[Diabetic dyslipoproteinemia]

Diabetic dyslipoproteinemia is considered to be an integral component of type 2 diabetes mellitus and the metabolic syndrome. Major pathogenetic factors include abdominal obesity, insulin resistance and hyperglycemia with increased hepatic secretion of triglyceride-rich lipoproteins. Elevated concentrations of triglycerides and cholesterol, together with decreased HDL cholesterol are therefore found. LDL cholesterol is either normal or only slightly increased, but at the same time, the composition of the LDL particles is altered. This metabolic disorder contributes considerably to the clearly elevated cardiovascular risk. Dyslipoproteinemia, usually in the form of hypertriglyceridemia, may also occur in type 1 diabetes mellitus. Since general measures and good blood sugar control often fail to achieve the desired lipid levels, many patients require medication, initially usually statins, but, where necessary, combination treatment. In patients with isolated hypertriglyceridemia, treatment with fibrates may also be considered.

Effect of Pioglitazone on Lipids in Well Controlled Patients with Diabetes Mellitus Type 2 - Results of a Pilot Study

INTRODUCTION

Patients with diabetes mellitus type 2 are characterized by a typical dyslipoproteinemia. Improvement in glucose control usually also ameliorates this dyslipoproteinemia. It is unclear whether different antidiabetic strategies differ in their effects on the lipid profile. Particularly, it is unknown whether glitazones improve lipid values independently of their effects on glucose metabolism.

METHODS

Ten patients well controlled on sulfonylureas (HbA1c 6.9 +/- 0.5 %) with diabetic dyslipoproteinemia were treated with additional pioglitazone (30 mg/d) for 3 months. Every 4 weeks the sulfonylurea dose was adjusted to keep HbA1c and fasting glucose constant. Before and after 3 months of pioglitazone therapy lipid metabolism was determined in detail (cholesterol, triglyceride, LDL-cholesterol, HDL-cholesterol, VLDL-cholesterol, VLDL-triglycerides, lipoprotein(a), LDL-subtype distribution by isopycnic density gradient ultracentrifugation).

RESULTS

Although glucose control remained unchanged (HbA1c 6.9 +/- 0.5 % vs. 6.8 +/- 0.6 %; fasting glucose concentration 7.7 +/- 1.1 vs. 7.3 +/- 1.3 mmol/l) we observed a significant reduction in triglyceride concentration (1.9 +/- 0.6 vs. 1.4 +/- 0.5 mmol/l, - 26 %, p < 0.01), a significant increase in HDL-cholesterol concentration (1.2 +/- 0.2 vs. 1.4 +/- 0.2 mmol/l, + 14 %, p < 0.05), a significant decrease in LDL/HDL-ratio (3.03 +/- 0.77 vs. 2.51 +/- 0.61, - 24 %, p < 0.05) and non-significant improvements in total cholesterol, LDL-cholesterol, VLDL-triglycerides, and VLDL-cholesterol concentrations. The LDL-subtype profile improved (significant reduction [- 20 %] in small dense LDL).

CONCLUSIONS

This pilot study indicates that at comparable fasting glucose concentration and at comparable HbA1c value pioglitazone is superior to sulfonylureas concerning the improvement of diabetic dyslipoproteinemia. Whether this relates to indirect effects (improvement in insulin sensitivity) or direct effects (stimulation of PPARalpha) remains to be determined.

Effects of ezetimibe on plasma lipoproteins in severely hypercholesterolemic patients treated with regular LDL-apheresis and statins

Ezetimibe, a cholesterol absorption inhibitor, can be combined with statins to lower LDL-cholesterol. We evaluated additional ezetimibe (10 mg/day) in a placebo-controlled, double blind, randomized cross-over study in 20 patients (age 56+/-9 years, m:f 10:10, BMI 27.5+/-4.0 kg/m(2)) suffering from severe hypercholesterolemia and CHD who were treated by statins and regular LDL-apheresis. Lipoproteins (cholesterol, triglycerides, LDL-cholesterol, HDL-cholesterol, VLDL-cholesterol, VLDL-triglycerides, lipoprotein(a)) were determined twice (before and during ezetimibe/placebo, each given for 5 weeks), dietary behaviour was analyzed once (3-days-protocol) during each treatment period. During ezetimibe the mean (+/-S.D.) preapheresis LDL-cholesterol concentration decreased from 159+/-26 mg/dl (4.11+/-0.67 mmol/l) to 133+/-28 mg/dl (3.44+/-0.72 mmol/l) (-16+/-11%, P<0.0001, Wilcoxon test) and the postapheresis LDL-cholesterol from 51+/-9 mg/dl (1.32+/-0.23 mmol/l) to 43+/-8 mg/dl (1.11+/-0.21 mmol/l) (-14+/-25%, P<0.05), while there was no significant change during placebo. Mean VLDL-cholesterol fell by 18+/-71% (P<0.05) during ezetimibe and was not significantly changed by placebo (+19+/-70%). Furthermore, during ezetimibe less plasma volume was treated (3725+/-1560 versus 3870+/-1549 ml, P<0.05). Ezetimibe had no effect on pre- and postapheresis triglyceride, HDL-cholesterol and lipoprotein(a) levels. The effect of ezetimibe was independent of the statin dose. Dietary behaviour did not change and no side effects were observed. Thus, in patients with severe LDL-hypercholesterolemia and CHD the addition of ezetimibe to intensive lipid lowering therapy (statins and LDL-apheresis) resulted in a further, clinically significant decrease of LDL-cholesterol.

