Background: Hyperglycemia during hospital stay is associated with adverse outcomes. Aim: To characterize the frequency of hyperglycemia in a tertiary hospital and to correlate it with length of hospital stay (LOS). Material and Methods: Review of medical records of hospitalized patients. Demographic data and laboratory data, previous diabetes mellitus (DM) history, current main diagnosis, unit of hospitalization and the two highest capillary blood glucose values from the analyzed period were recorded for each patient. LOS was obtained from electronic clinical records. Results: 210 subjects, aged 60 ± 19 years (104 women) were included. 113 patients (54%) developed hyperglycemia ≥ 140 mg/L. Thirty one percent of these had a previous history of diabetes and 29% had stress hyperglycemia (SHG). Patients with a history of DM had a higher average blood glucose than those with SHG (238.9 and 178.2 mg/dL, respectively, p < 0.01) and a greater percentage of cases with a blood glucose above 180 mg/dL (72 and 40.0%, respectively, p < 0.01). Hospital LOS was significantly longer in patients with hyperglycemia ≥ 140 mg/dL as compared with those with normoglycemia (29.3 and 12.8 days, respectively, p < 0.01). This association remained significant when introduced in a linear regression analysis including diagnosis, decreased glomerular filtration rate (GFR) and hospitalization unit (p < 0.01). Conclusions: Hyperglycemia during hospitalization affects more than half of hospitalized patients and is associated with a longer length of stay.

Background Despite aggressive treatment aimed at lowering LDL cholesterol (LDL-C) levels with statins, there is a high residual prevalence of cardiovascular diseases, which may depend on plasma cholesterol transported in other atherogenic lipoproteins. Aims To describe non-HDL cholesterol (non-HDL-C) levels in the Chilean population and their association with diabetes mellitus and cardiovascular disease. To evaluate compliance with non-HDL-C therapeutic goals -according to individual cardiovascular risk- at different levels of triglycerides, in comparison with LDL-C goal achievement. Material and Methods: We analyzed data from 2,792 Chilean subjects aged ≥ 15 years who were included in the 2009-2010 National Health Survey and had valid data for blood lipids, diabetes, and cardiovascular disease. Results Forty five percent of subjects had high non-HDL-C levels. The proportion of diabetic and non-diabetic subjects with high non-HDL-C levels was 81 and 42%, respectively (p < 0.01). A significant discordance was observed in the achievement of therapeutic objectives when LDL-C or non-HDL-C levels were considered, particularly in presence of triglycerides ≥ 150 mg/dl. Namely, 8% of the population showed elevated levels of high non-HDL-C despite adequate LDL-C levels. Conclusions Evaluation and management of elevated non-HDL-C in patients with adequate levels of LDL-C seems worthwhile considering the discordance observed between these blood cholesterol fractions. This strategy may be effective to reduce the residual cardiovascular risk in the Chilean population.

Background: Increased serum levels of LDL cholesterol and/or decreased values of HDL cholesterol are very relevant for atherosclerotic cardiovascular disease. Low HDL cholesterol is the most prevalent dyslipidemia in the Chilean population. Regarding reduced HDL cholesterol and high triglyceride levels, fibrates, nuclear receptor PPAR-a agonists that modulate transcription of genes involved in lipid metabolism, represent an important alternative for pharmacological management of dyslipidemia. However, recent clinical studies have been inconclusive with respect to their real benefit on atherosclerosis when used in combination with statins. Aim: To evaluate the impact of fibrate administration on HDL cholesterol metabolism and antioxidant plasma functionality using the mouse as experimental model. Methodology: Using wild-type C57BL/6 mice, ciprofibrate was administered at 0.2% in chow diet for 7 days. After treatment, plasma cholesterol and triglycerides levels, hepatic expression of key proteins involved in HDL cholesterol metabolism, liver cholesterol content, biliary cholesterol secretion, and plasma oxidative damage and antioxidant function were analyzed. Results: Ciprofibrate treatment significantly decreased plasma triglycerides levels and hepatic HDL receptor SR-BI expression. This latter finding was associated with increased HDL particle size, without changes in HDL cholesterol levels. Furthermore, ci-profibrate decreased hepatic expression of cholesterol transporters ABCG1 and ABCG8, but not ABCA1, which correlated with reduced liver cholesterol content and increased biliary cholesterol secretion. Fina-lly, fibrate therapy improved plasma antioxidant func-tion, even though increased nitrosative plasma protein damage was detected. Conclusion: This study has provided new information on metabolic and functional effects derived from fibrate use in mice and it may help to better understand recent clinical findings using this lipid-lowering drug class in humans.

