County-level socio-environmental factors and obesity prevalence in the United States

AIMS

To investigate high-risk sociodemographic and environmental determinants of health (SEDH) potentially associated with adult obesity in counties in the United States using machine-learning techniques.

MATERIALS AND METHODS

We performed a cross-sectional analysis of county-level adult obesity prevalence (body mass index ≥30 kg/m2) in the United States using data from the Diabetes Surveillance System 2017. We harvested 49 county-level SEDH factors that were used in a classification and regression trees (CART) model to identify county-level clusters. The CART model was validated using a 'hold-out' set of counties and variable importance was evaluated using Random Forest.

RESULTS

Overall, we analysed 2752 counties in the United States, identifying a national median (interquartile range) obesity prevalence of 34.1% (30.2%, 37.7%). The CART method identified 11 clusters with a 60.8% relative increase in prevalence across the spectrum. Additionally, seven key SEDH variables were identified by CART to guide the categorization of clusters, including Physically Inactive (%), Diabetes (%), Severe Housing Problems (%), Food Insecurity (%), Uninsured (%), Population over 65 years (%) and Non-Hispanic Black (%).

CONCLUSION

There is significant county-level geographical variation in obesity prevalence in the United States, which can in part be explained by complex SEDH factors. The use of machine-learning techniques to analyse these factors can provide valuable insights into the importance of these upstream determinants of obesity and, therefore, aid in the development of geo-specific strategic interventions and optimize resource allocation to help battle the obesity pandemic.

Clopidogrel monotherapy following dual antiplatelet therapy in patients with acute coronary syndrome post-drug-eluting stent implantation: a systematic review and direct/indirect treatment comparison

Background

In patients with acute coronary syndromes (ACS) receiving a drug-eluting stent (DES), treatment with dual antiplatelet therapy (DAPT) reduces the risk of recurrent ischemic events. Optimal duration of DAPT depends on patient characteristics and switching to single antiplatelet therapy (SAPT) is recommended after the course of DAPT.

Purpose

The aim of this study was to evaluate the comparative efficacy and safety of switching to clopidogrel SAPT following DAPT in patients with ACS post DES-implantation.

Methods

A systematic literature review (SLR) was conducted by searching MEDLINE®, Embase, and CENTRAL up to July 27, 2021. Randomized controlled trials (RCTs) and observational studies that evaluated clopidogrel SAPT following DAPT in adults with ACS post-DES implantation were included. Heterogeneity of included studies was vetted in a feasibility assessment. Random effects meta-analyses were conducted using the metafor package for R. Direct comparisons were conducted for clopidogrel vs. aspirin and clopidogrel vs. DAPT. Using the Bucher method, aspirin vs. DAPT was indirectly compared by taking the difference between their respective pooled treatment effects vs. clopidogrel. A sensitivity analysis was conducted by including studies with a follow-up of 12 months.

Results

Of 5,349 records identified, seven unique studies (four RCTs and three observational studies) were eligible to be included in the SLR and quantitative treatment comparison. Risk of major adverse cardiovascular events (MACE) was lower in patients who switched to clopidogrel SAPT after DAPT compared with those who switched to aspirin monotherapy (hazard ratio [HR]: 0.72; 95% confidence interval [CI]: 0.54, 0.98), and this difference was significant. No significant difference in risk of MACE was found between switching to clopidogrel SAPT after DAPT and continuation of DAPT (HR: 0.90; 95% CI: 0.65, 1.25). This finding was consistent with the sensitivity analysis representing studies with follow-up of 12 months (HR: 0.95; 95% CI: 0.69, 1.31). Risk of bleeding was not analysed due to insufficient data across included studies for patients with ACS. However, within-study findings from one RCT of 4,136 patients demonstrated a significantly lower risk of bleeding, defined as thrombolysis in myocardial infarction (major and/or minor, for switching to clopidogrel SAPT following DAPT compared with continuation of DAPT (0.54% vs. 1.17% of patients had bleeding [HR: 0.46; 95% CI: 0.23, 0.94]).