In vivo metabolism of LDL subfractions in patients with heterozygous FH on statin therapy

LDL can be subfractionated into buoyant (1.020-1.029 g/ml(-1)), intermediate (1.030-1.040 g/ml(-1)), and dense (1.041-1.066 g/ml(-1)) LDLs. We studied the rebound of these LDL-subfractions after LDL apheresis in seven patients with heterozygous familial hypercholesterolemia (FH) regularly treated by apheresis (58 +/- 9 years, LDL-cholesterol = 342 +/- 87 mg/dl(-1), triglycerides = 109 +/- 39 mg/dl(-1)) and high-dose statins. Apolipoprotein B (apoB) concentrations were measured in LDL subfractions immediately after and on days 1, 2, 3, 5, and 7 after apheresis. Compartmental models were developed to test three hypotheses: 1) that dense LDLs are derived from the delipidation of buoyant and intermediate LDLs (model A); 2) that dense LDLs are generated directly from LDL-precursors (model B); or 3) that a model combining both pathways (model C) is necessary to describe the metabolism of dense LDLs. In all models, it was assumed that apoB production and fractional catabolic rate (FCR) did not change with apheresis. Apheresis decreased buoyant, intermediate, and dense LDL-apoB by 60 +/- 12%, 67 +/- 5%, and 69 +/- 11%, respectively. Models B and C, but not model A, described the rebound data. The model with the greatest biological plausibility (model C) was used to estimate metabolic parameters. FCR was 1.05 +/- 0.86 d(-1), 0.48 +/- 0.11 d(-1), and 0.69 +/- 0.24 d(-1) for buoyant, intermediate, and dense LDLs, respectively. Dense LDL production was 17.3 +/- 0.2 mg/kg(-1)/d(-1), 58% of which was derived directly from LDL precursors (VLDL, IDL, or direct secretion), while 42% was derived from buoyant and intermediate LDLs. Thus, our data indicate that in statin-treated patients with heterozygous FH dense LDLs originate from two sources. Whether this is also valid in other metabolic situations (with predominant small, dense LDLs) remains to be determined.

[A 32-year old male patient with pathological humeral fracture, splenomegaly and thrombocytopenia]

We describe the case of a 32-year old male patient who presented with a pathological fracture of his right humerus, splenomegaly and thrombocytopenia, the typical symptoms of Gaucher's disease, a lysosomal storage disease. Diagnosis was confirmed by bone marrow biopsy (detection of lipid engorged macrophages - Gaucher cells), by a markedly diminished activity of acid, beta-Glucosidase and by showing two different mutations (764T/A, 1187G/A) in the gene encoding acid beta-Glucosidase. The first mutation causes an amino-acid substitution (phenylalanine to tyrosine). The second mutation causes a premature termination at amino-acid position 396. Enzyme replacement therapy was started with 60 Units/kg body weight, because of severe bone symptoms. Following the decrease in spleen size and increase in platelet count the dose was gradually tapered to 20 U/kg. After two years of enzyme replacement therapy platelet count and spleen volume have normalized and the bone lesions have almost disappeared.

Influence of Etofibrate on LDL-Subtype Distribution in Patients with Diabetic Dyslipoproteinemia

Low density lipoprotein (LDL-) particles can be subfractionated in large-buoyant (lb), intermediate-dense (id) and small-dense (sd) LDL-subtypes. Fibrates improve the LDL-subtype profile by reducing proatherogenic sd-LDL which are prominent in diabetic dyslipoproteinemia. We evaluated the effect of etofibrate on the LDL-subtype distribution in patients with type 2 diabetes mellitus (n = 13, 55 +/- 18 years, BMI 27.9 +/- 5.5 kg/m2, HbA1c 10.1 +/- 3.9 %) and diabetic dyslipoproteinemia (triglycerides 343 +/- 253 mg/dl, HDL-cholesterol 36 +/- 7 mg/dl, LDL-cholesterol 110 +/- 37 mg/dl). Plasma lipids (enzymatic methods) and LDL-subtypes (7 LDL-subfractions, density gradient ultracentrifugation) were measured before and during etofibrate therapy (500 mg/d, 7 - 16 weeks). Etofibrate significantly (p < 0.05, Wilcoxon-test) reduced triglycerides (- 31 +/- 60 %) and increased HDL-cholesterol (+ 24 +/- 22 %), whereas total cholesterol and LDL-cholesterol did not change. Cholesterol concentration decreased in sd-LDL by 12 % (p < 0.05), while it increased in id- and lb-LDL (+ 26 %,+ 39 %, respectively). Thus, the LDL-subtype profile showed a relative increase of the fraction of lb- (+ 13 +/- 32 %, n.s.) and id-LDL (+ 23 +/- 33 %, p < 0.05) and a relative decrease of the fraction of sd-LDL (- 19 +/- 18 %, p < 0.05). We conclude that etofibrate not only decreases triglycerides and increases HDL-cholesterol but also improves the LDL-subtype profile and thus may reduce the cardiovascular risk in patients with an abundance of sd-LDL such as diabetic patients.

Effect of atorvastatin on lipid parameters, LDL subtype distribution, hemorrheological parameters and adhesion molecule concentrations in patients with hypertriglyceridemia

BACKGROUND AND AIM

Hypertriglyceridemia is a risk factor for atherosclerosis that is typically associated with high concentrations of adhesion molecules, impaired hemorrheology and an unfavourable low-density lipoprotein (LDL) subtype distribution. We hypothesised that some of these risk markers might be beneficially influenced by lipid-lowering therapy with atorvastatin in hypertriglyceridemic patients.

METHODS AND RESULTS

Nineteen patents with primary hypertriglyceridemia were given 10 mg of atorvastatin per day for four weeks. Their cholesterol, triglyceride, LDL and high-density lipoprotein cholesterol (HDL-C) levels, LDL subtype profile, hemorrheological parameters and E-selectin, vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 concentrations were measured before and at the end of atorvastatin therapy. The levels of total and LDL cholesterol respectively decreased by 25% and 24% (both p < 0.001). Furthermore, cholesterol was reduced by 8-29% in all seven LDL subfractions (density range: 1.020-1.066 g/mL) (p < 0.05). The reduction in triglyceride concentrations was of marginal significance (9%, p = 0.1), but its degree positively correlated with the reduction of small-dense LDL (r = 0.5, p < 0.025). Plasma viscosity and blood viscosity at low shear rates were respectively reduced by 2% and 16% (both p < 0.05). The effect of the treatment on the concentrations of HDL-C, fibrinogen and adhesion molecules was not significant.

