Helmut Sinzinger

Muscular side effects of statins.

Lipid lowering has been shown to be effective in preventing primary and recurrent cardiovascular events and to save life. Statins almost exclusively used for this purpose meanwhile became one of the most widely prescribed families of drugs world-wide. Myopathies – mainly not well characterized – are the major group of side effects. We here review different types of clinical appearances, localizations, symptoms and the biochemical background. The data indicate that severe muscular side effects are rare. Patients and their doctors, however, easily overlook mild ones. Myopathic symptoms without any known biochemical correlate are not rare. No general guideline exists about exact diagnosis and differential diagnosis. Strict adherence to the measures of life-style change and performance of regular exercise can even further enhance significantly these side effects. Much more research should be directed onto the pathophysiological (genetic?) background to finally evaluate possible therapeutic consequences rather than simply to withdraw or change the respective statin.

Prevalence and relevance of thyroid dysfunction in 1922 cholesterol screening participants.

Controversy persists about the role of subclinical hypothyroidism in hypercholesterolemia. This study aimed to assess in a clinically healthy, middle-aged population of employees the prevalence of thyroid function disorders and their relation to demographic variables and cardiovascular risk factors. 1922 (former) employees were screened with follow-up of newly identified cases of undiagnosed (subclinical) hypothyroidism and hyperthyroidism. Thyroid stimulating hormone (TSH), prevalence and course of (subclinical) hypo- and hyperthyroidism and their relation to cardiovascular risk factors (cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, smoking, systolic and diastolic blood pressure) were assessed. The prevalence of newly diagnosed subclinical hypothyroidism (cut-off TSH concentration: 4.0 mU/L) was 1.1% (17 women and 5 men) with a mean TSH concentration of 7.37 (95% CI 5.18-9.56) mU/L. No case of overt hypothyroidism could be diagnosed. Elevated levels of antibodies to microsomal or thyroglobulin antigens were detected in six subjects with subclinical hypothyroidism (27.3%). Fifteen subjects (0.8%, 13 women and 2 men) had TSH concentrations below 0.1 mU/L. The cardiovascular risk profile of subjects with mild subclinical hypothyroidism was not different from subjects with normal TSH levels. The prevalence of subclinical hypothyroidism was 0.8% in normocholesterolemic (cholesterol <5.2 mmol/l) and 1.4% in hypercholesterolemic subjects (n.s.). One woman each with the subclinical form of the disease developed hypothyroidism or hyperthyroidism after 21 and 11 months of follow-up, respectively. Subclinical hypothyroidism and subclinical hyperthyroidism were rarely observed in a target group for coronary heart disease prevention. Mild subclinical hypothyroidism was not associated with any adverse cardiovascular risk profile. These results argue against indiscriminate measurements of TSH concentrations in clinically healthy subjects either with normocholesterolemia or hypercholesterolemia.

Short-term atorvastatin treatment improves endothelial function in hypercholesterolemic women.

Endothelial dysfunction represents the earliest stage of atherosclerosis and is usually present in hypercholesterolemia. Treatment with statins has been shown to normalize endothelial function in middle-aged men with hypercholesterolemia. We evaluated the effect over time of atorvastatin on the endothelial reactivity in postmenopausal hypercholesterolemic women (mean age, 58 +/- 6 years), receiving atorvastatin, 10 mg daily (n = 20) or American Heart Association step 1 diet (n = 10) for 8 weeks. Lipid profile and brachial artery flow-mediated vasodilation (FMV) were determined at baseline and after 1, 2, 4, and 8 weeks. FMV increased progressively in subjects treated with atorvastatin, and the difference was significant (p < 0.05 vs. baseline) after the second week (baseline 3.8 +/- 3%; first week, 4.8 +/- 3%; second week, 9.2 +/- 3%; fourth week, 11.0 +/- 3%; eighth week, 11.7 +/- 3%). No significant changes were observed in subjects receiving diet (baseline, 3.1 +/- 4%; first week, 2.4 +/- 2%; second week, 2.9 +/- 2%; fourth week, 3.1 +/- 2%; eighth week, 3.3 +/- 2%; p = NS). In the atorvastatin group, low-density lipoprotein (LDL) cholesterol showed a significant decrease since the first week (baseline, 228 +/- 37 mg/dl; first week, 171 +/- 32; second week, 147 +/- 27; fourth week, 139 +/- 29; eighth week, 135 +/- 27; all p < 0.05). In the control group, LDL cholesterol showed a smaller but significant (p < 0.05) reduction after the second week (baseline, 226 +/- 17 mg/dl; first week, 225 +/- 16; second week, 220 +/- 17; fourth week, 203 +/- 27; eighth week, 198 +/- 27). In conclusion, hypercholesterolemic women treated with atorvastatin show a significant improvement in endothelial reactivity after as early as 2 weeks of therapy. The extent to which these beneficial effects are attributable to cholesterol reduction or to a direct effect of the drug remains to be established.

