ANGPTL3 as a Drug Target in Hyperlipidemia and Atherosclerosis.

PURPOSE OF REVIEW: Elevated low-density lipoprotein cholesterol (LDL-C) and triglyceride-rich lipoproteins (TRLs) or remnants are important risk factors for the development of atherosclerotic cardiovascular disease (ASCVD). The ongoing challenge of not being able to achieve recommended LDL-C targets despite maximally tolerated lipid-lowering therapy (LLT) has led to the development of novel therapeutic agents including angiopoietin-like 3 (ANGPTL3) inhibitors. RECENT FINDINGS: ANGPTL3 is a glycoprotein produced by the liver that inhibits lipoprotein lipase and endothelial lipase. Data from genetic and clinical studies have shown that a lower ANGPTL3 level is associated with lower plasma LDL-C, triglyceride (TG), and other lipoproteins. Pharmacological inactivation of ANGPTL3 with the monoclonal antibody, evinacumab, results in a 50% reduction in LDL-C, even in patients with homozygous familial hypercholesterolemia (HoFH). The safe and effective targeted delivery of nucleic acid-based therapies will shape the future of the lipid arena. ANGPTL3 is a novel target in lipoprotein metabolism, targeting not only LDL-C via an LDL-receptor (LDLR) independent mechanism but also TRLs and carries a significant promise for further ASCVD risk reduction.

Inhibition of angiopoietin-like 3 for the management of severe hypercholesterolemia.

PURPOSE FOR REVIEW: Despite the therapeutic advances for patients with severe hypercholesterolemia, particularly those with homozygous familial hypercholesterolemia (HoFH), most patients are unable to achieve target low-density lipoprotein cholesterol (LDL-C) levels with the current available standard lipid-lowering therapy (LLT). We review the role of angiopoietin-like 3 (ANGPTL3) inhibition as an additional therapeutic option for severe hypercholesterolemia, particularly HoFH. RECENT FINDINGS: Evinacumab is a monoclonal antibody against ANGPTL3, and reduces LDL-C independent of LDL-receptor activity. ANGPTL3 inhibitors are effective in lowering LDL-C in patients with FH, with a 50% reduction in LDL-C in those with HoFH. Longer-term efficacy and safety have been demonstrated with reductions in LDL-C maintained following 48 weeks of therapy. Gene silencing strategies directed against ANGPTL3 include antisense oligonucleotide and small-interfering ribonucleic acid (siRNA). ARO-ANG3 is a siRNA directed against ANGPTL3 messenger ribonucleic acid and is associated with up to a 42% reduction in LDL-C. SUMMARY: With the promise of these emerging novel therapeutics directed against ANGPTL3 on the horizon, achieving acceptable target LDL-C levels in HoFH without the need for lipoprotein apheresis may finally be a realistic goal and we can anticipate a decrease in cardiovascular morbidity and mortality in these difficult to treat patients.

Unraveling the Whipple Triad: Non-Islet Cell Tumor-Induced Hypoglycemia.

Tumor-induced hypoglycemia (TIH) is a rare paraneoplastic phenomenon resulting from several tumor types and mechanisms. Insulinomas are the most common cause of TIH. However, non-islet cell tumors can also trigger hypoglycemia by releasing insulin-like growth factor 2 (IGF-II) or its precursor. We present a case of a 56-year-old woman experiencing spontaneous hypoglycemia due to a pleural-based solitary fibrous tumor. Diagnostic evaluations revealed diminished C-peptide levels, increased IGF-II, and a 4-fold increase in the IGF-II: IGF-I ratio, indicative of non-islet cell tumor hypoglycemia. Localization imaging identified a left pleural mass, confirming the diagnosis. Preoperatively, the patient received intravenous dextrose and corticosteroids, but surgical resection was essential for the resolution of symptoms. The identified tumor, a benign solitary fibrous tumor, was successfully removed, leading to an immediate postoperative cessation of hypoglycemia. Six years post resection, the patient remains symptom free. Managing TIH necessitates an early diagnosis aiming for complete tumor resection, with alternative approaches considered when complete resection is not possible. This case highlights the importance of a systematic diagnostic and management approach for TIH, emphasizing the need to identify the underlying cause, particularly in people without diabetes.

A challenging case of a pituitary macroadenoma and toxic thyroid adenoma with inappropriate TSH secretion.

