Adolescent and Young Adult Response to Hypothetical E-Liquid Flavor Restrictions.

OBJECTIVE: Rates of e-cigarette use among adolescents and young adults (AYAs) remain high despite several federal policy changes intended to limit their availability and appeal. The current study examined how restricting flavors would affect current AYA users' intentions to discontinue vaping, as a function of their current flavor preference. METHOD: In a national cross-sectional survey, AYA e-cigarette users (N = 1,414) completed measures of e-cigarette use, device type, e-liquid flavor (tobacco, menthol, cool mint, fruit ice, fruit/sweet), and intent to discontinue e-cigarette use in response to hypothetical federal product standards (i.e., tobacco and menthol or tobacco-only e-liquid). Logistic regression was used to model the association of preferred flavor with odds of discontinuing e-cigarette use (vs. continuing), for menthol and tobacco hypothetical product standards. RESULTS: Overall, 38.8% of the sample reported intent to discontinue using their e-cigarette if tobacco and menthol-flavored e-liquid were the only options available, whereas 70.8% would discontinue under a tobacco-only product standard. AYAs preferring fruit/sweet flavor were most sensitive to either restricted scenario, with odds of discontinuing use ranging from adjusted odds ratio (aOR) = 2.22 to aOR = 2.38 under a tobacco and menthol product standard and aOR = 1.33 to aOR = 2.59 under a tobacco-only product standard, compared with other flavor preferences. In addition, AYAs using cooling flavors (e.g., fruit ice) reported higher odds of discontinuing use under a tobacco-only product standard, compared with menthol flavor users, indicating an important distinction between these groups. CONCLUSIONS: Results indicate potential for flavor restrictions to reduce use of e-cigarettes among AYAs and suggest that a tobacco flavor product standard may result in the greatest discontinuation of use.

Ice flavours and non-menthol synthetic cooling agents in e-cigarette products: a review.

E-cigarettes with cooling flavours have diversified in ways that complicate tobacco control with the emergence of: (1) Ice-hybrid flavours (eg, 'Raspberry Ice') that combine cooling and fruity/sweet properties; and (2) Products containing non-menthol synthetic cooling agents (eg, Wilkinson Sword (WS), WS-3, WS-23 (termed 'koolada')). This paper reviews the background, chemistry, toxicology, marketing, user perceptions, use prevalence and policy implications of e-cigarette products with ice-hybrid flavours or non-menthol coolants. Scientific literature search supplemented with industry-generated and user-generated information found: (a) The tobacco industry has developed products containing synthetic coolants since 1974, (b) WS-3 and WS-23 are detected in mass-manufactured e-cigarettes (eg, PuffBar); (c) While safe for limited oral ingestion, inhalational toxicology and health effects from daily synthetic coolant exposure are unknown and merit scientific inquiry and attention from regulatory agencies; (d) Ice-hybrid flavours are marketed with themes incorporating fruitiness and/or coolness (eg, snow-covered raspberries); (e) WS-23/WS-3 concentrates also are sold as do-it-yourself additives, (f) Pharmacology research and user-generated and industry-generated information provide a premise to hypothesise that e-cigarette products with ice flavours or non-menthol cooling agents generate pleasant cooling sensations that mask nicotine's harshness while lacking certain aversive features of menthol-only products, (g) Adolescent and young adult use of e-cigarettes with ice-hybrid or other cooling flavours may be common and cross-sectionally associated with more frequent vaping and nicotine dependence in convenience samples. Evidence gaps in the epidemiology, toxicology, health effects and smoking cessation-promoting potential of using these products exist. E-cigarettes with ice flavours or synthetic coolants merit scientific and regulatory attention.

Characterizing different-flavored e-cigarette solutions from user-reported sensory attributes and appeal.

Scientists and regulators need parsimonious methods of characterizing flavored e-cigarettes which may vary widely in both chemical flavoring constituents and marketing descriptors. This laboratory experiment characterized user-reported appeal and experience of five cross-cutting sensory attributes (sweetness, bitterness, smoothness, harshness, coolness) of 10 common e-cigarette flavors. In a within-subject double-blind single-visit protocol, current nicotine/tobacco product users (N = 119) self-administered a single puff of each e-liquid flavor via a pod-style device and rated its appeal and sensory attributes on 0-100 scales. Custom-manufactured e-liquids, nicotine concentration: M (SD) = 23.4 (0.9) mg/mL, representative of commonly marketed fruit (green apple, strawberry), dessert (dark chocolate, vanilla), mint (peppermint, spearmint), nonmint cooling (menthol, koolada), and tobacco (subtle tobacco, full-flavored tobacco) flavor descriptors were used and their constituents were independently analyzed. Results largely demonstrated that a flavor's sensory attributes concorded with its marketed flavor descriptor. Among the 10 flavors, vanilla was rated sweetest (B[difference vs. mean of 9 other flavors] = 14.44, 95% CI [10.84, 18.03]), full-flavored tobacco was most bitter, B = 8.34, 95% CI [4.73, 11.96], subtle tobacco was most harsh, B = 5.69, 95% CI [1.70, 9.68], and peppermint scored highest in both smoothness, B = 6.98, 95% CI [3.13, 10.82], and coolness, B = 29.25, 95% CI [25.50, 33.01]. Flavors with higher appeal ratings tended to be sweeter, smoother, cooler, and less bitter and harsh. Chemical analysis found numerous flavoring constituents among study products without any clear differentiation of chemicals being present in particular flavor categories, which underscores the utility of using sensory ratings to characterize different-flavored e-cigarettes over and above constituent analyses. Characterizing e-cigarette flavors by subjective sensory attributes may be useful in future research and regulatory activities. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Effect of Exposure to e-Cigarettes With Salt vs Free-Base Nicotine on the Appeal and Sensory Experience of Vaping: A Randomized Clinical Trial.

