Higher Hepcidin Levels in Adolescents with Obesity Are Associated with Metabolic Syndrome Dyslipidemia and Visceral Fat.

Tightly regulated iron metabolism prevents oxidative stress. Hepcidin is a hormone that regulates iron flow in plasma; its production is induced by an iron overload and by inflammation. It inhibits iron entry into the circulation by blocking dietary absorption in the duodenum, the release of recycled iron from macrophages and the exit of stored iron from hepatocytes. Varied signals responding to iron stores, erythropoietic activity and host defense converge to regulate hepcidin production and thereby affect iron homeostasis. Although it is known that hepcidin increases when interleukin 6 (IL-6) increases, the relationship between hepcidin, dyslipidemia, insulin resistance (IR) and visceral adiposity index (VAI) in adolescents with obesity is unclear. In this cross-sectional study of 29 obese adolescents and 30 control subjects, we explored the difference of hepcidin, iron metabolism markers and IL-6 between obese and non-obese adolescents, and identified associations with inflammation, atherogenic dyslipidemia and IR. As compared to lean controls, obese participants showed 67% higher hepcidin: 14,070.8 ± 7213.5 vs. 8419.1 ± 4826.1 pg/mLc; 70% higher ferritin: 94.4 ± 82.4 vs. 55.1 ± 39.6 pg/mLa and 120% higher IL-6: 2.0 (1.1-4.9) vs. 0.9 (0.5-1.3) pg/mLd. Transferrin, soluble transferrin receptor and total body iron (as measured by sTFR/ferritin, log10 sTFR/ferritin ratio and sTFR/log ferritin ratios) were not different between the two cohorts. In the whole cohort, hepcidin correlated with VAI (r = 0.29a), sd-LDL (r = 0.31b), HOMA-IR (r = 0.29a) and IL-6 (r = 0.35c). In obese adolescents hepcidin correlated with TG (r = 0.47b), VLDL-C (r = 0.43b) and smaller LDL2 (r = 0.39a). Hepcidin elevation in adolescents with obesity is linked more to inflammation and metabolic alterations than to iron metabolism since the other markers of iron metabolism were not different between groups, except for ferritin. Studies addressing the long-term effects of higher hepcidin levels and their impact on subclinical anemia and iron status are warranted. a p < 0.05; b p < 0.01, c p < 0.001 dp < 0.0001.

Hipovitaminosis D en niños y adultos en un prestador de salud del Uruguay y su relación con el uso de antiepilépticos / The effect of antiepileptic drugs in adult and child hypovitaminosis D in a Uruguayan health institution / Hipovitaminose D em crianças e adultos em um provedor de saúde uruguaio e sua relação com o uso de medicamentos antiepilépticos

Resumen: Introducción: la hipovitaminosis D se encuentra ampliamente extendida a nivel mundial, con consecuencias clínicas a nivel óseo y extraóseo. Entre los factores que la causan se encuentran los antiepilépticos (AE). En Uruguay no se conoce su prevalencia en niños ni en pacientes que reciben AE. Objetivos: conocer la prevalencia de hipovitaminosis D de niños y adultos en un prestador de salud y compararla con la prevalencia en pacientes bajo tratamiento con AE. Método: estudio descriptivo, transversal, realizado entre marzo y diciembre de 2017. Las variables analizadas fueron: niveles de vitamina D, calcio, fósforo, fosfatasa alcalina y parathormona intacta. Se consideró insuficiencia de vitamina D niveles menores de 30 ng/ml y déficit niveles menores de 20 ng/ml. Resultados: se incluyeron 113 pacientes, 60 niños y 53 adultos. La prevalencia global de insuficiencia de vitamina D fue de 89% y déficit de 60%. En niños expuestos a AE, la media de vitamina D fue 17,5 ng/ml, y en niños no expuestos 19,6 ng/ml. En adultos la media de vitamina D fue de 18,1 en expuestos a AE y 16,9 en no expuestos. La diferencia de medias no fue estadísticamente significativa en niños ni en adultos. Se observaron niveles de calcemia significativamente descendidos en niños y adultos con AE. Conclusiones: la insuficiencia de vitamina D fue cercana a 90% y el déficit superó el 50%. No se encontraron diferencias significativas entre grupos en hipovitaminosis D, pero se observaron niveles de calcemia reducidos en los expuestos a AE. Es necesario continuar analizando los factores que la causan y sus consecuencias clínicas.

