• seasonal variation
• sudden cardiac death

• Humans
• Death, Sudden, Cardiac/epidemiology
• Death, Sudden, Cardiac/etiology
• Seasons
• Male
• Female
• Adult
• Registries
• Middle Aged
• United Kingdom/epidemiology
• Risk Factors
• Aged
• Retrospective Studies
• Young Adult
• Adolescent
• Autopsy

• Ambient Temperature
• Blood Pressure
• Cardiorenal Physiology
• Climate Change
• Environmental Health
• Global Warming
• Nephrology
• Urinary Electrolytes

• Humans
• Blood Pressure/physiology
• Male
• Female
• Electrolytes/urine
• Adult
• Bangladesh
• Middle Aged
• Hot Temperature
• Temperature
• Magnesium/urine

• Wellcome Trust

• Asymptomatic
• Dry Season
• Infection Length
• Malaria
• Sensing

• Plasmodium falciparum/physiology
• Plasmodium falciparum/pathogenicity
• Humans
• Seasons
• Malaria, Falciparum/parasitology
• Malaria, Falciparum/transmission
• Malaria, Falciparum/blood
• Child
• Child, Preschool
• Female
• Male
• Mali
• Infant
• Host-Parasite Interactions

• K23 AI076614 NIAID NIH HHS
• K24 AI144048 NIAID NIH HHS
• R01 AI141544 NIAID NIH HHS
• StG#759534 EC | ERC | HORIZON EUROPE European Research Council (ERC)
• Deutsches Zentrum für Infektionsforschung (DZIF)
• HHS | NIH | NIAID | Division of Intramural Research (DIR, NIAID)
• HHS | NIH | National Institute of Allergy and Infectious Diseases (NIAID)
• HHS | NIH | NIAID | Division of Microbiology and Infectious Diseases (DMID)

• Air temperature
• Atmospheric pressure
• Diet
• Melatonin
• Metabolism
• Photoperiod
• Seasonal rhythms
• Thyroid hormones

• Seasons
• Animals
• Humans
• Mammals/metabolism
• Thyroid Hormones/metabolism
• Photoperiod

• acute coronary syndrome (acs)
• air temperature
• atmospheric pressure
• daily changes
• season changes

• artificial intelligence
• catecholamines
• diagnosis
• false-positive
• laboratory tests
• metanephrines
• methoxytyramine

• Humans
• Pheochromocytoma/diagnosis
• Pheochromocytoma/pathology
• Artificial Intelligence
• Paraganglioma/diagnosis
• Paraganglioma/pathology
• Metanephrine/urine
• Adrenal Gland Neoplasms/diagnosis
• Adrenal Gland Neoplasms/pathology

• Humans
• Adult
• Blood Pressure
• Prospective Studies
• Temperature
• East Asian People
• Arterial Pressure

• acute cardiac events
• heart failure
• hospital admissions
• pollution
• spatiotemporal patterns
• weather

• Cross-over studies
• Esophageal and gastric varices
• Liver cirrhosis
• Temperature

Aging is an independent risk factor for the development of various diseases associated, among others, with detrimental blood levels of fat- and water-soluble vitamins. Thus, the objective of this study is to investigate age-related changes in blood levels of vitamin A, B12, C, D, and E. Subject serum vitamin levels were obtained from the combined National Health and Nutrition Examination Surveys (NHANES). NHANESIII and NHANES 1999–2000, 2001–2002, 2003–2004, and 2005–2006. The raw data set was stratified into five age groups G1- G5: 20 ≤ G1 < 30, 30 ≤ G2 < 40, 40 ≤ G3 < 50, 50 ≤ G4 < 60, and 60 ≤ G5 < 70 years of age. Age stratified data was cleaned using the modified Horn algorithm. The reference range for the vitamin level of a specific age group was defined as data between the first and third quartile of the subject defined by normal blood pressure and normal bone density. Age-dependent changes in serum/plasma vitamin levels were assessed using the bootstrap technique with 10,000 repeats and Bonferroni adjustment. There was a continuous increase in vitamin A, B12, D, and E levels in the blood. However, the vitamin C concentration remained virtually constant in all age groups. There was a lack of cross-correlations between lipid and water-soluble vitamin levels and blood pressure and bone health. The following reference levels for vitamin A, B12, C, D, and E in subjects older than 20 years of age were established: vitamin A: 1.32–2.8 mmol/L, vitamin B12: 257.94–498.33 pmol/L, vitamin C: 38.18–79.2 mmol/L, vitamin D: 76.33–199.36 nmol/L and vitamin E: 3.65–41.12 μmol/L.