Conclusion

Findings from this SLR suggest switching to clopidogrel SAPT after DAPT in ACS post-DES implantation has a lower risk of MACE compared with switching to aspirin monotherapy, and no difference in the risk of MACE compared with continuation of DAPT. There was insufficient data across the included studies to evaluate the bleeding risk, however, a single study indicated a lower bleeding risk with switching to clopidogrel SAPT.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Sanofi

MODELING REALITY: REVISITING CALVERT'S FITNESS SIMULATION

Wearable sensors have gained mainstream acceptance for health and fitness monitoring despite the absence of clinically validated analytic models for clinical decision support. Individual sensors measuring, say, EKG signal and heart rate can provide insight on cardiovascular response, but a more complete picture of health and fitness requires a more complete portfolio of sensors and data. This paper outlines the research underway to revisit and reconfigure the 1976 Calvert systems model of the effect of training on physical performance. Specifically, we use wearable sensor data from clinical trials to supplement a hybrid model created by nesting Perl's Performance-Potential model within Calvert's transfer function approach to system simulation. Contemporary simulation tools combined with wearables clinical trial data is the foundation for a more agile platform for simulation of fitness and exploration of causality between training and physical performance. This platform offers the opportunity to strategically integrate data from various wearable sensors in a fashion enabling improved support for post-injury and return to sport decision-making.

Comparison of gene expression profiles between Peyronie's disease and Dupuytren's contracture

OBJECTIVES

To compare the gene expression alterations in human Peyronie's disease (PD) and Dupuytren's disease (DD) to determine whether they share a common pathophysiology. Multiple mRNA expression profiles of human PD have previously shown that genes that regulate fibroblast replication, myofibroblast differentiation, collagen metabolism, tissue repair, and ossification are involved. DD, a palmar fascia fibrosis, may be associated with PD.

METHODS

Total RNA samples from PD plaques, normal tunica albuginea, Dupuytren's nodules, and normal palmar fascia (nine samples per group) were subjected to differential gene expression profile analysis (Clontech Atlas DNA microarray) comparing PD with tunica albuginea and DD with normal palmar fascia. Changes of more than 2.0 in PD and DD compared with tunica albuginea and normal palmar fascia, respectively, were recorded. Reverse transcriptase-polymerase chain reactions were performed for some genes whose expression was altered in PD.

RESULTS

Some of the gene families upregulated in both PD and DD were (a) collagen degradation: matrix metalloproteinase (MMP), with MMP2 and MMP9, and thymosins (MMP activators), with TMbeta10 and TMbeta4; (b) ossification: osteoblast-specific factors (OSFs) OSF-1 and OSF-2 (DD only); and (c) myofibroblast differentiation: RhoGDP dissociation inhibitor 1. The genes upregulated in PD only were decorin (an inhibitor of transforming growth factor-beta1 and a part of fibroblast replication/collagen synthesis) and early growth response protein. Reverse transcriptase-polymerase chain reaction confirmed these changes.

CONCLUSIONS

These data demonstrate that the pattern of alterations in the expression of certain gene families in PD and DD is similar, suggesting that they share a common pathophysiology and may be amenable to the same therapeutic regimens.

Gene expression in Peyronie's disease

Currently, surgical intervention is the only efficacious treatment for Peyronie's disease (PD), a fibromatosis of the tunica albuginea of the penis. Therapies based on the molecular pathways for this disease could provide alternatives to surgical treatment but only recently has the pathophysiology of the Peyronie's disease plaque been investigated at the molecular level. In this review, we examine the current knowledge of gene expression in the PD plaque and the relationship of PD with other fibrotic conditions such as Dupytren's disease. TGFbeta1, along with other growth factors, pro-fibrotic genes, and collagen, are expressed in fibroblasts and myofibroblasts. Myofibroblasts are normally involved in wound contracture and largely eliminated via apoptosis during the late stages of wound remodeling. In the PD plaque, however, these cells persist and may play an important role in the PD plaque fibrosis. The expression levels of TGFbeta1 and pro- and anti-fibrotic gene products, along with the nitric oxide/reactive oxygen species (NO/ROS) ratio in the tunica albuginea, appear to be essential for the formation and progression of the PD plaque and effect the expression of multiple genes. This can be assessed with the recently developed DNA-based chip arrays and results with the PD plaque have been encouraging. OSF-1 (osteoblast recruitment), MCP-1 (macrophage recruitment), procollagenase IV (collagenase degradation), and other fibrotic genes have been identified as being possible candidate regulatory genes. Finally, possible therapeutic avenues for gene-based therapy in the treatment of PD are discussed that may eventually reduce the need for surgical intervention.

