Ratio of lathosterol to campesterol in serum predicts the cholesterol-lowering effect of sitostanol-supplemented margarine

OBJECTIVE

Plant sterol/stanol margarines are recommended as a lipid-lowering dietary supplement in the treatment of hypercholesterolemia. Parameters predicting the individual cholesterol-lowering effect have not been elucidated so far. Therefore, we investigated the responsiveness to sitostanol-supplemented margarine in a specially selected population.

METHODS AND RESULTS

From a total number of 137 male subjects with hypercholesterolemia, eight subjects with the lowest and eight subjects with the highest ratios of lathosterol to campesterol in serum were included in the study. They received 1 g sitostanol-supplemented margarine b.i.d. for four weeks. Serum lipoproteins, the cholesterol precursor lathosterol, the plant sterols campesterol and sitosterol were measured. Subjects with a low ratio of lathosterol to campesterol had a significant decrease of serum total cholesterol (-14.2%; p < 0.01) and LDL cholesterol (-13.8%; p < 0.01; responder). In subjects with a high ratio there was no significant change in total cholesterol and LDL cholesterol (2.2 and 4.3%; non-responder).

CONCLUSION

The ratio of serum lathosterol to campesterol predicts the reduction of total cholesterol and LDL cholesterol during administration of sitostanol-supplemented margarine in patients with mild hypercholesterolemia.

Sitosterolemia—a rare disease

Elevated plasma plant sterol concentrations, xanthomatosis, and accelerated-often fatal-atherosclerosis at young age are the major findings in patients with homozygous sitosterolemia. A defect in the ABCG5 or ABCG8 co-transporter gene locus (STSL) causes an increased intestinal absorption and a decreased biliary elimination of all sterols, plant sterols as well as cholesterol, leading to a 50 to 200-fold increase in plasma plant sterol concentrations. A few recent publications indicate that even moderately elevated plasma plant sterol levels might be associated with an increased risk of atherosclerosis. This raises the question whether plant sterols themselves might be atherogenic or whether elevated plasma levels are a marker for a decreased ABCG5/G8 transporter activity which itself causes an increased risk for atherosclerosis. However, current data are too few to conclude that elevated plant sterol concentrations in plasma are an additional risk factor for coronary heart disease. But especially young patients suffering from xanthomatosis and/or atherosclerotic diseases with only mildly or moderately elevated plasma cholesterol should be screened for sitosterolemia by measurement of plasma plant sterol levels.

Lipoprotein metabolism in patients with anorexia nervosa: a case-control study investigating the mechanisms leading to hypercholesterolaemia

Hypercholesterolaemia is a common finding in patients with anorexia nervosa (AN). To investigate the type, frequency and pathophysiological mechanisms of changes in lipoprotein metabolism in AN we performed a cross-sectional study in fifty-eight female patients (mean age 24.2 years, BMI 15.3 (sd 1.5) kg/m(2)) and fifty-eight healthy age-matched controls (CO; BMI 22.2 (sd 1.7) kg/m(2)). Total cholesterol and LDL-cholesterol were higher in AN (5.5 (sd 1.3) v. 5.0 (sd 0.8) mmol/l, P=0.023; 3.6 (sd 1.1) v. 3.2 (sd 0.7) mmol/l, P=0.025 respectively). LDL particles were significantly more enriched in cholesterol and triacylglycerol in AN. In multiple regression analysis with LDL-cholesterol as the dependent and BMI, total body fat ( %), lathosterol:cholesterol ratio (endogenous cholesterol synthesis), 7alpha-hydroxy-4-cholesten-3-one (bile acid synthesis), non-esterified glycerol, free triiodothyronine and free thyroxine as independent variables, BMI was the only significant predictor in CO (R(2) 0.36, overall P=0.001). In AN the variability of LDL-cholesterol was significantly predicted by total body fat, free thyroxine, BMI, free triiodothyronine and non-esterified glycerol (R(2) 0.55, overall P<0.001). Subgroup analysis between restricting (AN-R) and binge-eating-purging patients (AN-B) indicated that in AN-R changes in lipoproteins, BMI and total body fat were more pronounced. AN-R patients had lower bile acid synthesis than AN-B (P=0.02). We conclude that elevated cholesterol concentrations in AN are generally due to an increase in LDL-cholesterol, which is mostly determined by the severe loss of body fat and the resulting changes in thyroid hormones, increased lipolysis and decreased endogenous cholesterol synthesis with resulting decrease in LDL removal. The clinical subtype of AN plays a major role in the mechanisms leading to hypercholesterolaemia.

Influence of rifampin on serum markers of cholesterol and bile acid synthesis in men

OBJECTIVE

It has been demonstrated in preliminary studies that rifampin, a semisynthetic antibiotic and known inducer of hepatic cytochrome P450 3A4, reduces serum concentrations of total bile acids only in individuals with liver disease and elevated serum bile acid levels.

METHODS

We studied the effect of rifampin on concentrations of surrogate serum markers of cholesterol and bile acid synthesis as well as of cholesterol absorption in 10 male subjects before and after administration of rifampin (600 mg/day) for 6 days. Cholesterol and its precursors were analyzed by gas-liquid chromatography (GLC), bile acid intermediates and individual bile acids by isotope-dilution methods using GLC-mass spectrometry (MS) or by high-performance liquid chromatography (HPLC).

