Paweł Bogdański

Green tea extract reduces blood pressure, inflammatory biomarkers, and oxidative stress and improves parameters associated with insulin resistance in obese, hypertensive patients.

Green tea (GT) consumption is known to be associated with enhanced cardiovascular and metabolic health. The purpose of this study is to examine the hypothesis that supplementation with GT alters insulin resistance and associated cardiovascular risk factors in obese, hypertensive patients. In a double-blind, placebo-controlled trial, 56 obese, hypertensive subjects were randomized to receive a daily supplement of 1 capsule that contained either 379 mg of GT extract (GTE) or a matching placebo, for 3 months. At baseline and after 3 months of treatment, the anthropometric parameters, blood pressure, plasma lipid levels, glucose levels, creatinine levels, tumor necrosis factor α levels, C-reactive protein levels, total antioxidant status, and insulin levels were assessed. Insulin resistance was evaluated according to the homeostasis model assessment-insulin resistance protocol. After 3 months of supplementation, both systolic and diastolic blood pressures had significantly decreased in the GTE group as compared with the placebo group (P < .01). Considerable (P < .01) reductions in fasting serum glucose and insulin levels and insulin resistance were observed in the GTE group when compared with the placebo group. Serum tumor necrosis factor α and C-reactive protein were significantly lower, whereas total antioxidant status increased in the GTE group compared with the placebo (P < .05). Supplementation also contributed to significant (P < .05) decreases in the total and low-density lipoprotein cholesterol and triglycerides, but an increase in high-density lipoprotein cholesterol. In conclusion, daily supplementation with 379 mg of GTE favorably influences blood pressure, insulin resistance, inflammation and oxidative stress, and lipid profile in patients with obesity-related hypertension.

Dietary Intake and Serum and Hair Concentrations of Minerals and their Relationship with Serum Lipids and Glucose Levels in Hypertensive and Obese Patients with Insulin Resistance

Inadequate minerals intake, as well as disruption of some metabolic processes in which microelements are cofactors, are suggested to lead to the development of hypertension. The role of minerals in the pathogenesis of hypertension still remains to be explained. In the present study, we sought to determine associations between serum and hair mineral concentrations and serum lipids and glucose levels. Forty obese hypertensive subjects with insulin resistance and 40 healthy volunteers were recruited in the study. Blood pressure, BMI, and insulin resistance were recorded in all subjects. Levels of lipids, glucose, sodium and potassium, iron, copper, zinc, magnesium, and calcium were assessed in serum. Iron, copper, zinc, magnesium, and calcium were assessed in hair. Dietary intake of the analyzed minerals was estimated. We found distinctly higher concentrations of serum iron and serum and hair calcium as well as markedly lower levels of hair zinc in the hypertensive subjects. The study group manifested also significantly lower daily intake of calcium, magnesium, and iron. We observed a relationship between the concentrations of iron, zinc, and copper in serum and hair and high and low range of cholesterol, triglycerides, and glucose serum levels in the studied patients. Moreover, this study demonstrated significant correlation between serum and hair concentrations of selected minerals and their dietary intake and levels of serum lipids and glucose and blood pressure in the study and the control groups. The obtained results seem to indicate the association between lipid and glucose metabolism and iron, copper, zinc, and calcium concentrations in blood and hair of hypertensive and obese patients with insulin resistance.

The effect of vitamin D supplementation on insulin and glucose metabolism in overweight and obese individuals: systematic review with meta-analysis

The aim of this systematic review was to assess the effect of vitamin D supplementation on glucose and insulin metabolism in overweight and obese subjects. The search process was based on the selection of publications listed in the databases: PubMed, Scopus, Web of Knowledge, Embase and the Cochrane library that met the inclusion criteria. Twelve randomized controlled trials were included. The analysed population consisted of 1181 individuals with BMIs >23 kg/m2. Changes in the concentration of 25(OH)D, fasting glucose, insulin and the HOMA-IR index were assessed. In the meta-regression analysis, a restricted maximum likelihood method was applied. To combine individual study results, a meta-analysis was performed. Vitamin D supplementation did not have an effect on glucose concentrations, insulin level and HOMA-IR values when the supplemented dose, time of supplementation and baseline of 25(OH)D concentration were taken under consideration in subgroup-analysis. This meta-analysis provides evidence that vitamin D supplementation has no significant effect on glucose and insulin metabolism in overweight and obese individuals.

Signatures of miR-181a on renal transcriptome and blood pressure.

