Seasonal and diurnal variations in cardiovascular risk factors and cardiovascular disease in older British men

Cardiovascular disease (CVD) is the leading cause of death worldwide, and its prevalence is higher among older adults. Moreover, two different temporal variations in CVD risk exist: (i) seasonal: in Europe the CVD mortality risk is higher in winter, when outdoor temperatures are lower; (ii) diurnal: CVD deaths occur more frequently in the morning. However, biological pathways of both seasonal and diurnal variations in CVD mortality have not been fully understood. In part, this may be due to lack of understanding of variations of underlying CVD risk factors in older adults, especially inflammatory markers and physical activity. Investigating physical activity variations is of special interest, as new findings could also potentially shape the development of physical activity guidelines for older people. The aims of this thesis are twofold: (i) to investigate seasonal variations in CVD risk factors and mortality, by using outdoor temperature as the main exposure variable and seasonal factor of interest; ii) to investigate time of day variations of CVD risk factors. To achieve these objectives, data from the British Regional Heart Study of older adults were used. Seasonal variation findings: lower outdoor temperatures were especially associated with higher blood pressure, higher LDL-Cholesterol, higher IL-6, lower physical activity levels, and with increased CVD and respiratory mortality. In conclusion, better protection against low temperatures, as well as staying active during cold weather, could help in reducing the CVD risk in older adults. Diurnal variation findings: some CVD risk factors levels, especially blood pressure, LDL-Cholesterol and IL-6, increased linearly over the course of the daytime (in between 08:00-19:00 hours). Future studies aiming to understand the causal pathways of the diurnal variation in CVD events could focus especially on these markers’ variations. Also, physical activity levels peaked in the morning, and initiatives encouraging more active behaviours in the afternoon/evening are needed

Trajectories of objectively measured physical activity in free-living older men.

BACKGROUND: The steep decline in physical activity (PA) among the oldest old is not well understood; there is little information about the patterns of change in PA and sedentary behaviour (SB) in older people. Longitudinal data on objectively measured PA data can give insights about how PA and SB change with age. METHODS: Men age 70-90 yr, from a United Kingdom population-based cohort wore a GT3X accelerometer over the hip annually on up to three occasions (56%, 50%, and 51% response rates) spanning 2 yr. Multilevel models were used to estimate change in activity. Men were grouped according to achieving ≥150 min·wk of MVPA in bouts of ≥10 min (current guidelines) at two or three time points. RESULTS: A total of 1419 ambulatory men had ≥600 min wear time on ≥3 d at ≥2 time points. At baseline, men took 4806 steps per day and spent 72.5% of their day in SB, 23.1% in light PA, and 4.1% in moderate-to-vigorous PA (MVPA). Mean change per year was -341 steps, +1.1% SB, -0.7% light PA, and -0.4% MVPA each day (all P 30 min increased from 5.1 by 0.1 per year (P = 0.02). CONCLUSIONS: Among older adults, the steep decline in total PA occurred because of reductions in MVPA, while light PA is relatively spared and sedentary time and long sedentary bouts increase

Gut dysbiosis and adaptive immune response in diet-induced obesity vs. Systemic inflammation

A mutual interplay exists between adaptive immune system and gut microbiota. Altered gut microbial ecosystems are associated with the metabolic syndrome, occurring in most obese individuals. However, it is unknown why 10-25% of obese individuals are metabolically healthy, while normal weight individuals can develop inflammation and atherosclerosis. We modeled these specific metabolic conditions in mice fed with a chow diet, an obesogenic but not inflammatory diet-mimicking healthy obesity, or Paigen diet-mimicking inflammation in the lean subjects. We analyzed a range of markers and cytokines in the aorta, heart, abdominal fat, liver and spleen, and metagenomics analyses were performed on stool samples. T lymphocytes infiltration was found in the aorta and in the liver upon both diets, however a significant increase in CD4+ and CD8+ cells was found only in the heart of Paigen-fed animals, paralleled by increased expression of IL-1, IL-4, IL-6, IL-17, and IFN-\u3b3. Bacteroidia, Deltaproteobacteria, and Verrucomicrobia dominated in mice fed Paigen diet, while Gammaproteobacteria, Delataproteobacteria, and Erysipelotrichia were more abundant in obese mice. Mice reproducing human metabolic exceptions displayed gut microbiota phylogenetically distinct from normal diet-fed mice, and correlated with specific adaptive immune responses. Diet composition thus has a pervasive role in co-regulating adaptive immunity and the diversity of microbiota

Reducción de los descartes en la pesca con trasmallo: resultados experimentales utilizando trasmallo con “faldón” en la pesca artesanal del camarón, Penaeus kerathurus, en el mar Ligur (Mediterráneo Occidental)