RESULTS

Treatment with rifampin resulted in a 70% increase (p = 0.008) of the serum concentration of the bile acid precursor 7alpha-hydroxy-4-cholesten-3-one, which is a marker for bile acid production. Serum total cholesterol was not altered, however, treatment with rifampin elevated the ratio of lathosterol to cholesterol, an indicator of cholesterol synthesis, by 23% (p = 0.037). Interestingly, serum concentration of total bile acids decreased slightly by 29% (p = 0.022), mainly due to a lowering of the secondary bile acid, deoxycholic acid (-60%; p = 0.005).

CONCLUSION

A 6-day treatment with rifampin induces a reduction of deoxycholic serum concentrations in healthy men associated with a moderate increase of serum markers of bile acid and endogenous cholesterol synthesis.

Enteric dysfunction in patients with asymptomatic HIV-infection versus patients with hypoproteinemia/hypalbuminemia and advanced HIV-infection

BACKGROUND

It is unclear whether enteric dysfunction and protein losses contribute to hypoproteinemia, which heralds poor survival in HIV infection.

METHODS

We investigated alpha-1-antitrypsin-clearance (AAT-CL), D-xylose resorption and total gut transition time in 14 HIV+ patients with hypoproteinemia (serum protein < 6 g/dl, albumin < 3 g/dl, median CD4-cell count 58/microl; (group I)), in 10 asymptomatic HIV+ patients (median CD4-cell count 290/microl, (group II)) and in 15 healthy volunteers (group III).

RESULTS

AAT-CL in group I (16.5 (2.9 278.2) ml/d; median (range)) was higher than in groups II (9.5 (1.7 23.1) ml/d) and III (10.6 (0.8 19.5) ml/d; p = 0.0114). Likewise, D-xylose recovery was on average threefold lower in group I than in groups II (p = 0.0009) and III ( p < 0.0001), whereas total gut transition time was significantly shorter in both HIV-infected groups (group I: 49.8 h (23.5-72.7), p=0.0431; group II: 32.6 h (23-54.6), p=0.0104) than in the healthy controls (group III 61.6 h (39.1-87.7)).

CONCLUSIONS

Thus, impaired intestinal resorption and enteral protein losses may contribute to hypoproteinemia in advanced HIV infection, whereas accelerated intestinal motility may be present already in asymptomatic stages of HIV infection.

Comparison of the hepatic clearances of campesterol, sitosterol, and cholesterol in healthy subjects suggests that efflux transporters controlling intestinal sterol absorption also regulate biliary secretion

BACKGROUND

Recently identified ABCG5/8 transporters are responsible in part for the different absorption rates of campesterol, sitosterol, and cholesterol. These transporters are also expressed in the liver and might regulate biliary sterol secretion.

AIMS

This study was therefore conducted to determine the biliary secretion rates and hepatic clearances of campesterol, sitosterol, and cholesterol.

SUBJECTS

Six healthy, male volunteers.

METHODS

Deuterium labelled sitosterol and campesterol, and unlabelled sitostanol were constantly infused together with a liquid formula using a duodenal perfusion technique. Biliary secretion and hepatic clearance rates were calculated from hourly bile and plasma samples.

RESULTS

Plasma concentrations of cholesterol, campesterol, and sitosterol averaged 167.5 (50) mg/dl (SD), 0.50 (0.22) mg/dl, and 0.30 (0.10) mg/dl, respectively. Sitosterol showed a significantly higher biliary secretion rate (1.23 (0.87) mg/h) than campesterol (0.76 (0.54) mg/h, p=0.0321), but both plant sterols had significantly lower biliary secretion rates compared with cholesterol (47.7 (17.5) mg/h; p=0.001 for both). Hepatic clearance of cholesterol (0.31 (0.18) dl/h) was significantly lower compared with campesterol (2.11 (2.51) dl/h) and sitosterol (4.97 (4.70) dl/h; p=0.028 for both), and the clearance of campesterol was significant lower compared with sitosterol (p=0.028).

CONCLUSION

The observed inverse relation between hepatic clearance and known intestinal absorption of cholesterol, campesterol, and sitosterol supports the hypothesis that the ABCG5/8 transporters regulating intestinal sterol absorption might also be involved in biliary sterol excretion.

Isotopomer spectral analysis of intermediates of cholesterol synthesis in human subjects and hepatic cells

Steroid intermediates of the cholesterol synthesis pathway are characterized by rapid turnover rates relative to cholesterol due to their small pool size. Because the small pools will label rapidly, these intermediates may provide valuable information about the incorporation of isotopes in de novo synthesis of cholesterol and related compounds. The labeling of cholesterol synthesis intermediates from [1-(13)C]acetate was investigated in human subjects and in liver cell models by means of isotopomer spectral analysis (ISA). In human subjects, infusing [1-(13)C]acetate into the duodenum for 12 h demonstrated that approximately 50% of the plasma lathosterol pool was derived from de novo synthesis during this interval. The lipogenic acetyl-CoA precursor pool enrichment reached a constant value within 3 h of the start of the infusion. In vitro studies indicated that liver cell models decrease de novo lathosterol synthesis when cholesterol synthesis is inhibited by statins or cholesterol-containing serum. We propose a new calculation to increase the accuracy and precision of cholesterol synthesis estimates in vivo combining the ISA of lathosterol and cholesterol.