MicroRNA-181a binds to the 3′ untranslated region of messenger RNA (mRNA) for renin, a rate-limiting enzyme of the renin-angiotensin system. Our objective was to determine whether this molecular interaction translates into a clinically meaningful effect on blood pressure and whether circulating miR-181a is a measurable proxy of blood pressure. In 200 human kidneys from the TRANScriptome of renaL humAn TissuE (TRANSLATE) study, renal miR-181a was the sole negative predictor of renin mRNA and a strong correlate of circulating miR-181a. Elevated miR-181a levels correlated positively with systolic and diastolic blood pressure in TRANSLATE, and this association was independent of circulating renin. The association between serum miR-181a and systolic blood pressure was replicated in 199 subjects from the Genetic Regulation of Arterial Pressure of Humans In the Community (GRAPHIC) study. Renal immunohistochemistry and in situ hybridization showed that colocalization of miR-181a and renin was most prominent in collecting ducts where renin is not released into the systemic circulation. Analysis of 69 human kidneys characterized by RNA sequencing revealed that miR-181a was associated with downregulation of four mitochondrial pathways and upregulation of 41 signaling cascades of adaptive immunity and inflammation. We conclude that renal miR-181a has pleiotropic effects on pathways relevant to blood pressure regulation and that circulating levels of miR-181a are both a measurable proxy of renal miR-181a expression and a novel biochemical correlate of blood pressure.

Concentrations of omentin and vaspin versus insulin resistance in obese individuals

INTRODUCTION Omentin and vaspin are adipokines manifesting a potentially protective action against obesity-associated metabolic disturbances. AIM Evaluation of relationship between serum concentrations of omentin and vaspin on one hand and indices of insulin resistance and anthropometric parameters in obese individuals on the other. MATERIAL AND METHODS The studies were conducted on 64 individuals. The investigated group (37 obese patients) included the subgroup with normal glucose tolerance (NGT) and with abnormal glucose tolerance (AGT). The control group (n=27) included healthy individuals with normal body weight. In all participants anthropometric analyses and biochemical tests, including estimation of omentin and vaspin concentrations were performed, and insulin resistance by HOMA-IR was evaluated. RESULTS Concentrations of examined adipokines manifested no significant differences between the examined groups. Median values of the index defining ratio between studied adipokine and degree of insulin resistance, i.e. omentin/HOMA-IR, proved to be different in the investigated and the control group while no such difference could be noted in cases of vaspin/HOMA-IR indices. In the studied population a negative relationship was detected between serum concentration of omentin and systolic blood pressure (p<0.04). Values of omentin/HOMA-IR index manifested a correlation with values of most anthropometric parameters (p<0.0001), blood pressure (p<0.0001) concentrations of TG (p<000.1) and HDL (p<0.0001), ISIbasal (p<0.00001), ISIgly (p<0.0001), Quicki (p<0.00001) and fasting insulinaemia (p<0.00001). In the case of vaspin/HOMA-IR index only its positive relationship with HDL concentration was noted (p<0.05). CONCLUSION In context of date of correlation, multiple regression and values of area of under receiver operating characteristics curve omentin, as compared to vaspin, seems to provide a better predictor of insulin resistance in obese individuals.

Effects of Endurance and Endurance Strength Training on Body Composition and Physical Capacity in Women with Abdominal Obesity.

Aims: To compare the effects of endurance training with endurance strength training on the anthropometric, body composition, physical capacity, and circulatory parameters in obese women. Methods: 44 women with abdominal obesity were randomized into groups A and B, and asked to perform endurance (A) and endurance strength training (B) for 3 months, 3 times/week, for 60 min. Dual-energy X-ray absorptiometry and Graded Exercise Test were performed before and after training. Results: Significant decreases in body mass, BMI, total body fat, total body fat mass, and waist and hip circumference were observed after both types of intervention. Marked increases in total body lean and total body fat-free mass were documented in group B. In both groups, significant increases in peak oxygen uptake, time to exhaustion, maximal work rate, and work rate at ventilatory threshold were accompanied by noticeably decreased resting heart rate, resting systolic blood pressure, and resting and exercise diastolic blood pressure. No significant differences were noticed between groups for the investigated parameters. Conclusion: Our findings demonstrate evidence for a favorable and comparable effect of 3-month endurance and endurance strength training on anthropometric parameters, body composition, physical capacity, and circulatory system function in women with abdominal obesity.

Supplementation with L-arginine favorably influences plasminogen activator inhibitor type 1 concentration in obese patients. A randomized, double blind trial.

Background: Elevated plasminogen activator inhibitor type 1 (PAI 1) plays an important role in the pathogenesis of excess blood coagulability in obese patients. L-arginine supplementation has shown to be associated with enhanced cardiovascular and metabolic health. The aim of the study was to assess the effect of L-arginine supplementation on PAI 1 concentration and to evaluate the relation to changes in nitric oxide (NO) plasma level, insulin sensitivity (M value), and total antioxidant status (TAS) in obese patients. Material/subjects and methods: A randomized, double-blind, placebo-controlled study was conducted from March 2010 to June 2011. Eighty-eight obese patients were randomly assigned to receive either 9 g of L-arginine or placebo daily for 6 months. At baseline and after 6 months, selected anthropometrical measurements and blood biochemical analyses were performed, and PAI 1, NO, TAS levels were assessed. Insulin sensitivity was evaluated using the hyperinsulinemic euglycemic clamp technique. Results: We found that 6-month L-arginine supplementation resulted in significant decrease of PAI 1. Significant increase of NO, TAS, and insulin sensitivity level were noticed. In a group of patients treated with L-arginine, negative correlation between a change of insulin sensitivity value and a change of PAI 1 concentration was found. Conclusions: The present findings demonstrate favorable influence of L-arginine supplementation on PAI 1 concentration in obese patients. Beneficial influence is related to insulin sensitivity improvement. The potential therapeutic role of L-arginine administration in patients with obesity needs further investigation.