Importance: Alkaline free-base nicotine is bitter and a respiratory irritant. High-nicotine electronic cigarette (e-cigarette) products contain acid additives that change nicotine from a free-base to a protonated salt chemical form, which could improve the sensory experience of vaping, particularly among never smokers unaccustomed to inhaling free-base nicotine. Objective: To determine whether exposure to e-cigarettes with salt vs free-base nicotine formulations improves the appeal and sensory experience of vaping e-cigarettes and whether nicotine formulation effects differ by e-cigarette flavor and ever combustible cigarette smoking status. Design, Setting, and Participants: Single-visit double-blind within-participant randomized clinical trial was conducted in an academic medical center outpatient clinical research facility in Southern California. Participants were 119 individuals with past 30-day e-cigarette or combustible cigarette use aged 21 years or older recruited from November 2019 to March 2020. Interventions: Participants self-administered standardized puffs of each 10 differently flavored e-cigarette solutions using a pod-style device. Each flavor was administered in salt (benzoic acid added) and free-base (no benzoic acid) nicotine formulations with commensurate nicotine concentrations (mean, 23.6 mg/mL). The 20 solutions were administered in randomly assigned sequences. Immediately after puffing each solution, participants rated appeal and sensory attributes. Main Outcomes and Measures: Self-reported appeal (mean of like, dislike [reverse-scored], and willingness to use again ratings) and 4 sensory attributes (sweetness, smoothness, bitterness, and harshness; analyzed individually) on visual analog scales with not at all and extremely anchors (range, 0-100). Results: Of the 119 participants; 39 (32.8%) were female. The mean (SD) age was 42.1 (14.4) years; 105 (88.2%) were ever combustible cigarette smokers, and 66 (55.5%) were current e-cigarette users. Salt vs free-base nicotine formulations produced higher ratings of appeal (salt vs free-base mean difference effect estimate: b = 12.0; 95% CI, 9.9-14.1; P < .001), sweetness (b = 9.3; 95% CI, 7.1-11.4; P < .001), and smoothness (b = 17.4; 95% CI, 15.2-19.6; P < .001) and lower ratings of bitterness (b = -13.3; 95% CI, -15.4 to -11.2; P < .001) and harshness (b = -21.0; 95% CI, -23.2 to -18.7; P < .001). Nicotine formulation effects largely generalized across different flavors and the smoothness-enhancing and harshness-reducing effects of nicotine salt were stronger in never vs ever cigarette smokers. Conclusions and Relevance: In this randomized clinical trial of adult current nicotine or tobacco product users, controlled exposure to e-cigarette puffs with salt vs free-base nicotine formulations appeared to increase product appeal and improve the sensory experience of vaping, particularly among never smokers. Regulatory policies limiting acid additives in e-cigarettes might reduce the appeal of high-nicotine e-cigarettes among populations deterred from vaping e-cigarettes that emit harsh aerosol. Trial Registration: ClinicalTrials.gov Identifier: NCT04399031.

Flavor and Nicotine Effects on E-cigarette Appeal in Young Adults: Moderation by Reason for Vaping.

Objectives: Effective regulations that reduce nicotine vaping among young adult dual (combustible and e-cigarette) users may differ depending on whether e-cigarettes are used for helping with smoking cessation. This laboratory experiment examined flavor and nicotine effects on e-cigarette product appeal among young adult dual users, stratified by reported use of e-cigarettes to quit smoking. Methods: Dual users aged 18-35 years that did (N = 31) or did not (N = 22) report vaping for the purpose of quitting smoking puffed e-cigarette solutions varied by a flavor (fruit, menthol, tobacco) and nicotine (nicotine-containing [6 mg/mL], nicotine-free) with-in-participant design. After puffing each solution, participants rated appeal. Results: In main effect analyses, non-tobacco (vs tobacco) flavors increased appeal and nicotine-containing (vs nicotine free) solutions reduced appeal similarly in dual users who did and did not vape to quit smoking. Interaction analyses found non-significant trend evidence that fruit and menthol flavors suppressed nicotine's appeal-reducing effects more powerfully in those that did not vape to quit smoking (flavor × nicotine × vape to quit smoking, ps = .05-.06). Conclusions: Non-tobacco flavors might increase e-cigarette product appeal in young adult dual users overall and disproportionately suppress nicotine's appeal-reducing effects in those that vape for purposes other than assisting with smoking cessation.

Outcomes of shipped live donor kidney transplants compared with traditional living donor kidney transplants.

The disparity between kidney transplant candidates and donors necessitates innovations to increase organ availability. Transporting kidneys allows for living donors and recipients to undergo surgery with a familiar transplant team, city, friends, and family. The effect of shipping kidneys and prolonged cold ischemia time (CIT) with living donor transplantation outcomes is not clearly known. This retrospective matched (age, gender, race, and year of procedure) cohort study compared allograft outcomes for shipped live donor kidney transplants and nonshipped living donor kidney transplants. Fifty-seven shipped live donor kidneys were transplanted from 31 institutions in 26 cities. The mean shipping distance was 1634 miles (range 123-2811) with mean CIT of 12.1 ± 2.8 h. The incidence of delayed graft function in the shipped cohort was 1.8% (1/57) compared to 0% (0/57) in the nonshipped cohort. The 1-year allograft survival was 98% in both cohorts. There were no significant differences between the mean serum creatinine values or the rates of serum creatinine decline in the immediate postoperative period even after adjusted for gender and differences in recipient and donor BMI. Despite prolonged CITs, outcomes for shipped live donor kidney transplants were similar when compared to matched nonshipped living donor kidney transplants.