Continuous intravenous heparin administration in humans causes a decrease in serum lipolytic activity and accumulation of chylomicrons in circulation

5-Fluorouracil-associated severe hypertriglyceridaemia with positive rechallenge

Chemotherapy-induced hypertriglyceridaemia (HTG) is a potential serious adverse event. Severe HTG with triglycerides (TG) >11.3 mmol/L (1000 mg/dL) can cause acute pancreatitis in addition to cardiovascular diseases such as coronary artery disease. While the association of capecitabine (5-fluorouracil (5-FU) prodrug) with clinically relevant HTG is a well-known adverse reaction, 5-FU is not typically associated with HTG. We here report the case of a patient who developed 5-FU-associated grade 4 HTG with TG level raising up to 37.1 mmol/L (3286 mg/dL) occurring after the ninth cycle of adjuvant FOLFOX (Fluorouracil and Oxaliplatin) chemotherapy. Fenofibrate treatment and diet were started. Chemotherapy was postponed and then resumed for two additional cycles. However, severe HTG recurred shortly after. Chemotherapy was therefore permanently stopped. Approximately 8 weeks after chemotherapy discontinuation, TG fell back to range at 2.1 mmol/L (189 mg/dL) allowing interruption of fenofibrate without HTG recurrence at 3 months.

The role of apheresis and insulin therapy in hypertriglyceridemic acute pancreatitis-a concise review

Severe hypertriglyceridemia (HTG) is the third most common cause of acute pancreatitis (AP) and is involved in its pathogenesis. Chylomicrons increase blood viscosity and induce ischemia, while free fatty acids induce inflammation and distant organ damage. Conservative treatment options include fasting and insulin; limited evidence shows their comparable efficacy. Plasma exchange might provide more rapid lowering of triglycerides and amelioration of systemic effects of severe AP. Available data from controlled studies show only moderately faster lowering of triglycerides with apheresis (about 70% vs. 50% with conservative treatment within 24 h) and limited data from non-randomized studies show no improvement in clinical outcomes. New evidence is expected soon from ongoing large randomized trials. Until then, insulin may be used in mild HTG-AP and plasma exchange should be considered only in severe HTG-AP, especially if the decline of triglycerides with conservative treatment is slow, and in HTG-AP during pregnancy.

Severe Hypertriglyceridaemia and Chylomicronaemia Syndrome-Causes, Clinical Presentation, and Therapeutic Options

We have reviewed the genetic basis of chylomicronaemia, the difference between monogenic and polygenic hypertriglyceridaemia, its effects on pancreatic, cardiovascular, and microvascular complications, and current and potential future pharmacotherapies. Severe hypertriglyceridaemia (TG > 10 mmol/L or 1000 mg/dL) is rare with a prevalence of <1%. It has a complex genetic basis. In some individuals, the inheritance of a single rare variant with a large effect size leads to severe hypertriglyceridaemia and fasting chylomicronaemia of monogenic origin, termed as familial chylomicronaemia syndrome (FCS). Alternatively, the accumulation of multiple low-effect variants causes polygenic hypertriglyceridaemia, which increases the tendency to develop fasting chylomicronaemia in presence of acquired factors, termed as multifactorial chylomicronaemia syndrome (MCS). FCS is an autosomal recessive disease characterized by a pathogenic variant of the lipoprotein lipase (LPL) gene or one of its regulators. The risk of pancreatic complications and associated morbidity and mortality are higher in FCS than in MCS. FCS has a more favourable cardiometabolic profile and a low prevalence of atherosclerotic cardiovascular disease (ASCVD) compared to MCS. The cornerstone of the management of severe hypertriglyceridaemia is a very-low-fat diet. FCS does not respond to traditional lipid-lowering therapies. Several novel pharmacotherapeutic agents are in various phases of development. Data on the correlation between genotype and phenotype in FCS are scarce. Further research to investigate the impact of individual gene variants on the natural history of the disease, and its link with ASCVD, microvascular disease, and acute or recurrent pancreatitis, is warranted. Volanesorsen reduces triglyceride concentration and frequency of pancreatitis effectively in patients with FCS and MCS. Several other therapeutic agents are in development. Understanding the natural history of FCS and MCS is necessary to rationalise healthcare resources and decide when to deploy these high-cost low-volume therapeutic agents.