Antecedentes: Las dislipidemias, ya sea un aumento en los niveles de colesterol LDL y/o una disminución en las cifras de colesterol HDL, son muy relevantes para el desarrollo de la enfermedad cardiovascular ateroesclerótica, siendo el colesterol HDL bajo la dislipidemia más frecuente en la población chilena. Con respecto al colesterol HDL bajo y los tri -glicéridos elevados, los fibratos, agonistas del receptor nuclear PPAR-a que modula la transcripción de genes involucrados en el metabolismo de lípidos, representan una importante alternativa de manejo farmacológico de las dislipidemias. Sin embargo, estudios clínicos recientes no han sido concluyentes con respecto a su beneficio real sobre el control de la ateroesclerosis cuando se usan combinados con estatinas. Objetivo: Evaluar el impacto de la administración de fibratos sobre el metabolismo del colesterol HDL y la función antioxidante del plasma usando el ratón como modelo experimental. Metodología: Los ratones de la cepa C57BL/6 fueron tratados con ciprofibrato al 0,2% en dieta control durante 7 días. Luego del tratamiento, se analizaron los niveles de colesterol plasmático y triglicéridos, la expresión hepática de proteínas claves involucradas en el metabolismo de colesterol HDL, el contenido de colesterol hepático, la secreción de colesterol biliar y el daño oxidativo y la función antioxidante plasmática. Resultados: El tratamiento con ciprofibrato disminuyó significativamente los niveles de triglicéridos plasmáticos y la expresión hepática del receptor de HDL SR-BI, efecto que se correlacionó con un aumento en el tamaño de las partículas de HDL, pero no en los niveles de colesterol HDL. Además, el ciprofibrato disminuyó los niveles proteicos de los transportadores de colesterol ABCG1 y ABCG8, aunque no modificó ABCA1, en conjunto con una reducción del contenido hepático de colesterol y un aumento en la secreción de colesterol hacia la bilis. Finalmente, el uso de este hipolipemiante mejoró la función antioxidante del plasma, aunque se detectó un aumento en el daño nitrosativo de las proteínas plasmáticas. Conclusión: Este estudio ha permitido obtener nueva información sobre el efecto metabólico y funcional de la administración de fibratos en ratones, lo cual podría ayudar comprender los resultados de estudios clínicos recientes que han usado esta clase de hipolipemiantes en humanos.

Background: Plasma high density lipoproteins (HDL) are involved in reverse cholesterol transport mediated by the scavenger receptor class B type I (SR-BI). Nicotinic acid increases HDL cholesterol levels, even though its specific impact on SR-BI dependent-cellular cholesterol transport remains unknown. Aim: To determine the effect of nicotinic acid on HDL particle functionality in cholesterol efflux and uptake mediated by SR-BI in cultured cells in hypoalphalipoproteinemic patients. Material and Methods: In a pilot study, eight patients with low HDL (≤ 40 mg/dL) were treated with extended release nicotinic acid. HDL cholesterol and phospholipid levels, HDL2 and HDL3 fractions and HDL particle sizes were measured at baseline and post-therapy. Before and after nicotinic acid treatment, HDL particles were used for cholesterol transport studies in cells transfected with SR-BI. Results: Nicotinic acid treatment raised total HDL cholesterol and phospholipids, HDL2 levels as well as HDL particle size. Nicotinic acid significantly increased HDL cholesterol efflux and uptake capacity mediated by SR-BI in cultured cells. Conclusions: Nicotinic acid therapy increases SR-BI-dependent HDL cholesterol transport in cultured cells, establishing a new cellular mechanism by which this lipid-lowering drug appears to modulate HDL metabolism in patients with hypoalphalipoproteinemia.