Effects of green tea supplementation on inflammation markers, antioxidant status and blood pressure in NaCl-induced hypertensive rat model

ABSTRACT Background: Recent studies indicate the important role of chronic inflammation and oxidative stress in the pathogenesis of hypertension. Green tea, due to the high content of catechins, shows high antioxidant activity. Objective: To determine the effect of supplementation with green tea extract on the blood pressure, on the concentration of selected parameters of inflammation and antioxidant status in the model of high-sodium-diet induced hypertension. Design: The study lasted 42 days. The experimental population consisted of 30 rats. The rats were divided into three groups. The rats in the control group were fed a standard diet with 35 g of NaCl per kg of diet, in the second group hypertensive rats were fed a standard diet with NaCl (35 g/kg diet) and with an extract of green tea (2 g/kg diet). The third group consisted of hypertensive rats fed a standard diet with NaCl (35 g/kg diet), and 4 g of green tea extract/kg diet. Results: Supplementation with green tea had no effect on body mass of rats on a high-sodium diet. At the end of the experiment systolic blood pressures in SH2 and SH4 groups were significantly lower than in the control group SK. The SH4 group was characterized by a significantly lower diastolic blood pressure value and concentration of TNF-α in comparison to the SK group. The rats from both SH2 and SH4 groups were characterized by higher total antioxidant status values compared to the control group. Discussion: The mechanism of the beneficial effects of green tea on blood pressure is not clear, but it is believed that it is related to its omnidirectional properties. Conclusions: Supplementation of green tea has a beneficial effect on blood pressure, markers of inflammation and antioxidant status in an experimental model of hypertension.

The genetic basis of obesity complications

Intensive research is currently being performed into the genetic background of excess body mass compli- cations such as diabetes, cardiovascular disorders, especially atherosclerosis and coronary heart disease. Chronic inflammation is an important process in the pathogenesis of obesity, wherein there is an aberrant ex- pression of genes encoding adipokines. Visceral tissue is characterized by a higher expression and secretion of interleukin-8, interleukin-1ß and plasminogen activator inhibitor 1 in the subcutaneous tissue secretion of leptin prevails. An important complication of obesity is obstructive sleep apnea, often observed in Prader- Willi syndrome. The genetic background of sleep apnea may be a polymorphism of the SREBF1 gene. The consequence of excess body mass is metabolic syndrome, which may be related to the occurrence of the rs926198 variant of gene encoding caveolin-1. The genes of transcription factor TCF7L2 and PPAR-γ2 take part in the pathogenesis of diabetes development. It has been demonstrated that oncogenes FOS, FOSB, and JUN may be co-responsible not only for obesity but also for osteoporosis and colorectal cancer. It has been shown that weight loss causes a modification in the expression of about 100 genes involvedt in the production of substances such as cytokines and other responsible for chronic inflammation in obesity. In future studies on the complications of obesity, such scientific disciplines as proteomics, peptidomics, metabolomics and transcriptomics should be used. The aim of this study is to present the current state of knowledge about the genetic basis of obesity complications.

The influence of selected antihypertensive drugs on zinc, copper, and iron status in spontaneously hypertensive rats.

Mineral homeostasis in hypertensive patients may be affected by hypotensive drugs. The aim of this study was to assess the influence of selected antihypertensive drugs on mineral homeostasis in a rat model of hypertension. Eight-week-old male spontaneously hypertensive rats (SHRs) were treated with perindopril, metoprolol, indapamide, amlodipine, or no drug for 45 days. In another experiment, the SHRs were treated with indapamide or amlodipine in the presence of zinc and copper gluconate supplement. Lipids, glucose, and insulin levels along with superoxide dismutase and catalase activities were assayed in serum. Iron, zinc, and copper concentrations in serum, erythrocytes, and tissues were determined using the flame atomic absorption spectrometry. Blood pressure was measured using a tail-cuff plethysmograph. Treatment with indapamide and amlodipine was found to significantly lower zinc levels in serum, erythrocytes, livers, and spleens of the SHRs, as well as copper levels in the kidneys, compared with the control no-drug group. A markedly higher concentration of glucose was found in the indapamide-treated rats. Supplementing the indapamide-treated SHRs with zinc and copper gluconate resulted in a significant decrease in both systolic and diastolic blood pressure, and also lowered serum glucose and triglyceride concentrations and HOMA (homeostasis model assessment-insulin resistance) values. The results show that indapamide and amlodipine disturb zinc and copper homeostasis in SHRs. Supplementation with zinc and copper restores mineral homeostasis in SHRs treated with indapamide and amlodipine, and also corrects metabolic imbalances while improving the antihypertensive efficiency of indapamide.