Comparable Triglyceride Reduction With Plasma Exchange and Insulin in Acute Pancreatitis - A Randomized Trial

Background and Aims

Both insulin and plasma exchange (PE) are used in hypertriglyceridemic acute pancreatitis (HTG-AP). Our aim was to compare the efficacy of both treatments.

Methods

A randomized, parallel group study performed in a tertiary hospital in 22 HTG-AP patients with non-severe prognosis and triglycerides between 15 and 40 mmol/L. Patients were randomized to daily PE or insulin infusion until triglycerides were <10 mmol/L. Primary outcome was % reduction in triglycerides within 24 h. Secondary outcomes were days needed to lower triglycerides <10 mmol/L, highest CRP and percentage of patients with a severe course of pancreatitis.

Results

There was a trend toward a greater decrease in triglycerides within the first 24 h in the PE group (67 ± 17% vs. 53 ± 17%, p = 0.07), but the absolute difference was modest [mean difference of 6 mmol/L (14% of initial value)]. Triglycerides fell below 10 mmol/L in a median (IQR) of 1 (1-2) and 2 (1-2) days, respectively (p = 0.25). Secondary outcomes related to disease severity were also comparable: highest CRP 229 vs. 211 mg/L (p = 0.69) and severe course of pancreatitis in 2/11 cases in both groups (p = 1.0). Regarding treatment complications, there was one mild hypoglycemia and one allergic reaction during PE. Survival was 100% in both groups.

Conclusion

There was no significant difference, but only a trend toward a greater decrease in triglycerides with PE, and the clinical course was also comparable. These results do not support universal use of PE in patients with HTG-AP.

Clinical Trial Registration

[ClinicalTrials.gov], identifier [NCT02622854].

Prevention of Triglyceridemia by (Non-)Anticoagulant Heparin(oids) Does Not Preclude Transplant Vasculopathy and Glomerulosclerosis

Background: In renal transplantation, chronic transplant dysfunction (CTD) is associated with increased PCSK9 and dyslipidemia. PCSK9 is an enzyme that increases plasma cholesterol levels by downregulating LDLR expression. We recently showed increased PCSK9-syndecan-1 interaction in conditions of proteinuria and renal function loss. Treatment with heparin(oids) might be a therapeutic option to improve dyslipidemia and CTD. We investigated the effects of (non-)anticoagulant heparin(oids) on serum lipids, syndecan-1 and PCSK9 levels, and CTD development. Methods: Kidney allotransplantation was performed from female Dark Agouti to male Wistar Furth recipients. Transplanted rats received daily subcutaneous injections of saline, unfractionated heparin, and RO-heparin or NAc-heparin (2 mg heparin(oid)/kg BW) until sacrifice after 9 weeks of treatment. Results: Saline-treated recipients developed hypertension, proteinuria, and loss of creatinine clearance (all p < 0.05 compared to baseline), along with glomerulosclerosis and arterial neo-intima formation. Saline-treated recipients showed significant increase in plasma triglycerides (p < 0.05), borderline increase in non-HDLc/HDLc (p = 0.051), and ∼10-fold increase in serum syndecan-1 (p < 0.05), without significant increase in serum PCSK9 at 8 weeks compared to baseline. Heparin and non-anticoagulant RO-heparin administration in transplanted rats completely prevented an increase in triglycerides compared to saline-treated recipients at 8 weeks (both p < 0.05). Heparin(oids) treatment did not influence serum total cholesterol (TC), plasma syndecan-1 and PCSK9 levels, creatinine clearance, proteinuria, glomerulosclerosis, and arterial neo-intima formation, 8 weeks after transplantation. Combining all groups, increased syndecan-1 shedding was associated with TC (r = 0.5; p = 0.03) and glomerulosclerosis (r = 0.53; p = 0.021), whereas the non-HDLc/HDLc ratio was associated with the neo-intimal score in the transplanted kidneys (r = 0.65; p < 0.001). Conclusion: Prevention of triglyceridemia by (non-)anticoagulant heparin(oids) neither influenced PCSK9/syndecan-1 nor precluded CTD, which however did associate with the shedding of lipoprotein clearance receptor syndecan-1 and the unfavorable cholesterol profile.