Antifibrotic role of inducible nitric oxide synthase

Long-term treatment in rats with l-NAME, an isoform-non-specific inhibitor of nitric oxide synthase (NOS), leads to fibrosis of the heart and kidney, suggesting that nitric oxide (NO) may play a role in preventing tissue fibrosis. In this process, a likely target of NO is the quenching of reactive oxygen species (ROS) through peroxynitrite formation, and one possible source for this NO is inducible NOS (iNOS). Using Peyronie's disease (PD) tissue from both human specimens and from a rat model of PD as the source of fibrotic tissue, we investigated if NO derived from iNOS could act as such an antifibrogenic defense mechanism by determining whether: (a) tunical ROS and iNOS are increased in PD; and (b) the long-term inhibition of iNOS activity decreases the NO/ROS balance in the tunica albuginea thereby promoting collagen deposition. It was determined that in the human PD plaque, iNOS mRNA and protein, ROS, collagen, and the peroxynitrite marker, nitrotyrosine, were all increased in comparison to the normal tunica. In the rat model of PD, the fibrotic plaque also showed significant increases in iNOS mRNA and protein, nitrotyrosine, ROS as measured by heme oxygenase-1, and collagen when compared with the normal control tunica. When a selective inhibitor of iNOS, L-NIL, was given to rats with the PD-like plaque, this resulted in a decrease in nitrotyrosine levels but intensified ROS levels and collagen deposition. These data demonstrate that: (a) iNOS induction occurs in both the human and rat PD fibrotic plaque; and (b) that the NO derived from iNOS appears to counteract ROS formation and collagen deposition. Because the inhibition of iNOS activity leads to a decrease in the NO/ROS ratio, thereby favoring the development of fibrosis, it is proposed that iNOS induction in this tissue may be a protective mechanism against fibrosis and abnormal wound healing.

Identification of retinoic acid-responsive elements on the HNF1alpha and HNF4alpha genes

Hepatocyte nuclear factor 1alpha (HNF1alpha) and HNF4alpha are liver-selective transcription factors and are essential for hepatocyte differentiation. This study demonstrates that HNF1alpha as well as HNF4alpha genes contain a direct repeat with a space of one nucleotide (DR1)-retinoic acid (RA) response element that can be bound and regulated by RA and retinoid x receptor alpha (RXRalpha) complex. Transient transfection experiments showed that RA increased the promoter activity of the HNF1alpha and HNF4alpha genes in Hep3B cells. Overexpression of RXRalpha further enhanced the activities of both genes. Two putative RXRalpha binding sites on the HNF1alpha (-295 to -276) and HNF4alpha (-418 to -399) genes have been characterized. By transient transfection, both sites positively responded to RA, and overexpression of RXRalpha in Hep3B cells increased the regulatory effect. Gel mobility shift assay demonstrated that these two DR-1 sites could be bound by RXRalpha specifically. These data suggest that the differentiation effect of RA on hepatocyte may be due to direct interaction of RXRalpha with the RA-responsive elements on the HNF1alpha and HNF4alpha genes.

Molecular mechanisms regulating the effects of oxytocin on myometrial intracellular calcium

Oxytocin stimulates an increase in intracellular calcium in uterine myometrium by several mechanisms. Several lines of evidence indicate that the oxytocin receptor is functionally coupled to GTP-binding proteins of the G alpha q/11 class which stimulate phospholipase C activity. The IP3 generated as a result of phospholipase C activation can trigger release of calcium from intracellular stores. The finding that the oxytocin-stimulated increase in intracellular calcium in myometrial cells is greater in the presence of extracellular calcium than that in its absence indicates that oxytocin also has effects on calcium entry. This action is nifedipine-insensitive but may involve indirect stimulation of calcium entry through release-operated channels. An anti-G alpha q/11 antibody inhibits both oxytocin-stimulated GTPase activity and phospholipase C activity in myometrial membranes. The stimulation by oxytocin of phosphoinositide turnover in COS cells transfected with a plasmid expressing the oxytocin receptor is enhanced by cotransfection of G alpha q. Co-transfection of intracellular domains of the oxytocin receptor causes varying degrees of interference with oxytocin-stimulated phosphoinositide turnover. The data suggest that more than one intracellular domain is involved in oxytocin receptor/G-protein coupling. Oxytocin receptor stimulation of phospholipase C is inhibited by cAMP. This occurs in myometrial cells and in COS cells transfected with a plasmid expressing the receptor. The inhibitory mechanism involves the action of protein kinase A and is probably targeted indirectly at the G alpha q/11 /phospholipase C coupling step.

