Cardiovascular Outcomes among Combustible-Tobacco and Electronic Nicotine Delivery System (ENDS) Users in Waves 1 through 5 of the Population Assessment of Tobacco and Health (PATH) Study, 2013-2019

BACKGROUND

Prior studies have not clearly established risk of cardiovascular disease (CVD) among smokers who switch to exclusive use of electronic nicotine delivery systems (ENDS). We compared cardiovascular disease incidence in combustible-tobacco users, those who transitioned to ENDS use, and those who quit tobacco with never tobacco users.

METHODS

This prospective cohort study analyzes five waves of Population Assessment of Tobacco and Health (PATH) Study data, Wave 1 (2013-2014) through Wave 5 (2018-2019). Cardiovascular disease (CVD) incidence was captured over three intervals (Waves 1 to 3, Waves 2 to 4, and Waves 3 to 5). Participants were adults (40+ years old) without a history of CVD for the first two waves of any interval. Change in tobacco use status, from exclusive past 30 day use of any combustible-tobacco product to either exclusive past 30 day ENDS use, dual past 30 day use of ENDS and combustible-tobacco, or no past 30 day use of any tobacco, between the first two waves of an interval was used to predict onset of CVD between the second and third waves in the interval. CVD incidence was defined as a new self-report of being told by a health professional that they had congestive heart failure, stroke, or a myocardial infarction. Generalized estimating equation (GEE) analyses combined 10,548 observations across intervals from 7820 eligible respondents.

RESULTS

Overall, there were 191 observations of CVD among 10,548 total observations (1.7%, standard error (SE) = 0.2), with 40 among 3014 never users of tobacco (1.5%, SE = 0.3). In multivariable models, CVD incidence was not significantly different for any tobacco user groups compared to never users. There were 126 observations of CVD among 6263 continuing exclusive combustible-tobacco users (adjusted odds ratio [AOR] = 1.44; 95% confidence interval (CI) 0.87-2.39), 15 observations of CVD among 565 who transitioned to dual use (AOR = 1.85; 0.78-4.37), and 10 observations of CVD among 654 who quit using tobacco (AOR = 1.18; 0.33-4.26). There were no observations of CVD among 53 who transitioned to exclusive ENDS use.

CONCLUSIONS

This study found no difference in CVD incidence by tobacco status over three 3 year intervals, even for tobacco quitters. It is possible that additional waves of PATH Study data, combined with information from other large longitudinal cohorts with careful tracking of ENDS use patterns may help to further clarify this relationship.

Stem Cell Pluripotency Genes Klf4 and Oct4 Regulate Complex SMC Phenotypic Changes Critical in Late-Stage Atherosclerotic Lesion Pathogenesis

Supplemental Digital Content is available in the text.

Background:

Rupture and erosion of advanced atherosclerotic lesions with a resultant myocardial infarction or stroke are the leading worldwide cause of death. However, we have a limited understanding of the identity, origin, and function of many cells that make up late-stage atherosclerotic lesions, as well as the mechanisms by which they control plaque stability.

Methods:

We conducted a comprehensive single-cell RNA sequencing of advanced human carotid endarterectomy samples and compared these with single-cell RNA sequencing from murine microdissected advanced atherosclerotic lesions with smooth muscle cell (SMC) and endothelial lineage tracing to survey all plaque cell types and rigorously determine their origin. We further used chromatin immunoprecipitation sequencing (ChIP-seq), bulk RNA sequencing, and an innovative dual lineage tracing mouse to understand the mechanism by which SMC phenotypic transitions affect lesion pathogenesis.

Results:

We provide evidence that SMC-specific Klf4- versus Oct4-knockout showed virtually opposite genomic signatures, and their putative target genes play an important role regulating SMC phenotypic changes. Single-cell RNA sequencing revealed remarkable similarity of transcriptomic clusters between mouse and human lesions and extensive plasticity of SMC- and endothelial cell-derived cells including 7 distinct clusters, most negative for traditional markers. In particular, SMC contributed to a Myh11^-, Lgals3⁺ population with a chondrocyte-like gene signature that was markedly reduced with SMC-Klf4 knockout. We observed that SMCs that activate Lgals3 compose up to two thirds of all SMC in lesions. However, initial activation of Lgals3 in these cells does not represent conversion to a terminally differentiated state, but rather represents transition of these cells to a unique stem cell marker gene–positive, extracellular matrix-remodeling, “pioneer” cell phenotype that is the first to invest within lesions and subsequently gives rise to at least 3 other SMC phenotypes within advanced lesions, including Klf4-dependent osteogenic phenotypes likely to contribute to plaque calcification and plaque destabilization.

Conclusions:

Taken together, these results provide evidence that SMC-derived cells within advanced mouse and human atherosclerotic lesions exhibit far greater phenotypic plasticity than generally believed, with Klf4 regulating transition to multiple phenotypes including Lgals3⁺ osteogenic cells likely to be detrimental for late-stage atherosclerosis plaque pathogenesis.

Telephone-based weight loss support for patients with knee osteoarthritis: a pragmatic randomised controlled trial

OBJECTIVE

To determine the effectiveness of telephone-based weight loss support in reducing the intensity of knee pain in patients with knee osteoarthritis, who are overweight or obese, compared to usual care.

