Effect of frailty status on mortality risk among chilean community-dwelling older adults

INTRODUCTION

The study of frailty and its effect on the risk of mortality in older people is of utmost importance, but understanding the critical factors is still limited. Our main objective was to analyze the association of frailty with all-cause mortality in a prospective community cohort of older people.

METHODS

A five-year longitudinal follow-up study was conducted with 1,174 community-dwelling older adults (men and women≥65 years old) from different Family Health Centers and community groups from Chile. We evaluated the functional risk, socioeconomic status, and anthropometric variables. The frailty status was evaluated by modified Fried criteria.

RESULTS

The diagnosis of frailty was reached in 290 older adult participants, who had significantly increased 5-year all-cause mortality independently of age, sex, cognitive impairment, and socioeconomic status (adjusted HR 1.51, 1.06-2.15).

CONCLUSION

Frailty is a predictor of increased mortality independently of age, sex, socio-economic and cognitive factors.

RhoA/rho kinase pathway activation in age-associated endothelial cell dysfunction and thrombosis

The small GTPase RhoA and the downstream Rho kinase (ROCK) regulate several cell functions and pathological processes in the vascular system that contribute to the age-dependent risk of cardiovascular disease, including endothelial dysfunction, excessive permeability, inflammation, impaired angiogenesis, abnormal vasoconstriction, decreased nitric oxide production and apoptosis. Frailty is a loss of physiological reserve and adaptive capacity with advanced age and is accompanied by a pro-inflammatory and pro-oxidative state that promotes vascular dysfunction and thrombosis. This review summarises the role of the RhoA/Rho kinase signalling pathway in endothelial dysfunction, the acquisition of the pro-thrombotic state and vascular ageing. We also discuss the possible role of RhoA/Rho kinase signalling as a promising therapeutic target for the prevention and treatment of age-related cardiovascular disease.

Analysis of myocardial infarction incidence and case-fatality in the last three decades in the province of Girona

INTRODUCTION AND OBJECTIVES

Myocardial infarction (MI) incidence and case fatality trends are highly informative but relatively untested at the population level. The objective of this work was to estimate MI incidence and case fatality in the Girona population aged 35-74 years, and to determine their 30-year trends (1990-2019).

METHODS

The REGICOR (Girona Heart Registry) monitored MI incidence and case fatality rates from 1990 to 2008. For the period 2008 to 2019, we linked discharges from Girona hospitals (n=4 974 977) and mortality registry (n=70 405) during this period. Our linkage algorithm selected key MI diagnostic codes and removed duplicates. Estimates from the linkage algorithm and the REGICOR registry were compared using chi-square tests for overlapping years (2008-2009). We estimated the annual percent change (APC) of standardized MI incidence and 28-day case fatality, and analyzed their trends using joinpoint regression.

RESULTS

MI incidence and case fatality estimates were similar in the linkage algorithm and the REGICOR registry. We observed significant decreasing trends in the incidence of MI. The trend was APC, -0.96% (95% confidence interval (95%CI), -1.4 to -0.53) in women from 1990 to 2019 and -4.2% (95%CI, -5.5 to -3.0) in men from 1994 to 2019. The largest decrease in case fatality was -3.8% (95%CI, -5.1 to -2.5) from 1995 to 2003 in women and -2.4% (95%CI, -2.9 to -1.9) from 1995 to 2004 in men, mainly due to prehospital case fatality declines: -1.8% (95%CI, -2.6 to -1.1) in men and -3.2% (95%CI, -4.6 to -1.8) in women.

CONCLUSIONS

In Girona, MI incidence and case fatality decreased between 1990 and 2019. The incidence showed a slow but continuous decrease while case fatality only stabilized in the last decade, particularly in women.

Effects of Extraction Methods on Phenolic Content, Antioxidant and Antiplatelet Activities of Tomato Pomace Extracts

Aqueous and ethanolic extracts of tomato pomace were examined with the aim of optimizing the extraction process of compounds with cardioprotective activity. Once the results of the ORAC response variables, total polyphenols, °Brix, and antiplatelet activity of the extracts were obtained, a multivariate statistical analysis was performed using the Statgraphics Centurion XIX software. This analysis showed that the most relevant positive effects in the inhibition of platelet aggregation were 83 ± 2% when using the agonist TRAP-6, when the working conditions were the type of tomato pomace conditioning (drum-drying process at 115 °C), phase ratio (1/8), type of solvent (ethanol 20%), and type of extraction (ultrasound-assisted solid-liquid extraction). The extracts with the best results were microencapsulated and characterized by HPLC. The presence of chlorogenic acid (0.729 mg/mg of dry sample) was found, a compound that has a potential cardioprotective effect documented in various studies, in addition to rutin (2.747 mg/mg of dry sample) and quercetin (0.255 mg/mg of dry sample). These results show that the extraction efficiency of compounds with cardioprotective activity depends largely on the polarity of the solvent, thus playing an important role in the antioxidant capacity of the extracts of tomato pomace.

Cholesterol and hypertension treatment but not time-dependent covariates or competing risks improve coronary risk prediction: the REGICOR study

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Carlos III Health Institute Agency for Management of University and Research Grants

Background

Cardiovascular (CV) risk functions are the recommended tool to identify high-risk individuals. However, discrimination of CV risk functions is not optimal. While the effect of biomarkers in CV risk prediction has been extensively studied, there is no data of CV risk functions including time-dependent covariates, competing risks and treatments.

Aim

To examine the effect of including time-dependent covariates, competing risks and treatments in CV risk prediction.

Methods

Participants from the REGICOR population cohorts (North-Eastern Spain) aged 35-74 years without previous history of cardiovascular disease were included (n=8,470). Coronary and stroke events, and mortality due to other CV causes or to cancer were recorded during the follow-up (median=12.6 years). A multi-state Markov model was constructed to include competing risks and time-dependent classical risk factors and treatments (2 measurements). This model was compared to Cox models with the basal measurement of classical risk factors, treatments or competing risks. Models were cross-validated and compared by their discrimination (area under the ROC curve), calibration (Hosmer-Lemeshow test) and reclassification (categorical net reclassification index).

Results

Cancer mortality was the event with the highest cumulative incidence. In coronary event prediction, cholesterol and hypertension treatment addition to classical risk factors, improved significantly discrimination by 2% and reclassification by 7-9%. In stroke event prediction, inclusion of time-dependent covariates decreased significantly discrimination by 3-5%.

Conclusion

Coronary risk prediction improves when cholesterol and hypertension treatment are included in risk functions. Coronary/stroke prediction does not improve with 2 measurements of covariates or with competing risks.