Summary: Thyroid-stimulating hormone-secreting pituitary adenomas (TSHomas) are rare, accounting for less than 1% of all pituitary adenomas. We present a case of hyperthyroidism secondary to a likely TSHoma and coexisting functional thyroid adenoma. Laboratory errors and familial abnormalities in thyroid function tests were ruled out, and a diagnosis of the toxic thyroid adenoma was confirmed on a thyroid uptake scan. However, the triiodothyronine suppression test was contraindicated due to the patient's cardiovascular disease, and the thyrotropin-releasing hormone stimulation test, measurement of glycoprotein hormone alpha-subunit, and genetic testing were unavailable. Magnetic resonance imaging of the brain revealed a suprasellar pituitary macroadenoma measuring 40 mm × 20.3 mm × 17 mm. The patient was initiated on carbimazole; however, thyroid stimulating hormone and thyroxine levels remained elevated. The patient declined trans-sphenoidal surgery and was treated with radioactive iodine to manage the toxic thyroid adenoma, leading to reduced thyroxine levels and symptom improvement. Unfortunately, the patient passed away before long-acting somatostatin analogs became available. This case highlights the diagnostic and therapeutic challenges involved in managing thyrotoxicosis with dual etiology. Learning points: Hyperthyroidism can have multiple etiologies, which can coexist in the same patient. Persistent discordant thyroid function tests warrant further investigation. The gold standard for diagnosis of TSHomas remains immunohistochemical analysis of the tumor tissue.

The Hurdle of Access to Emerging Therapies and Potential Solutions in the Management of Dyslipidemias.

This review explores the many barriers to accessing lipid-lowering therapies (LLTs) for the prevention and management of atherosclerotic cardiovascular disease (ASCVD). Geographical, knowledge, and regulatory barriers significantly impede access to LLTs, exacerbating disparities in healthcare infrastructure and affordability. We highlight the importance of policy reforms, including pricing regulations and reimbursement policies, for enhancing affordability and streamlining regulatory processes. Innovative funding models, such as value-based pricing and outcome-based payment arrangements, have been recommended to make novel LLTs more accessible. Public health interventions, including community-based programs and telemedicine, can be utilized to reach underserved populations and improve medication adherence. Education and advocacy initiatives led by patient advocacy groups and healthcare providers play a crucial role in raising awareness and empowering patients. Despite the barriers to access, novel LLTs present a big opportunity to reduce the burden of ASCVD, emphasizing the need for collaborative efforts among policymakers, healthcare providers, industry stakeholders, and patient advocacy groups to address these barriers to improve access to LLTs globally.

Targeting PCSK9 and Beyond for the Management of Low-Density Lipoprotein Cholesterol.

Reducing low-density lipoprotein cholesterol (LDL-C) levels is crucial to the prevention of atherosclerotic cardiovascular disease (ASCVD). However, many patients, especially those at very high ASCVD risk or with familial hypercholesterolemia (FH), do not achieve target LDL-C levels with statin monotherapy. The underutilization of novel lipid-lowering therapies (LLT) globally may be due to cost concerns or therapeutic inertia. Emerging approaches have the potential to lower LDL-C and reduce ASCVD risk further, in addition to offering alternatives for statin-intolerant patients. Shifting the treatment paradigm towards initial combination therapy and utilizing novel LLT strategies can complement existing treatments. This review discusses innovative approaches including combination therapies involving statins and agents like ezetimibe, bempedoic acid, cholesterol ester transfer protein (CETP) inhibitors as well as strategies targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) and angiopoietin-like protein 3 (ANGPTL3) inhibition. Advances in nucleic acid-based therapies and gene editing are innovative approaches that will improve patient compliance and adherence. These strategies demonstrate significant LDL-C reductions and improved cardiovascular outcomes, offering potential for optimal LDL-C control and reduced ASCVD risk. By addressing the limitations of statin monotherapy, these approaches provide new management options for elevated LDL-C levels.

Point-of-care testing compared to gold-standard laboratory methods in the measurement of serum lipids.

BACKGROUND: Cardiovascular disease is the leading cause of mortality worldwide, with dyslipidaemia being one of the major risk factors. Point-of-care testing (POCT) allows for the rapid measurement of serum lipids. The aim of this study was to assess the accuracy of serum lipid measurement by the Fujifilm™ NX700 POCT compared to a gold-standard clinical laboratory method (Medpace, Leuven, Belgium). METHODS: This was a prospective, observational study conducted at the Lipid Clinic at Charlotte Maxeke Johannesburg Academic Hospital from July to September 2022. Participants were known to have a lipid disorder, most commonly, familial hypercholesterolaemia. Samples sent for lipid measurement by standard laboratory methods were simultaneously measured by the Fujifilm™ NX700 POCT. RESULTS: Lipograms evaluating total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and calculated low-density lipoprotein cholesterol (LDL-C) were obtained from 115 participants. No statistically significant difference was noted between the parameters tested on the different platforms. The Fujifilm™ NX700 POCT correctly identified > 91% of serum lipid results as normal or abnormal, as defined by NCEP-ATP III criteria, and exhibited good sensitivity and specificity for each parameter. Lin's concordance correlation coefficient demonstrated a strong correlation for all parameters; TC (ρc = 0.9861), HDL-C (ρc = 0.95919), LDL-C (ρc = 0.98134) and TG (ρc = 0.92775). Bland-Altman plots identified low bias and a good level of agreement between the two test methods. CONCLUSION: The Fujifilm™ NX700 POCT compared favourably with gold-standard laboratory methods in the determination of serum lipid measurements, allowing for rapid screening at the primary healthcare level.