Hemorheological Parameters in Diabetic Patients: Role of Glucose Lowering Therapies.

Diabetes mellitus influences several important hemorheological parameters including blood viscosity, erythrocyte aggregation and deformability. In the present study, 159 type-2 diabetic patients and 25 healthy controls were involved. Patient's age, body weight, body mass index (BMI), smoking habits, physical activity, history of cardiovascular diseases, current antidiabetic therapy and concomitant medication were recorded. Patients were grouped according to their antidiabetic treatment with insulin, or with one or more of the following antidiabetic drugs: metformin, sulfonylureas, acarbose, or no antidiabetic therapy. Hemorheological measurements (hematocrit, erythrocyte aggregation, plasma fibrinogen, whole blood and plasma viscosity), von Willebrand factor activity, and platelet aggregation measurements were performed. Platelet aggregation was investigated with the method of Born. Plasma viscosity and red blood cell aggregation were significatly higher in diabetes. No significant difference was found in hemorheological parameters between different antidiabetic regimens. Whole blood and plasma viscosity and red blood cell aggregation correlated with glucose levels but not with HbA1C levels. In conclusion, plasma and whole blood viscosity, as well as red blood cell aggregation appear to be associated with concurrent hyperglycemia, but not with the quality of glycemic control or the applied antidiabetic treatment. Platelet aggregation induced by ADP or epinephrine does not seem to be associated with diabetes even at subthreshold doses.

Characteristics of Patients Referred To A Specialized Headache Clinic.

Headache is a common problem with great effect both on the individual and on the society. Recent studies raised the possibility of increasing rate of specialty referrals, inappropiate treatment and advanced imaging for simple headache. The aim of our study was to analyze the characteritics of patients (including duration of symptoms, headache type, brain imaging, treatment) referred to our specialized headache clinic between 01/01/2014 and 01/01/2015 by their general practitioners and primary care neurologists due to chronic/treatment-resistant headache syndromes. 202 patients (mean age 53.6 ± 17.6 years) were evaluated in our clinic (102 females, mean age 50.14 ± 16.11 years and 100 males, mean age 57 ± 18.1 years). Migraine (84/202) and tension-type (76/202) were the most common syndromes. 202 plain brain CT, 60 contrast-enhanced CT and 128 MRI were carried out by their general practitioners or other healthcare professioners including neurologists before referral to our headache centre. Despite of extensive brain imaging appropiate treatment was started less than 1/3 of all patients and significant proportion received benzodiazepines or opioid therapy. Furthermore, more than 10% of referred patients presented with secondary headache including one meningitis. The management of headache is still a challenge for primary care physicians leading to medical overuse. Vast majority of our patients should not be referred to our specialized headache clinic as they had uncomplicated headache or other underlying conditions than pain.

Association between XRCC1 polymorphisms and head and neck cancer in a Hungarian population.

BACKGROUND: Head and neck cancer is a significant current health problem in Hungary because the mortality of this cancer has increased by 387% in the last thirty-two years. Because of the important role of the XRCC1 gene in DNA repair, we wanted to test the effects of the Arg194Trp and Arg399Gln polymorphisms of XRCC1 on the clinical outcome of head and neck cancer. PATIENTS AND METHODS: A polymerase chain reaction-restriction fragment lenght polmorphism (PCR-RFLP) method was used. A total of 108 samples were taken from intraoperatively removed formalin-fixed, and paraffin-embedded blocks of tissue. An age- and sex-matched cancer-free control group was used to compare the frequency of polymorph variants. RESULTS: No significant difference was found between patients and controls in repect of the investigated polymorphisms. A significant difference was found between the patients with different XRCC1 194 polymorph status in clinical stage SIII. The survival proportion of patients with the Arg194Arg genotype was significantly lower than of those with the Arg194Trp genotype. CONCLUSION: The complex analysis of these factors may provide the basis for personal risk assessment and an opportunity for individualised therapy.

GSTM, GSTT and p53 polymorphisms as modifiers of clinical outcome in colorectal cancer.

BACKGROUND: Cancer of the colorectal region is the second most frequent cause of death among malignant diseases. The influence of two allelic polymorphisms of GSTM1 and GSTT1, and that of p53 gene codon 72 on colon cancer was investigated. PATIENTS AND METHODS: Intraoperatively removed tissue samples were processed from colorectal cancer patients. Cancer-free human samples were used as matched controls. Samples were digested with proteinase-K. DNA solution was used for PCR amplification. RESULTS: No significant difference was found between tumor patients and controls in the investigated polymorphisms. A significant association was found in Dukes' B stage patients between the GSTM1 and p53 gene variants and survival. In patients with GSTM1 null genotype and p53 Arg/Pro heterozygotes or Pro/Pro homozygotes the chance of survival is significantly lower than in the case of GSTM1+ and p53 Arg/Arg variants (p=0.009 and p=0.008, respectively). CONCLUSION: The significance of the investigated polymorphisms in prognosis is dependent on the tumor stage. These parameters might be used in certain cases as prognostic biomarkers in clinical diagnostics and in the planning of individual therapy.

Relation of platelet aggregation and fibrinogen levels to advancing age in aspirin- and thienopyridine-treated patients.