Antioxidant Capacity and Antiplatelet Activity of Aqueous Extracts of Common Bean (Phaseolus vulgaris L.) Obtained with Microwave and Ultrasound Assisted Extraction

Phaseolus vulgaris L. has beneficial effects on several chronic non-communicable diseases (e.g., cardiovascular diseases) related to oxidative stress. This redox state may influence platelet activation and aggregation; which is crucial in thrombus formation. In this work, the antiplatelet and antioxidant potential of aqueous extracts obtained by green processes, microwave-assisted extraction and ultrasound-assisted extraction, from 25 landraces of common beans were investigated. Phenol content and antioxidant potential were determined using the Folin-Ciocalteu method, total monomeric anthocyanin and ORAC assay, respectively. The antiplatelet potential of the extracts was explored by turbidimetry. Microwave extraction showed higher phenol content and antioxidant activity in most extracts. Soja landrace extract obtained by microwave-assisted extraction showed higher phenol content and antioxidant activity (893.45 ± 87.30 mg GAE/g and 35,642.85 ± 2588.88 ORAC μmolTE/g, respectively). Although most of the extracts obtained by microwave-assisted extraction showed antiplatelet activity, the extract of Hallado Aleman landrace obtained by ultrasound-assisted extraction (IC50 = 0.152 ± 0.018 mg/mL) had the highest antiplatelet potential. The extraction method, MAE and UAE, influences the biological potential of the beans, specifically the antiplatelet activity and antioxidant activity. The functional value of this legume for direct consumption by the population was evidenced, as well as its inclusion in food formulations.

Pathophysiology of deep vein thrombosis

Deep venous thrombosis is a frequent, multifactorial disease and a leading cause of morbidity and mortality. Most of the time deep venous thrombosis is triggered by the interaction between acquired risk factors, such as hip fracture, pregnancy, and immobility, and hereditary risk factors such as thrombophilias. The mechanisms underlying deep venous thrombosis are not fully elucidated; however, in recent years, important advances have shed light on the role of venous flow, endothelium, platelets, leukocytes, and the interaction between inflammation and hemostasis. It has been described that the alteration of venous blood flow produces endothelial activation, favoring the adhesion of platelets and leukocytes, which, through tissue factor expression and neutrophil extracellular traps formation, contribute to the activation of coagulation, trapping more cells, such as red blood cells. Thus, the concerted interaction of these phenomena allows the formation and growth of the thrombus. In this work, the main mechanisms involved in the pathophysiology of deep vein thrombosis will be described.

Sweet Potato (Ipomoea batatas L.) Phenotypes: From Agroindustry to Health Effects

Sweet potato (SP; Ipomoea batatas (L.) Lam) is an edible tuber native to America and the sixth most important food crop worldwide. China leads its production in a global market of USD 45 trillion. SP domesticated varieties differ in specific phenotypic/genotypic traits, yet all of them are rich in sugars, slow digestible/resistant starch, vitamins, minerals, bioactive proteins and lipids, carotenoids, polyphenols, ascorbic acid, alkaloids, coumarins, and saponins, in a genotype-dependent manner. Individually or synergistically, SP’s phytochemicals help to prevent many illnesses, including certain types of cancers and cardiovascular disorders. These and other topics, including the production and market diversification of raw SP and its products, and SP’s starch as a functional ingredient, are briefly discussed in this review.

Role of Phaseolus vulgaris L. in the Prevention of Cardiovascular Diseases-Cardioprotective Potential of Bioactive Compounds

In terms of safe and healthy food, beans play a relevant role. This crop belongs to the species of Phaseolusvulgaris L., being the most consumed legume worldwide, both for poor and developed countries, the latter seek to direct their diet to healthy feeding, mainly low in fat. Phaseolus vulgaris L. stands out in this area-an important source of protein, vitamins, essential minerals, soluble fiber, starch, phytochemicals, and low in fat from foods. This species has been attributed many beneficial properties for health; it has effects on the circulatory system, immune system, digestive system, among others. It has been suggested that Phaseolus vulgaris L. has a relevant role in the prevention of cardiovascular events, the main cause of mortality and morbidity worldwide. Conversely, the decrease in the consumption of this legume has been related to an increase in the prevalence of cardiovascular diseases. This review will allow us to relate the nutritional level of this species with cardiovascular events, based on the correlation of the main bioactive compounds and their role as cardiovascular protectors, in addition to revealing the main mechanisms that explain the cardioprotective effects regulated by the bioactive components.

Potential Therapies to Protect the Aging Heart Against Ischemia/Reperfusion Injury

Despite important advances in the treatment of myocardial infarction that have significantly reduced mortality, there is still an unmet need to limit the infarct size after reperfusion injury in order to prevent the onset and severity of heart failure. Multiple cardioprotective maneuvers, therapeutic targets, peptides and drugs have been developed to effectively protect the myocardium from reperfusion-induced cell death in preclinical studies. Nonetheless, the translation of these therapies from laboratory to clinical contexts has been quite challenging. Comorbidities, comedications or inadequate ischemia/reperfusion experimental models are clearly identified variables that need to be accounted for in order to achieve effective cardioprotection studies. The aging heart is characterized by altered proteostasis, DNA instability, epigenetic changes, among others. A vast number of studies has shown that multiple therapeutic strategies, such as ischemic conditioning phenomena and protective drugs are unable to protect the aged heart from myocardial infarction. In this Mini-Review, we will provide an updated state of the art concerning potential new cardioprotective strategies targeting the aging heart.

Antiplatelet Activity of Cucurbita maxima

Natural extracts constitute an important source in the prevention of noncommunicable diseases, such as cardiovascular diseases. The pumpkin, Cucurbita maxima, is widely consumed in Chile. Pumpkin seeds, despite having crude protein, lipids, and carbohydrates, are regarded as agro-industrial waste. In this work, we correlated the antiplatelet activity of aqueous, ethanolic, and methanolic extracts from pumpkin seeds with their bioactive compounds. In vitro platelet aggregation and activation studies were performed by turbidimetry and flow cytometry, respectively. Results reveal that the extracts inhibited, in a dose-dependent manner, platelet aggregation induced by adenosine diphosphate, thrombin receptor activator peptide 6 (TRAP-6), and collagen. Pumpkin seed extracts inhibited P-selectin secretion and glycoprotein IIb/IIIa activation on TRAP-6-activated platelets. They were found to be rich in fatty acids and a powerful source of plant-based protein, which could be related to the high antiplatelet potential identified in extracts. This research demonstrated that pumpkin seed extracts could be a candidate in the prevention of thrombotic events.

Association of Kidney Disease, Potassium, and Cardiovascular Risk Factor Prevalence with Coronary Arteriosclerotic Burden, by Sex

The present study aimed to determine the relationship between the prevalence of cardiovascular risk factors and the number and severity of coronary artery atherosclerotic lesions obtained by coronary angiography. We reviewed and analyzed 1642 records from consecutive patients at the Catheter Laboratory of Talca Regional Hospital in Chile between March 2018 and May 2019. Patients were stratified according to the presence and severity of atherosclerotic lesions: 632 (38.5%) had no lesions or <30% stenosis and 1010 (61.5%) had at least one coronary atherosclerotic lesion with ≥30% stenosis (CALS-30). CALS-30 was more frequent in males, smokers, and patients with diabetes and/or hypertension (all p-values < 0.02). Serum potassium, glycaemia, creatinine and glomerular filtration rates were also associated with CALS-30 (all p-values < 0.01) in males. The age and the proportion of males with CALS-30 increased with the number of risk factors (p-values for trends < 0.001). Our results showed a stronger association between the accumulation of risk factors and CALS-30 in women than in men. Serum potassium levels were inversely associated with CALS-30 in men but not in women.