• Acute heart failure
• Ambient temperature
• Heart failure with preserved ejection fraction
• Heart failure with reduced ejection fraction
• Hypertension

• Aldosterone awakening response
• Aldosterone daytime levels
• Awakening time
• Chronic stress
• Salivary aldosterone
• Sleep duration

Physiological heat adaptations can be induced following various protocols that use either artificially controlled (i.e. acclimation) or naturally occurring (i.e. acclimatisation) environments. During the summer months in seasonal climates, adequate exposure to outdoor environmental heat stress should lead to transient seasonal heat acclimatisation.

The aim of the systematic review was to assess the available literature and characterise seasonal heat acclimatisation during the summer months and identify key factors that influence the magnitude of adaptation.

English language, full-text articles that assessed seasonal heat acclimatisation on the same sample of healthy adults a minimum of 3 months apart were included.

Studies were identified using first- and second-order search terms in the databases MEDLINE, SPORTDiscus, CINAHL Plus with Full Text, Scopus and Cochrane, with the last search taking place on 15 July 2021.

Studies were independently assessed by two authors for the risk of bias using a modified version of the McMaster critical review form.

Data for the following outcome variables were extracted: participant age, sex, body mass, height, body fat percentage, maximal oxygen uptake, time spent exercising outdoors (i.e. intensity, duration, environmental conditions), heat response test (i.e. protocol, time between tests), core temperature, skin temperature, heart rate, whole-body sweat loss, whole-body and local sweat rate, sweat sodium concentration, skin blood flow and plasma volume changes.

Twenty-nine studies were included in this systematic review, including 561 participants across eight countries with a mean summer daytime wet-bulb globe temperature (WBGT) of 24.9 °C (range: 19.5–29.8 °C). Two studies reported a reduction in resting core temperature (0.16 °C; p < 0.05), 11 reported an increased sweat rate (range: 0.03–0.53 L·h⁻¹; p < 0.05), two observed a reduced heart rate during a heat response test (range: 3–8 beats·min⁻¹; p < 0.05), and six noted a reduced sweat sodium concentration (range: − 22 to − 59%; p < 0.05) following summer. The adaptations were associated with a mean summer WBGT of 25.2 °C (range: 19.6–28.7 °C).

The available studies primarily focussed on healthy male adults and demonstrated large differences in the reporting of factors that influence the development of seasonal heat acclimatisation, namely, exposure time and duration, exercise task and environmental conditions.

Seasonal heat acclimatisation is induced across various climates in healthy adults. The magnitude of adaptation is dependent on a combination of environmental and physical activity characteristics. Providing environmental conditions are conducive to adaptation, the duration and intensity of outdoor physical activity, along with the timing of exposures, can influence seasonal heat acclimatisation. Future research should ensure the documentation of these factors to allow for a better characterisation of seasonal heat acclimatisation.

CRD42020201883.

The online version contains supplementary material available at 10.1007/s40279-022-01677-0.

• nomogram
• physical examination
• scrotum
• temperature
• testicular torsion

• Humans
• Japan/epidemiology
• Male
• Nomograms
• Pain
• Physical Examination
• Retrospective Studies
• Scrotum/diagnostic imaging
• Spermatic Cord Torsion/diagnostic imaging
• Spermatic Cord Torsion/epidemiology

• 16-B-1-24 Saitama Medical University
• 30-F-1-02 Saitama Medical Center Research Fund
• JP19K18597 JSPS KAKENHI

• aneurysm
• aorta
• chronobiology
• chronotherapeutics
• genetics
• management

Lower body negative pressure (LBNP) application simulates hemorrhage. We investigated how seasons affect coagulation values at rest and during LBNP. Healthy participants were tested in cold (November–April) and warm (May–October) months. Following a 30-min supine period, LBNP was started at −10 mmHg and increased by −10 mmHg every five minutes until a maximum of −40 mmHg. Recovery was for 10 min. Blood was collected at baseline, end of LBNP, and end of recovery. Hemostatic profiling included standard coagulation tests, calibrated automated thrombogram, thrombelastometry, impedance aggregometry, and thrombin formation markers. Seven men (25.0 ± 3.6 years, 79.7 ± 7.8 kg weight, 182.4 ± 3.3 cm height, and 23.8 ± 2.3 kg/m² BMI) and six women (25.0 ± 2.4 years, 61.0 ± 8.4 kg weight, 167 ± 4.7 cm height, and 21.8 ± 2.4 kg/m² BMI) participated. Baseline levels of prothrombin (FII), tissue factor (TF) and markers for thrombin generation F1+2 and the thrombin/antithrombin complex (TAT) were higher during summer. Factor VIII, prothrombin fragment 1+2 (F1+2), TAT and the coagulation time showed significant increases during LBNP in both seasons. Some calibrated automated thrombography variables (Calibrated automated thrombography (CAT): lag, time to peak (ttPeak), peak) shifted in a procoagulant direction during LBNP in summer. Red blood cell counts (RBC), hemoglobin and white blood cell counts (WBC) decreased during LBNP. LBNP application reduced prothrombin time in winter and activated partial thromboplastin time in summer. Greater levels of FII, TF, F1+2, and TAT—a more pronounced LBNP-induced procoagulative effect, especially in CAT parameters (lag time (LT), Peak, ttPeak, Velindex)—were seen in summer. These results could have substantial medical implications.