CONCLUSIONS

Atorvastatin (10 mg/day) not only reduced the plasma concentrations of atherogenic lipoproteins but also improved the LDL-subtype profile and reduced plasma and blood viscosity in patients with hypertriglyceridemia; however, it failed to significantly lower triglyceride concentrations.

Influence of simvastatin on LDL-subtypes in patients with heterozygous familial hypercholesterolemia and in patients with diabetes mellitus and mixed hyperlipoproteinemia

This study evaluates the influence of simvastatin on lipid concentrations and on LDL-subtype distribution in patients with heterozygous familial hypercholesterolemia and in patients with type 2 diabetes and mixed hyperlipoproteinemia. Nine patients with familial hypercholesterolemia (LDL-cholesterol: 7.1 +/- 1.1 mmol/L, triglycerides: 1.3 +/- 0.4 mmol/L) and 8 patients with type 2 diabetes mellitus and mixed hyperlipoproteinemia (HbA1c 6.8 +/- 1.1%, LDL-cholesterol: 4.8 +/- 0.7 mmol/L, triglycerides: 2.5 +/- 1.1 mmol/L) were examined. Cholesterol concentration was determined in 7 LDL-subfractions isolated by density gradient ultracentrifugation before and during simvastatin treatment (10-20 mg/d, 4 weeks). Simvastatin decreased LDL-cholesterol (-34%/-30%, all p < 0.05) and triglycerides (-2%, n.s./-25%, p < 0.05), but had little effect on HDL-cholesterol (+7%/+2%, n.s.) in patients with familial hypercholesterolemia and diabetes mellitus, respectively. In both groups a significant reduction of cholesterol in each LDL-subfraction was observed. Large-buoyant (LDL-1, LDL-2) and intermediate-dense (LDL-3, LDL-4) LDL were reduced more than small-dense (LDL-5-LDL-7) LDL-subtypes (-36%/-38%/-23%, respectively) in patients with familial hypercholesterolemia, while in diabetic patients cholesterol reduction was uniform in all LDL-subtypes (-29%/-27%/-31%, respectively). Simvastatin decreases cholesterol concentration in all LDL-subfractions in patients with familial hypercholesterolemia and in patients with diabetes mellitus with mixed hyperlipoproteinemia. However, the relative reduction of individual LDL-subtypes differed between both groups. This suggests that the effect of simvastatin on LDL-subtype distribution depends on the type of underlying hyperlipoproteinemia.

[Effect of glucose control on lipid levels in patients with type 2 diabetes]

BACKGROUND AND OBJECTIVE

The dyslipoproteinemia characterizing patients with type 2 diabetes is a major risk factor for atherosclerosis. Prospective studies indicate that an improved glucose control is associated with lower lipid levels. In this study we evaluated whether an improvement of the lipid status can also be observed in a routine clinical setting. Furthermore, we evaluated how many patients achieve lipid target levels by improving glucose control.

METHODS

In 51 type 2 diabetics (60 +/- 12 ys., 29 men, 22 women) lipid values were determined before and after improvement of glucose metabolism (6 - 12 weeks, HbA1c 7.9 +/- 1.9 % vs. 7.1 +/- 1.3 %). Patients on lipid-lowering medication or with atherosclerosis were excluded. The improved glucose control was achieved by starting/intensifying treatment with diet (n = 5), acarbose (n = 5), metformin (n = 10), sulfonylurea/glinide (n = 12) or insulin (n = 19).

RESULTS

The decrease in HbA1c was associated with a decrease in total cholesterol (232 +/- 64 vs. 216 +/- 35 mg/dl, p < 0.05) and triglycerides (348 +/- 448 vs. 216 +/- 139 mg/dl, p < 0.01), while HDL- and LDL-cholesterol did not change significantly. Only in patients with triglycerides > 200 mg/dl did changes in HbA1c-levels correlate with changes in triglyceride-levels (r(2) = 0.32, p = 0.012). Lipid target levels were reached in seven of 51 patients (five of 51 patients before improvement of HbA1c).

CONCLUSION

Although in routine clinical practice an improvement in HbA1c results in better lipid values. This improvement is small and is usually not sufficient to reach lipid target levels.

Global cardiovascular risk in children and their families: the Prevention Education Program (PEP), Nürnberg

BACKGROUND AND AIM

The Prevention Education Program (PEP) is a 14-year prospective study designed to identify and evaluate cardiovascular risk factors in school-children and their families. The second aim of the PEP is to test the hypothesis that the individual risk can be changed by family lifestyle modifications.

METHODS AND RESULTS

We here report on the evaluation of the global cardiovascular risk constellation in 3283 adults and 3220 children and adolescents (aged up to 16 years): 36% of the children were passive smokers and 35% of the adults were smokers. The prevalence of low-density lipoprotein-hypercholesterolemia was nearly identical in the children (> or = 130 mg/dL) and adults (> or = 155 mg/dL), being respectively 17% and 18%. Low high-density lipoprotein-cholesterol concentrations (< or = 35 mg/dL) were recorded in 4% of the adults and 2% of the children. The prevalence of hypertriglyceridemia was 6% in adults (> or = 200 mg/dL) and 5% in children (> or = 130 mg/dL). Nine percent of the adults were obese (body mass index > 30 kg/m2) and 6% of the children (> 20% ref. weight). High blood pressure was found in 16% of the adults and 17% of the children.

CONCLUSIONS

Because of the high prevalence of risk factors in childhood, primary prevention of cardiovascular diseases should start as soon as children start school.