Hypertriglyceridemia-Induced Pancreatitis and a Lipemic Blood Sample: A Case Report and Brief Clinical Review

Hypertriglyceridemia is the third most common cause of acute pancreatitis after gallstones and long-term alcohol use. There are specific therapeutic options unique to hyperglyceridemia-induced pancreatitis, such as continuous insulin therapy and plasmapheresis, emphasizing the importance of identifying hypertriglyceridemia as the cause. Triglyceride levels > 1000 mg/dL may result in a visibly lipemic blood sample. Lipemic samples may interfere with laboratory equipment, resulting in erroneous levels or the inability to measure several serum blood tests. Consider hypertriglyceridemia as a cause for acute pancreatitis in the setting of a lipemic blood sample or when gallstones have been excluded.

Comparison of the injection of low-molecular weight heparin in the arterial vs. venous blood line for preventing extracorporeal circuit clotting during hemodialysis

Low-molecular weight heparins (LMWH) are widely used for preventing clotting during hemodialysis (HD). Although injection in the venous blood line is recommended to avoid initial loss of LMWH through the dialyzer, LMWH is still frequently administered in the arterial blood line at the start of dialysis. This study aimed to compare the safety and efficacy of the same enoxaparin dose administered through the venous blood line or arterial blood line. We also evaluated antifactor Xa (aXa) activity according to the injection route and dialysis modalities: high-flux (HF) HD, medium cut-off (MCO) HD, and online hemodiafiltration (OL-HDF). Forty-three patients were studied over 18 consecutive dialysis sessions using a fixed enoxaparin dose (20 or 40 mg), first administered through the arterial blood line bolus and then through the venous blood line for another 18 sessions. Compared to arterial blood line administration, venous blood line bolus resulted in a significant increase in median post-dialysis aXa activity: 0.16 (0.1-0.6) IU/ml versus 0.31 (0.1-1.3) IU/ml, respectively, p = 0.006. After arterial blood line bolus of 40 mg enoxaparin, median post-dialysis aXa activity was significantly lower with OL-HDF compared to HF-HD: 0.14 (0.1-0.35) versus 0.32 (0.15-0.49), p = 0.02. A trend for lower clotting within lines and bubble trap using venous blood line bolus was observed. In conclusion, venous blood line enoxaparin injection is safe in OL-HDF patients. However, in HF-HD and MCO-HD, venous blood line injection of 40 mg enoxaparin may increase overdosing risk. Thus, aXa activity should be monitored in HF-HD and MCO-HD patients at risk of bleeding and/or on vitamin K antagonists and careful surveillance is required when administering a 40 mg enoxaparin dose through the venous blood line route.

Hypertriglyceridemia may contribute to stroke and pancreatitis: A case report and review of the literature

Hypertriglyceridemia (HTG) is one of the most common clinical dyslipidemia. Nevertheless, stroke and acute pancreatitis co-occurrence due to hypertriglyceridemia are extremely rare. We present a case of hypertriglyceridemia-associated stroke and pancreatitis in a 39-year-old woman. The patient's laboratory tests reported high triglyceride concentrations beyond the instrument's detection range, and radiological examination showed typical signs of cerebral infarction and acute pancreatitis. The patient received combined blood purification therapy, intravenous thrombolysis with urokinase, and conservative treatment of pancreatitis. We discuss the clinical features, pathogenesis, diagnosis, and treatment of hypertriglyceridemic stroke and pancreatitis combined with the relevant literature. We reviewed the mechanisms by which triglycerides contribute to atherosclerosis and acute pancreatitis. We point out the superiority of combined blood purification therapy and caution physicians about the effects of prescribed drugs on blood lipids.

Current Diagnosis and Management of Primary Chylomicronemia

Primary chylomicronemia (PCM) is a rare and intractable disease characterized by marked accumulation of chylomicrons in plasma. The levels of plasma triglycerides (TGs) typically range from 1,000 - 15,000 mg/dL or higher.

PCM is caused by defects in the lipoprotein lipase (LPL) pathway due to genetic mutations, autoantibodies, or unidentified causes. The monogenic type is typically inherited as an autosomal recessive trait with loss-of-function mutations in LPL pathway genes ( LPL , LMF1 , GPIHBP1 , APOC2 , and APOA5 ). Secondary/environmental factors (diabetes, alcohol intake, pregnancy, etc.) often exacerbate hypertriglyceridemia (HTG).