Quitting cigarette smoking results in a fast improvement of in vivo oxidation injury (determined via plasma, serum and urinary isoprostane).

Isoprostanes (IP) have been identified as reliable markers of in vivo oxidation injury. Recently, in vascular tissue and blood as well as urine of cigarette smokers, increased IP values have been discovered. We examined 47 adults (26 males, 21 females; aged 30-66 years), admitted to a cardiovascular unit on an outpatient basis, with various risk factors but without any sign of manifestation of atherosclerosis. Refraining from cigarette smoking for a few days resulted in a significant drop of plasma, serum, and urinary 8-epi-PGF(2alpha). Thereafter, a further continuous decrease was monitored, reaching a steady state after about 4 weeks after quitting cigarette smoking. Prevalues of 8-epi-PGF(2alpha) were higher, depending on the type and number of risk factors; the decrease after quitting, however, was comparable. These results indicate that exsmokers may rapidly recover from their enhanced in vivo oxidation.

Reduced umbilical artery prostacyclin formation in complicated pregnancies

Prostacyclin synthesis is severely depressed in the umbilical arteries of neonates of mothers with gestational diabetes mellitus, juvenile-onset diabetes mellitus, or preeclamptic symptoms, and of mothers who smoke during pregnancy and diabetic mothers who smoke. The reduced production of prostacyclin might be responsible for an increased abortion rate and a higher rate of intrauterine fetal death because of a decrease in placental perfusion and umbilical blood flow.

The isoprostane, 8-epi-PGF2α, is accumulated in coronary arteries isolated from patients with coronary heart disease

OBJECTIVE In the present study we wanted to know whether 8-epi-PGF2 alpha, which belongs to the class of isoprostanes formed by free radical-mediated peroxidation of arachidonic acid and arachidonyl-containing phospholipids, is enriched in isolated coronary arteries of patients suffering from coronary heart disease (CHD, n = 23) who received allograft heart transplants as compared to vessels derived from patients with dilative cardiomyopathy (CMP, n = 19) or from healthy heart donors (controls, n = 6). METHODS Sections from the isolated coronary arteries were analysed by semiquantitative immunohistochemistry by determining the area and intensity of positive reaction for 8-epi-PGF2 alpha in the vascular intima and media. In addition, the 8-epi-PGF2 alpha content was determined using a specific immunoassay after extraction and purification. RESULTS The immunohistochemical results indicated that 8-epi-PGF2 alpha is significantly enriched in arteries from patients suffering from CHD as compared to CMP (P < 0.0001). In controls, significantly less immunostaining was observed. Furthermore, a significant positive correlation between semiquantitative immunohistochemistry and radioimmunological determination was observed too. CONCLUSIONS From our findings we conclude that 8-epi-PGF2 alpha is especially accumulated in coronary arteries from CHD patients and therefore is likely to be involved in atherogenesis.

Passive smoking and platelet thromboxane.

While active smoking is known to enhance platelet thromboxane production, no data on passive smoking is available yet. The influence of single and repeated exposure to passive smoke for 60 minutes in a 18 m3 room was assessed in non-smokers as compared to sex and age matched smokers. All the evaluated measures (malondialdehyde, plasma thromboxane B2, 11-dehydro-thromboxane B2, serum thromboxane B2, conversion of exogenous arachidonic acid to thromboxane B2 and to hydroxy-5, 8,10-heptadecatrienoic acid) were higher in smokers than non-smokers at baseline, immediately and 6 hours after passive exposure to cigarette smoke. Repeated exposure of non-smokers rendered their platelets more activated becoming close to the behaviour of smokers. These results indicate that passive smoking may activate thromboxane A2 release from the platelets, contributing to the development of hemostatic imbalance.

Antioxidant status in thyroid dysfunction.