Effect of atorvastatin on low-density lipoprotein subtypes in patients with different forms of hyperlipoproteinemia and control subjects

Atorvastatin is a potent hydroxy-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitor that decreases low-density lipoprotein (LDL) cholesterol and triglyceride concentrations, but little is known about its effects on LDL subtype distribution in different types of hyperlipoproteinemia. Thus, we evaluated the influence of atorvastatin (10 mg/d, 4 weeks) on lipid concentrations and LDL subtype distribution in patients with hypercholesterolemia (n = 9; LDL cholesterol, 227 +/- 30 mg/dL; triglycerides, 137 +/- 56 mg/dL), patients with type 2 diabetes and dyslipoproteinemia (n = 11; LDL cholesterol, 163 +/- 34 mg/dL; triglycerides, 260 +/- 147 mg/dL), and controls (n = 10; LDL cholesterol, 116 +/- 20 mg/dL; triglycerides, 130 +/- 47 mg/dL). Cholesterol concentration was determined in 7 LDL subfractions isolated by density gradient ultracentrifugation before and during atorvastatin treatment. Atorvastatin decreased LDL cholesterol (-36%, -28%, and -41%, all P <.01) and triglyceride (-4%, NS; -2%, NS; -24%, P <.05) concentrations but had little effect on high-density lipoprotein (HDL) cholesterol (-1%, NS; +10%, P <.05; +6%, NS) in hypercholesterolemic, diabetic, and control subjects, respectively. In all 3 groups, a significant reduction in cholesterol in each LDL subfraction was observed. Large-buoyant (LDL-1, LDL-2) and intermediate-dense (LDL-3, LDL-4) LDL were reduced more than small-dense (LDL-5 through LDL-7) LDL in hypercholesterolemic (-45%, -35%, and -32%, P <.05) and control subjects (-48%, -44%, and -25%, P <.05), but in diabetic patients cholesterol reduction was uniform in all LDL subtypes (-32%, -27%, and -29%, P =.45). Thus, atorvastatin decreases cholesterol concentration in all LDL subfractions in hypercholesterolemic, diabetic, and control subjects. However, the relative reduction of individual LDL subtypes differed between these groups. This finding suggests that the effect of atorvastatin on LDL subtype distribution depends on the type of underlying hyperlipoproteinemia.

Parameters of childhood obesity and their relationship to cardiovascular risk factors in healthy prepubescent children

OBJECTIVE

To investigate which of the currently applied parameters to assess childhood overweight best predict cardiovascular risk factors.

DESIGN

Cross-sectional study comparing five different methods to define overweight with respect to their power to predict cardiovascular risk factors.

SUBJECTS

A total of 838 healthy children from the Prevention-Education-Program (Nuremberg, Germany; age 4-9 y, 405 boys, 433 girls).

MEASUREMENTS

Obesity parameters-body mass index (BMI), ponderal index (PI), the sum of triceps and subscapular skinfold thickness (SFT), percentage body fat (%BF) using SFT and two different regression formulas (Slaughter, %BF-SL; Dezenberg, %BF-DZ). Overweight defined by the 90th age- and sex-specific percentile of each obesity parameter. Comparison of LDL- and HDL-cholesterol, apolipoprotein-B (apo-B), triglycerides (TG), fibrinogen and blood pressure values (SBP/DBP) between normal-weight and overweight children.

RESULTS

When overweight is defined by BMI or PI, all cardiovascular risk factors are significantly (P<0.01) different between overweight and normal-weight children (BMI: TG+20.5%, HDL-chol.-8.6%, LDL-chol.+9.6%, apo-B+6.8%, SBP+7.4%, DBP+8.6%, fibrinogen+13.2%; PI: TG+24.3%, HDL-chol.-6.1%, LDL-chol.+9.0%, apo-B+7.4%, SBP+5.9%, DBP+6.7%, fibrinogen+13.9%), while SFT, %BF-SL and %BF-DZ did not predict all cardiovascular risk factors. A sex-specific analysis showed that in girls BMI and PI both predict cardiovascular risk factors, while in boys this is only valid for BMI.

CONCLUSION

In prepubescent children, height-to-weight indices such as BMI or PI better predict cardiovascular risk factors than obesity parameters using skinfold measurement. The BMI may be superior to the PI as the association between BMI and cardiovascular risk factors is less affected by gender.

The Prevention Education Program (PEP) Nuremberg: design and baseline data of a family oriented intervention study

OBJECTIVE

We describe the design and baseline data of the Prevention Education Program (PEP), a home-based and family oriented intervention program, aimed to assess and improve cardiovascular risk factors in school children and their families during an intervention period of 10 y.

DESIGN AND METHODS

At study entry all participants were randomized either to an intervention group (screening and intervention program) or to a control group (risk screening, general advice). Cardiovascular risk factors (hypertension, elevated lipids, smoking, obesity) as well as dietary behaviour are evaluated yearly using structured interview, physical examination, laboratory analysis, and seven-day dietary protocol.

RESULTS

During the years 1993-1998, 3547 adults (age 36.2+/-7 y) and 3495 children (age 6.5+/-2 y) were recruited. Adults show a high prevalence of risk factors: hypertension 21%; active smoking 39%, elevated LDL-cholesterol 19%; and obesity 42%. Children exhibit these risk factors in comparable frequency: hypertension 20%; passive smoking 44%; elevated LDL-cholesterol 17%; and obesity 19%. The analysis of the dietary protocols (1926 adults, 1569 children) shows that both generations adhere to a diet exceeding the recommended fat intake (adults 38% of total energy, children 38%), while carbohydrate intake (adults 43% of total energy intake, children 50%) is reduced compared to NCEP-(step I)-guidelines.

CONCLUSION

The finding, that children show a prevalence of risk factors which is comparable to that found in adults, supports the need for an early beginning of intervention. Since both generations adhere to an unhealthy diet which contributes to cardiovascular risk, dietary intervention may be a promising method in primary prevention of cardiovascular risk.