• LBNP
• coagulation
• seasons
• thrombelastometry
• thrombin generation
• trhombogram

• Seasonality
• Stem cells
• Unrelated donors

• adipose
• diabetes
• hypertension
• obesity
• vascular

Several studies have examined the cardiovascular effects of atmospheric parameters as separate factors; however, few have investigated atmospheric parameters’ joint effects. We aim to explore the joint effects of atmospheric parameters on acute cardiovascular diseases (ACVDs) and on major cardiovascular risk factors (CRFs). We correlated all ACVD admissions with major CRFs and local atmospheric conditions during a 5-year study period. A seasonal variation was detected in a higher incidence rate during cold atmospheric conditions. There were significant incidence relative ratios, including: 1.140 (95% CI [1.020, 1.283]) for daily temperature change (≥5 °C); 0.991 (95% CI [0.988, 0.994]) for average daily temperature; and 1.290 (95% CI [1.090, 1.599]) for the interaction of daily temperature change (≥5 °C) with humidity change (≥40%). We observed a significant association between the atmospheric parameters’ joint effects and hyperlipidaemia, diabetes, and previous ACVDs. Patients with diabetes had the highest significant incidence relative ratio at 2.429 (95% CI [1.088, 5.424]) for humidity-temperature interactions. Thus, the atmospheric parameters’ joint effects play an important role as minor CRFs. These unfavourable atmospheric situations are predicted to increase the number of ACVDs mainly. Our study may help to organize prevention strategies more effectively and to reduce cardiovascular risks.

Brown adipose tissue (BAT) is sympathetically activated and induces thermogenesis during cold exposure, thereby influencing energy expenditure and body fat levels. The very low frequency (VLF) components of pulse rate variability could be a form of thermogenic sympathetic nervous activity, but no clear relationship has yet been reported between VLF activity and BAT density. We therefore aimed to evaluate the association between them.

We enrolled 20 adults in winter and 20 matched adults in summer. We assessed BAT densities based on total hemoglobin concentrations ([total-Hb]) measured with near-infrared time-resolved spectroscopy. We calculated VLF activity from pulse rate variability measurements.

BAT density ([total-Hb]; winter 70.5 ± 17.0 μM, summer 57.8 ± 18.3 μM) and VLF activity (winter 6.7 ± 0.8, summer 6.1 ± 0.9) were significantly higher in winter than in summer (P < 0.05). However, there was no significant correlation between VLF activity and BAT density in either season.

Each parameter exhibited seasonal variation, but we failed to observe any significant correlations.

• Autonomic nervous system
• Brown adipose tissue
• Near-infrared time-resolved spectroscopy
• Seasonality

• Hypertensive intracerebral hemorrhage
• epidemiology
• meteorologic factors
• subarachnoid hemorrhage

• blood cells
• miRNA
• plasma
• serum
• stability

Transient global amnesia (TGA) is a stereotypic condition characterized by anterograde and retrograde amnesia that typically resolves within 24 hours. The pathophysiology of TGA is still unclear. We noted that patients hospitalized with TGA tend to appear in seasonal clusters, and decided to investigate this phenomenon.

Every patient with acute presentation of amnesia at our medical center is hospitalized for observation and evaluation. We reviewed the monthly occurrence of TGA in our patient population between 2000 and 2014, and compared this to non-TGA hospitalizations during the same time period.

During the analysis period, 154 patients who met the criteria for TGA were hospitalized, as well as 259,007 non-TGA hospitalizations. The annual occurrence of TGA ranged from 5 to 16 hospitalizations. There were 91 TGA events in women and 63 in men, in subjects aged 62.8±10.6 years (mean±SD). The incidence was maximal during December [odds ratio (OR)=2.83, 95% confidence interval (CI)=1.20–6.67] and March (OR=2.77, 95% CI=1.17–6.56), and minimal from April to August. The incidence exhibited an increase followed by a decrease from October to February. A seasonal trend was observed as well, with incidence peaks occurring in winter (OR=1.82, 95% CI=1.12–2.96) and spring (OR=1.80, 95% CI=1.10–2.94).