This study aimed to test the effectiveness of a “guarding net”, a device placed at the bottom of a trammel net, for reducing unwanted catches in the caramote prawn trammel net fishery of the Ligurian Sea. This specialized and profitable fishery is affected by unwanted catches that generate high discard rates and damage to the nets, with environmental impacts and costs for fishermen. The experimental study consisted in comparing the catches of a standard trammel net (STN) with those of two “experimental” trammel nets, e.g. STNs provided with a guarding net of 19 cm (TGN20) and 24 cm height (TGN25), respectively. The guarding net, a strip of gillnet placed at the bottom of the net, can be considered a by-catch reducer device (BRD). Some fishermen of the investigated fishery have been using this device for several years. The results of the 15 experimental fishing trials performed from June to July 2016 indicate that the guarding nets significantly reduce discards (e.g. crabs and other invertebrates); the biomass of the unwanted species caught was 75% lower than that produced by the STN. The catch rates of the target species obtained with TGN20 and TGN25 were also significantly lower than those of the STN, though of a lesser amount. Nonetheless, this economic loss can be compensated by the decrease in sorting time and material and labour costs that can be achieved using the guarding net.El objetivo de este trabajo fue testar los efectos de un “faldón”, una red colocada en la parte inferior de un trasmallo, para reducir los descartes en la pesquería del camarón del mar Ligur. Se trata de una pesquería especializada y rentable, afectada por capturas no deseadas, que generan descartes y daños a las redes, con impacto ambiental y costes para los pescadores. Se llevaron a cabo pescas experimentales, para comparar la captura de un trasmallo estándar (STN) con la de dos trasmallos “experimentales”, construidos a partir de un trasmallo estándar, con el ajuste de un faldón de 19 cm de altura (TGN20), y de un faldón de 24 cm (TGN25). Este faldón, una banda de red de enmalle, se puede considerar como un dispositivo reductor de capturas accesorias (BRD). Algunos pescadores de la pesquería investigada ya utilizan este dispositivo desde hace algunos años. Los resultados de las quince pruebas experimentales, realizadas de junio a julio 2016, muestran que el faldón de red de enmalle contribuye significativamente a reducir los descartes (cangrejos y otros invertebrados), con una reducción de la biomasa de las especies descartadas hasta el 75%, respecto al trasmallo estándar. Al mismo tiempo, también las tasas de captura de las especies objetivo obtenidas con TGN20 y TGN25 fueron significativamente más bajas que las del STN, aunque de menor magnitud. Sin embargo, esta pérdida económica puede ser compensada por la disminución del tiempo de trabajo, de los costes del material y de la mano de obra, que se pueden lograr utilizando un trasmallo con “faldón”

Trajectories of Objectively Measured Physical Activity in Free-Living Older Men

ABSTRACT Background: The steep decline in physical activity (PA) among the oldest old is not well understood; there is little information about the patterns of change in PA and sedentary behaviour (SB) in older people. Longitudinal data on objectively measured PA data can give insights about how PA and SB change with age. Methods: Men age 70–90 yr, from a United Kingdom population-based cohort wore a GT3X accelerometer over the hip annually on up to three occasions (56%, 50%, and 51% response rates) spanning 2 yr. Multilevel models were used to estimate change in activity. Men were grouped according to achieving ≥150 min·wk−1 of MVPA in bouts of ≥10 min (current guidelines) at two or three time points. Results: A total of 1419 ambulatory men had ≥600 min wear time on ≥3 d at ≥2 time points. At baseline, men took 4806 steps per day and spent 72.5% of their day in SB, 23.1% in light PA, and 4.1% in moderate-to-vigorous PA (MVPA). Mean change per year was −341 steps, +1.1% SB, −0.7% light PA, and −0.4% MVPA each day (all P 30 min increased from 5.1 by 0.1 per year (P = 0.02). Conclusions: Among older adults, the steep decline in total PA occurred because of reductions in MVPA, while light PA is relatively spared and sedentary time and long sedentary bouts increase

Objectively measured physical activity, sedentary behaviour and all-cause mortality in older men: does volume of activity matter more than pattern of accumulation?