Oral contraceptives moderately effect bone resorption markers and serum-soluble interleukin-6 receptor concentrations

This study investigated the effect of ethinylestradiol(EE2)-containing oral contraceptives on mineral and bone metabolism and on serum soluble-interleukin-6-receptor (sIL-6R) during the menstrual cycle. Twelve women, aged 24.3 +/- 2.9 years, were examined. Blood and 24-hour and fasting urine samples were obtained during one menstrual cycle between cycle day 3-5 (t(1)), cycle day 10-12 (t(2)), cycle day 24-26 (t(3)), and again on day 3-5 of the next cycle (t(4)). EE2 intake was 0 mg at t(1), 30 mg at t(2), 30 mg at t(3) and 0 mg at t(4). Fasting renal phosphorus and calcium excretions were slightly reduced at t(2) and t(3) compared with t(1) and t(4) (P < 0.05-0.001). Moreover, renal excretion of the bone resorption marker C-Teleopeptide was at t(3) reduced by 26% compared with t(1)(P < 0.01) and by 13% compared with t(4)(P > 0.05). Fasting sIL-6R levels were 16.5% lower at t(2) and 12% lower at t(3) than at t(4) (P < 0.01 and P < 0.05). sIL-6R was correlated with total deoxypyridinoline excretion (r = +0.35; P < 0.05) and with fasting renal excretions of calcium (r = +0.36; P < 0.05) and phosphorus (r = +0.29; P < 0.05). In summary, our data suggest that in young women, cyclic monthly oral contraceptive intake is associated with small, but significant variations in bone resorption processes and in serum sIL-6R levels. Results are a further indication that monthly fluctuations of bone resorption in young women are mediated by sex hormones and that osteoclastic activity is stimulated by cytokines in vivo.

Metabolism and drug interactions of 3-hydroxy-3-methylglutaryl coenzyme A-reductase inhibitors (statins)

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA)-reductase inhibitors (statins) are mainly considered for long-term use and often constitute part of a multiple-drug regime. Besides common adverse drug effects, such as nausea, abdominal discomfort and headaches, all statins harbour the risk of myopathy and fatal rhabdomyolysis. Usually, the frequency of myopathy is low but the incidence increases during concomitant drug therapy. Statins do not differ in their pharmacodynamic property. Therefore, the differences in their pharmacokinetic profiles, i.e. affinity for metabolising enzymes, constitute the rationale for choosing a specific statin especially for combination therapy. In order to point out harmful combinations of therapeutics, this review summarises the pharmacokinetic data of six clinically used statins (atorvastatin, cerivastatin, fluvastatin, lovastatin, pravastatin and simvastatin) with special regard to metabolism and drug interactions. In summary, statins that lack a significant hepatic metabolism, i.e. pravastatin, or that are metabolised by more than one cytochrome P450 isoenzyme, i.e. fluvastatin, or whose metabolism is taken over by other cytochrome P450 isoenzymes in case of blockage of the main metabolising enzyme, i.e. cerivastatin, are the least prone to drug interactions. Nevertheless, in case of a specific concomitant drug therapy known to be associated with a higher risk of adverse events, i.e. cyclosporin A and statin, clinical symptoms of myopathy and biochemical data, such as increasing serum creatine phosphokinase, should be monitored carefully.

Olmesartan medoxomil: influence of age, renal and hepatic function on the pharmacokinetics of olmesartan medoxomil

Olmesartan medoxomil was rapidly absorbed and converted to olmesartan in elderly hypertensive patients, and in patients with renal and hepatic dysfunction. No olmesartan medoxomil itself was detected in plasma. Pharmacokinetic steady state was reached within the first few days after oral dosing. In elderly (65-75 years old), after 80 mg olmesartan medoxomil once daily, and very elderly (> or = 75 years old) hypertensive patients after 10 mg daily, steady-state Cmax and area under the curve (AUC(0-24 h)) values were up to 44% higher compared with young patients (< 46 years). Steady-state elimination half-life values were also longer in elderly (12.8 h) and very elderly patients (16.5 h) compared with young patients (10.6 and 12.3 h, respectively). At steady state after 10 mg olmesartan medoxomil daily in patients with renal impairment, both Cmax and AUC(0-24 h) increased as creatinine clearance (CLCR) decreased, and renal clearance (CLR) decreased with decreasing CLCR. Steady-state Cmax and AUC(0-24 h) values in patients with mild (CLCR, 40-59 ml/min) and moderate (CLCR, 20-30 ml/min) were up to 39 and 82% higher than the values in healthy subjects. After single oral doses of 10 mg olmesartan medoxomil daily to patients with mild (Child-Pugh score < or = 6) and moderate (score 7-9) hepatic impairment, Cmax was generally similar to that in healthy matched subjects, but AUC increased by 30 and 48%, respectively, and was reflected in small increases in absolute bioavailability values compared with healthy subject controls. Excretion of olmesartan in urine also increased with the degree of hepatic impairment, indicating a compensatory excretion mechanism in this disease state. Since the increased plasma concentrations (Cmax and AUC(0-24 h)) in elderly and very elderly patients, and in mild and moderate renal and hepatic impairment, were several-fold lower than plasma concentrations observed in other studies after 80 mg olmesartan medoxomil daily that were well tolerated, a dosing adjustment in these groups is not considered necessary. In patients with severe renal impairment, however, consideration should be given to a lower starting dose, and it is recommended that the daily dose should not exceed 20 mg daily (compared with 40 mg daily for the general patient population).

Elevated soluble tumour necrosis factor receptor serum concentrations and short-term mortality in liver cirrhosis without acute infections

BACKGROUND

Serum concentrations of the soluble 75-kDa tumour necrosis factor receptor (sTNF-R 75) are elevated in patients with severe liver disease and may be linked to mortality as well as to prognostic markers related to clinical outcome and metabolic functions in patients with liver cirrhosis.