Summary: Introduction: hypovitaminosis D is a highly spread condition worldwide, with clinical consequences that affect bone directly, among other manifestations. Antiepileptic drugs are among factors that cause this deficiency. In Uruguay, there is no information about hypovitaminosis D in children or patients who receive antiepileptic drugs. Objectives: to learn about the prevalence of hypovitaminosis D in children and adults in a health institution and to compare it with the prevalence in patients receiving antiepileptic drugs. Method: descriptive, transversal study conducted from March through December, 2017. The following variables were analysed: vitamin D, calcium, phosphorous, alkaline phosphatase and intact parathyroid hormone. Vitamin D insufficiency was defined as vitamin D levels of less than 30 ng per mL and deficiency as D levels of less than 20 ng per mL. Results: 113 patients were included in the study, 60 of which were children and 53 adults. Global prevalence of vitamin D insufficiency was 89% and deficiency was 60%. In children taking antiepileptic drugs, the average vitamin D value was 17.5 ng/ml and it was 19.6 ng/ml for those not exposed to those drugs. In adults, the average vitamin D value was 18.1 in the population taking antiepileptic drugs and 16.9 in patients not taking that medication. The difference between average values was not statistically significant in children or adults. Calcemia levels observed were significantly lower in both children and adults taking antiepileptic drugs. Conclusions: vitamin D insufficiency was close to 90% and deficiency was over 50%. No significant differences were found between hypovitaminosis D groups, although reduced calcemia was observed in patients exposed to antiepileptic drugs. Further studies are necessary to analyse factors that cause this condition and its clinical consequences.

Resumo: Introdução: a hipovitaminose D está amplamente difundida em todo o mundo, com consequências clínicas a nível ósseo e extraósseo. Entre os fatores que a causam estão os medicamentos antiepilépticos (AE). No Uruguai, sua prevalência em crianças ou em pacientes adultos recebendo AE não é conhecida. Objetivos: conhecer a prevalência de hipovitaminose D em crianças e adultos em um prestador de serviços de saúde e compará-la com a prevalência em pacientes em tratamento com AE. Método: estudo transversal descritivo realizado entre março e dezembro de 2017. As variáveis analisadas foram: níveis de vitamina D, cálcio, fósforo, fosfatase alcalina e paratormona intacta. Níveis menores que 30 ng / ml e níveis de déficit menores que 20 ng / ml foram considerados como insuficiência de vitamina D. Resultados: foram incluídos 113 pacientes, 60 crianças e 53 adultos. A prevalência global de insuficiência de vitamina D foi de 89% e déficit de 60%. Em crianças expostas à AE, a média de vitamina D foi de 17,5 ng / ml e em crianças não expostas de 19,6 ng / ml. Em adultos, a média de vitamina D foi de 18,1 nos expostos ao AE e de 16,9 nos não expostos. A diferença nas médias não foi estatisticamente significativa nas crianças nem nos adultos. Níveis de cálcio significativamente diminuídos foram observados em crianças e adultos com EA. Conclusões: a insuficiência de vitamina D foi próxima a 90% e o déficit ultrapassou 50%. Não foram encontradas diferenças significativas entre os grupos na hipovitaminose D, mas níveis reduzidos de cálcio foram observados naqueles expostos a EA. É necessário continuar analisando os fatores que o causam e suas consequências clínicas.

Serum aspirin esterase activity is lower in end-stage renal disease patients than in healthy control subjects and increases after haemodialysis.

BACKGROUND: Studies regarding aspirin metabolism can be important in patients with renal failure who have an increased risk of cardiovascular diseases. We undertook this study to assess the aspirin esterase (AE) status in end-stage renal disease (ESRD) patients. METHODS: A total of 42 patients on long-term haemodialysis (HD) with a mean dialysis course of 6.1 y were recruited. RESULTS: Serum AE levels were 44% lower and cholinesterase (ChE) levels were 22% lower in ESRD patients before dialysis as compared with control subjects (P = 0.0001). A very strong correlation was found between AE and ChE levels. AE levels increased on average 28% after dialysis with adjustments for age, gender, total cholesterol, triglyceride and high-density lipoprotein cholesterol (P = 0.002). In addition, ChE levels were significantly increased (48%) after dialysis (P = 0.0001). Changes in AE activity were significantly and positively correlated with those of ChE (r = 0.427, P = 0.005). When we adjusted for several confounders, we found that the changes in AE activity operated by dialysis are significant independently of age, gender, aspirin (ASA) intake, cholesterol, triglycerides, high-density lipoprotein cholesterol and ChE. CONCLUSIONS: We report that serum AE activity is significantly lower in ESRD and that treatment by HD results in an increase of activity. We confirm that AE is associated with lipid parameters and ChE. Our results show variations in ASA catabolism between the dialysis sessions, suggesting an oscillating pattern in ASA disposal in these patients. The mechanisms for reduced AE activity in uraemia and the effects of HD need further investigation.

Serum cholesterol concentration associated with aspirin esterase activity in older people: preliminary data.