Validity and trends of myocardial infarction incidence and case-fatality estimated from linked administrative databases

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): CIBERCV of cardiovascular diseases; CIBERESP.

OnBehalf

REGICOR investigators

Background

Although myocardial infarction (MI) severity trends are systematically measured with mortality rates, MI incidence trends and the precision of its estimation by linkage of anonymized electronic databases are relatively untested. We validated a linked-data method (LDM) to estimate a population MI incidence and case-fatality, and to analyse the 1990-2016 trends in North-Eastern Spain. 

Methods

LDM consisted of linking MI hospital discharges (n = 4,533,981) and mortality registry data (n = 40,676) for 2008-2016, selecting key MI diagnostic codes. The prospective REGICOR study, including all MI cases in Girona, 1990-2009, was used as the gold standard for validation purposes. Standardized MI cumulated incidence and 28-day case fatality for population aged 35-74 years was calculated, 1990-2016 trends were analysed by linear and joinpoint regression and annual percentage change (APC).

Results

LDM and REGICOR MI incidence and case-fatality estimates were similar for 2008-09 (Table). LDM MI incidence and case-fatality significantly decreased: APC 1990-2016 [95% CI]) was -1.8 [-2.6;-0.9] in women, and APC 2002-2016  -2.8 [-3.8;-1.8] in men; case-fatality APC 1990-2016 was -4.7% [-5.7;-3.8] in women and APC 1995-2005 -6.5%[-8.5;-4.5] in men. 

Conclusions

LDM in population aged 35-74 reliably estimated MI incidence and case-fatality. MI incidence and case-fatality significantly decreased after 1990.

Comparative analysis of REGICOR vs LDM REGICOR 2008-2009 LDM 2008-2009 Estimate 95% CI Estimate 95% CI P-Value Cumulated incidence Men 245.4 228.3; 262.5 239.7 222.5; 256.3 0.626 Women 61.1 52.6; 69.6 58.2 49.9; 66.4 0.626 Overall 28-day case-fatality Men 23.5% 19.7; 27.2 21.3% 17.8; 24.9 0.422 Women 19.3% 6.7; 31.9 17.7% 6.3; 29.1 0.855 In-hospital case-fatality Men 6.9% 4.8; 9.0 5.7% 3.8; 7.6 0.394 Women 5.0% 1.9; 8.2 3.7% 1.0; 6.5 0.540 Pre-hospital case-fatality Men 16.5% 11.8; 21.3 15.6% 11.2; 20.1 0.791 Women 14.2 % 6.6; 21.9 14.0% 6.3; 21.7 0.961 CI Confidence Interval

The Role of Coffee and its Bioactive Components in Platelet Function and Aging

Cardiovascular diseases (CVD) are known to be the world's leading cause of death, and different factors are known to increase the risk of death, including aging, mainly due to increased oxidative stress and inflammation observed in older people. Acute myocardial infarctions and cerebrovascular accidents belong to CVD, and are the ones that cause the most deaths and disabilities, where greater platelet activation plays an important role in pathophysiology. These diseases are more prevalent in older people, which have a clear relationship with increased platelet function and are strongly related to aging. Platelet function is affected by diet, which varies in its requirements and characteristics according to age. Coffee belongs to the family of diet elements that can alter platelet function and an increase in coffee consumption with advancing age and a U-shaped correlation with the risk of CVD have been reported. However, the effect of coffee consumption and its bioactive compounds on platelet function and aging presents controversial evidence, and therefore, a complex effect is not fully elucidated in the cardiovascular system. This review focuses on the relationship between coffee consumption (and its constituent bioactive compounds), and platelet function, and aging.

Anti-platelet activity and chemical characterization by UPLC-DAD-ESI-QTOF-MS of the main polyphenols in extracts from Psidium leaves and fruits

In Costa Rica, two species of Psidium fruits, P. guajava and P. friedrichsthalianum, are widely consumed as food and used in folk medicine. Although studies have revealed the health effects of these fruits, there has been little research showing the antiplatelet activity of these species. This work evaluated the antiplatelet potential of aqueous extracts made from leaves and fruits of pink guava and Costa Rican guava. Platelet aggregation was induced by the platelet agonists ADP, TRAP-6, collagen and PMA. Platelet activation and secretion were studied using flow cytometry. The chemical profiles of the four extracts were characterized using UPLC-DAD-ESI-QTOF-MS. The studies revealed that the aqueous extracts of leaves and fruits of P. guajava and P. friedrichsthalianum inhibited platelet aggregation induced by ADP (4 µM), TRAP-6 (5 µM), collagen (1 µg mL^-1) and PMA (100 nM), and the effect was dependent on the extract concentration. Extracts of leaves and fruits of pink guava and Costa Rican guava reduced secretion of P-selectin and activation of GP IIb/IIIa. The extracts of leaves and fruits of pink guava and Costa Rican guava proved to be a rich source of phenolic compounds, mainly quercetin aglycones and proanthocyanidins derived from (epi) catechin units. Other compounds such as ellagitannins, and benzophenones were also putatively identified. This research showed that P. guajava and P. friedrichsthalianum could potentially be used for the prevention of thrombotic events.

Antiplatelet effects of bioactive compounds present in tomato pomace

Cardiovascular diseases (CVD) currently account for nearly half of no communicable diseases. Epidemiological studies have demonstrated the cardiovascular protective role of a diet rich in vegetables and fruits. In this context, our research outcomes have demonstrated the antiplatelet activities of fruits and vegetable extracts widely consumed, among which tomato was highlighted in our lab work. Tomato pomace, a major byproduct of tomato paste production, consists of skin and seeds and is a rich source of bioactive compounds. Tomato pomace has potent antithrombotic effects, even greater than the tomato. Given the large volumes of an industrial generation of tomato pomace, there is an opportunity to use this by-product to obtain a functional product with antiaggregant and antithrombotic properties that could be useful as an additive in health foods and thus prevent CVD. This review will focus on the platelet as the target for the antithrombotic actions exerted by the different bioactive compounds present in tomato pomace.

Platelet Anti-Aggregant Activity and Bioactive Compounds of Ultrasound-Assisted Extracts from Whole and Seedless Tomato Pomace

Tomato paste production generates a residue known as tomato pomace, which corresponds to peels and seeds separated during tomato processing. Currently, there is an opportunity to use tomato pomace to obtain a functional extract with antithrombotic properties, such as platelet anti-aggregant activity. The aim of this study was to evaluate the yield and inhibitory activity of different extracts of tomato pomace on in vitro platelet aggregation, comparing this activity with commercial cardioprotective products, and quantify bioactive compounds. Aqueous or ethanolic/water (1:1) extracts of whole tomato pomace, seedless tomato pomace, tomato pomace supplemented with seeds (50% and 20%), and only seeds were obtained with different ultrasound-assisted extraction times. The inhibition of platelet aggregation was evaluated using a lumi-aggregometer. The quantification of bioactive compounds was determined by HPLC-MS. From 5 g of each type of tomato pomace sample, 0.023-0.22 g of a dry extract was obtained for the platelet aggregation assay. The time of sonication and extraction solvent had a significant role in platelet anti-aggregant activity of some extracts respect the control. Thus, the most active extracts decreased adenosine diphosphate (ADP)-induced platelet aggregation from 87 ± 6% (control) to values between 26 ± 6% and 34 ± 2% (p < 0.05). Furthermore, different ultrasound-assisted extraction conditions of tomato pomace fractions had varied concentration of flavonoids and nucleosides, and had an effect on extract yield.