PATIENTS AND METHODS

We prospectively studied the relation of sTNF-R 75 to Child-Pugh score points and serum markers of bile acid (total serum bile acids and 7alpha-hydroxycholesterol), lignocaine (lignocaine metabolite (MEGX) liver function test results) and albumin metabolism (albumin and prealbumin) in 10 healthy individuals and 30 patients with cirrhosis, all free of acute infections. In patients with cirrhosis mortality was recorded for 15 months.

RESULTS

Soluble TNF-R 75 concentrations correlated with Child-Pugh score points (r = 0.440, p = 0.015), MEGX test results (r(S) = -0.604, p < 0.001) and prealbumin (r(S) = -0. 527, p < 0.001) in cirrhosis. Nonsurviving patients had almost threefold higher median sTNF-R 75 concentrations (29 ng/ml) than survivors (11 ng/ml) (p = 0.003). Soluble TNF-R 75 serum concentrations with an optimal cut off > 14 ng/ml were significantly more accurate in predicting patient mortality than Child-Pugh score points in a receiver-operator characteristic curve analysis.

CONCLUSION

Soluble TNF-R 75 serum concentrations appear to be a promising new risk factor for mortality in patients with cirrhosis without acute infections.

Physiologic fluctuations of serum estradiol levels influence biochemical markers of bone resorption in young women

We investigated the effect of physiologic variations in sex hormone levels during the menstrual cycle on biomarkers of bone turnover. Blood and 24-h and fasting urine samples were obtained in nine women (age, 25.1+/-3.0 yr) with regular menstrual cycles during the early follicular period (t1), 3 days before ovulation (t2), 3 days after ovulation (t3), at the midluteal period (t4) and again during the early follicular period of the next cycle (t5). All subjects had a calcium intake covering current dietary recommendations (above 1,000 mg/day, standardized food record). Serum calcium, phosphorus, calcitriol, 24-h and 2-h fasting urinary calcium, and phosphorus excretion remained constant during the menstrual cycle. Serum 25-hydroxyvitamin D3 levels decreased slightly from the beginning until the end of the study (P<0.05), indicating low cutaneous vitamin D synthesis during wintertime. The serum levels of sex hormones showed typical monthly variations, with the lowest estradiol (E2) levels at t1 and t5. Fasting 2-h pyridinoline (Pyd) concentrations (a marker of bone resorption) fell from t1 to t3 and rose again at t5 (P<0.01). Similar variations were observed for the resorption marker deoxypyridinoline (Dpd; P<0.05). The amplitude of the two biomarkers was 32% and 33%, respectively. The serum levels of the carboxyterminal propeptide of type I collagen (a marker of bone formation) showed an inverse cyclic pattern, as compared with the pyridinium cross-links. Low concentrations were observed at t1; a rise occurred until t3 and was followed by a decrease until t5 (P<0.05). A similar cyclic pattern was observed for serum PTH levels, with the highest concentrations at t3 (P<0.05). Dpd and Pyd values were significantly correlated with serum E2 levels (r = 0.52; P<0.0001 and r = 0.50; P<0.001, respectively). Neither progesterone nor LH nor FSH was correlated with Pyd or Dpd levels. The data suggest that normal menstrual cycling in young women is associated with monthly fluctuations in bone turnover. This physiological effect of the menstrual cycle is most probably related to variations in serum E2 concentrations.

Interferon/antioxidant combination therapy for chronic hepatitis C--a controlled pilot trial

The effects of two forms of antioxidative co-therapy were analyzed in 24 interferon-alpha (IFN)-naive patients with chronic hepatitis C who were randomized to either receive IFN monotherapy (3 x 4.5 million units IFN-alpha 2a per week), (group A), or IFN and N-acetylcysteine (N-acetylcysteine (NAC) 1.800 mg/day) plus sodium selenite (400 microg/day) supplementation (group B), or treatment as in group B plus vitamin E (544 IU/day) (group C), over 24 weeks. Changes in histology, normalization of ALT, reduction of viral RNA, serum levels of glutathione, selenium, vitamin E, erythrocyte glutathione peroxidase, trolox equivalent antioxidative capacity (TEAC), thiobarbituric acid reactive substances (TBARS) and protein carbonyl groups were measured. Low baseline TEAC and elevated TBARS indicated increased oxidative stress before therapy, which was not affected by antioxidant supplementation. At the end of treatment complete responses were found in 3/8, 2/8 and 6/8 patients in groups A, B and C, respectively, but liver histology had not significantly improved. Vitamin E treated patients had a 2.4 greater chance (95% CI: 1.05-5.5) of obtaining a complete response and had significantly greater reduction in viral load (P = 0.028) than patients without vitamin E. Relapses, i.e. re-appearance of detectable hepatitis C virus (HCV) RNA and/or re-elevation of ALT-activity occurred in 7 out of the 11 responders within 6 months after termination of therapy (group A: 2/3, group B: 1/2 and group C: 4/6). Thus, no overall beneficial effect of antioxidant/IFN therapy was detected. However, the apparent trend towards a more favorable outcome with vitamin E supplementation warrants to further study this substance as an adjuvant to IFN therapy in chronic hepatitis C.

Increased high-density lipoprotein cholesterol in patients with epilepsy treated with carbamazepine: a gender-related study

PURPOSE

Long-term treatment with carbamazepine (CBZ) may alter serum lipoprotein concentrations. Gender-related examinations, however, are rare and inconsistent in their results.

METHODS

To examine possible sex differences, serum lipoproteins were analyzed in 127 clinic outpatients (56 women and 71 men) with epilepsies with focal or secondarily generalized tonic-clonic seizures (or both) treated with a CBZ monotherapy. Results were compared with a control group of 177 blood donors (67 women and 110 men) matched for age and weight.

