living in the city, were selected by the method of multistage cluster sampling with proportional allocation. Diabetes was diagnosed by previous history or if fasting blood glucose was > or = 7.8 mmol/l ( > or = 7.8 mmol/l ( > or = 140 mg/dl). RESULTS: The crude rate prevalence of NIDDM was 8.7%, with an age-adjusted rate of 10.6% for women and 6.0% for men. Age strongly influenced diabetes prevalence, with a chi 2 of risk tendency of 39.1 (P < 0.00005). A significant proportion (5.9%) of younger individuals (35-44 years of age) was affected by the disease. Diabetes was associated with advanced age, had a greater impact in the low-income group, and showed increased odds ratio for hypertension, dyslipidemias, and myocardial infarction in men and women and for obesity only in women. CONCLUSION: There is a high prevalence of NIDDM in Mexico City that also strikes a significant group of younger individuals. Associated coronary risk factors are also common and more prevalent in diabetic individuals. Current epidemiological data in Mexico and Mexican-Americans in the U.S. suggest that we may be on the ascending limb for diabetes and cardiovascular disease. There is a critical need for resources to be allocated to programs for primary and secondary prevention, which must be well structured and organized so that proper standards of care are followed to prevent progression of the disease.