Introduction: high density lipoproteins (HDL) have important cardiovascular protective effects mediated by their role in reverse cholesterol transport as well as other functional activities, including significant anti-inflammatory and antioxidant properties. It has been shown that HDL anti-inflammatory and antioxidant functions are defective in metabolically stable diabetic patients; however they have not been evaluated during a hyperglycemic crisis. Aim: to determine the antioxidant activity of HDL during a severe diabetic decompensation and to analyze whether this function is restored after resolution of the acute event. Methods: the antioxidant activity of HDL was measured in vitro by a fluorescent assay in plasma samples obtained from diabetic patients with acute metabolic decompensation at admission, recovery within the hospital and follow-up in ambulatory care. As a comparison, HDL particles from some healthy subjects were used as controls. Results: the HDL antioxidant function was significantly reduced in patients during an acute diabetic decompensation compared with the control group, and was gradually restored reaching normal values during the ambulatory follow-up. Hyperglycemic crisis also showed low plasma paraoxonase-1 activity, which increased significantly during at follow-up. Conclusion: HDL particles isolated from acute diabetic descompensated patients exhibit a significantly and reversibly low antioxidant capacity, which is probably due to a reduced paraoxonase-1 activity.

Introducción: las lipoproteínas de alta densidad (HDL) tienen un importante efecto protector cardiovascular mediado por su función durante el transporte reverso del colesterol, así como por otras actividades, incluyendo una significativa acción antiinflamatoria y antioxidante. La funcionalidad antiinflamatoria y antioxidante de las HDL está alterada en los pacientes diabéticos crónicos estables, aunque no existe mayor información en caso de una crisis hiperglicémica. Objetivo: determinar si durante un estado de descompensación diabética aguda las partículas de HDL exhiben un deterioro de su función antioxidante y si esta logra recuperarse una vez resuelto el cuadro agudo. Métodos: la actividad antioxidante de las HDL se midió mediante un ensayo de fluorescencia in vitro en muestras plasmáticas de pacientes diabéticos con descompensación aguda obtenidas tanto al ingreso, alcanzada la resolución intrahospitalaria del evento agudo, así como en un control ambulatorio post-hospitalización. Como comparación, se analizaron partículas de HDL de algunos sujetos sanos como condición control. Resultados: la actividad antioxidante de las HDL en pacientes con descompensación diabética aguda fue significativamente menor a la observada en el grupo control sano, y esta se fue recuperando progresivamente hasta normalizarse en el momento del control ambulatorio. La crisis hiperglicémica también demostró una baja actividad plasmática de la enzima antioxidante paraoxonasa-1, la cual aumentó significativamente en el control ambulatorio. Conclusión: las partículas de HDL presentes en pacientes con una descompensación diabética aguda presentan una reducción significativa y reversible de su capacidad antioxidante, probablemente como consecuencia de una alteración en la actividad de la paraoxonasa-1.

Cerebrotendinous Xanthomatosis (CTX), a rare lipid storage disorder, is caused by recessive loss-of-function mutations of the 27-sterol hydroxylase (CYP27A1), producing an alteration of the synthesis of bile acids, with an accumulation of cholestanol. Clinical characteristics include juvenile cataracts, diarrhea, tendon xanthomas, cognitive impairment and other neurological manifestations. Early diagnosis is critical, because treatment with chenodeoxycholic acid may prevent neurological damage. We studied the CYP27A1 gene in two Chilean CTX patients by sequencing its nine exons, exon-intron boundaries, and cDNA from peripheral blood mononuclear cells. Patient 1 is a compound heterozygote for the novel substitution c.256-1G > T that causes exon 2 skipping, leading to a premature stop codon in exon 3, and for the previously-known pathogenic mutation c.1183C > T (p.Arg395Cys). Patient 2 is homozygous for the novel mutation c.1185-1G > A that causes exon 7 skipping and the generation of a premature stop codon in exon 8, leading to the loss of the crucial adrenoxin binding domain of CYP27A1.

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disease, caused by genetic deficiency of the 27-hydroxylase enzyme (encoded by CYP27A1). It plays a key role in cholesterol metabolism, especially in bile acid synthesis and in the 25-hydroxylation of vitamin D3 in the liver. Its deficiency causes reduced bile acid synthesis and tissue accumulation of cholestanol. Clinical manifestations are related to the presence of cholestanol deposits and include tendon xanthomas, premature cataracts, chronic diarrhea, progressive neurologic impairment and less frequently coronary heart disease, early onset osteoporosis and abnormalities in the optic disk and retina. An early diagnosis and treatment with quenodeoxycholic acid may prevent further complications, mainly neurological manifestations. This review summarizes cholesterol metabolism related to bile acid synthesis, physiopathology, biochemistry and treatment of cerebrotendinous xanthomatosis.