DESIGN

We conducted a parallel randomised controlled trial (RCT), embedded within a cohort multiple RCT of patients on a waiting list for outpatient orthopaedic consultation at a tertiary referral hospital in NSW, Australia. Patients with knee osteoarthritis, classified as overweight or obese [body mass index (BMI) between ≥27 kg/m² and <40 kg/m²] were randomly allocated to receive referral to an existing non-disease specific government funded 6-month telephone-based weight management and healthy lifestyle service or usual care. The primary outcome was knee pain intensity measured using an 11-point numerical rating scale (NRS) over 6-month follow-up. A number of secondary outcomes, including self-reported weight were measured. Data analysis was by intention-to-treat according to a pre-published analysis plan.

RESULTS

Between May 19 and June 30 2015, 120 patients were randomly assigned to the intervention (59 analysed, one post-randomisation exclusion) or usual care (60 analysed). We found no statistically significant between group differences in pain intensity [area under the curve (AUC), mean difference 5.4, 95%CI: -13.7 to 24.5, P = 0.58] or weight change at 6 months (self-reported; mean difference -0.4, 95%CI: -2.6 to 1.8, P = 0.74).

CONCLUSIONS

Among patients with knee osteoarthritis who are overweight, telephone-based weight loss support, provided using an existing 6-month weight management and healthy lifestyle service did not reduce knee pain intensity or weight, compared with usual care.

TRIAL REGISTRATION NUMBER

ACTRN12615000490572.

Use of carbon fibers for repair of abdominal-wall defects in rats

Carbon in the form of 8-micron fibers induces growth of connective tissue. The purpose of this study was to measure and histologically characterize tissue ingrowth occurring in carbon fibers implanted for up to 12 months in abdominal-wall defects in rats, compared with polypropylene mesh. Carbon fibers induced significantly more tissue ingrowth than polypropylene mesh at 6 to 12 months postoperatively. The predominant tissues associated with carbon fibers and polypropylene mesh were dense connective tissue and fat, respectively. Fragmentation of the implants did not occur, and implant debris was not found in the regional lymph nodes. Carbon fibers are potentially useful for reinforcing abdominal-wall defects.

Day care and illness: evidence, cost, and public policy

Parents, pediatricians, social scientists, and policymakers have become increasingly concerned that infants and children in day care, especially those younger than 3 years of age, are at risk for morbidity associated with several types of acute illness. We have examined the empirical evidence on the impact of day-care attendance on frequency of respiratory illnesses, diarrhea, hepatitis A, meningitis, and cytomegalovirus disease in children, day-care staff, and household contacts. The short- and long-term costs of day-care-associated illnesses were assessed, wherever possible within a benefit-cost framework. Available evidence suggests that children in day care, and sometimes their teachers and household contacts, have higher rates of diarrhea, hepatitis A, meningitis, and possible otitis media than children not in day care. There is only weak or moderate evidence that children and their families are at risk for high rates of respiratory illness (other than otitis media) or cytomegalovirus infection. Taken together, the excess of these illnesses among children in day care may impose moderate net costs on families and on society. Revisions of state regulatory policy regarding health practices in day care and policy initiatives designed to provide parents with more information and authority are recommended to protect the health and development of children in day care.

Public school aggression among children with varying day-care experience

59 children with varying amounts and types of day-care experience were followed over their first 2 or 3 years of public schooling. Schoolteachers rated aggressiveness of several types and in several situations by these children, and also supplied information about managing the children, about children's use of strategies to avoid conflict, and about several associated skills and behaviors. Multivariate analyses indicated that children who had attended a cognitively oriented day-care program beginning in infancy were more aggressive than all other groups of children who had attended day care. Aggression among these children, however, declined over time, the children were not considered difficult to manage, and they were well liked by teachers. It was speculated that the increased aggressiveness among children attending cognitively oriented day care may have been caused by several problems of adaptation to the school setting.

Effects of repeated assessment on standardized test performance by infants

Infant-intervention programs that evaluate their effectiveness by repeatedly testing infants with standardized tests may confound intervention effects with repeated-testing effects. Further, maternal participation in testing may increase infants' test scores, either directly by giving infants practice with test-like items at home between test administrations or indirectly by helping infants adapt to the test setting. Thirty-five infants were tested at 3-month intervals between 4 and 28 months of age with the Bayley Scales of Infant Development and at 31 months of age with the Stanford-Binet; 25 infants were tested with the Bayley at 4 months and the Stanford-Binet at 31 months. Mothers of some infants in each group participated in the testing process. Between-subjects analysis on the Stanford-Binet revealed no effects for repeated testing or maternal participation. Within-subjects analyses for repeatedly tested groups demonstrated that maternal presence during testing, but not repeated testing, was associated with significantly higher Bayley scores. It was concluded that maternal presence is a potent influence on Bayley performance, that repeated experience with the Bayley biased neither performance on another standardized test of development nor subsequent Bayley performance, and that infant intervention programs are not likely to confound their evaluation designs by testing infants repeatedly.