Effects of atorvastatin versus fenofibrate on lipoprotein profiles, low-density lipoprotein subfraction distribution, and hemorheologic parameters in type 2 diabetes mellitus with mixed hyperlipoproteinemia

Diabetic dyslipoproteinemia characterized by hypertriglyceridemia, low high-density lipoprotein (HDL) cholesterol, and often elevated low-density lipoprotein (LDL) cholesterol with predominance of small, dense LDL is a strong risk factor for atherosclerosis. It is unclear whether fibrate or statin therapy is more effective in these patients. We compared atorvastatin (10 mg/day) with fenofibrate (200 mg/day), each for 6 weeks separated by a 6-week washout period in 13 patients (5 men and 8 women; mean age 60.0+/-6.8 years; body mass index 30.0+/-3.0 kg/m2) with type 2 diabetes mellitus (hemoglobin A1c 7.3+/-1.1%) and mixed hyperlipoproteinemia (LDL cholesterol 164.0+/-37.8 mg/dl, triglycerides 259.7+/-107 mg/dl, HDL cholesterol 48.7+/-11.0 mg/dl) using a randomized, crossover design. Lipid profiles, LDL subfraction distribution, fasting plasma viscosity, red cell aggregation, and fibrinogen concentrations were determined before and after each drug. Atorvastatin decreased all LDL subfractions (LDL cholesterol, -29%; p <0.01) including small, dense LDL. Fenofibrate predominantly decreased triglyceride concentrations (triglycerides, -39%; p <0.005) and induced a shift in LDL subtype distribution from small, dense LDL (-31%) to intermediate-dense LDL (+36%). The concentration of small, dense LDL was comparable during therapy to both drugs (atorvastatin 62.8+/-19.5 mg/dl, fenofibrate 63.0+/-18.1 mg/dl). Both drugs induced an increase in HDL cholesterol (atorvastatin +10%, p <0.05; fenofibrate +11%, p = 0.06). In addition, fenofibrate decreased fibrinogen concentration (-15%, p <0.01) associated with a decrease in plasma viscosity by 3% (p <0.01) and improved red cell aggregation by 15% (p <0.05), whereas atorvastatin did not affect any hemorheologic parameter. We conclude that atorvastatin and fenofibrate can improve lipoprotein metabolism in type 2 diabetes. However, the medications affect different aspects of lipoprotein metabolism.

Efficacy of different low-density lipoprotein apheresis methods

Low-density lipoprotein (LDL) apheresis is a treatment option in patients with coronary heart disease and drug resistant hypercholesterolemia. Various apheresis systems based on different elimination concepts are currently in use. We compared the efficacy of 4 different apheresis systems concerning the elimination of lipoproteins. The study included 7 patients treated by heparin extracorporeal LDL precipitation (HELP), 10 patients treated by immunoadsorption, 8 patients treated by dextran-sulfate adsorption, and 4 patients treated by cascade filtration. Ten subsequent aphereses were evaluated in patients undergoing regular apheresis for more than 6 months. Total cholesterol decreased by approximately 50% with all 4 systems. LDL cholesterol (LDL-C) (64-67%) and lipoprotein a [Lp(a)] (61-64%) were decreased more effectively by HELP, immunoadsorption, and dextran-sulfate apheresis than by the less specific cascade filtration system [LDL-C reduction 56%, Lp(a) reduction 53%]. Triglyceride concentrations were reduced by 40% (dextran-sulfate) to 49% (cascade filtration) and high-density lipoproteins (HDL) by 9% (dextran-sulfate) to 25% (cascade filtration). On the basis of plasma volume treated, HELP was the most efficient system (LDL-C reduction 25.0%/L plasma), followed by dextran-sulfate (21.0%/L plasma), cascade (19.4%/L plasma), and immunoadsorption (17.0%/L plasma). However, a maximal amount of 3 L plasma can be processed with HELP due to concomitant fibrinogen reduction while there is no such limitation with immunoadsorption. Therefore, the decision of which system should be used in a given patient must be individualized taking the pre-apheresis LDL concentration, concomitant pharmacotherapy, and fibrinogen concentration into account.

Influence of atorvastatin versus simvastatin on fibrinogen and other hemorheological parameters in patients with severe hypercholesterolemia treated with regular low-density lipoprotein immunoadsorption apheresis

Low-density lipoprotein (LDL) apheresis is a treatment option in patients with coronary artery disease and elevated LDL cholesterol concentrations if maximal drug therapy fails to achieve adequate LDL cholesterol reduction. This therapy is more effective when combined with strong lipid-lowering drugs, such as atorvastatin. However, conflicting data have been published concerning the effect of atorvastatin on fibrinogen concentration. Therefore, we investigated the effect of atorvastatin compared to simvastatin on fibrinogen concentration and other hemorheological parameters in patients treated by weekly LDL apheresis. Hemorheological parameters were, studied twice in 9 patients (4 female, 5 male, 54.0+/-8.9 years) with coronary artery disease treated by weekly LDL immunoadsorption, once during concomitant simvastatin therapy (40 mg daily) and once during atorvastatin therapy (40 mg daily). Fibrinogen concentration, plasma and blood viscosity at different shear rates, parameters of red cell aggregation at stasis and shear rate 3/s, and erythrocyte filterability were determined 7 days after the last LDL apheresis after each drug had been given for a minimum for 8 weeks. Fibrinogen concentration did not show any statistically significant difference during therapy with atorvastatin (3.09+/-0.36 g/L) compared to simvastatin (3.13+/-0.77 g/L). Plasma and blood viscosity as well as erythrocyte filterability were also unchanged. The increase in red cell aggregation at stasis during atorvastatin treatment (5.82+/-1.00 U versus 4.89+/-0.48 U during simvastatin; p < 0.05) was inversely correlated with a lower high-density liprotein (HDL) cholesterol concentration (1.17+/-0.21 mmol/L versus 1.31+/-0.30 mmol/L during simvastatin; p < 0.05). LDL cholesterol showed a strong trend to lower concentrations during atorvastatin (4.14+/-0.61 mmol/L versus 4.56+/-0.66 mmol/L during simvastatin; p = 0.07), despite a reduced plasma volume treated (3,547+/-1,239 ml during atorvastatin versus 3,888+/-1,206 mL during simvastatin; p < 0.05). In conclusion, fibrinogen concentration and other hemorheological parameters were unchanged during atorvastatin compared to simvastatin therapy with the exception of a higher red cell aggregation at stasis. Therefore, with respect to hemorheology, we conclude that atorvastatin should not be withheld from hypercholesterolemic patients regularly treated with LDL immunoadsorption.