Frail older adults show a distinct plasma microvesicle profile suggesting a prothrombotic and proinflammatory phenotype

In a global context of advanced aging, geriatric diseases such as frailty syndrome face challenges in the search for biomarkers and preventive strategies. Frailty has been associated with atherothrombotic pathologies. Circulating microvesicles (cMVs), phospholipid-rich vesicles with a size of 0.1-1.0 μm, have been shown to participate in atherothrombosis onset and progression. We have hypothesized that cMVs from platelets, and vascular and immune cells, are increased in frail older adults. To verify this, a prevalent-case control study was designed with 28 frail older and 27 nonfrail older adults older than 64 years. Frailty was defined by Fried's phenotype. Total cMVs, annexin V positive (AV+)-cMVs, and annexin V negative (AV^- )-cMVs derived from blood and vascular cells were measured by flow cytometry. In the analysis of total cMVs, the frail group presented higher levels of CD14⁺ /CD142⁺ (p = .042), CD41a⁺ /CD142⁺ (p = .041), and CD56⁺ (p = .025), CD14⁺ cMVs (p = .043), and CD16⁺ /CD14⁺ (p = .019) cMVs levels. Within the phosphatidylserine-exposing cMVs (AV⁺ ), the frail group showed higher CD14⁺ /AV⁺ (p = .044), CD9⁺ /AV⁺ (p = .031), P2RY12⁺ /AV⁺ (p = .028), and CD235a⁺ /AV⁺ (p = .043) cMVs concentrations. Finally, within AV^- cMVs, the frail group showed higher CD142⁺ /CD41a⁺ /AV^- cMVs concentrations originated from platelets (p = .027), CD56⁺ /AV^- originated from natural killer cells (p = .022), and CD34⁺ /AV^- cMVs from hematopoietic stem cells (p = .037). In summary, frail older adults present higher concentrations of platelet-, leukocyte-, and hematopoietic cell-derived cMVs compared to robust age-matched older adults. These cMVs may be involved in the deregulation of the immune system, endothelial damage, and increased risk of thrombosis associated with frailty.

Polypharmacy Is Associated with Frailty, Nutritional Risk and Chronic Disease in Chilean Older Adults: Remarks from PIEI-ES Study

AIM

To analyze the relationship between polypharmacy and variables as frailty and other chronic comorbidities in Chilean older adults.

DESIGN

Cross-sectional study.

PARTICIPANTS

One thousand two hundred and five older adults aged 65 and older.

METHODS

The presence or absence of frailty syndrome was determined according to Fried criteria. Data collection was made through questionnaires conducted by an interview.

RESULTS

The prevalence of polypharmacy was 37.59%. The prevalence of hyperpolypharmacy was 2%. Increased prevalence of frailty was demonstrated regarding the progression of the state of polypharmacy. When analyzing the contribution of frailty respect polypharmacy condition, frail state, nutritional risk and obesity are founded as a factor associated with polypharmacy. Regarding chronic disease, hypertension (OR: 8.039, p<0.0001), type 2 diabetes (OR: 4.001, p<0.0001) and respiratory diseases (OR: 2.930, p<0.0001) were associated to polypharmacy. It was found a strong and significant positive correlation between polypharmacy prevalence and frailty score (polypharmacy condition, Spearman R: 0.89, p=0.033; hyperpolypharmacy condition, Spearman R: 0.94, p=0.016). When analyzing the contribution of the polypharmacy to the presence of frailty, polypharmacy condition (OR: 1.510, p<0.05), cognitive impairment (OR: 3.887, p<0.001), obesity (OR: 1.560, p<0.01) and nutritional risk (OR: 2.590, p<0.001) are associated to frailty.

CONCLUSION

Frailty and chronic conditions as nutritional risk, obesity, hypertension, type 2 diabetes and respiratory disease are an important risk factor for the development of polypharmacy in Chilean older adults. Likewise, polypharmacy condition was observed to be a risk factor for frailty, demonstrating the bidirectional relationship between both conditions. Frailty syndrome evaluation in Chilean older adults could be an important alternative for polypharmacy prevention.

Impacts of Physical Environment Perception on the Frailty Condition in Older People

Frailty increases the vulnerability of older people who commonly develop a syndrome leading to growing dependence and finally often death. Physical environment conditions may affect the severity of the syndrome positive or negatively. The main objective of this study was to analyse the conditions of different urban physical environments and their relationship with the frailty syndrome in older people. Geographic Information Systems (GIS) analyses were performed to detect global and local geographic clustering. Investigating 284 adults with ages from 60 to 74 years old from Talca City, Chile, we found spatial clustering of frailty conditions registered for older people, with hotspots of high and low values associated with areas of different urban infrastructures and socioeconomic levels into the city. The spatial identifications found should facilitate exploring the impact of mental health programmes in communities exposed to disasters like earthquakes, thereby improving their quality of life as well as reducing overall costs. Spatial correlation has a great potential for studying frailty conditions in older people with regard to better understanding the impact of environmental conditions on health.

Effect of advanced glycation end products on platelet activation and aggregation: a comparative study of the role of glyoxal and methylglyoxal

Advanced glycation end products (AGEs) arising from dietary intake have been associated with numerous chronic diseases including cardiovascular diseases. The interaction between platelets and AGEs has been proposed to play a role in the etiology of cardiovascular diseases. However, the effects of the interaction between platelets and Maillard reaction products generated from glyoxal (Gly) or methylglyoxal (MG) are poorly understood. In this work, the effects of AGEs generated by the reaction between Gly or MG with Lys or bovine serum albumin (BSA) on platelet activation and aggregation were assessed. AGEs were generated incubating Gly or MG with Lys or BSA during 5 hours or 14 days, respectively. AGEs generation were characterized by kinetic studies and by amino acid analysis. Human platelet-rich plasma (PRP) was incubated with different concentrations of AGEs from Lys-MG or Lys-Gly and BSA-MG or BSA-Gly. Platelet activation was determined quantifying the expression of CD62 (P-selectin) in PRP exposed to different AGEs concentrations. It was found that Lys-MG and Lys-Gly induced an increase in P-selectin expression (p < .05), being 33.9% higher for Lys-MG when compared to Lys-Gly. Platelets incubated in the presence of BSA-MG and BSA-Gly did not show an increase in the P-selectin expression. Platelet aggregation was significantly higher for the mixture Lys-MG (in all the range of concentrations evaluated), whereas for Lys-Gly it was only significant the highest concentration (Lys 168 µM/Gly 168 µM). It was observed a significant increase in platelet aggregation induced by ADP for samples BSA-Gly. AGEs formed with MG-Lys induce a higher activation and aggregation of platelets when compared to those formed from Gly-Lys.