OBJECTIVES: To understand how device-measured sedentary behaviour and physical activity are related to all-cause mortality in older men, an age group with high levels of inactivity and sedentary behaviour. METHODS: Prospective population-based cohort study of men recruited from 24 UK General Practices in 1978-1980. In 2010-2012, 3137 surviving men were invited to a follow-up, 1655 (aged 71-92 years) agreed. Nurses measured height and weight, men completed health and demographic questionnaires and wore an ActiGraph GT3x accelerometer. All-cause mortality was collected through National Health Service central registers up to 1 June 2016. RESULTS: After median 5.0 years' follow-up, 194 deaths occurred in 1181 men without pre-existing cardiovascular disease. For each additional 30 min in sedentary behaviour, or light physical activity (LIPA), or 10 min in moderate to vigorous physical activity (MVPA), HRs for mortality were 1.17 (95% CI 1.10 to 1.25), 0.83 (95% CI 0.77 to 0.90) and 0.90 (95% CI 0.84 to 0.96), respectively. Adjustments for confounders did not meaningfully change estimates. Only LIPA remained significant on mutual adjustment for all intensities. The HR for accumulating 150 min MVPA/week in sporadic minutes (achieved by 66% of men) was 0.59 (95% CI 0.43 to 0.81) and 0.58 (95% CI 0.33 to 1.00) for accumulating 150 min MVPA/week in bouts lasting ≥10 min (achieved by 16% of men). Sedentary breaks were not associated with mortality. CONCLUSIONS: In older men, all activities (of light intensity upwards) were beneficial and accumulation of activity in bouts ≥10 min did not appear important beyond total volume of activity. Findings can inform physical activity guidelines for older adults

Smartphone detection of atrial fibrillation using photoplethysmography: a systematic review and meta-analysis

OBJECTIVES: Timely diagnosis of atrial fibrillation (AF) is essential to reduce complications from this increasingly common condition. We sought to assess the diagnostic accuracy of smartphone camera photoplethysmography (PPG) compared with conventional electrocardiogram (ECG) for AF detection. METHODS: This is a systematic review of MEDLINE, EMBASE and Cochrane (1980-December 2020), including any study or abstract, where smartphone PPG was compared with a reference ECG (1, 3 or 12-lead). Random effects meta-analysis was performed to pool sensitivity/specificity and identify publication bias, with study quality assessed using the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies-2) risk of bias tool. RESULTS: 28 studies were included (10 full-text publications and 18 abstracts), providing 31 comparisons of smartphone PPG versus ECG for AF detection. 11 404 participants were included (2950 in AF), with most studies being small and based in secondary care. Sensitivity and specificity for AF detection were high, ranging from 81% to 100%, and from 85% to 100%, respectively. 20 comparisons from 17 studies were meta-analysed, including 6891 participants (2299 with AF); the pooled sensitivity was 94% (95% CI 92% to 95%) and specificity 97% (96%-98%), with substantial heterogeneity (p<0.01). Studies were of poor quality overall and none met all the QUADAS-2 criteria, with particular issues regarding selection bias and the potential for publication bias. CONCLUSION: PPG provides a non-invasive, patient-led screening tool for AF. However, current evidence is limited to small, biased, low-quality studies with unrealistically high sensitivity and specificity. Further studies are needed, preferably independent from manufacturers, in order to advise clinicians on the true value of PPG technology for AF detection

Objectively measured physical activity, sedentary time and subclinical vascular disease: Cross-sectional study in older British men.

Low physical activity (PA) and high levels of sedentary time (ST) are associated with higher cardiovascular disease (CVD) risk among older people. However, their independent contribution and importance of duration of PA and ST bouts remain unclear. We investigated associations between objectively measured PA, ST and non-invasive vascular measures, markers of CVD risk. Cross-sectional study of 1216 men from the British Regional Heart Study, mean age 78.5years, measured in 2010-2012. Carotid intima thickness (CIMT), distensibility coefficient (DC) and plaque presence were measured using ultrasound; pulse wave velocity (cfPWV) and augmentation index (AIx) using a Vicorder. PA and ST were measured using hip-worn ActiGraph GT3X accelerometers. After adjusting for covariates, each additional 1000 steps per day was associated with a 0.038m/s lower cfPWV (95% CI=-0.076, 0.0003), 0.095 10(-3) kPa(-1) higher DC (95% CI=0.006, 0.185), 0.26% lower AIx (95% CI=-0.40, -0.12) and a 0.005mm lower CIMT (95% CI=-0.008, -0.001). Moderate and vigorous PA (MVPA) was associated with lower AIx and CIMT, light PA (LPA) with lower cfPWV and CIMT and ST with higher cfPWV, AIx and CIMT and lower DC. LPA and ST were highly correlated (r=-0.62). The independence of MVPA and ST or MVPA and LPA was inconsistent across vascular measures. Bout lengths for both PA and ST were not associated with vascular measures. In our cross-sectional study of older men, all PA regardless of intensity or bout duration was beneficially associated with vascular measures, as was lower ST. LPA was particularly relevant for cfPWV and CIMT