The signs, symptoms, and complications of chylomicronemia include eruptive xanthomas, lipemia retinalis, hepatosplenomegaly, and acute pancreatitis with onset as early as in infancy. Acute pancreatitis can be fatal and recurrent episodes of abdominal pain may lead to dietary fat intolerance and failure to thrive.

The main goal of treatment is to prevent acute pancreatitis by reducing plasma TG levels to at least less than 500-1,000 mg/dL. However, current TG-lowering medications are generally ineffective for PCM. The only other treatment options are modulation of secondary/environmental factors. Most patients need strict dietary fat restriction, which is often difficult to maintain and likely affects their quality of life.

Timely diagnosis is critical for the best prognosis with currently available management, but PCM is often misdiagnosed and undertreated. The aim of this review is firstly to summarize the pathogenesis, signs, symptoms, diagnosis, and management of PCM, and secondly to propose simple diagnostic criteria that can be readily translated into general clinical practice to improve the diagnostic rate of PCM. In fact, these criteria are currently used to define eligibility to receive social support from the Japanese government for PCM as a rare and intractable disease.

Nevertheless, further research to unravel the molecular pathogenesis and develop effective therapeutic modalities is warranted. Nationwide registry research on PCM is currently ongoing in Japan with the aim of better understanding the disease burden as well as the unmet needs of this life-threatening disease with poor therapeutic options.

Low-Molecular-Weight Heparin Combined With Insulin Versus Insulin Alone in the Treatment of Hypertriglyceridemic Pancreatitis (LIHTGP Trial): Study Protocol for a Multicenter, Prospective, Single-Blind, Randomized Controlled Trial

OBJECTIVE

Currently, insulin and/or heparin/low-molecular-weight heparin (LMWH) serve as an early lipid-lowering treatment for hypertriglyceridemic pancreatitis (HTGP). However, whether the clinical prognosis of combining LMWH with insulin is superior to using insulin alone remains unknown. This trial will compare the clinical outcomes of LMWH with insulin and an insulin regimen for emergency lipid-lowering treatment in HTGP patients.

METHODS

In total, 476 eligible participants will be recruited from 18 hospitals throughout China. Participants in the LMWH group will receive LMWH combined with insulin, whereas insulin alone will be administered to those in the insulin group. The patients will be followed up at 3 and 6 months after discharge. Adverse reactions will be evaluated by the safety monitoring committee. Safety outcomes and adverse events will also be recorded.

RESULTS

The study is registered in the Chinese Clinical Trial Registry (No: ChiCTR1900023640). Recruitment will begin in August 2019 and will be completed in December 2021 (http://www.chictr.org.cn/index.aspx). No data are available now.

CONCLUSIONS

The trial will investigate the efficacy of using LMWH combined with insulin as an emergency lipid-lowering treatment in reducing new organ failure, mortality, hospital stays, and expenses compared using with insulin alone for patients with HTGP.

Hypertriglyceridemia and acute pancreatitis

Hypertriglyceridemia is the third most common cause of acute pancreatitis. It typically occurs in patients with an underlying disorder of lipoprotein metabolism and in the presence of a secondary condition such as uncontrolled diabetes, alcohol abuse, or medication use. The presentation of hypertriglyceridemia-induced pancreatitis is similar to that of acute pancreatitis due to other causes; however, patients with hypertriglyceridemia-induced pancreatitis are more likely to have severe disease courses and have a higher likelihood of persistent organ failure. The initial treatment of hypertriglyceridemia-induced pancreatitis is also similar to acute pancreatitis from other causes and consists of aggressive fluid resuscitation, pain control, and nutritional support. Hypertriglyceridemia is specifically treated with apheresis or insulin therapy when necessary. The prompt recognition of hypertriglyceridemia in the setting of acute pancreatitis is essential in both the initial and long-term management of this disease and are essential to prevent recurrent acute pancreatitis. The review seeks to highlight the etiology, pathogenesis, and clinical course of hypertriglyceridemia-induced acute pancreatitis.

EarLy Elimination of Fatty Acids iN hypertriglyceridemia-induced acuTe pancreatitis (ELEFANT trial): Protocol of an open-label, multicenter, adaptive randomized clinical trial

INTRODUCTION

Acute pancreatitis (AP) is a life-threatening inflammatory disease, with no specific pharmacological treatment. However, concerning some etiologies, early specific intervention (such as ERCP in biliary AP) has proven to be remarkably beneficial. Hypertriglyceridemia (HTG) induces severe pancreatic damage by several direct (cellular damage) and indirect (deterioration of microcirculation) mechanisms. Published data suggest that early removal of triglycerides (TGs) and toxic free fatty acids (FFAs) may be advantageous; however, high-quality evidence is still missing in the literature.