RESULTS

Total cholesterol, low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol were higher in both male and female patients treated with CBZ compared with controls. The known sex difference in serum lipoprotein concentrations (i.e., higher LDL cholesterol and triglycerides but lower HDL cholesterol in men) was confirmed in controls and patients treated with CBZ, with the exception of LDL cholesterol. The HDL as well as the LDL differences were significantly more pronounced in women treated with CBZ than in men when compared with their controls. These results were independent of the dose of CBZ and plasma concentrations. Lathosterol, a cholesterol precursor, and its ratio to cholesterol, an indicator of cholesterol synthesis, were not different, when compared between gender and different HDL groups.

CONCLUSIONS

The observed increase in HDL cholesterol in patients with CBZ, especially in women, might correlate with the previously reported diminished rate of death from coronary heart disease in patients with epilepsy as HDL exerts an antiatherogenic effect.

Garlic preparations for prevention of atherosclerosis

On the basis of a number of new rigorously designed controlled studies, there is increasingly less evidence for lipid lowering properties of garlic preparations. Many other aspects of garlic drugs, such as direct effects on vessel walls (aortic elasticity, effects of antioxidant properties on early steps in atherosclerosis formation) or anti-platelet aggregation effects, are still awaiting further elucidation in clinical studies.

Effect of a garlic oil preparation on serum lipoproteins and cholesterol metabolism: a randomized controlled trial

CONTEXT

Garlic-containing drugs have been used in the treatment of hypercholesterolemia even though their efficacy is not generally established. Little is known about the mechanisms of action of the possible effects on cholesterol in humans.

OBJECTIVE

To estimate the hypocholesterolemic effect of garlic oil and to investigate the possible mechanism of action.

DESIGN

Double-blind, randomized, placebo-controlled trial.

SETTING

Outpatient lipid clinic.

PATIENTS

We investigated 25 patients (mean age, 58 years) with moderate hypercholesterolemia.

INTERVENTION

Steam-distilled garlic oil preparation (5 mg twice a day) vs placebo each for 12 weeks with wash-out periods of 4 weeks.

MAIN OUTCOME MEASURES

Serum lipoprotein concentrations, cholesterol absorption, and cholesterol synthesis.

RESULTS

Baseline lipoprotein profiles were (mean [SD]): total cholesterol, 7.53 (0.75) mmol/L (291 [29] mg/dL); low-density lipoprotein cholesterol (LDL-C), 5.35 (0.78) mmol/L (207 [30] mg/dL); high-density lipoprotein cholesterol (HDL-C), 1.50 (0.41) mmol/L (58 [16] mg/dL); and triglycerides, 1.45 (0.73) mmol/L (127 [64] mg/ dL). Lipoprotein levels were virtually unchanged at the end of both treatment periods (mean difference [95% confidence interval]): total cholesterol, 0.085 (-0.201 to 0.372) mmol/L (3.3 [-7.8 to 14.4] mg/dL), P=.54; LDL-C, 0.001 (-0.242 to 0.245) mmol/L (0.04 [-9.4 to 9.5] mg/dL), P=.99; HDL-C, 0.050 (-0.028 to 0.128) mmol/L (1.9 [-1.1 to 4.9] mg/dL), P=.20; triglycerides, 0.047 (-0.229 to 0.135) mmol/L (4.2 [-20.3 to 12.0]) mg/dL, P=.60. Cholesterol absorption (37.5% [10.5%] vs 38.3% [10.7%0], P=.58), cholesterol synthesis (12.7 [6.5] vs 13.4 [6.6] mg/kg of body weight per day, P=.64), mevalonic acid excretion (192 [66] vs 187 [66] microg/d, P=.78), and changes in the ratio of lathosterol to cholesterol in serum (4.4% [24.3%] vs 10.6% [21.1%], P=.62) were not different in garlic and placebo treatment.

CONCLUSIONS

The commercial garlic oil preparation investigated had no influence on serum lipoproteins, cholesterol absorption, or cholesterol synthesis. Garlic therapy for treatment of hypercholesterolemia cannot be recommended on the basis of this study.

In vitro cytopathogenicity of the human immunodeficiency virus (HIV)-1 predicts survival in HIV-infected hemophiliacs independent from CD4 cell count

In addition to quantification of viral load the graded cytopathogenicity of the human immunodeficiency virus may provide prognostic information for the course of HIV infection. However, the prognostic value of graded cytopathogenicity in addition to the CD4 count has not been evaluated in a large longitudinal study. Therefore a total of 216 HIV-seropositive hemophiliacs have been followed up from 1985 to 1998 (mean follow-up 70.4 +/- SD 26 months, median 72, range: 12 to 120 months). In vitro virulence was determined according to cytopathic effects on freshly isolated PBMC of healthy donors and graded from A (strongest cytopathogenic effect) to D (no cytopathic isolate effect). Survival was analyzed among patients with different virus isolates by Kaplan-Meier statistics (log rank) and factors independently associated with decreased survival were analyzed by Cox hazard regression analysis. - A virus isolate A was found in 22 (10.2%) patients, a virus isolate B was found in 21 (9.3%) patients, a virus isolate C was found in 9 (4.2%) and a virus isolate D was found in 10 (4.2%) patients. Mean survival times were 48 months (95% Confidence Interval (CI) = 36 - 60) in patients with isolate A, 72 months (CI = 36 - 108) with isolate B, 84 months (CI = 48-120) with isolate C, 72 months (60 - 96) with isolate D and 96 months (CI = 96 - 108) in patients with a negative virus culture (p < 0.001). Cox regression analysis indicated significant associations with outcome for young age (p <0.001), positive virus culture (p < 0.0001) and CD4 count (p < 0.0001) as independent predictors of survival. The presence of an isolate A revealed the strongest odds ratio (6.3, 95% CI 2.9-13.2). Our data indicate that the presence of a virus isolate A represents a strong risk factor for mortality in the course of HIV infection. Besides quantification of viral load and CD4 count, the graded cytopathogenicity may provide additional information for early and aggressive antiretroviral treatment, since the mean survival in patients with cytopathogenic virus isolates is reduced significantly.

