Effect of 3-month L-arginine supplementation on insulin resistance and tumor necrosis factor activity in patients with visceral obesity.

BACKGROUND: The role of tumor necrosis factor alpha (TNF-alpha), one of the adipose tissue products, in the pathogenesis of insulin resistance is well-documented. Many recent studies have shown beneficial influence of L-arginine supplementation on cardiovascular system. However, molecular mechanisms of its positive actions are not fully elucidated. AIM: The aim of the study was to evaluate the influence of L-arginine supplementation on tumor necrosis factor alpha, insulin resistance and selected anthropometric and biochemical parameters in patients with visceral obesity. PATIENTS AND METHODS: 60 patients with visceral obesity were randomly assigned to either receive 9 g of L-arginine or placebo for 3 months. 20 healthy lean subjects were used as control. Selected anthropometrical measurements and blood biochemical analyses were performed at baseline and after 3-months. TNF-alpha and its soluble receptor 2 (sTNFR2) were assessed in both treated groups. Insulin resistance in the participants was evaluated according to the homeostasis model assessment-insulin resistance (HOMA-IR) protocol. RESULTS: The concentration of insulin, TNF-a and sTNFR2 and HOMA-IR level in both obese groups significantly exceeded these observed in the control. Basal TNF-alpha and sTNFR2 concentrations were positively correlated with basal body mass index (BMI), waist circumference, percent of body fat and HOMA-IR. We found that 3-month L-arginine supplementation resulted in significant decrease of HOMA-IR and insulin concentration. Only insignificant tendency to decrease of TNF-alpha and sTNFR2 was observed. CONCLUSIONS: Our results confirm TNF-alpha role in the complex pathogenesis of insulin resistance in patients with visceral obesity. 3-months L-arginine supplementation in a dose of 9 g improves insulin sensitivity in patients with visceral obesity with no impact on tumor necrosis factor alpha concentration.

The effect of oral L-arginine supplementation on fasting glucose, HbA1c, nitric oxide and total antioxidant status in diabetic patients with atherosclerotic peripheral arterial disease of lower extremities.

INTRODUCTION: Numerous studies indicate hyperglycemia and oxidative stress as factors responsible for endothelium dysfunction and the following development of angiopathy. Increased production of free radicals by vascular endothelium causes disturbance in production and/or decreases bioaccessibility of nitric oxide (NO). It has been suggested that L-arginine supplementation is a reasonable method to increase endothelium NO production and lower free radicals formation. There is a growing number of evidence showing that dietary supplementation of arginine reverses endothelial dysfunction associated with major cardiovascular risk factors and ameliorates many common cardiovascular disorders. OBJECTIVE: The aim of the study was to evaluate the potential influence of two-months oral L-arginine supplementation on fasting glucose, HbA1c, nitric oxide and total antioxidant status (TAS). MATERIALS AND METHODS: 38 patients with atherosclerotic peripheral arterial disease of lower extremities at Fontaine's stage II and coexisting type 2 diabetes and 12 healthy volunteers as control group were studied. All patients were treated with oral L-arginine (3 x 2 g/day) for two months. Fasting glucose, HbAlc, nitric oxide and total antioxidant status (TAS) were measured before and after the study. RESULTS: Fasting glucose and HbAlc did not change significantly after L-arginine treatment. Statistically significant increase in NO concentration and TAS level was found. CONCLUSIONS: Oral two-month supplementation with L-arginine (3 x 2 g/day) had no effect on fasting glucose and HbA1 level in diabetic patients with atherosclerotic peripheral arterial disease of lower extremities at Fontaine's stage II. The supplementation of L-arginine led to substantial increase in NO concentration and TAS level in these patients, suggesting its indirect antioxidative effect.

Supplementation with L-arginine does not influence arterial blood pressure in healthy people: a randomized, double blind, trial.