METHODS

Design: ELEFANT is a randomized controlled, multicenter, international trial testing the concept that early elimination of TGs and FFAs from the blood is beneficial in HTG-AP. The study will be performed with the adaptive "drop-the-loser" design, which supports the possibility of dropping the inferior treatment arm, based on the results of the interim analysis. Patients with HTG-AP defined by TG level over 11.3 mmol/l (1000 mg/dL) are randomized into three groups: (A) patients who undergo plasmapheresis and receive aggressive fluid resuscitation; (B) patients who receive insulin and heparin treatment with aggressive fluid resuscitation; and (C) patients with aggressive fluid resuscitation. Please note that all intervention must be started within 48 h from the onset of abdominal pain. Exclusion criteria are designed logically to decrease the possibility of any distorting effects of other diseases. The composite primary endpoint will include both severity and mortality.

RESULTS

Our null hypothesis is that early elimination of HTG and FFAs reduces the risk of mortality and severity of AP. Sample size calculation suggests that 495 patients will need to be enrolled in order to confirm or reject the hypothesis with a 10% dropout, 80% power and 95% significance level. The general safety and quality checks required for high-quality evidence will be adhered to. The study will be organized between February 2020 and December 2025.

CONCLUSION

Our study would provide the first direct evidence for or against early intervention in HTG-induced AP.

FTY720 Attenuates Acute Pancreatitis in Hypertriglyceridemic Apolipoprotein CIII Transgenic Mice

Hypertriglyceridemic pancreatitis (HTGP) is often encountered clinically as a common form of recurrent acute pancreatitis (AP). It is important to evaluate the management of severe hypertriglyceridemia (HTG) or anti-inflammation in the prophylaxis of HTGP in the clinic. FTY720 (2-amino-2[2-(4-octylphenyl) ethyl]-1, 3-propanediol) is a new anti-inflammatory agent with low toxicity and reported to ameliorate lung injury with pancreatitis in rat. We evaluated its protective affection on AP induced by seven hourly intraperitoneal injection of cerulein in apolipoprotein CIII transgenic mice with severe HTG. FTY720 at 1.5 mg/kg was administered by gastric lavage daily for 3 days before induction of AP. The effects of FTY720 to protect against HTGP were assessed by serum amylase, pancreatic pathological scores, immunostaining, and the expression of inflammatory cytokine genes. As a result, injection of cerulein resulted in more severe pathological changes of AP and higher monocyte chemoattractant protein 1 expression in the pancreas in transgenic than in nontransgenic mice. FTY720 pretreatment improved the pathological severity of AP and decreased the expression of monocyte chemoattractant protein 1 in the pancreas significantly, especially near fourfold reduction in transgenic mice. However, FTY720 did not affect plasma triglyceride levels, and other inflammatory factors and plasma amylase were not correlated with the extent of pancreatic damage in AP with or without FTY720 administration. In summary, our study in a new model, apolipoprotein CIII transgenic mice, demonstrated that HTG mice are susceptible to induction of AP. Prophylactic treatment of FTY720 can significantly attenuate cerulein-induced AP and hence warrant further investigation of sphingosine-1-phosphate receptors agonist for potential clinical application in recurrent attacks of HTGP.

Multiorgan system dysfunction in the chylomicronemia syndrome

OBJECTIVE

To describe an extreme presentation of the chylomicronemia syndrome resulting in multiorgan system dysfunction.

PATIENT

A 40-year-old African American male with no past medical history presented with multiorgan system dysfunction manifested by acute respiratory failure and acute kidney injury. He was noted to have very-high triglyceride levels (>5000 mg/dL) at admission.

INTERVENTIONS

An echocardiogram showed normal cardiac function. Amylase and lipase were normal. We confirmed the chylomicronemia syndrome with a triglyceride assay. The associated hyperviscosity was treated with plasmapheresis to reduce the plasma triglyceride level.

RESULTS

After 3 sessions of plasmapheresis, his triglyceride levels were significantly reduced, his oxygenation improved, and his acute kidney injury resolved. He was successfully extubated on day 7 of the intensive care unit stay. His diabetes and hypertriglyceridemia were newly diagnosed and drug therapy was instituted with home discharge on day 14.