Sodium selenite and N-acetylcysteine in antiretroviral-naive HIV-1-infected patients: a randomized, controlled pilot study

BACKGROUND

The aim of this work was to study the effects of combined oral administration of N-acetylcysteine (NAC) and sodium selenite (Se) on plasma glutathione (GSH), lymphocyte subpopulations and viral load in asymptomatic human immunodeficiency virus (HIV)-infected patients.

METHODS

We used a prospective, randomized and controlled therapy trial with partial crossover. Twenty-four antiretroviral-naive HIV-infected outpatients at Centers for Disease Control (CDC)'93 stages I and II were randomized to receive the antioxidant combination NAC 600 mg t.i.d. and Se 500 micrograms per day for either 24 weeks (group A, n = 13) or from the end of week 12 (group B, n = 11) until the end of week 24. Thus, group B served as untreated control during the first 12 weeks.

RESULTS

There was (a) a trend towards an increase in the percentage of CD4+ lymphocytes after 6 weeks (P = 0.08); (b) an increase in the CD4/CD8 ratio after 6 and 12 weeks (P = 0.02 and P = 0.04 respectively); and (c) a decrease in the absolute CD8/CD38 count and percentage of lymphocytes after 6 weeks (P = 0.002 and P = 0.033 respectively) and 12 weeks (P = 0.033, P = 0.1 respectively) in group A compared with the control period of group B. The effects observed in group A were, however, not paralleled to the same extent by group B after crossing-over to treatment after 12 weeks. In addition, erythrocyte glutathione peroxidase (GSH-Px) activity and GSH, glutathionedisulphide (GSSG) concentrations and the reduced/total GSH ratio were not affected by the treatment. Serum selenium levels increased significantly (P < 0.001) upon treatment. Viral load was not altered.

CONCLUSIONS

The changes in lymphocyte subsets after NAC/Se treatment were not comparable to those after standard antiretroviral drug therapy. This, however, does not preclude per se possible benefits of antioxidant supplementation in HIV disease.

How do clinicians practicing in the U.S. manage Helicobacter pylori-related gastrointestinal diseases? A comparison of primary care and specialist physicians

OBJECTIVES

We sought to examine the extent to which physicians recognize H. pylori as a causal agent in peptic ulcer disease or as a potential cofactor in other gastrointestinal diseases, and to observe how this knowledge has influenced diagnostic and therapeutic practices.

METHODS

We used a national mail survey in the U.S. between February and May of 1996, querying 5994 U.S. physicians (family/general practitioners [FPs], internists [IMs], and gastroenterologists) selected at random from three different membership databases of professional associations.

RESULTS

The response rate was 52%. More than 95% of physicians who treat symptoms empirically would prescribe acid suppressant therapy rather than anti-H. pylori therapy. Between 43% and 66% of physicians, varying in frequency by medical specialty, would treat the infection in H. pylori-positive patients with nonulcer dyspepsia. In confirmed peptic ulcer disease, between 88% and 100% of physicians would treat the H. pylori infection, depending on the physician group and whether or not the presentation of an ulcer was recurrent. Although 103 distinct anti-H. pylori regimens were reported, 89% of the gastroenterologists and 70% of the primary care physicians (PCPs) used combinations of antimicrobials with reported cure rates of at least 80%.

CONCLUSIONS

General knowledge regarding H. pylori-associated diseases was widespread among primary care physicians and gastroenterologists. However, anti-H. pylori therapies judged ineffective were reported as the first choice regimen by 5% of gastroenterologists and 18% of primary care physicians. Gastroenterologists appear to implement the latest scientific developments in the field rapidly whereas PCPs manifest a delayed response, due to either insufficient knowledge or to other factors influencing their approach to treatment.

How do practicing clinicians manage Helicobacter pylori-related gastrointestinal diseases in Germany? A survey of gastroenterologists and family practitioners

BACKGROUND

Since the bacterium H. pylori was identified in 1982, overwhelming evidence has implicated it as the causal factor in the occurrence and relapse of peptic ulcer disease. The major objective of this study was to examine the extent to which physicians recognize H. pylori as a causal agent in peptic ulcer disease or as potential cofactor in other gastrointestinal diseases, and the extent to which this knowledge has influenced diagnostic and therapeutic practices.

MATERIALS AND METHODS

Using a national mail survey in Germany in September 1995, 1197 family practitioners and 1197 gastroenterologists were selected for the study.

RESULTS

Of the surveyed physicians, 756 (32%) responded. Family practitioners treated almost 50% of their patients with initial presentation of suspected ulcer disease without ordering further diagnostic tests. More than 25% of the family practitioners and 14% of the gastroenterologists reported that they do not treat diagnosed H. pylori infection in the first presentation of duodenal ulcer. At the time we conducted the study, 22% of responding family practitioners and 5% of responding gastroenterologists treated the first presentation of H. pylori-positive ulcer disease with regimens determined to be ineffective according to the available literature.

