Cardiovascular risk associated with nicotinamide use in keratinocyte cancer patients

Summary: Abstract Body: Nicotinamide, a water-soluble form of niacin, has previously been shown to reduce the incidence of new keratinocyte cancers in at-risk immunocompetent persons over a one-year period; however, recent concerns have been raised regarding niacin supplementation and increased cardiovascular risk. This retrospective cohort study evaluated the safety of nicotinamide in patients with a history of non-melanoma skin cancer (NMSC) by studying its association with major adverse cardiovascular events (MACE) using real-world data from the TriNetX platform (2011–2023). Patients with a history of NMSC who received at least three prescriptions for oral nicotinamide (n=1714) were compared to those who never received nicotinamide but were prescribed zinc (n=8858). The index date was defined as the first prescription of either medication. Propensity score matching (PSM) was employed to adjust for potential confounders. MACE was defined by a new diagnosis of ischemic heart disease, transient cerebral ischemic attack, stroke, or cardiac arrest. Both short (3 months to 1 year) and long-term (1-3 years) follow-up periods post-index date were examined. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards models. After PSM, 1671 patients were included in each group. The nicotinamide group did not demonstrate a significantly increased risk of MACE in the short (adjusted HR: 1.18; 95% CI: 0.81-1.72) or long term (1.08; 0.79-1.49) compared to the control group. Our findings indicate oral nicotinamide is not associated with an increased risk of MACE within a 3-year follow-up period and suggest it remains a safe option for skin cancer prevention in those with a history of NMSC. Chaw Ning Lee^{1, 2}, Carolyn Lee^{1, 3} 1. Dermatology, Stanford University, Palo Alto, CA, United States. 2. Dermatology, National Cheng Kung University, Tainan City, Tainan City, Taiwan. 3. Stanford Cancer Institute, Stanford University, Palo Alto, CA, United States. Clinical Research: Epidemiology and Observational Research