CONCLUSIONS

Severe chylomicronemia can cause multiorgan system dysfunction related to hyperviscosity. Early institution of plasmapheresis to reduce the triglyceride-rich lipoproteins can improve tissue perfusion and prevent further organ damage.

Treatment options for severe hypertriglyceridemia (SHTG): the role of apheresis

Hypertriglyceridemia is associated with a number of severe diseases such as acute pancreatitis and coronary artery disease. In severe hypertriglyceridemia (SHTG, triglycerides > 1,000 mg/dL), rapid lowering of plasma triglycerides (TG) has to be achieved. Treatment regimes include nutritional intervention, the use of antihyperlipidemic drugs, and therapeutic apheresis. Apheretic treatment is indicated in medical emergencies such as hypertriglyceridemic pancreatitis.

Reviewing the current literature, plasmapheresis appears to be a safe and useful therapeutic tool in patients suffering from SHTG. Apheretic treatment is able to remove the causative agent for pancreatic inflammation. Data suggests that the use of apheresis should be performed as early as possible in order to achieve best results. The use of plasmapheresis, however, is limited due to the rather high costs and the limited availability of the procedure.

Hypertriglyceridaemia, LPL deficiency and pancreatitis -pathogenesis and therapeutic options

Severe hypertriglyceridaemia (HTG) is recognised as the third most common cause of acute pancreatitis. While secondary causes of HTG such as excess alcohol, obesity and diabetes are well recognised, identification and treatment of primary genetic disorders such as lipoprotein lipase (LPL) deficiency remain a challenge. HTG secondary to such genetic disorders does not respond to established medical therapy, resulting in recurrent episodes of acute pancreatitis. A very low fat diet remains first-line therapy in the treatment of severe HTG secondary to LPL deficiency, and in resistant cases insulin, heparin and plasma apheresis are used with some success. Viral vector-delivered gene therapy is a novel treatment option that is currently being tested in patients with LPL deficiency with promising results.

Severe hypertriglyceridemia and pancreatitis: presentation and management

PURPOSE OF REVIEW

Hypertriglyceridemia (HTG) is a well recognized cause of acute pancreatitis accounting for approximately up to 10% of all cases and even up to 50% of all cases in pregnancy. Both primary and secondary disorders of lipoprotein metabolism may be associated with hypertriglyceridemic pancreatitis (HTGP). The purpose of this review is to provide an overview of the current studies on presentation and management of HTGP.

RECENT FINDINGS/CONCLUSION

Hydrolysis of triglycerides by pancreatic lipase and formation of free fatty acids that induce inflammatory changes are postulated to account for the development of HTGP, yet the exact pathophysiology remains unclear. The clinical features of patients with HTGP are generally not different from patients with acute pancreatitis of other causes, and there is some evidence that HTGP is associated with a higher severity or a higher complication rate. There is no clear evidence as to which HTG patients will develop pancreatitis. Several studies have evaluated the effect of apheresis, the benefit of insulin and/or heparin treatment and the use of different antihyperlipidemic agents in HTGP. Dietary modifications resemble the key features in the long-term management of HTG. Whether HTG may cause chronic pancreatitis in the long-term follow-up remains controversial.

Hypertriglyceridemic pancreatitis: presentation and management

Hypertriglyceridemia (HTG) is reported to cause 1-4% of acute pancreatitis (AP) episodes. HTG is also implicated in more than half of gestational pancreatitis cases. Disorders of lipoprotein metabolism are conventionally divided into primary (genetic) and secondary causes, including diabetes, hypothyroidism, and obesity. Serum triglyceride (TG) levels above 1,000 mg/dl are usually considered necessary to ascribe causation for AP. The mechanism for hypertriglyceridemic pancreatitis (HTGP) is postulated to involve hydrolysis of TG by pancreatic lipase and release of free fatty acids that induce free radical damage. Multiple small studies on HTGP management have evaluated the use of insulin, heparin, or both. Many series have also reported use of apheresis to reduce TG levels. Subsequent control of HTG with dietary restrictions, antihyperlipidemic agents, and even regular apheresis has been shown anecdotally in case series to prevent future episodes of AP. However, large multicenter studies are needed to optimize future management guidelines for patients with HTGP.