Synthesis of antiplatelet ortho-carbonyl hydroquinones with differential action on platelet aggregation stimulated by collagen or TRAP-6

Cardiovascular diseases are the leading cause of death in the world. Platelets have a major role in cardiovascular events as they bind to the damaged endothelium activating and forming thrombi. Although some hydroquinone scaffold-containing compounds have known antiplatelet activities, currently there is a lack of evidence on the antiplatelet activity of hydroquinones carrying electron attractor groups. In this work, we evaluate the antiplatelet effect of a series of ortho-carbonyl hydroquinone derivatives on cytotoxicity and function of human platelets, using collagen and thrombin receptor activator peptide 6 (TRAP-6) as agonists. Our structure-activity relationship study shows that gem-diethyl/methyl substitutions and the addition/modifications of the third ring of ortho-carbonyl hydroquinone scaffold influence on the selective index (IC₅₀ TRAP-6/IC₅₀ Collagen) and the inhibitory capacity of platelet aggregation. Compounds 3 and 8 inhibit agonist-induced platelet aggregation in a non-competitive manner with IC₅₀ values of 1.77 ± 2.09 μM (collagen) and 11.88 ± 4.59 μM (TRAP-6), respectively and show no cytotoxicity. Both compounds do not affect intracellular calcium levels and mitochondrial bioenergetics. Consistently, they reduce the expression of P-selectin, activation of glycoprotein IIb/IIIa, and release of adenosine triphosphate and CD63 from platelet. Our findings may be used for further development of new drugs in platelet-related thrombosis diseases.

Older adults with frailty syndrome present an altered platelet function and an increased level of circulating oxidative stress and mitochondrial dysfunction biomarker GDF-15

INTRODUCTION

The elderly population is increasing worldwide and in Chile, it is expected to grow rapidly. The World Health Organization (WHO) ICOPE guideline (Integrated Care for Older People) emphasizes the importance of frailty diagnosis to prevent dependence. Frailty in older adults is considered an indicator of vulnerability and poor health outcomes, of multifactorial etiology. Our objective was to investigate the association of activation of coagulation and increased risk of thrombosis with frailty in people older than 64 years. A prevalent-case control study was designed with 28 frail older and 27 robust older adults (non-frail, control group) older than 64 years. Frailty was defined by Fried's Phenotype, Platelet aggregation and activation plasma levels of Thromboxane B2 (TXB2), 8-isoprostane and Growth Differentiation Factor-15 (GDF-15) were determined.

RESULTS

Compared to healthy controls, frail older adults, had a) higher percentage of platelet aggregation induction with ADP 4 μM (82.85% (3.35) and 73.41% (3.26), p-value = 0.024) and subaggregant dose of ADP (30.83% (7.47) and 13.25% (3.21), p-value = 0.002); b) higher platelet activation: P-selectin exposure (18.23% (4.41) and 6.96% (1.08), p-value = 0.011), and activated GPIIβ-IIIα (21.51% (3.41) and 8.26% (1.18), p-value = 0.001), at the baseline level and against a subaggregant dose ADP: P-selectin exposure (46.93% (5.95) and 13.41% (3.35), p-value = 0.002) and activated GPIIβ-IIIα (43.29% (6.04) and 26.71% (4.92), p-value = 0.024); c) higher plasma levels of TXB2 (201.8 ng/mL (59.53-236.3) and 45.77 ng/mL (25.14-98.26), p-value<0.0001), d) elevated plasma levels of 8-isoprostane (70.94 pg/mL, IQ: 65.89-99,96 and 56.24 pg/mL, IQ: 42.18-74.81, p-value = 0.001), and e) higher plasma GDF-15 levels (2,379 pg/mL, IQ: 1,845-4,121and 1367 pg/mL, IQ: 1190-1747, p-value = 0.0001).

DISCUSSION

Older adults with frailty syndrome have an upregulated platelet activity that may contribute to an increased risk of thrombosis and aspirin resistance. The elevated oxidative stress and increases of GDF-15 levels might be related to altered platelet responsiveness in frail patients.

CONCLUSION

The determination of biomarkers of platelet dysfunction, oxidative stress and cell senescence/mitochondrial dysfunction may contribute to frailty diagnosis, and approaches aimed at regulating platelet function in frail older adults could contribute to its prevention and treatment.

Natural Bioactive Compounds As Protectors Of Mitochondrial Dysfunction In Cardiovascular Diseases And Aging

Diet, particularly the Mediterranean diet, has been considered as a protective factor against the development of cardiovascular diseases, the main cause of death in the world. Aging is one of the major risk factors for cardiovascular diseases, which have an oxidative pathophysiological component, being the mitochondria one of the key organelles in the regulation of oxidative stress. Certain natural bioactive compounds have the ability to regulate oxidative phosphorylation, the production of reactive oxygen species and the expression of mitochondrial proteins; but their efficacy within the mitochondrial physiopathology of cardiovascular diseases has not been clarified yet. The following review has the purpose of evaluating several natural compounds with evidence of mitochondrial effect in cardiovascular disease models, ascertaining the main cellular mechanisms and their potential use as functional foods for prevention of cardiovascular disease and healthy aging.

Antiplatelet Activity of Natural Bioactive Extracts from Mango (Mangifera Indica L.) and its By-Products

The potential antiplatelet aggregation effects of mango pulp and its by-products (peel, husk seed, and seed) due to the presence of bioactive compounds were explored. Among them, mango seed exhibited a 72% percentage inhibition of platelet aggregation induced by adenosine 5'-diphosphate (ADP) agonist with a demonstrated dose-dependent effect. This biological feature could be caused by the chemical differences in phenolic composition. Mango seed was especially rich in monogalloyl compounds, tetra- and penta-galloylglucose, ellagic acid, mangiferin, and benzophenones such as maclurin derivatives and iriflophenone glucoside. Mangiferin showed an inhibitory effect of 31%, suggesting its key role as one of the main contributors to the antiplatelet activity of mango seed. Therefore, mango seed could be postulated as a natural source of bioactive compounds with antiplatelet properties to design functional foods or complementary therapeutic treatments.

AEROBIC CAPACITY OF CHILEAN ADULTS AND ELDERLY: PROPOSAL OF CLASSIFICATION BY REGIONAL PERCENTILES

ABSTRACT Introduction Aerobic fitness is an important predictor that contributes to the preservation of functional independence during the aging process. Its measurement represents a fundamental tool in the identification of multiple health problems. Objective To compare the aerobic capacity of adults and elderly subjects through international studies and to develop percentiles by age group using the LMS method. Methods A cross-sectional descriptive study was conducted with 1146 subjects (437 men and 709 women). The age group of the sample ranged from 50 to 84 years. The subjects evaluated came from the physical activity programs offered by the National Sports Institute (IND) and by the city council of Talca (Chile). Body mass, stature, oxygen saturation (SatO2), six-minute walk test, and systolic and diastolic blood pressure were assessed. Body Mass Index (BMI) was calculated for both sexes. The LMS method was used to propose the percent distribution. Results Aerobic capacity decreases with age (28.5% for men and 29.9% for women). There was a negative relationship between age and the six-minute walk test (men r = -0.13 and women r = -0.39). There was a discrepancy between the elderly subjects in the current study and those from international studies. The normative data for the classification of aerobic fitness were expressed in percentiles (p3, p5, p10, p15, p25, p50, p75, p85, p90, p95 and p97). Conclusion The aerobic performance of elderly subjects diminishes as they age; in addition, the current results differ from international studies, which motivated the development of percentiles to classify aerobic fitness in everyday situations, especially in places with few resources and particularly where field tests are considered a priority for large-scale physical evaluation. Level of evidence II; Diagnostic studies – investigation of diagnostic test.