Background: Diabetes mellitus (DM) is a recognized atherosclerotic cardiovascular disease (ACVD) risk factor. This association has yet to be quantified in the Chilean population. Aim: To compare the frequency of ACVD between diabetic and non-diabetic Chilean subjects. Material and Methods: Data was extracted from the Chile National Health Survey (ENS) performed in 2009-2010. DM diagnosis was made with fasting glucose. ACVD (coronary, cerebral and peripheral vascular disease) was established by self-report. Major cardiovascular risk factors were identified by clinical and laboratory assessment. Results: A total of 5,416 adults (2,200 men and 3,216 women) were surveyed in ENS 2009-2010. Of these, 508 were diabetic and 375 reported ACVD. ACVD frequency was 16.1% and 6.1% in diabetic and non-diabetic subjects, respectively. In diabetic men, the frequency of ACVD steadily increased with age, from 5.1% to 22.1%. In diabetic women, the highest frequency of ACVD (17.4%) was found in ages ranging from 45 to 54 years. In people younger than 54 years, the odds ratio for ACVD in diabetic compared to non-diabetic subjects, was 3.59 in men (χ2 = 4.03 p < 0.03) and 5.26 in women (χ2 = 7.7 p < 0.007). Cardiovascular risk factors and metabolic syndrome were significantly more common in diabetic subjects with reported ACVD. Conclusions: DM is associated with an increased frequency of ACVD and cardiovascular risk factors in Chilean adults. In line with international reports, our findings suggest that DM is also a cardiovascular risk factor in Chile, particularly relevant for women.

Background: The health associated costs of obesity can represent between 2% and 9% of the total health costs of a given country. Aim: To assess the impact of obesity on health care costs and absenteeism in a cohort of mine workers. Patients and wethods: Prospective study of 4.673 men, employees of a mining company, aged 49 ± 7 years that were followed for 24 ± 11 months. Total health care cost and days of sick leave were recordedfor each individual. The association between obesity and these variables was analyzed by logistic regression adjusting for co-morbidities, age and other variables. Results: Mean annual health care costs for obese workers were 17% higher (p <0.001) compared to workers with normal weight and 58% higher (p <0.001) for workers with severe and morbid obesity. Mean annual days of sick leave increased by 25%o in the obese (p =0.002) and by 57%o in subjects with severe and morbid obesity (p <0.001). For health care costs the most significant predictors were: presence of diabetes mellitus (Odds ratio (OR) 6.21, 95%o confidence intervals (95% CI) 4.9 to 7.9), hypertension (OR 3-99; 95% CI3-4 to 4.6) and severe and morbid obesity (OR 2.55, 95%o CI 1.9 to 3-4). For absenteeism the most significant predictors were: presence of diabetes mellitus (OR 1.58, 95%> CI 1.2 to 2.0), hypertension (OR 1,34, 95%> CI 1.2 to 1.6) and severe and morbid obesity (OR 1.50, 95%o CI 1.1 to 2.1). Conclusions: Obesity increases significantly health care costs and absenteeism.

The regulation of gene expression is crucial for the normal development and the homeostatic maintenance of body tissues. Thus, its malfunction may determine a variety of human disease conditions. A growing body of evidence has shown the overwhelming relevance of a new class of gene expression regulators: the heterodimeric nuclear receptors, a family of structurally related proteins involved in multiple biological functions. In response to activating ligands, these molecules bind to specific genomic regulatory regions where they can coordinately modify the transcriptional activity of several genes involved in the main metabolic pathways of lipids and carbohydrates in cells. These functional properties have stimulated the study of the relationships between heterodimeric nuclear receptors and various disease conditions, such as dyslipidemias and diabetes mellitus. Here we review the experimental, clinical and epidemiological evidences that support the relevance of these transcriptional regulators in the pathophysiology of the most prevalent and lethal diseases in Western countries. We also explore the potential therapeutic impact of new strategies based in the pharmacological modulation of the heterodimeric nuclear receptors. (Rev Méd Chile 2005; 133: 1483-92)