Plasma Lipoprotein Abnormalities in Hemodialysis Patients—Clinical Implications and Therapeutic Guidelines

Patients with advanced stages of chronic kidney disease (CKD) have an increased risk of death from cardiovascular disease (CVD). Dyslipidemias are associated with atherosclerotic vascular changes and the risk of occurrence of acute myocardial infarction in hemodialysis patients. However, management of dyslipidemia in hemodialysis patients does not appear to be actively carried out in routine practice. Presumably, there are three reasons for this reluctance to lipid-lowering in hemodialysis patients. First, there are epidemiological data showing the inverse relationship between cholesterol and mortality rate; a high cholesterol predicts a better survival. Second, lipids are not usually measured using standard fasting serum, but a non-fasting specimen. Third, although hypertriglyceridemia is the most common abnormality, fibrates are contraindicated in patients with renal failure because of a high risk of rhabdomyolysis. These issues are discussed in the current review article. Based on published work, lipid lowering would not increase the death rate if carried out without worsening malnutrition. The National Kidney Foundation K/DOQI Clinical Practice Guidelines recommend a reduction in fasting LDL-C below 100 mg/dL for the prevention of CVD in dialysis patients. Practically, however, the use of non-HDL-C measured by casual blood samples might be sufficient for the risk assessment in many hemodialysis patients. Statins are a good choice for lipid-lowering in dialysis patients. Furthermore, lipoprotein profile might be improved by an inventive use of dialyzer membranes, dialysate solutions, and other dialysis-related medications. For severe hypercholesterolemia, LDL-apheresis is another choice for consideration. Further studies are needed to clearly prove the benefit of lipid reduction in hemodialysis patients and those with CKD at earlier stages.

Lipoprotein lipase in hemodialysis patients: indications that low molecular weight heparin depletes functional stores, despite low plasma levels of the enzyme

BACKGROUND

Lipoprotein lipase (LPL) has a central role in the catabolism of triglyceride-rich lipoproteins. The enzyme is anchored to the vascular endothelium through interaction with heparan sulphate proteoglycans and is displaced from this interaction by heparin. When heparin is infused, there is a peak of LPL activity accompanied by a reduction in triglycerides (TG) during the first hour, followed by a decrease in LPL activity to a stable plateau during the remaining session while TG increase towards and beyond baseline. This suggests that tissue stores of LPL become depleted. It has been argued that low molecular weight (LMW) heparins cause less disturbance of the LPL system than conventional heparin does.

METHODS

We have followed LPL activity and TG during a dialysis-session with a LMW heparin (dalteparin) using the same patients and regime as in a previous study with conventional heparin, i.e. a primed infusion.

RESULTS

The shape of the curve for LPL activity resembled that during the earlier dialyses with conventional heparin, but the values were lower during dialysis with dalteparin. The area under the curve for LPL activity during the peak period (0-180 minutes) was only 27% and for the plateau period (180-240 minutes) it was only 36% of that observed with conventional heparin (p < 0.01). These remarkably low plasma LPL activities prompted us to re-analyze LPL activity and to measure LPL mass in frozen samples from our earlier studies. There was excellent correlation between the new and old values which rules out the possibility of assay variations as a confounding factor. TG increased from 2.14 mmol/L before, to 2.59 mmol/L after the dialysis (p < 0.01). From 30 minutes on, the TG values were significantly higher after dalteparin compared to conventional heparin (p < 0.05).

CONCLUSION

These results indicate that LMW heparins disturb the LPL system as much or more than conventional heparin does.

Usefulness of lipoprotein changes during acute coronary syndromes for predicting postdischarge lipoprotein levels

The aim of our study was to evaluate the lipoprotein changes that occur during acute coronary events, and to determine the lipoprotein threshold levels that identify patients who require future statin therapy. Lipoprotein levels were measured at admission, at 6 hours, the morning after admission, before discharge, and 3 months after discharge in patients with myocardial infarction and unstable angina. Patients with myocardial infarction on thrombolytic therapy (n = 63) and patients with unstable angina (n = 33) had a decrease in low-density lipoprotein (LDL) cholesterol levels < or = 24 hours after admission (-12 +/- 20% and -6 +/- 23%, respectively), but these levels returned to baseline before discharge. In patients with myocardial infarction who did not receive thrombolytic therapy (n = 37), the decrease was more gradual and peaked before hospital discharge (-7 +/- 19%). There was good correlation between LDL cholesterol levels at admission and after discharge, especially in normotriglyceridemic patients. Over 90% of patients with LDL cholesterol > or = 125 mg/dl on the morning after admission were candidates for statin therapy after discharge. Thus, the need for future statin therapy can be predicted with fair reliability during the initial 24 hours after admission. However, elevated baseline triglyceride levels significantly affect these LDL cholesterol changes and complicate prediction of long-term lipoprotein levels.