Antiplatelet protocol: Effects of ingesting a tomato pomace extract on human platelet aggregation

Consumption of tomato and tomato-based products is associated with risk reduction of cardiovascular disease (CVD). Protective effect of tomato is not clearly understood, but there is an interest in its ability to affect platelet aggregation (coagulation). Therefore, the aim of the present study is to describe the protocol of a single blind, parallel design (3-groups), placebo controlled trial, which will assess acute and "acute upon 5-day repeated dose" effects of ingesting a tomato pomace extract on platelet aggregation. Participants will be randomized to receive a flavoured water either with 1 g tomato pomace extract, 2.5 g tomato pomace extract or placebo negative control. A total of 99 people are required to complete (n = 33/group). Each group will ingest either a treatment or placebo once daily, for 5-days and blood samples will be taken to analyze platelet aggregation. For 14-days preceding the baseline assessment day and for the 5-day period of intervention, participants will have to exclude some foods/beverages from their diet, which are known to affect platelet function. The present study is expected to generate significant information about the effect of tomato pomace extract consumption on platelet function of volunteers.

Methodology of generation and purification of anti-beta 2 glycoprotein I antibodies

In this Method Article we are showing the methodology for generation and purification of Anti-Beta 2 Glycoprotein I (β₂GPI) antibodies. First β₂GPI was purified from human plasma, and recognized by Western Blot and anti-β₂GPI antibodies of serum from patients with antiphospholipid syndrome (APS). The C57BL/6 mice were immunized intraperitonealy with 150 μg of protein in adjuvant (β₂GPI or bovine serum albumin) on days 1, 8 and 14. Then the anti-β₂GPI antibodies were purified by affinity chromatography (Affi-Gel protein A sepharose) and affinity column using human β₂GPI coupled to CNBr-activated Sepharose 4B. Titles of anti-β₂GPI antibodies were determined by ELISA assays.

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We purified β₂GPI with great efficacy and that is recognized antigenically by serum from patients with SAP or an anti-β₂gpi antibody.

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We found that our purified antibody had 13 fold increased activity in ELISA test compared with the control and in Western Blot recognized with β₂GPI (reference and purified).

Roles of Phenolic Compounds in the Reduction of Risk Factors of Cardiovascular Diseases

The population is now living longer during the period classified as "elderly" (60 years and older), exhibiting multimorbidity associated to the lengthening of the average life span. The dietary intake of phenolic compounds (PC) may affect the physiology, disease development and progression during the aging process, reducing risk factors of age related diseases. The aim of this review is to briefly describe some of the possible effects of a series of PC on the reduction of risk factors of the onset of cardiovascular diseases, considering their potential mechanisms of action. The main actions described for PC are associated with reduced platelet activity, anti-inflammatory effects, and the protection from oxidation to reduce LDL and the generation of advanced glycation end products. Preclinical and clinical evidence of the physiological effects of various PC is presented, as well as the health claims approved by regulatory agencies.

Lipid Metabolism and Signaling in Platelet Function

Modern society has changed its diet composition, transitioning to a higher intake of saturated fat with a 50% increase of cardiovascular risk (CVD). Within the context of increased CVD, there is an induction of a prothrombotic phenotype mainly due to increased platelet reactivity as well as decreased platelet response to inhibitors. Platelets maintain haemostasis through both blood components and endothelial cells that secrete inhibitory or stimulatory molecules to regulate thrombus formation. There exist a correlation between platelets' polyunsaturated fatty acid (PUFA) and the increase in platelet reactivity. The aim of this chapter is to review the metabolism of the main PUFAs involved in platelet function associated with the role that their enzyme-derived oxidized metabolites exert in platelet function and fate. Finally, how lipid metabolism in the organism affect platelet aggregation and activation and the pharmacological modulation of these processes will also be discussed.

Anti-aggregation effect on platelets of Indiplon a hypnotic sedative non-benzodiazepine drug

Cardiovascular diseases are one of the main public health problems, and many of them, their pathophysiology involves alterations in platelet activity. Platelet activation is an essential event that is regulated by the intracellular concentrations of Ca2+ and cAMP. Interestingly, it has been shown that the activation of adenosine A2A receptors increases cAMP levels and produces the inhibition of platelet aggregation, which appears as a potential target for regulation of platelet activity. Therefore, we tried to activate A2A receptors using Indiplon, a drug developed for the treatment of insomnia, and analyze its effect on platelet activity in vitro. Our results indicate that Indiplon is able to interact in silico with the adenosine A2A receptor (ΔG_bind of -73.321 kcal/mol, similar to that obtained with adenosine), which is involved in the regulation of platelet cAMP levels. In functional studies using PRP, a reduction in platelet aggregation induced by ADP was observed in the presence of Indiplon at 500 μM with a percentage of inhibition 70%, where the use of specific inhibitors (ZM241385 and MSX-2) of the A2A receptor also blocked these effects reducing the percentage of inhibition to 41% and 34.1%, respectively. Also, the use of Indiplon produced a decrease in the expression in the membrane of P-selectin. Thus, Indiplon acts as an A2A receptor agonist and whose activation results in inhibition of platelet aggregation and activation, showing a possible cardiovascular protective role.

The cAMP/PKA Pathway Inhibits Beta-amyloid Peptide Release from Human Platelets

The main component of Alzheimer's disease (AD) is the amyloid-beta peptide (Aβ), the brain of these patients is characterized by deposits in the parenchyma and cerebral blood vessels known as cerebral amyloid angiopathy (CAA). On the other hand, the platelets are the major source of the Aβ peptide in circulation and once secreted can activate the platelets and endothelial cells producing the secretion of several inflammatory mediators that finally end up unchaining the CAA and later AD. In the present study we demonstrate that cAMP/PKA pathway plays key roles in the regulation of calpain activation and secretion of Aβ in human platelets. We confirmed that inhibition of platelet functionality occurred when platelets were incubated with forskolin (molecule that rapidly increased cAMP levels). In this sense we found that platelets pre-incubated with forskolin (20 μM) present a complete inhibition of calpain activity and this effect is reversed using an inhibitor of protein kinase A. Consequentially, when platelets were inhibited by forskolin a reduction in the processing of the APP with the consequent decrease in the Aβ peptide secretion was observed. Therefore our study provides novel insight in relation to the mechanism of processing and release of the Aβ peptide from human platelets.

