Recent findings question the role of Niacin, also known as nicotinic acid, in cardiovascular health, revealing its dangerous impact on vascular inflammation. Careful approaches are advised for cardiovascular management.
Cardiovascular disease remains a huge health burden globally, despite decades of research and intervention. In 2019, Asia accounted for 58% of deaths caused by cardiovascular disease alone. This condition is commonly associated with low high-density lipoprotein cholesterol (HDL-C) and high low-density lipoprotein cholesterol (LDL-C) levels. Niacin, also known as nicotinic acid or vitamin B3, has been used as a supplement to manage the levels.
Found naturally in various foods such as meat, fish, legumes, seeds, mushrooms, and certain vegetables and also synthesised in the liver, niacin plays an essential role in managing cholesterol levels and neuroprotection. Later, niacin usage has also expanded to include managing primary hyperlipidaemia and mixed dyslipidaemia, reducing triglyceride levels, and preventing cardiovascular events in combination with statins. However, recent findings published in Nature Medicine unveiled that contrary to its previously established role in managing cholesterol levels, excessive niacin intake may elevate the risk of cardiovascular disease. This paradox highlights the complexity of niacin’s impact on heart health and emphasises the need for a comprehensive understanding and investigation of its role in cardiovascular disease management.
Exploring Niacin’s Role in Cardiovascular Disease Management
In 2019, a review sought to evaluate the evidence of using niacin as an approved treatment for cardiovascular disease. The authors investigated 119 clinical trials involving niacin as a treatment for cardiovascular disease and a meta-analysis to include over 35,000 patients with cardiovascular disease or dyslipidaemia. Their analysis revealed that niacin supplementation did not offer additional clinical benefits when combined with statins.
Although treating with niacin alone was associated with reducing some cardiovascular events- acute coronary syndrome, stroke, and revascularisation, these were two clinical trials conducted in the 1970s and 1980s, suggesting that the relevance to today’s patients with different cardiovascular risk profiles may be uncertain. Moreover, no correlation was found between changes in HDL-C levels and cardiovascular outcomes. Despite these emerging studies challenging the efficacy of niacin as an adjunct to statin therapy, the United States FDA continues to maintain approval for secondary cardiovascular disease prevention, primary hyperlipidaemia, and mixed dyslipidaemia management.
Recent Study Unveils Niacin’s Dark Side: Vascular Inflammation
Recently published in Nature Medicine, a ground-breaking study unearthed alarming associations between niacin and heightened cardiovascular disease risk. The authors found that the serum levels of two terminal niacin metabolites were linked to an increased 3-year risk of major adverse cardiovascular events. The findings were also confirmed in two independent cohorts from the USA and Europe, totalling 3,163 individuals. The serum levels of these metabolites were positively correlated with levels of soluble vascular adhesion molecule 1 (sVCAM-1), which is a biomarker of endothelium dysfunction that is associated with hypertension and atherosclerosis, indicating that niacin has a potential role in exacerbating vascular inflammation. Such inflammation results in injury and stiffening of the vascular wall, impairing blood flow and causing ischemic damage.
Niacin’s Potential Beyond Cardiovascular Health
Given the nuanced perspectives on niacin’s role in cardiovascular disease management, emerging research may suggest potential benefits in non-alcoholic fatty liver disease and chronic obstructive pulmonary disease. One cohort study of 4315 patients with non-alcoholic fatty liver disease revealed that higher dietary niacin intake was linked to a lower risk of all-cause mortality. Another study in Scientific Reports found that higher dietary niacin intake was correlated with lower chronic obstructive pulmonary disease. These new studies warrant further investigation and therapeutic innovation into the potential of niacin supplementation to mitigate other diseases.
Navigating Niacin Supplementation: To Supplement or Not
In light of conflicting evidence, healthcare professionals face the challenge of judiciously advising patients on niacin supplementation. Additionally, patients should be advised on using niacin based on current clinical guidelines and individual patient needs. Here are some general points that healthcare professionals may consider:
- Assess the Patient: Evaluate the patient’s overall health, medical history, and specific conditions that may benefit from niacin therapy. If the patient is on statins, advise against niacin supplementation.