CONCLUSIONS

Gastroenterologists preferred to treat H. pylori infection when the associated disease was one for which a causal relationship had been more clearly established, while family practitioners showed less discrimination. In order to provide optimal therapy aimed at minimizing the course and consequences of H. pylori-related diseases, researchers in the field must ensure continuous dissemination of current knowledge.

The low-dose monoethylglycinexylidide test: assessment of liver function with fewer side effects

The hepatic metabolism of lidocaine (1 mg/kg intravenously) to its metabolite monoethylglycinexylidide (MEG-X) is the basis of the standard MEG-X test. To reduce the lidocaine-induced side effects, we evaluated the MEG-X formation after 0.5 and 1 mg/kg lidocaine intravenously in subjects with normal (n = 5) and severely impaired liver function (n = 7) (study I). From this study, a low-dose test (MEG-X concentration 30 minutes after 50 mg lidocaine intravenously [MEG-X30min] normalized to standard MEG-X test results) was developed. Sensory side effects from this low dose and from the standard MEG-X test were compared in a double-blind, randomized, cross-over study (study II) comprising 15 individuals with normal liver function and 45 patients with cirrhosis (15 Child A, 15 Child B, and 15 Child C). In study I, MEG-X formation rate was dose-independent in patients with severely impaired liver function. In study II, normalized MEG-X test results (ranging from < or = 4 to 120 microg/L) were virtually identical to the standard test results (mean difference: -1.9 microg/L; 95% confidence interval [CI]: -5.3; 1.5 microg/L). Fewer individuals experienced side effects (30% vs. 53%) with the low-dose test (P = .0013). In a multivariate analysis, the Child-Pugh score was inversely related to the occurrence of side effects. The low-dose MEG-X test gives almost identical results to the standard MEG-X test and is associated with fewer side effects, which occur less often in individuals with more severely compromised liver function.

Serum selenium, plasma glutathione (GSH) and erythrocyte glutathione peroxidase (GSH-Px)-levels in asymptomatic versus symptomatic human immunodeficiency virus-1 (HIV-1)-infection

OBJECTIVES

Antioxidant defense status was investigated in HIV-infected patients by measuring serum selenium, erythrocyte glutathione peroxidase (GSH-Px) activity, plasma thiol (-SH) and glutathione (GSH) concentrations along with the assessment of the clinical stage and surrogate markers of HIV-disease.

DESIGN, SETTING AND SUBJECTS

Serum selenium levels were determined cross-sectionally in 104 sequentially selected HIV-infected patients (83 outpatients and 21 patients with ongoing AIDS defining events). The patients were classified into three stages of the disease, I, II and III according to the 1993 Centers For Disease Control (CDC) classification system for HIV-infection. GSH-Px activities, plasma SH and plasma GSH concentrations were determined in a subset of 24 patients at stage I and 12 patients at stage III with an active AIDS-defining disease.

RESULTS

Mean serum selenium levels were lower in CDC stage II (68.7 +/- 20.9 micrograms/l; P < 0.01; n = 34) and stage III (51.4 +/- 14.7 micrograms/l; P < 0.01; n = 37) HIV-infected patients than in healthy subjects (89.2 +/- 20.9 micrograms/l; n = 72) and stage I patients (82.3 +/- 20.5; microgram/l; n = 33). Serum selenium levels were positively correlated with CD4-count (r = 0.42; P < 0.001; n = 104) and inversely with levels of soluble tumor necrosis factor receptors type II (r = -0.58; P < 0.01; n = 35), neopterin (r = -0.5; P < 0.001; n = 80) and beta 2-microglobulin (r = -0.4; P < 0.001; n = 94). Hepatitis C virus (HCV) and HIV-coinfected patients at CDC stages I and II showed markedly lower selenium concentrations compared to HIV-infected patients without concomitant HCV-infection. Serum selenium and GSH-Px activity in hospitalized AIDS patients was significantly lower as compared to asymptomatic patients and healthy subjects, whereas plasma SH and GSH concentrations were lower in both, asymptomatic -and AIDS-patients, than in the controls.

CONCLUSION

The results show that stages I-III of HIV-disease are characterized by significant impairments of antioxidative defenses provided by selenium, GSH-Px, SH-groups and GSH.

Immunosuppression may lead to progression of hepatitis C virus-associated liver disease in hemophiliacs coinfected with HIV

OBJECTIVE

The aim of this study was to examine the interaction between HIV and hepatitis C virus (HCV) in hemophiliacs coinfected with the viruses and to investigate the possible relationship between immunosuppression and liver failure.

METHODS

To identify risk factors for impending liver failure in hemophiliacs coinfected with HIV and HCV, we analyzed clinical and laboratory parameters, including CD4 count, aminotransferases (ALT, AST), cholinesterase, alkaline phosphatase, bilirubin, and gamma-glutamyltransferase, during 3 yr of follow-up (1990-1993) in four groups of patients: hemophiliacs with progressive immunodeficiency who were coinfected with HCV and HIV (group A, n = 49); hemophiliacs with stable immune function who were seropositive for HIV and HCV (group B, n = 95); hemophiliacs who were infected with HCV but not HIV (group C, n = 72); and homosexuals with progressive immunodeficiency who were infected with HIV but not HCV (group D, n = 24).

RESULTS

Univariate analysis of data for group A showed a significant rise in gamma-glutamyltransferase and alkaline phosphatase (p < 0.01) that was not seen in groups B, C, and D. In a multivariate Cox regression analysis, age (odds ratio, 1.054 per yr; 95% confidence interval, 1.014-1.096 per yr), decline in CD4 count (odds ratio, 1.063 per cell/microl; 95% confidence interval, 1.037-1.091 per cell/microl), and alkaline phosphatase level (odds ratio, 1.012 per U/L; 95% confidence interval, 1.002-1.021 per U/L) emerged as independent determinants of death.