Spatial analysis for the epidemiological study of cardiovascular diseases: A systematic literature search

Cardiovascular diseases (CVDs) are the primary cause of death and disability in de world, and the detection of populations at risk as well as localization of vulnerable areas is essential for adequate epidemiological management. Techniques developed for spatial analysis, among them geographical information systems and spatial statistics, such as cluster detection and spatial correlation, are useful for the study of the distribution of the CVDs. These techniques, enabling recognition of events at different geographical levels of study (e.g., rural, deprived neighbourhoods, etc.), make it possible to relate CVDs to factors present in the immediate environment. The systemic literature presented here shows that this group of diseases is clustered with regard to incidence, mortality and hospitalization as well as obesity, smoking, increased glycated haemoglobin levels, hypertension physical activity and age. In addition, acquired variables such as income, residency (rural or urban) and education, contribute to CVD clustering. Both local cluster detection and spatial regression techniques give statistical weight to the findings providing valuable information that can influence response mechanisms in the health services by indicating locations in need of intervention and assignment of available resources.

Atomic-level characterization and cilostazol affinity of poly(lactic acid) nanoparticles conjugated with differentially charged hydrophilic molecules

Nanotherapeutics is a promising field for numerous diseases and represents the forefront of modern medicine. In the present work, full atomistic computer simulations were applied to study poly(lactic acid) (PLA) nanoparticles conjugated with polyethylene glycol (PEG). The formation of this complex system was simulated using the reactive polarizable force field (ReaxFF). A full picture of the morphology, charge and functional group distribution is given. We found that all terminal groups (carboxylic acid, methoxy and amino) are randomly distributed at the surface of the nanoparticles. The surface design of NPs requires that the charged groups must surround the surface region for an optimal functionalization/charge distribution, which is a key factor in determining physicochemical interactions with different biological molecules inside the organism. Another important point that was investigated was the encapsulation of drugs in these nanocarriers and the prediction of the polymer-drug interactions, which provided a better insight into structural features that could affect the effectiveness of drug loading. We employed blind docking to predict NP-drug affinity testing on an antiaggregant compound, cilostazol. The results suggest that the combination of molecular dynamics ReaxFF simulations and blind docking techniques can be used as an explorative tool prior to experiments, which is useful for rational design of new drug delivery systems.

Immune System Dysfunction in the Elderly

Human aging is characterized by both physical and physiological frailty that profoundly affects the immune system. In this context aging is associated with declines in adaptive and innate immunity established as immunosenescence. Immunosenescence is a new concept that reflects the age-associated restructuring changes of innate and adaptive immune functions. Thus elderly individuals usually present chronic low-level inflammation, higher infection rates and chronic diseases. A study of alterations in the immune system during aging could provide a potentially useful biomarker for the evaluation of immune senescence treatment. The immune system is the result of the interplay between innate and adaptive immunity, yet the impact of aging on this function is unclear. In this article the function of the immune system during aging is explored.

Platelet Aging In Vivo Is Associated with Activation of Apoptotic Pathways: Studies in a Model of Suppressed Thrombopoiesis in Dogs

The mechanism(s) involved in the clearance of senescent platelets are largely unknown. We have recently demonstrated that platelet aging in vivo is associated with loss of membrane phospholipid asymmetry, a universal phenomenon in cells undergoing apoptosis. Thus, we postulated that senescent platelets may exhibit programmed cell death changes, which may trigger their removal from circulation. Since platelets contain the apoptosis machinery as well as mitochondria, a key organelle in the regulation of apoptosis, we studied the appearance of apoptotic-like changes during platelet aging in vivo. To investigate this, we assessed changes in mitochondrial membrane potential (Δψ) in circulating canine platelets during decline in platelet count after suppression of thrombopoiesis by estradiol injection, a validated model to obtain circulating platelets of increasing mean age. Phosphatidylserine (PS) exposure was determined by flow cytometry by binding of FITC-labeled annexin V. Mitochondrial Δψ was studied with the cationic lipophilic dye DIOC6 (3) and the J-aggregate-forming cation JC-1 and analysis by flow cytometry. The proportion of platelets with exposed PS rose significantly with age, from 2.88% before to 6.7%, 8 days after estradiol injection. By flow cytometry it was demonstrated a significant decreased in DIOC6 (3) fluorescence (median fluorescence intensity 791 ± 98 vs 567 ± 102 day 0 vs day 8 post injection of estradiol, respectively; n: 11; p <0.01), consistent with mitochondrial Δψ collapse. JC-1 has the unique property of forming J-aggregates under high mitochondrial Δψ (red fluorescence, FL2) whereas the monomeric form fluoresces in green (FL1). Aged platelets in vivo, loaded with JC-1, exhibited a significant increase in FL1/FL2 ratio (2.5 ± 1.7 vs 4.7 ± 1.6, day 0 vs day 8 post injection of estradiol, respectively; n: 13; p <0.05), confirming the mitochondrial Δψ alteration.

The results show that platelet aging in vivo is associated with a decrease in mitochondrial Δψ and PS exposure. In conclusion, our data provide for the first time, evidence that platelet senescence is associated with changes characteristics of apoptosis, which may promote their removal from circulation.

Platelet Aging In Vivo Is Associated with Loss of Membrane Phospholipid Asymmetry

The mechanism(s) involved in the clearance of senescent platelets are largely unknown. The loss of membrane phospholipid (PL) asymmetry, with phosphatidylserine (PS) exposure appears to be an important signal for the ingestion by macrophages of apoptotic nucleated cells and it has also been suggested as a signal for the removal of aged erythrocytes. Accordingly, it seems possible that the clearance of normal aged platelets from circulation might be triggered by PS exposure. To investigate this, we determined PS exposure in human aging platelets taking advantage of the relationship between platelet density and platelet age and in dog platelets in a model of platelet aging in vivo. PS exposure was determined in two experimental conditions: 1) human platelet density subpopulations obtained by centrifugation in arabinogalactan gradients; 2) circulating canine platelets during decline in platelet count after suppression of thrombopoiesis following estradiol injection. PS exposure was determined by flow cytometry after labeling the cells with FITC-conjugated annexin V. The proportion of human platelets with exposed PS was significantly higher in high density (HD) platelets compared to low density (LD) platelets (11.3 ± 8.0% vs 5.2 ± 3.7%; p <0.05, respectively). In dogs, the proportion of cells with exposed PS rises dramatically with age, from 3.1 ± 0.4% before to 17.7 ± 12.3% ten days after estradiol injection. These findings suggest that platelet aging is associated with loss of phospholipid asymmetry and PS exposure on the outer leaflet of cell membrane, which may play an important role in the recognition and subsequent removal of senescent platelets.

Docking and quantitative structure-activity relationship of bi-cyclic heteroaromatic pyridazinone and pyrazolone derivatives as phosphodiesterase 3A (PDE3A) inhibitors

PDE3s belong to the phosphodiesterases family, where the PDE3A isoform is the major subtype in platelets involved in the cAMP regulation pathway of platelet aggregation. PDE3A inhibitors have been designed as potential antiplatelet agents. In this work, a homology model of PDE3A was developed and used to obtain the binding modes of bicyclic heteroaromatic pyridazinones and pyrazolones. Most of the studied compounds adopted similar orientations within the PDE3A active site, establishing hydrogen bonds with catalytic amino acids. Besides, the structure-activity relationship of the studied inhibitors was described by using a field-based 3D-QSAR method. Different structure alignment strategies were employed, including template-based and docking-based alignments. Adequate correlation models were obtained according to internal and external validations. In general, QSAR models revealed that steric and hydrophobic fields describe the different inhibitory activities of the compounds, where the hydrogen bond donor and acceptor fields have minor contributions. It should be stressed that structural elements of PDE3A inhibitors are reported here, through descriptions of their binding interactions and their differential affinities. In this sense, the present results could be useful in the future design of more specific and potent PDE3A inhibitors that may be used for the treatment of cardiovascular diseases.