BACKGROUND AND OBJECTIVES: It cannot be excluded that supplementation with L-arginine, by improving function of endothelium and hypotensive effect, can be advantegeous in prevention of cardiovascular diseases in healthy people. However, reports about hypotensive effect of L-arginine in healthy people are unclear. Moreover, no research including ambulatory blood pressure measurement (ABPM) has been conducted so far. Therefore, the aim of our study was to show if 4-week supplementation of healthy people with L-arginine influences blood pressure measured with ABPM. MATERIALS AND METHODS: The study was carried out on 19 healthy people randomized to 6 g/24-hour, 12 g/24-hours of L-arginine or placebo. ABPM was carried out 4 times: before randomization, after 2 and 4 weeks of supplementation and 2 weeks after finishing supplementation. RESULTS: It was found that 4 weeks of supplementation of healthy people with L-arginine (6 or 12 g/24-hour) led to nonsignificant decrease of systolic and diastolic blood pressure; the decrease was greater during night. CONCLUSION: These findings showed that supplementation with L-arginine is not necessarily advantageous in healthy people.

Twenty-four hour ambulatory blood pressure monitoring in young and elderly hypertensive subjects.

The aim of our study was to compare blood pressure (BP) measured by 24-h ambulatory monitoring in young and elderly hypertensives and to find a dependency between left ventricular mass (LVM) and different pressure ratios. We also estimated the calcium ionized concentration and serum lipids in all subjects. Two hypertensive groups divided accordingly by age were studied. The duration of hypertension was similar in both groups. The Oxford Medilog ABP was used for the arterial BP recordings. Mean arterial BP, BP loads and night/day mean arterial pressure ratio were evaluated. In both groups left ventricular mass index (LVMI) were calculated. The serum calcium ionized concentration (Ca++) was estimated and serum lipids were determined. We found 10 non-dippers in the young group and seven non-dippers in the elderly hypertensives. LVM and LVMI were comparable in both groups. We showed the correlation of the nocturnal mean arterial pressure with LVM in elderly hypertensives and the dependency of nocturnal BP load with LVM in this group. Serum calcium ionized concentration was significantly decreased in the elderly patients, and LDL-cholesterol was significantly higher in this group. We found a negative correlation between serum calcium and triglycerides in young and elderly hypertensives. We found more non-dippers in the young hypertensives and a positive correlation between LVM and nocturnal mean arterial pressure and nocturnal BP load in elderly subjects. These results suggest the cardiovascular prognosis is not good in both groups. The prognosis in elderly hypertensives was also worsened by the low serum calcium ionized and high LDL-cholesterol concentrations.

[Clinical characteristics of patients with hypertension resistant to antihypertensive drug therapy]. / Charakterystyka kliniczna chorych z nadcisnieniem tetniczym opornym na leczenie hipotensyjne.

Two groups of hypertensive patients: 137 responsive (on one or two drugs) and 162 resistant on antihypertensive treatment in the similar age were compared. Resistant patients (on three or more drugs) characterize by significantly higher body weight and BMI, longer history of hypertension, more frequent hypertension prevalance in family members and lower education. Level of triglycerides in resistant on antihypertensive treatment patients was significantly higher than in responsive patients. Insulin level in blood in 31 patients with essential hypertension was significantly higher than in 36 healthy persons and 20 patients with renovascular hypertension and resistant on antihypertensive therapy. In 14 patients with essential hypertension resistant to treatment insulin level one hour after oral glucose load was significantly (p < 0.01) higher than in 16 patients with essential hypertension responsive to antihypertensive treatment.

[Uric acid and arterial hypertension. IV. Relation between serum uric acid level, the extent of vascular changes and heart enlargement in primary arterial hypertension]. / Kwas moczowy a nadcisnienie tetnicze. IV. Zaleznosc pomiedzy stezeniem kwasu moczowego w surowicy a zaawansowaniem zmian naczyniowych i przerostu miesnia sercowego w nadcisnieniu tetniczym pierwotnym.