CONCLUSIONS

Our data suggest that progressive immune dysfunction in hemophiliacs coinfected with HIV and HCV may influence progression of liver failure. In these patients cholestasis is an additional prognostic marker for survival that may reflect both exhausted immunity and impaired liver function.

Differences in the response of serum lipoproteins to fenofibrate between women and men with primary hypercholesterolaemia

OBJECTIVE

We studied possible sex differences of the effect of fenofibrate on serum lipoproteins. Twenty-three patients with primary hypercholesterolaemia (10 postmenopausal women and 13 aged-matched men) were treated with slow-release fenofibrate for 96 weeks.

RESULTS

Steady state lipoprotein concentrations were reached after 12 and 24 weeks of treatment in women and men, respectively. During the subsequent follow-up the lipoprotein concentrations remained constant. In women total and low-density lipoprotein (LDL) cholesterol decreased from 299 to 234 mg.dl-1 and from 210 to 151 mg.dl-1, respectively, and in men from 265 to 233 mg.dl-1 and from 192 to 160 mg.dl-1. The decrease in triglycerides was also more pronounced in women (-42%) than in men (-18%). High-density lipoprotein (HDL) cholesterol increased significantly in women from 53 to 63 mg.dl-1 but not in men (45 to 50 mg.dl-1). Since the changes in LDL and HDL cholesterol occurred in opposite directions, the decrease in LDL/HDL cholesterol ratio was accentuated in both groups. However, this ratio was decreased almost twofold in women (-41%) compared to men (-23%). Although the serum concentrations of fenofibric acid were 1.3-fold higher in women than in men, which was probably due to the higher body weight in men (1.2-fold), this difference can hardly explain the favorable effect on lipoproteins in women.

CONCLUSION

The present study indicates that fenofibrate might be very effective by reducing the concentrations of atherogenic lipoproteins in postmenopausal women.

Prevalence of and risk factors for Helicobacter pylori infection in the western part of Germany

OBJECTIVE

To ascertain the prevalence of Helicobacter pylori infection in Germany and to identify risk factors associated with H. pylori seroconversion.

METHODS

Two hundred and sixty blood donors (169 men, 91 women; median age 29 years, range 18-61 years, 92% with German parents, all white) were studied. None had previously been treated for H. pylori infection. Their serum samples were analysed for H. pylori immunoglobulin (lg) G antibodies with a validated enzyme-linked immunosorbent assay (ELISA). All subjects completed a complex questionnaire under supervision. Special attention was paid to their present and childhood (at the age of 8 years) living conditions. To identify independent risk factors for seropositivity, a multivariate, stepwise forward, unconditional, logistic regression analysis was performed.

RESULTS

In total, 102 participants (39.2%) were seropositive for H. pylori. Seroprevalence increased significantly with age (21.1% aged 21 or younger compared with 60.0% over 51 years of age). According to the multivariate analysis of the unclassified data [odds ratio (95% confidence interval)], variables such as age [1.04 (1.01-1.07) per year], persons per room in household in childhood [2.14 (1.07-4.26)] and number of children (< 8 years) in household at present [1.79 (1.01-3.16) per child] were significantly and independently associated with H. pylori seroprevalence.

CONCLUSION

Crowded living conditions in childhood affect current H. pylori status. In addition, the number of children in the present household increases the risk of infection for the adult family members. This suggests that children are an additional source of infection, probably due to close and frequent physical contact outside the immediate family.

[Scintigraphy of the parathyroid glands with 99mTc-MIBI]

AIM

Since about 3 years 99mTc-MIBI is used instead of 201Tl/99mTc subtraction scintigraphy for the localization of parathyroid involvement in hyperparathyroidism (HPT). The sensitivity of the new method was evaluated.

PATIENTS AND METHODS

24 patients aged between 28 and 83 years with surgically confirmed primary HPT were studied. Planar images were acquired 15 minutes and 3 hours after tracer injection. Additionally, in 9 patients dynamic images were obtained for 2 hours to study tracer kinetics.

RESULTS

19 out of 24 adenomas (79%) were identified correctly with 99mTc-MIBI.

CONCLUSION

The sensitivity of the scintigraphy using 99mTc-MIBI is in the range of the 201Tl/99mTc subtraction scintigraphy. Because of the superior logistic and the lower radiation exposure, 99mTc-MIBI can replace the 201Tl/99mTc scintigraphy in the preoperative diagnostic assessment.

Short-term memory: no evidence of effect of rapid-repetitive transcranial magnetic stimulation in healthy individuals

The effect of rapid-repetitive transcranial magnetic stimulation (rr-TMS) on the immediate verbal and visuospatial memory span was assessed by computerized neuropsychological testing in 11 healthy volunteers. The objective was to test whether rr-TMS may be utilized as a non-invasive tool for evaluation of memory function. The subjects had to memorize series of numbers (Digit-Span test) or the position of cubes (Corsi-Block test) shown to them on a computer screen and actively reproduce them immediately after the presentation. Synchronous with the appearance of each item an rr-TMS train of 550 ms duration was delivered to the left or right anterolateral parietal as well as superior and posterior lateral temporal region at 50 Hz and with approximately 1.0 T stimulation intensity. Statistical comparison of memory performance during rr-TMS and baseline testings without stimulation revealed no significant changes. No adverse effects were observed. Thus, rr-TMS does not affect short-term memory performance in healthy individuals under the stimulation conditions described above.