Impact of walkability with regard to physical activity in the prevention of diabetes

Walkability, a component of urban design intended to facilitate pedestrian traffic, depends on parameters associated with the connectivity of routes, population density and availability of destinations in the neighbourhood. The aim is to achieve levels of physical activity related to the prevention of risk factors associated with diseases, such as diabetes and the improvement of glycaemia control. It is important to consider that the effects of walkability depend on its relation with other variables present in the neighbourhood, e.g., environmental and socioeconomic factors. Considering this, improving walkability levels could be an effective strategy to reduce disease, the prevalence of diabetes in particular, in the population and thus reduce public spending. To investigate these relationships, PUBMED and ScienceDirect databases were searched using the following key words: Diabetes, Walkability and Physical activity.

Guanosine exerts antiplatelet and antithrombotic properties through an adenosine-related cAMP-PKA signaling

BACKGROUND

Guanosine is a natural product and an endogenous nucleoside that has shown to increase during myocardial ischemia. Platelets are critically involved in ischemic coronary events. It remains unknown, however, whether guanosine may affect platelet activation and function. We sought to investigate the potential antiplatelet and antithrombotic properties of guanosine and decipher the mechanisms behind.

METHODS

We firstly assessed the effects of guanosine on platelet activation/aggregation upon stimulation with several platelet agonists including adenosine diphosphate (ADP), collagen, arachidonic acid (AA), and TRAP-6. Guanosine antithrombotic potential was also evaluated both in vitro (Badimon perfusion chamber) and in vivo (murine model). In addition we assessed any potential effect on bleeding. At a mechanistic level we determined the release of thromboxane B2, intraplatelet cAMP levels, the binding affinity on platelet membrane, and the activation/phosphorylation of protein kinase A (PKA), phospholipase C (PLC) and PKC.

RESULTS

Guanosine markedly inhibited platelet activation/aggregation-challenged by ADP and, although to a lesser extent, also reduced platelet aggregation challenged by collagen, AA and TRAP-6. Guanosine significantly reduced thrombus formation both in vitro and in vivo without significantly affects bleeding. Guanosine antiplatelet effects were associated with the activation of the cAMP/PKA signaling pathway, and a reduction in thromboxane B2 levels and PLC and PKC phosphorylation. The platelet aggregation and binding affinity assays revealed that guanosine effects on platelets were mediated by adenosine.

CONCLUSION

Guanosine effectively reduces ADP-induced platelet aggregation and limits thrombotic risk. These antithrombotic properties are associated with the activation of the cAMP/PKA signaling pathway.

Study of the interactions between Edaglitazone and Ciglitazone with PPARγ and their antiplatelet profile

Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-activated transcription factor with an important role in lipid metabolism, inflammation and cardiovascular diseases. PPARγ ligands have inhibitory effects on platelet aggregation via the cAMP pathway, which may confer them a protective cardioprotective role. Edaglitazone and Ciglitazone are two chemically-similar thiazolidinedione (TZD) drugs that have been described as potent PPARγ agonists; however, Edaglitazone is over 100 times more potent than Ciglitazone. Here, we report a computational study to describe the ligand binding and the experimental antiplatelet profiles of Edaglitazone and Ciglitazone. Both ligands presented similar orientations within the PPARγ binding site. Their polar heads exhibit complex hydrogen bond networks with the residues at arm I pocket, while their hydrophobic tails are oriented inside arm II or the entrance pocket. The bulkier and longer tail of Edaglitazone exhibited additional hydrophobic interactions, explaining its stronger binding to PPARγ supported by binding affinity calculations. On the other hand, both Edaglitazone and Ciglitazone displayed an antiplatelet activity, but only Edaglitazone retained such effect at low concentrations. Furthermore, we evidenced that Edaglitazone increases intraplatelet cAMP levels and prevents PPARγ secretion, explaining its greater antiplatelet activity. Altogether, the more potent PPARγ agonist Edaglitazone seems to be a potent antiplatelet agent.

Platelet oxidative stress as a novel target of cardiovascular risk in frail older people

The average lifespan of humans and the percentage of people entering the 65 and older age group are growing rapidly. Within this age group, cardiovascular diseases (CVD) increase steeply and are the most common cause of death. During aging, experimental and clinical studies support the pivotal role played by reactive oxidant species in the mechanism of platelet activation. Frailty has been implicated as a causative and prognostic factor in patients with CVD. Oxidative stress is increased in frail older people, and may lead to accelerated aging and higher incidence of oxidative diseases such as CVD. The present article aims to highlight the relative contribution of platelet oxidative stress as a key target of frailty in elderly people with CVD.

Adenosine A2A receptor agonists with potent antiplatelet activity

Selected adenosine A_2A receptor agonists (PSB-15826, PSB-12404, and PSB-16301) have been evaluated as new antiplatelet agents. In addition, radioligand-binding studies and receptor-docking experiments were performed in order to explain their differential biological effects on a molecular level. Among the tested adenosine derivatives, PSB-15826 was the most potent compound to inhibit platelet aggregation (EC₅₀ 0.32 ± 0.05 µmol/L) and platelet P-selectin cell-surface localization (EC₅₀ 0.062 ± 0.2 µmol/L), and to increase intraplatelets cAMP levels (EC₅₀ 0.24 ± 0.01 µmol/L). The compound was more active than CGS21680 (EC₅₀ 0.97±0.07 µmol/L) and equipotent to NECA (EC₅₀ 0.31 ± 0.05 µmol/L) in platelet aggregation induced by ADP. In contrast to the results from cAMP assays, K_i values determined in radioligand-binding studies were not predictive of the A_2A agonists' antiplatelet activity. Docking studies revealed the key molecular determinants of this new family of adenosine A_2A receptor agonists: differences in activities are related to π-stacking interactions between the ligands and the residue His264 in the extracellular loop of the adenosine A_2A receptor which may result in increased residence times. In conclusion, these results provide an improved understanding of the requirements of antiplatelet adenosine A_2A receptor agonists.

Geographic clustering of elderly people with above-norm anthropometric measurements and blood chemistry

The global percentage of people over 60 is strongly increasing and estimated to exceed 20% by 20,150, which means that there will be an increase in many pathological conditions related to aging. Mapping of the location of aging people and identification of their needs can be extremely valuable from a social-economic point of view. Participants in this study were 148 randomly selected adults from Talca City, Chile aged 60-74 at baseline. Geographic information systems (GIS) analyses were performed using ArcGIS software through its module Spatial Autocorrelation. In this study, we demonstrated that elderly people show geographic clustering according to above-norm results of anthropometric measurements and blood chemistry. The spatial identifications found would facilitate exploring the impact of treatment programmes in communities where many aging people live, thereby improving their quality of life as well as reducing overall costs.