Abstract Our study was designed to test and compare the levels of enzymatic antioxidants (ARS), endogenous peroxides (POX), non-enzymatic antioxidants (Antiox-cap) and anti-oxidized low-density lipoprotein (LDL) antibody titers (oLAb) in hyperthyroid and hypothyroid patients. We measured POX, ARS, Antiox-cap and oLAb in the plasma from 68 patients (34 patients with hyperthyroidism, thyroid-stimulating hormone (TSH) <0.04; and 34 patients with hypothyroidism, TSH >4.0) and 34 healthy euthyroid controls. POX were highest in hyperthyroid patients, but differences between hyperthyroid and hypothyroid patients and controls were not significant. ARS were significantly higher in patients compared to controls. Antiox-cap were significantly lower in patients compared to controls. oLAb were significantly higher in hypothyroid patients compared to controls and hyperthyroid patients. Our study shows that both hyperthyroidism and hypothyroidism are associated with enhanced oxidative stress involving enzymatic and non-enzymatic antioxidants. Higher POX in hyperthyroid patients might reflect the hypermetabolic state of these patients. oLAb, indicating progression of atherosclerosis, were highest in hypothyroid patients.

A consensus protocol for white blood cells labelling with technetium-99m hexamethylpropylene amine oxime

Since its introduction in 1976 as an imaging procedure, the use of labelled leucocyte scintigraphy has continued to increase. Nowadays it is a routine procedure in most nuclear medicine departments for the investigation of different inflammatory pathologies involving leucocytic infiltration. These include bone and soft tissue infections, inflammatory bowel disease, vascular prosthesis infection and fever of unknown origin [1–4]. Despite their non-specificity, the use of non-polar, lipid-soluble chelates is still the most efficient way to label leucocytes. Indium-111 oxine was the first to be described in 1976 [5] and has been the agent of choice for many years. Other indium chelates such as 111In-tropolone [6] and 111In-mercapto-pyridineN-oxide [7] have been demonstrated to label leucocytes as efficiently as 111In-oxine in plasma medium, but their use has not been so widespread. Although efficient in many ways, the use of 111In-oxine has become less attractive due to its cost, inconvenient supply, and the unfavourable physical characteristics of 111In. Technetium-99m has excellent characteristics for scintigraphic imaging and is cheap and available at any time. For this reason, many investigators have tried to find a 99mTc-chelate able, like 111In-chelates, to enter cells and to bind a cytoplasmatic component without loss of leucocyte viability. 99mTc-propylene amine oximes (PnAO) were originally developed as lipophilic diffusible radiopharmaceuticals for brain imaging [8]. The dl diastereoisomer complex of 99mTc-hexamethylpropylene amine oxime (HMPAO) was found to have the highest brain concentration [9]. Because of its neutral, lipophilic character, this radiopharmaceutical is able to diffuse through the cell membrane and bind intracellular components. Soon 99mTc-HMPAO proved to be useful as a leucocyte labelling agent [10, 11]. Since 1988 99mTc-HMPAO has been commercially available. Nevertheless, its use is accompanied by a large variety of labelling methodologies which, although they in general do not induce any significant damage on labelled cells, can influence the image quality and interpretation of results. The International Society of Radiolabelled Blood Elements (ISORBE), founded in 1989 in Vienna (Austria) with the primary objective of providing a forum for exchange of knowledge and experience, decided to crutinize various methods and to suggest a uniform procedure for radiolabelling leucocytes with 99mTcHMPAO.

A simple and safe technique for sterile autologous platelet labelling using “Monovette” vials

A simple technique of autologous platelet labelling is described, which allows labelling within 40 min, and has the advantage of low costs, as no laminar air flow is required. Blood (16 ml) was withdrawn into 4 ml ACD, 500 ng prostacyclin was added. After 10 min sedimentation the vials were centrifuged for 5 min at 150 g. The plateletrich plasma in the supernatant was centrifuged at 500 g for 10 min to obtain a platelet pellet. The platelet-poor plasma was preserved in a sterile syringe and the platelet pellet was resuspended in 1 ml tyrode buffer. The cell suspension was labelled at 37° C for 5 min with 100 μCi 111In-oxine sulphate and reinjected after dilution with the plasma. Mean labelling efficiency was 90%±3%, mean recovery 2 h after reinjection 76%±3% (mean±SD).