In our present study we investigated the association between platelet aggregation in patients treated with the most widely used antiplatelet agents (100 and 300-325 mg acetylsalicylic acid (ASA), 75 mg clopidogrel, 500 mg ticlopidine and the combination of 100 mg aspirin and 75 mg clopidogrel), fibrinogen levels and aging. Between 2001 and 2005 we measured in vitro platelet aggregation in 5026 vascular patients according to the method of Born. Platelet aggregation was tested with 5 and 10 microM adenosine-diphosphate, 2 microg/ml collagen and 10 microM epinephrine stimulants. Fibrinogen level was simultaneously measured in a subgroup of 3243 patients. The subjects were divided by age into decades. Platelet aggregation increased significantly with advancing age in the case of 100 and 300-325 mg ASA-treated patients (p<0.001). In aspirin-treated patients also fibrinogen levels increased with aging (p<0.001). There was no association between platelet aggregation or fibrinogen levels and aging either in patients treated with 75 mg clopidogrel or with 500 mg ticlopidine. Thienopyridine-treated patients exhibited significantly lower fibrinogen levels than ASA-treated individuals (p<0.001). Our results suggest that advancing age is associated with elevated platelet aggregability in widely used antiplatelet regimens that might contribute to higher risk of cardiovascular events in the elderly.

Viscosity, hemostasis and inflammation in atherosclerotic heart diseases.

BACKGROUND: In atherosclerotic diseases vascular reserve is impaired and pressure gradient is decreased, therefore the reduced blood fluidity can lead to tissue ischemia more rapidly. In previous investigations we demonstrated the deterioration of plasma and whole blood viscosities in patients with acute ischemic coronary syndromes, chronic coronary artery disease, and percutaneous transluminal coronary angioplasty. METHODS: Hemorheological variables (plasma and whole blood viscosities, hematocrit, red blood cell aggregation), hemostaseological parameters (plasma fibrinogen and von Willebrand factor (vWf)), and platelet aggregation were detected in more recent studies in cardio- and cerebrovascular diseases, and diabetes mellitus. Common risk factors (lipid profile, smoking, glucose level, previous diseases) and medication were also recorded. RESULTS: High portion of vascular patients were demonstrated to have poor ex vivo platelet inhibition. Effective antiplatelet treatment detected by aggregometry was related to lower plasma fibrinogen concentration and red blood cell aggregation and was also associated with less recurrent vascular events during the follow-up (p < 0.001). Beside the impaired hemorheological characteristics, the diabetic patients showed elevated vWf activity, which turned to correlate with hemoglobin A1c concentration (p < 0.01) rather than the fasting glucose. SUMMARY: Our studies indicate the active role and interaction of hemorheological and hemostaseological factors in atherosclerotic heart diseases.

Hemorheological methods in drug research.

Development of new drugs is a sophisticated process that requires several, different methods. In our experiments we have applied two rheological models to study experimental and clinically used drugs. The antioxidant properties of several agents were estimated by erythrocyte filtration technique. The known antioxidant compound vitamin E was used to validate our measurements. An experimental cardioprotective agent, H-2545 provided significant protection against oxidative changes in red blood cell filterability (p<0.001). Although some of the examined, known cardiovascular drugs also showed significant antioxidant effect, they were less efficient than H-2545 and the scavenger effect of this novel agent exceeded the antioxidant properties of vitamin E. Modification of mexiletine with a pyrroline ring improved significantly its antioxidant capacity suggesting this molecular segment to be responsible for the antioxidant effect. In our second model the antiplatelet effect of experimental poly(ADP-ribose) polymerase (PARP) inhibitors was evaluated. Two widely used antiplatelet agents: acetyl salicylic acid and eptifibatide served as controls in the validation of the measurements. PARP inhibitors reduced ADP-induced platelet aggregation in a dose-dependent manner (p<0.05). However, their hindrance on platelet aggregation waned as the concentration of ADP rose. Regarding the platelets' role in the development of ischemic vascular diseases, the antiaggregating property of PARP inhibitors may exert additional beneficial effects on tissue blood supply under conditions of compromised vascular flow.

[Effects of cardiovascular risk factors on hemorheologic parameters in cerebrovascular patients]. / A kardiovaszkuláris rizikófaktorok hatása az agyérbetegek hemoreológiai viszonyaira.

INTRODUCTION: Hemorheological factors are of significance in the determination of flow characteristics of blood and play an important role in the pathogenesis of cerebrovascular diseases. AIMS AND METHODS: In this study the changes of rheological factors--hematocrit (Hct), plasma fibrinogen concentration (PFC), whole blood (WBV) and plasma viscosity (PV), red blood cell aggregation (AI) and deformability and the association between these parameters and cardiovascular risk factors were investigated in 297 patients (173 males, 124 females, mean age: 60 11 years) with chronic phase (3 months after onset) ischemic cerebrovascular diseases, and in 68 healthy volunteers (30 males, 38 females, mean age: 36 6 years). RESULTS: All investigated hemorheological factors were significantly (p < 0.05-0.0001) elevated in cerebrovascular patients compared to normal controls, the rise in Hct, WBV and PV are some of the most prominent findings. In the group of hypertensive, hyperlipidemic patients, smokers and alcoholics Hct, PFC, WBV, PV and AI were significantly (p < 0.05-0.0001) higher compared to healthy controls, the same factors except plasma fibrinogen concentration showed association with diabetic history. Comparing cerebrovascular patients with or without risk factors, the most severe hemorheological deficit was observed in patients with hyperlipidemia and smoking habits. CONCLUSIONS: In this study the authors proved in chronic ischemic cerebrovascular patients that hemorheological abnormalities persist in most cases for a long time after an acute stroke, significant correlation could be seen between blood rheology and cardiovascular risk factors. Examination of rheological parameters can support to choose the optimal medical treatment in the secondary prevention of stroke, correction of hemorheological disturbances can reduce the risk of recurrent stroke.