Evidence for the involvement of several intracellular domains in the coupling of oxytocin receptor to G alpha(q/11)

In order to probe the nature of oxytocin receptor (OTR)/G alpha(q/11) protein coupling, we examined the effect of co-expression of OTR intracellular domains on oxytocin-stimulated phosphoinositide turnover in COSM6 cells overexpressing OTR and G alpha(q). Co-expression of G alpha(q) enhanced the oxytocin response maximally at a pOTR/pG alpha(q) plasmid transfection ratio of 1:0.16. In cells co-expressing OTR and G alpha(q/11), oxytocin stimulated phosphoinositide turnover with an EC50 of 48 nM. Co-transfection with plasmids expressing OTR intracellular domains inhibited oxytocin-stimulated phosphoinositide turnover by 23 +/- 6% (1i), 37 +/- 4% (2i), 55 +/- 6% (3i), and 40 +/- 6% (4i), respectively (P < 0.01). Expression of the 3i loop of the alpha(1B)-adrenergic receptor, which also couples to G alpha(q/11), inhibited phosphoinositide turnover by 35 +/- 2% (P < 0.01), while expression of the 3i loop of the dopamine 1A receptor, which couples to G alpha(s), had no effect. While these data indicate a functional role for the OTR 3i loop, they also suggest that interactions with more than one intracellular domain probably mediate the coupling of OTR to the G alpha(q/11) class of GTP-binding proteins.

Oxytocin stimulates myometrial guanosine triphosphatase and phospholipase-C activities via coupling to G alpha q/11

Oxytocin stimulates phosphoinositide turnover in myometrium. To elucidate whether the coupling mechanism involves the interaction of oxytocin receptor with GTP-binding proteins, we examined oxytocin stimulation of guanosine triphosphatase (GTPase) activity and phospholipase-C activity in rat and human myometrial membranes. Oxytocin consistently stimulated both GTPase and phospholipase-C activities, and both stimulations were attenuated by an antibody directed against the carboxyl-terminals of the GTP-binding proteins, G alpha q and G alpha 11. Neutralization of the antibody by preincubation with antigenic peptide reversed this inhibition. [Thr4,Gly7]oxytocin, a specific oxytocin receptor agonist, stimulated both GTPase and phospholipase-C activities, and the stimulations were also inhibited by anti-G alpha q/11 IgG. Immunoreactive GTP-binding proteins, G alpha q and G alpha 11, and phospholipase-C beta 3 isoforms were present in myometrial membranes. These results indicate that stimulation of phospholipase-C activity by oxytocin in myometrium is mediated via G alpha q, G alpha 11, or a closely related GTP-binding protein, probably coupling to phospholipase-C beta.

A comparison of microtubule assembly in brain extracts from young and old rats

Microtubule assembly was examined in the high-speed supernatant from homogenates of young (2-4 months old) and old (more than 24 months old) rat brains and significant age-related differences in microtubule assembly were found in the absence of exogenous GTP. In extracts from young brains, the increase in absorbance at 350 nm, which reflects the assembly reaction, was characterized by three phases (lag, elongation, and steady state) superimposed on a slow continuous increase due to non-specific aggregation. However, assembly in extracts from old brains, was very sluggish, in some cases barely more rapid than the non-specific aggregation reaction. Two to three times as much protein was assembled into cold-labile microtubules in extracts from young brains than from old brains. When 1 mM GTP was included in the assembly solutions the patterns of assembly in extracts from young and old brains became similar, with about the same amount of protein assembled into cold-labile microtubules. The assembly of tubulin purified from rat brains showed no differences between young and old. Results showed that extracts from old brains contained a higher GTPase activity than extracts from young brains. The sluggish assembly in extracts from old brains could be due to a deficiency in GTP or an inefficient regeneration of GTP.