Influence of LDL apheresis on LDL subtypes in patients with coronary heart disease and severe hyperlipoproteinemia

Epidemiologic studies and in vitro experiments indicate that low density lipoprotein (LDL) subtypes differ concerning their atherogenic potential. Small, dense LDL are more atherogenic than large, buoyant LDL. LDL apheresis is a potent therapeutic modality to lower elevated LDL-cholesterol. It is unknown whether such therapy induces a shift in the LDL subtype distribution. In this study we evaluated the influence of LDL apheresis on the LDL subtype distribution in patients with CHD and familial hypercholesterolemia (FH, n = 22), combined hyperlipidemia (CHLP, n = 6), or Lp[a]-hyperlipoproteinemia (Lp[a]-HLP, n = 4) regularly treated by LDL apheresis (immunoadsorption (n = 14), HELP apheresis (n = 8), dextran sulfate adsorption (n = 7), cascade filtration (n = 3)). On the basis of 6 LDL subfractions (d 1.020;-1.057 g/mL) isolated by density gradient ultracentrifugation the LDL-density profile was determined in each patient before and after apheresis. There was a relative increase of LDL-subfractions 1, 2, and 3 (P < 0.01, P < 0. 05, and P < 0.01, respectively) and a concomitant decrease of LDL subfractions 5 and 6 (P < 0.05) after apheresis. Subgroup analysis indicates that the degree of the small, dense LDL reduction was much more prominent in patients with CHLP compared to patients with FH or Lp[a]-HLP, whereas the type of apheresis technique had no effect. The extent of small, dense LDL reduction correlated with the preapheresis concentrations of small, dense LDL and triglycerides but not with the extent of triglyceride reduction.We conclude that LDL apheresis not only decreases LDL mass, but also improves LDL-density profile, particularly in patients with CHLP.

The prevention education program (PEP). A prospective study of the efficacy of family-oriented life style modification in the reduction of cardiovascular risk and disease: design and baseline data

We describe design and baseline data of the Prevention Education Program (PEP), a home-based and family-oriented intervention program, aimed to assess and improve cardiovascular risk factors in school children and their families during an intervention period of 10 years. Started in 1994 in the German town of Nuremberg, currently 37 elementary schools (22 control and 15 intervention schools) are enrolled including 1740 families (1740 first graders, 3046 parents, and 1521 siblings). Major cardiovascular risk factors as well as dietary behavior are evaluated yearly using structured interview, physical examination, laboratory analysis, and seven-day-dietary protocols. The intervention package is applied to all families from intervention schools using regular home visits, health curricula and group sessions. Primary outcome is any reduction in cardiovascular risk factors by dietary intervention and health education compared to the control group getting only written information on the individual risk profile. The presented baseline data showing a high prevalence of cardiovascular risk factors in adults and in their children underline the need for such an intervention program in Germany.

Low density lipoprotein apheresis by membrane differential filtration (cascade filtration)

Membrane differential filtration (MDF) is an apheresis technique with which atherogenic lipoproteins can be eliminated from plasma on the basis of particle size. In 52 patients (REMUKAST Study, 1,702 treatments), low density lipoprotein (LDL) cholesterol was decreased by 61%, high density lipoprotein (HDL) cholesterol by 42%, and fibrinogen by 54%. Our own results in 3 patients show decreases of 62%, 31%, and 59%, respectively; lipoprotein (a) (Lp[a]) was reduced by 58%. The elimination of atherogenic lipoproteins was accompanied by a loss of macromolecules (IgM: 55%, IgG: 27%, alpha 2-macroglobulin: 49%) resulting in improved hemorrheologic parameters. Although HDL is eliminated with each apheresis session, pretreatment concentrations of HDL cholesterol increased by 24% during regular apheresis for 1 year (26 patients, REMUKAST Study). However, preapheresis concentrations of other macroglobulins such as immunoglobulins remained decreased compared to concentrations obtained before the first apheresis session (IgM: 34%, IgG: 23%, and IgA: 16%). We conclude that MDF apheresis is an effective method to lower elevated concentrations of atherogenic lipoproteins. The concomitant loss of other macromolecules transiently improves hemorrheology but demands a close monitoring of immunoglobulin concentrations as a safety parameter.

Lipoprotein (a) metabolism estimated by nonsteady-state kinetics

Lipoprotein (a) [Lp(a)] is a low-density lipoprotein (LDL) particle with an additional apolipoprotein named apo(a). The concentration of Lp(a) in plasma is determined to a large extent by the size of the apo(a) isoform. Because elevated Lp(a) concentrations in plasma are associated with risk for premature coronary heart disease it is important to determine whether variations in production or catabolism mediate differences in Lp(a) concentration. We determined metabolic parameters of Lp(a) in 17 patients with heterozygous familial hypercholesterolemia or severe mixed hyperlipidemia by fitting a monoexponential function to the rebound of Lp(a) plasma concentration following LDL-apheresis. In 8 of those 17 patients this was done twice following two different aphereses. Although this approach allows one to estimate metabolic parameters without the use of a tracer, it requires several major assumptions such as that apheresis itself does not change production or catabolism of Lp(a) and that Lp(a) metabolism can be described by a single compartment. One apheresis decreased Lp(a) concentration by 59.1+/-8.3%. The fractional catabolic rate (FCR) was 0.16+/-0.12 d(-1) and production rate 6.27+/-5.26 mg x kg(-1) x d(-1). However, observed (concentration before first apheresis) and predicted steady-state concentrations differed considerably (more than 20%) in 9 of 17 patients, indicating that not all assumptions were fulfilled in all patients. Production rate but not FCR was correlated with Lp(a) plasma concentration (r2 = 0.43, P = 0.004) and molecular weight of apo(a) (r2 = 0.48, P = 0.011), which confirms radiotracer experiments showing that variations in Lp(a) plasma concentrations are due to differences in production not catabolism. When parameters were estimated twice in a subgroup of eight patients, satisfactory reproducibility was observed in six patients. Although parameters determined on two occasions correlated well, only FCR was concordant (intraclass correlation coefficient). Thus, despite the limitations arising from the assumptions implicit to this method, metabolic parameters of Lp(a) can be estimated from the rebound of plasma concentration following apheresis.