Lipoprotein lipase during continuous heparin infusion: tissue stores become partially depleted

Lipoprotein lipase (LPL) and hepatic lipase (HL) are located at vascular surfaces in extrahepatic tissues and in the liver, respectively. Heparin displaces the enzymes into the circulating blood. Animal studies have shown that the liver takes up and degrades LPL. To explore whether heparin leads to a depletion of tissue stores, we followed the lipase activities in plasma during an 8-hour primed infusion of heparin in 10 healthy subjects. After an initial peak, the HL activity decreased slowly after a time curve similar to that for activated partial thromboplastin time. The time curve for LPL was different. After the initial peak, the activity dropped by almost 80%, from 30 to 120 minutes, and then leveled off to a plateau that corresponded to about 15% of the peak level. A second bolus of heparin was given to 4 subjects after 4 hours. The plasma LPL activity increased, but only to about 35% of the original peak level. We conclude that when heparin releases LPL into plasma, the lipase becomes liable to be taken up and degraded by the liver. After less than 1 hour, the stores of LPL have been exhausted, and recruitment of lipase into plasma depends on a slow but stable delivery of newly synthesized molecules.

Effect of heparin-stimulated plasma lipolytic activity on VLDL APO B subclass metabolism in normal subjects

Heparin given intravenously enhances lipolysis, although fasting lipids are not markedly altered in long-term administration. In the present study we investigated heparin-induced acute perturbation of VLDL subclass metabolism. Eight men were examined during a control study and during an 8.5 h infusion of heparin. 2H3-leucine was used as tracer and kinetic constants derived using a non-steady-state model. Heparin infusion increased both plasma lipoprotein and hepatic lipase activity and raised plasma FFAs two-fold (P < 0.001). The fractional catabolic rate (FCR) of VLDL1 apo B increased on heparin (25.7 +/- 4.2 and 10.8 +/- 1.7 pools/d, heparin vs. control, P < 0.02). The FCR of VLDL2 apo B increased to 12.6 +/- 1.9 pools/d on heparin vs. 8.8 +/- 1.1 pools/d during the control (NS). Total VLDL apo B production was not significantly changed (824 +/- 45 and 692 +/- 91 mg/d, heparin vs. control, NS). We conclude that during heparin infusion, the catabolism of especially large triglyceride-rich VLDL1 apo B is greatly increased. However, although the FFA levels were high during the heparin study, the production of total VLDL apo B did not rise. These findings are consistent with the known action of heparin on lipoprotein lipase but indicate that acute increase in plasma FFA levels does not lead to a rise in VLDL apo B production.

Successful outcome in severe pregnancy-associated hyperlipemia: a case report and literature review

Severe hypertriglyceridemia causing pancreatitis is a rare complication of pregnancy, usually occurring in the second and third trimesters. Treatment includes a very low-fat diet, intravenous fluids, total parenteral nutrition, and plasma apheresis. In this article, the authors report the case of a pregnant woman who presented with a plasma triglyceride level of 65 mmol/L, abdominal pain, and a threatened abortion at 8 weeks of gestation. Treatment included restriction of dietary fat to below 10% of total calories, liquid protein supplementation, multiple hospitalizations for treatment with intravenous fluids, and total parenteral nutrition. Continuous intravenous heparin was started at 29 weeks of gestation for pulmonary embolism. This was associated with a dramatic decrease in plasma triglyceride levels. A normal female child was born at 37 weeks of gestation. The mother's weight at 2 weeks postpartum was 15 lb below her pregnant weight. It was concluded that a successful pregnancy is possible even when plasma triglyceride levels are very high early in the pregnancy.

Targeting the glycosaminoglycan-binding sites on proteins

Sulfated glycosaminoglycans bind to a wide variety of proteins, and in so doing have important roles in diverse biological processes. Selective mimics or inhibitors of protein-glycosaminoglycan interactions could have broad application in biology and medicine.