aggravate gastrointestinal conditions such as peptic ulcer disease, gastroesophageal reflux disease, and pancreatitis. Hiccups may occur due to nicotine’s vasodilatory effects on blood vessels in skeletal muscle. As an activator of the sympathetic nervous system, nicotine can cause light-headedness or dizziness, headache, and increased saliva production. Due to nicotine’s vasoconstrictive effects in the skin and heart, nicotine gum transiently increases heart rate and blood pressure, and consequently myocardial work. However, there is no consensus information available regarding the cardiovascular risk of NRT relative to smoking. Furthermore, smoking while using NRT has not been shown to increase the risk of a cardiovascular event. In addition to following chewing instructions, the dose of nicotine gum can be adjusted for individuals experiencing side effects. Safety concerns Dependence Compared to cigarettes, NRT products deliver nicotine to the brain more slowly and produce lower levels of nicotine in the blood. No relationship has been established between NRT use and risk of dependence when products are used as instructed. Cancer No causal relationship has been shown between exposure to nicotine in NRT and cancer. Dental health and TMJ disorders Nicotine gum is sugar-free. Chewing nicotine gum does not increase risk for cavities or gum disease beyond the inherent risk associated with nicotine. However, nicotine gum may exacerbate poor dentition and may not be compatible with dental appliances such as dentures, bridges, and crowns. The frequent chewing associated with nicotine gum use can also worsen temporomandibular joint (TMJ) disorders. Cardiovascular health Smoking increases the risk for acute cardiovascular events such as myocardial infarction and stroke, and chronic cardiovascular disease such as atherosclerosis. However, no association has been established between NRT and increased cardiovascular risk. Side effects of nicotine gum include increased heart rate and blood pressure (see side effects, above), but nicotine gum is not contraindicated in individuals with coronary disease. Diabetes Nicotine from cigarettes is known to increase blood sugar levels and promote insulin resistance in type 2 diabetics. However, there is insufficient evidence regarding the relationship between NRT and diabetes. Hyperlipidemia No relationship has been established regarding NRT use and its impact on cholesterol, HDL, or LDL levels. Hepatotoxicity Nicotine that enters the gastrointestinal system is largely metabolized by the liver. Nicotine used in NRT products has not been shown to cause or worsen liver damage. Reproduction and development There is insufficient evidence to establish a relationship between NRT use in pregnancy and increased risk