OBJECTIVE: Metabolism of aspirin (acetylsalicylic acid), commonly used in older people for the prevention of cardiovascular disease, is important to the effectiveness of this drug. Whereas part of aspirin hydrolysis occurs in blood, there is a paucity of information in regards to circulating aspirin esterase activity in various physiological and pathological conditions. High aspirin esterase activity, corresponding to faster aspirin hydrolysis (thus aspirin non-responsiveness), may occur in cardiovascular disease-prone states. The objective of this study was to investigate the effects of cardio-metabolic variables such as cholesterol on serum aspirin esterase activity in older people who participated in an intervention study on physical activity. METHODS: A total of 18 non-medicated subjects (7 men/11 women, mean age 67.8 years, body mass index = 23.4 +/- 3.3 kg/m(2)), who completed a 3-month interventional program for a mild-to-moderate increase in physical activity, were analyzed. The body mass index, plasma glucose, serum total cholesterol and aspirin esterase activity were measured in the pre- and post-interventional phases of the study. RESULTS: During the interventional period, the changes in aspirin esterase activity correlated significantly and positively with those of total cholesterol concentrations (r = 0.542, P = 0.020; beta = 0.609, P = 0.035 in a multiple linear regression analysis after adjusting for all the measured variables). CONCLUSION: The results suggest that cholesterol metabolism alterations may be associated with aspirin metabolism in older people.

Paraoxonase-1 concentrations in end-stage renal disease patients increase after hemodialysis: correlation with low molecular AGE adduct clearance.

BACKGROUND: Hemorrhagic stroke and ischemic heart disease continue to be key problems in patients with end stage renal failure. Reduced serum paraoxonase (PON-1) activity has been described in these patients, which could contribute to the accelerated development of atherosclerosis. We hypothesized that retention of uremic toxins and or "middle molecules" including advanced glycation (AGE) free adducts and peptides could play a mechanistic role in decreasing PON-1 activity. METHODS: We enrolled 22 ESRD patients undergoing hemodialysis in whom paired pre- and post-dialysis samples were studied along with 30 age-matched control subjects. RESULTS: ESRD patients showed a 76% decrease in PON-1 activity. As expected, ESRD patients had an increase in lipoperoxides and advanced oxidation protein products (AOPP). Our patients had a 3-fold increase in serum AGEs and a striking 10-fold increase in low molecular weight (<10 kDa) AGEs. Post-dialysis samples in all patients displayed an increase in PON-1 activity, which ranged from 4 to 40% of the predialysis value. HDL-cholesterol, apoAI, free cholesterol (as a LCAT surrogate), HDL-subclasses and TG did not change significantly after dialysis. Changes in PON-1 activity display a good correlation (r=0.66, p<0.001) with rates in which creatinine and urea are cleared. Clearance of low molecular weight AGEs after hemodialysis explains 79% of the changes in PON-1 activity and are hence a much better predictor than creatinine changes (r=0.89, p<0.00). In vitro incubation of paraoxonase with serum ultrafiltrates show a time and concentration dependent inhibition of PON-1 by the ultrafiltrates, an inhibition that is up to 3 times higher (from 8 to 24%) when chronic renal failure patients are the source of the ultrafiltrate. CONCLUSION: We showed that HD results in a significant, consistent increase in the activity of the antioxidant enzyme PON-1. The effect, correlates with the effectiveness of dialysis to clear creatinine and urea, and with the clearance of AGE adducts of low molecular weight. This effect was replicated in vitro, showing time and dose dependency. Our results suggest that another cause for the observed lower PON-1 concentrations in CRF are the retention of low-middle molecules and demonstrate a positive effect of hemodialysis in the delicate oxidant-antioxidant state of these patients, that should be weighted against other pro-oxidant effects that have also been shown to occur previously. If the hypothesis that AGEs are the main culprits is proved in further research, this opens a putative therapeutic avenue for AGE blockers in ESRD.

Nitration of human plasminogen by RAW 264.7 macrophages reduces streptokinase-induced plasmin activity.

Despite many years of study, clinical trials of new drugs to prevent thrombosis have often been disappointing. Part of the problem lies in our incomplete understanding of the regulation of plasminogen activation and/or inhibition in vivo. We have previously shown that in vitro nitration of plasminogen in plasma by peroxynitrite resulted in decreased plasmin activity. We hypothesized that macrophages may be agents of plasminogen nitration and designed this study to prove this hypothesis. We first better characterized our previous observations using purified plasminogen instead of whole plasma, studied the time and concentration dependence of these reactions, and co-incubated plasminogen with macrophages, as well as with non-inflammatory cells as controls, to assess nitration and impaired activity. When plasminogen (10 micromol/L) is incubated in the presence of SIN-1 (0.01-2 mmol/L), plasmin activity (generated by streptokinase) is reduced in a time- and concentration-dependent fashion. We performed experiments incubating human plasminogen in the presence of murine RAW264.7 macrophages, allowing for free diffusion of reactive oxygen species, while preventing the action of proteases. In this way we show that incubation of plasminogen with macrophages also decreases plasmin activity, while increasing nitration of the molecule, an effect that is already apparent after 2 h and reaches a plateau of 60% inhibition after 24 h of incubation. This effect appears specific for macrophages, since 31EG4 murine mammary cells used in parallel and under the same conditions failed to produce any deleterious changes in plasminogen. Our data on quick functional inactivation of plasminogen by nitration, mediated by macrophages, adds a new pathophysiological dimension to our previous work showing plasminogen as a target for peroxynitrite damage. Nitrosative stress may be implicated in impaired fibrinolysis. New therapeutic approaches for nitrosative stress in atherosclerosis and diabetes should limit the formation of superoxides and peroxynitrite.