- Monitor for Side Effects: Be aware of potential side effects, such as flushing, redness on the skin due to blood vessel dilation, and more severe side effects, such liver damage, and discuss them with the patient.
- Dosage and Formulation: Based on the patient’s condition and tolerance, consider the patient’s potential total niacin intake from niacin-fortified foods and choose the appropriate dosage and formulation (immediate-release, sustained-release, etc.).
- Diet and Lifestyle: Encourage a balanced diet and healthy lifestyle alongside niacin supplementation. To avoid excessive niacin intake, advise patients to monitor their intake of niacin-fortified foods. This is especially if they are already taking niacin supplements.
- Regular Follow-Up: Schedule regular follow-ups to monitor the patient’s response to the treatment and make any necessary adjustments, including dietary modifications to manage niacin intake.
Regional Guidelines and Clinical Practices: Insights from Singapore
For the most accurate and personalised advice, healthcare professionals should refer to the specific guidelines applicable in their region and consult with their patients to determine the best course of action. For instance, in Singapore, statins are always the first-line drug for patients with elevated LDL-C levels and hyperlipidemia. Niacin is used as an alternative when a patient’s LDL-C cholesterol remains above target despite being on the maximum tolerated dose of statin, or in cases of severe hypertriglyceridemia when statin therapy is not indicated as first line therapy. According to the guidelines, adding ezetimibe on top of statins is first considered for hyperlipidemia and elevated LDL-C levels before considering niacin.
Embracing Knowledge for Enhanced Patient Care
In conclusion, niacin’s effects on heart health reveal a complex picture. Historically seen as helpful in managing cholesterol levels and mitigating cardiovascular risk, recent studies challenge its efficacy. Ultimately, supplementing with niacin necessitates careful consideration while remaining abreast of evolving guidelines and research. Therefore, by integrating evidence-based practices with personalised patient care, healthcare professionals can ensure optimal outcomes and improved cardiovascular health for their patients.
References
- Zhao, D. (2021). Epidemiological features of cardiovascular disease in Asia. JACC: Asia, 1(1), 1–13. https://doi.org/10.1016/j.jacasi.2021.04.007
- Ferrell, M., Wang, Z., Anderson, J.T., Lan, Y., Hsieh, M., Wu, J., … & Smiley, Z. (2024). A terminal metabolite of niacin promotes vascular inflammation and contributes to cardiovascular disease risk. Nature Medicine, 30(4), 424–434. https://doi.org/10.1038/s41591-023-02793-8
- D’Andrea, E., Hey, S.P., Ramirez, C.L., & Kesselheim, A.S. (2019). Assessment of the role of niacin in managing cardiovascular disease outcomes: A systematic review and meta-analysis. JAMA Network Open, 2(4), e192224. https://doi.org/10.1001/jamanetworkopen.2019.2224
- Pan, J., Zhou, Y., Pang, N., & Yang, L. (2024). Dietary niacin intake and mortality among individuals with nonalcoholic fatty liver disease. JAMA Network Open, 7(2), e2354277. https://doi.org/10.1001/jamanetworkopen.2023.54277
- Li, W.W., Ren, K.L., Yu, J., Wang, S., Liu, Q., & Zhang, L. (2024). Association of dietary niacin intake with the prevalence and incidence of chronic obstructive pulmonary disease. Scientific Reports, 14, 2863. https://doi.org/10.1038/s41598-024-53387-4
- Tai, E. S., Chia, B. L., Bastian, A. C., Chua, T. S. J., Ho, S. C. W., Koh, T. S., Low, L. P., Tey, J., Poh, K. K., Tan, C. E., Ting, P., Tham, T. Y., Toh, S. A. E. S., & van Dam, R. M. (2017). Ministry of Health Clinical Practice Guidelines: Lipids. Singapore Medical Journal, 58(3), 155-166. https://doi.org/10.11622/smedj.2017018