In forty patients with essential hypertension correlation between serum uric acid and some clinical features of hypertensive disease i.e. severity and time of duration of arterial hypertension, the extent of vascular, retinal changes and left ventricular wall thickness was evaluated. Results showed that diastolic arterial pressure and the extent of retinal changes are significantly higher in hypertensive patients with concomitant hyperuricemia in comparison with normal uricemia patients with essential hypertension. Positive correlation was found between serum uric acid and diastolic as well as mean arterial pressure. Moreover, patients with essential hypertension and hyperuricemia demonstrated left ventricular hypertrophy in comparison with normal uricemia in hypertensive patients. Elevated serum uric acid in essential hypertension should be regarded as an early "harbinger" of disposition to the quick progress of vascular changes.

[Selected hemodynamic parameters in overweight patients with mild and moderate hypertension treated with low caloric diet]. / Wybrane parametry hemodynamiczne u chorych z nadwaga i nadcisnieniem tetniczym lagodnym i umiarkowanym leczonych dieta niskokaloryczna.

Basic haemodynamic parameters - blood volume (BV), cardiac output (CO), stroke volume (SV), and total peripheral resistance (TPR) were studied in two groups of overweight patients with mild and moderate hypertension. Each group consisted of 15 subjects. The patients of the first group were kept on low caloric diet (1000-1100 cal per day). Patients of the second-control-group were treated with propranolol (120 mg per day). The duration of each study was 24 weeks. Blood pressure fell due to body weight reduction. BV, CO and SV decreased without changes in TPR. In the control group treated with propranolol in which the body weight did not change a fall in blood pressure, cardiac output, and stroke volume was seen without changes in blood volume and total peripheral resistance values.

[Effect of intravenous administration of cimetidine on renal excretion of calcium, phosphates, magnesium and adenosine cyclic monophosphate]. / Wplyw dozylnego podania cymetydyny na nerkowe wydalanie wapnia, fosforanów, magnezu oraz cyklicznego adenozynomonofosforanu.

An effect of cimetidine on parathyroid glands functioning in healthy subjects was evaluated. Serum calcium, phosphate, and magnesium concentrations together with renal excretion++ of these ions in healthy subjects as well as cAMP excretion++ in selected individuals were determined before and following intravenous administration of cimetidine (Altratmet Lek Ljublijana) in total dose of 500 mg (50 mg injected rapidly as a bolus following with 450 mg in an intravenous infusion during 60 minutes). No significant changes in serum calcium, phosphates, and magnesium concentrations were noted. Renal clearance of calcium and magnesium remained unchanged whereas renal phosphate excretion++ increased from 10.69 +/- 4.9 mL/min to 15.1 +/- 5.41 mL/min (p less than 0.02). Excretion++ of 3.5 cAMP increased from 2.65 +/- 2.19 nM/min to 5.16 +/- 2.0 nM/min (p less than 05). The obtained results do not exclude stimulating effect of intravenous cimetidine on parathyroid glands. Cimetidine given intravenously in the bleeding gastric or duodenal ulcers in the course of the primary hyperparathyroidism+ may decrease serum phosphate levels due to increased exretion of this ion with the urine.

[The effect of a low caloric diet on blood pressure and left ventricular hypertrophy in overweight hypertensive patients]. / Wplyw leczenia dieta niskokaloryczna chorych z lagodnym i umiarkowanym nadcisnieniem tetniczym oraz nadwaga na zmiany cisnienia tetniczego krwi i mase lewej komory serca.

Low-caloric diet is one of the non-pharmacological methods of treatment of hypertension. The study was performed to assess the efficacy of such a regimen in overweight patients with hypertension. 30 patients (17 female, 13 male mean age 46 +/- 7.23) were studied. They were divided into two groups each consisting of 15 patients. The first group was treated with a low-caloric diet (1000-1100 kcal per day), the second with propranolol 120 mg daily. At the beginning and at the end of the treatment clinical and echocardiographic investigations were performed. In the patients treated by a low-caloric diet blood pressure and left ventricular hypertrophy significantly decreased. Propranolol treatment lowered blood pressure but did not reduce left ventricular hypertrophy.