Atorvastatin compared with simvastatin in patients with severe LDL hypercholesterolaemia treated by regular LDL apheresis

OBJECTIVES

Atorvastatin is a new potent HMG-CoA reductase inhibitor. We evaluated whether patients with coronary heart disease and severe hypercholesterolaemia showing insufficient LDL (low-density lipoprotein) cholesterol reduction despite combined therapy with simvastatin and regular LDL apheresis will benefit from atorvastatin therapy.

SETTING

Tertiary care centre, university hospital.

METHODS

In 21 patients treated by LDL apheresis, concomitant simvastatin therapy (40 mg day-1) was replaced by atorvastatin (40 mg day-1) and increased to 60 and 80 mg day-1 (each for 3 months) if no side-effects were reported and NCEP treatment goals were not reached.

RESULTS

In 20 of 21 patients (95%), atorvastatin resulted in significant reduction of LDL cholesterol compared with simvastatin (by 10%, additional 8% and additional 1%, with 40, 60 and 80 mg day-1, respectively). In four patients, NCEP treatment goals were reached (in three by atorvastatin alone, and in one by atorvastatin and apheresis). Patients with little reduction in LDL cholesterol to 40 mg day-1 atorvastatin benefited most by increasing the dose to 60 mg day-1 (additional 13% reduction), whilst those responding to atorvastatin 40 mg day-1 benefited less (additional 1.9% reduction). During atorvastatin therapy, significantly less plasma had to be treated during apheresis resulting in shorter apheresis time. Eight patients (38%) reported side-effects, resulting in discontinuation of atorvastatin in three (14%) and dose reduction in five patients (24%), whilst no elevation of biochemical markers was observed.

CONCLUSION

Concomitant atorvastatin therapy is superior to simvastatin therapy in patients with severe hypercholesterolaemia treated with regular LDL apheresis, but is associated with a high rate of subjective side-effects.

Comparison of sequences for depicting bone marrow alterations in osteomyelitis applied in a low field strength magnetic resonance imaging system

OBJECTIVE/PATIENTS

To investigate the efficacy of standard sequences of a low field system for the detection of osteomyelitis, we tested T1wI pre and post i.v. contrast, T2w and fat suppressed IR sequences.

DESIGN

On the basis of clinical and laboratory evidence, pathology reports, and three phase granulocyte scintigraphy, osteomyelitis was diagnosed in 18 of 21 patients with Charcot's joints. A consecutive low and high field magnetic resonance (MR) scan confirmed osteomyelitic bone marrow changes in the same osseous regions. These 18 diabetic patients were then studied on a 0.2 Tesla dedicated MR system (Esaote ArtoScan) using T1wI (SE: relaxation time (TR) 520/echo time (TE) 24: axial and coronal) before and after i.v. application of 0.1 mmol/l Gd-DTPA/kg BW, T2w imaging (TSE: TR 3500/TE 80 or TR 2000/TE 120: axial), and fat suppressed inversion recovery (IR) imaging (short tau inversion recovery (STIR): TR 3000/TE 30/TI 80 or inversion recovery gradient echo (IRGE)/fat suppressed IRGE (GEFS): TR 1000/TE 16m 80: coronal).

RESULTS

The SE T1w sequence showed a significantly higher contrast-to-noise ratio (CNR) before administration of i.v. contrast. The TSE T2w pulse sequence demonstrated bone marrow changes superiorily utilizing a TE of 120 ms (CNR = 16.5+/-2.7 compared to 5.5+/-2.5 with TE = 80 ms). The IRGE showed a higher CNR than the standard STIR (CNR = 19.2+/-2.5 compared to 12.4+/-2.9).

CONCLUSION

Fat suppressed IRGE imaging and longer TE in T2w TSE sequences result in a significantly better CNR in osteomyelitis. This way, using optimized sequences, low field systems are apt to depict bone marrow changes in the course of osteomyelitis.

Course of islet autoantibody titers during Ig-immunoadsorption in a patient with newly diagnosed type 1 diabetes

The purpose of this study was to determine whether and to what extent diabetes-specific autoantibodies can be removed from the plasma by Ig-immunoadsorption therapy. We followed the course of islet cell antibodies (ICA), insulin antibodies (I[A]A), glutamic acid decarboxylase antibodies (GADA) and antibodies to the protein tyrosine phosphatase IA-2 (IA2A) in a patient with newly diagnosed insulin-dependent diabetes mellitus (IDDM) under multiple immunoadsorption treatments over 6 months. Autoantibodies were not removed from the plasma as efficiently as expected when compared to the removal of total immunoglobulin (IgG). Whereas IgG levels were lowered by 70-90% through each immunoadsorption treatment, antibodies to insulin were reduced by an average of 83%, IA2A by 36% and GADA by only 9% directly after treatment. ICA were > 320 JDF U at diabetes onset and remained above this level. During the 6 months of multiple immunoadsorption therapies, I[A]A levels showed a 24-fold increase due to stimulation of insulin antibody production by exogenous insulin substitution, IA2A levels remained unchanged (average 6% increase), and GADA levels were reduced by an average of 39% compared to antibody titers at onset. All four antibodies were highly positive in the eluate from the immunoadsorption columns. We showed that antibodies to pancreatic islet cells can be reduced by immunoadsorption, but as for plasmapheresis the effect is incomplete and transient for most of the antibodies. If there is clinical benefit through immunoadsorption therapy--as has been shown for newly diagnosed IDDM patients treated with plasmapheresis--our data suggest that this may be due to factors other than the sufficient removal of antibodies.

Apolipoprotein E polymorphism has no independent effect on plasma levels of lipoprotein(a)

Previous studies show conflicting results concerning an influence of apolipoprotein E (apo E) phenotype on lipoprotein(a) (Lp(a)) plasma levels. We speculated that it is not the apo E phenotype itself but rather its effect on plasma lipid concentrations that might influence Lp(a) levels. In 1562 subjects concentrations of triglycerides, LDL-cholesterol and Lp(a) were measured by standard laboratory methods. Apo(a) and apo E isoforms were determined by sodium dodecyl sulfate gel electrophoresis and isoelectric focusing, respectively, followed by immunoblotting. An univariate analysis revealed a significant influence of apo(a) isoforms, apo E phenotype, triglycerides and LDL-cholesterol on Lp(a) plasma levels (ANOVA: P < 0.001, P < 0.02, P < 0.001 and P < 0.001, respectively). In a multivariate analysis, however, the influence of the apo E phenotype was no longer significant (P>0.10), whereas apo(a) isoforms, LDL-cholesterol quintiles and triglyceride quintiles explained 29.2, 2.8 and 1.0% of the variation of the Lp(a) levels (for all three variables: P < 0.001). We conclude that apo E polymorphism does not exert an independent effect on Lp(a) concentrations. Any influence is mediated through the effect of apo E polymorphism on plasma lipids.

Low lipoprotein (a) levels during acute viral hepatitis

High serum concentrations of lipoprotein (a) [Lp(a)] are considered a risk factor for premature atherosclerosis. Besides apolipoprotein B-100, Lp(a) consists of apolipoprotein (a) [apo(a)], which shows a remarkable size polymorphism. The serum concentration of Lp(a) is considerably influenced by this apo(a) phenotype. Because Lp(a) is synthesized in the liver, we wondered whether and to what extent Lp(a) levels might be affected by acute liver disease. We compared Lp(a) serum concentrations in 74 patients (54% male, 46% female; mean age, 46 years) with acute viral hepatitis (32, 28, and 14 with hepatitis A, B, and C, respectively) with those in 404 healthy controls (57% men, 43% women; mean age, 47 years). In addition, the intraindividual course of Lp(a) concentration during and after acute hepatitis was followed in a subgroup of 23 patients (15, 6, and 2 with hepatitis A, B, and C, respectively). During acute hepatitis, median Lp(a) concentrations in the patient group were significantly diminished compared with controls (7 vs. 17 mg/dL;P < .0001, Mann-Whitney test). Any bias by an unequal isoform distribution was excluded because there was no significant difference in the isoform distribution between patients and controls (P > .10, chi2 test). Furthermore, the decrease in Lp(a) concentration during acute hepatitis was independent of the molecular weight of the apo(a) isoform. Longitudinally observed patients showed a marked increase in Lp(a) concentration during convalescence (7 to 32 mg/dL;P < .0001, Wilcoxon test). Our results show that acute hepatitis is associated with decreased Lp(a) serum levels. Further studies are needed to evaluate whether Lp(a) serum concentration might be clinically useful as a parameter of liver function.

Cardiac autonomic nerve function and insulin sensitivity in obese subjects

OBJECTIVE

To investigate whether obesity influences cardiac autonomic nerve function.

DESIGN

Comparing two groups of subjects with different degrees of obesity to normal weight controls.

SUBJECTS

19 healthy controls (mean age 33 y, BMI 21.7 +/- 0.2 kg/m2) and 17 obese non-diabetic subjects (mean age 39 y, BMI 33.7 +/- 1.8 kg/m2).

MEASUREMENTS

Insulin sensitivity was calculated by an oral glucose tolerance test. Autonomic nerve function was evaluated by analysing the variation of the heart frequency at rest (coefficient variation of R-R intervals, REST 1), during deep respiration, at a Valsalva maneuver (longest/shortest R-R interval during inspiration hold) and by the Ewing test (ratio between the 30th and 15th R-R interval after reaching up-right position).

RESULTS

The obese showed a lower insulin sensitivity than healthy controls (3.09 vs 4.60 mg x l2/mmol x mU x min, P < 0.001). Their variation in heart frequency was reduced (REST 1: 1.95 vs 2.9, P < 0.01, Valsalva: 1.30 vs 1.52 and Ewing test: 1.03 vs 1.14, P < 0.05). However, patients with moderate (BMI 31.7 kg/m2) or severe obesity (39.0 kg/m2) with identical insulin sensitivity had no significant difference in autonomic nerve function. Except for the Ewing test all measured parameters for the evaluation of cardiac autonomic nerve function correlated with the degree of diminished insulin sensitivity (REST 1: r = 0.475, P < 0.001).

CONCLUSION

Moderate obesity with significantly decreased insulin sensitivity is associated with impaired cardiac autonomic nerve function.

Lipoprotein(a) concentrations and phenotypes in controls and patients with hypercholesterolemia or hypertriglyceridemia

Lipoprotein(a) [Lp(a)] concentrations are known to be stable under various dietary and drug regimens. Little is known about the influence of hyperlipoproteinemia on Lp(a) levels. Therefore, we investigated Lp(a) concentrations and apolipoprotein(a) [apo(a)] polymorphism in 147 patients with hypertriglyceridemia and in 93 patients with hypercholesterolemia and compared them with 404 subjects without hyperlipoproteinemia (controls). Despite a similar apo(a) isoform and phenotype distribution, Lp(a) concentrations differed significantly (P < .0001) between the three groups. The median Lp(a) level in control subjects was 17 mg/dL (mean, 38 mg/dL), compared with 38 mg/dL (mean, 56 mg/dL) in patients with hypercholesterolemia and 9 mg/dL (mean, 21 mg/dL) in those with hypertriglyceridemia. These differences persisted after exclusion of 61 subjects with coronary heart disease. The inverse correlation between the molecular weight of the apo(a) isoforms and the Lp(a) concentration was preserved within each group (P < .001), but for every molecular weight range studied the level of Lp(a) was always higher in patients with hypercholesterolemia and always lower in those with hypertriglyceridemia than in controls. We conclude that hypertriglyceridemia or hypercholesterolemia have profound--but divergent--influences on the concentration of Lp(a).