Our findings suggest that the incidence of TGA exhibits seasonal variations. This observation may help to improve the understanding of the pathophysiology underlying TGA.

• amnesia
• incidence
• seasonality
• transient global amnesia

• Cardiovascular diseases
• hemodynamic
• nervous system
• risk factors
• sympathetic

• air temperature
• body mass index
• outdoor exercise
• systolic blood pressure
• walking intensity

• Air pollution
• Cardiovascular disease
• Circadian
• Meteorology
• Season
• Trigger

• Acute Disease
• Cardiovascular Diseases/etiology
• Circadian Rhythm
• Humans
• Seasons

• Adolescent
• Adrenal Gland Neoplasms/blood
• Adrenal Gland Neoplasms/diagnosis
• Adult
• Aged
• Aged, 80 and over
• Child
• Female
• Forearm/blood supply
• Hot Temperature
• Humans
• Male
• Metanephrine/blood
• Middle Aged
• Normetanephrine/blood
• Pheochromocytoma/blood
• Pheochromocytoma/diagnosis
• Regional Blood Flow
• Seasons

This paper review seasonal patterns across twelve cardiovascular diseases: Deep venous thrombosis, pulmonary embolism, aortic dissection and rupture, stroke, intracerebral hemorrhage, hypertension, heart failure, angina pectoris, myocardial infarction, sudden cardiac death, venricular arrythmia and atrial fibrillation, and discuss a possible cause of the occurrence of these diseases. There is a clear seasonal trend of cardiovascular diseases, with the highest incidence occurring during the colder winter months, which have been described in many countries. This phenomenon likely contributes to the numbers of deaths occurring in winter. The implications of this finding are important for testing the relative importance of the proposed mechanisms. Understanding the influence of season and other factors is essential when seeking to implement effective public health measures.

• Cardiovascular diseases
• Periodicity
• Seasons

Cold is a seasonal and circadian risk factor for cardio- and cerebrovascular morbidity and mortality. Colder temperatures have been associated with higher blood pressure (BP), based on studies which show that BP levels measured during the summer months are generally lower than those measured during the winter months. Residents in geographic areas which have greater seasonal temperature differences show greater fluctuation in BP. Surprisingly, atmospheric pressure, rainfall, and humidity were not related to BP levels. The increased sympathetic nervous activity due to cold, as evidenced by elevated BP and by plasma and urinary catecholamines, has been proposed as being the underlying etiology. Patients with heart failure may experience, in cold conditions, endothelial dysfunction and produce fewer endogenous vasodilators (e.g., nitric oxide, prostaglandins) and more endogenous vasoconstrictors (e.g., endothelin), thus increasing afterload. Arterial stiffness is also related to seasonal BP changes. Increased BP, arterial stiffness and endothelial dysfunction could predispose to increased coronary and cerebrovascular events. Improved protection against lower temperatures or increased doses of existing medications or the addition of newer medications could lead to a reduction in increased cardiovascular mortality in winter. Here, we briefly review findings from existing literature and provide an update on seasonal long-term variation in BP along with the related complications.

• Seasonal variations
• Circadian variations
• Outdoor temperature
• Seasonal effects
• Blood pressure
• Hypertension

The skin, the body's largest organ, plays an important role in the biotransformation/detoxification and elimination of xenobiotics and endogenous toxic substances, but its role in oxidative stress and insulin resistance is unclear. We investigated the relationship between skin detoxification and oxidative stress/insulin resistance by examining burn-induced changes in nicotinamide degradation. Rats were divided into four groups: sham-operated, sham-nicotinamide, burn, and burn-nicotinamide. Rats received an intraperitoneal glucose injection (2 g/kg) with (sham-nicotinamide and burn-nicotinamide groups) or without (sham-operated and burn groups) coadministration of nicotinamide (100 mg/kg). The results showed that the mRNA of all detoxification-related enzymes tested was detected in sham-operated skin but not in burned skin. The clearance of nicotinamide and N¹-methylnicotinamide in burned rats was significantly decreased compared with that in sham-operated rats. After glucose loading, burn group showed significantly higher plasma insulin levels with a lower muscle glycogen level than that of sham-operated and sham-nicotinamide groups, although there were no significant differences in blood glucose levels over time between groups. More profound changes in plasma H₂O₂ and insulin levels were observed in burn-nicotinamide group. It may be concluded that decreased skin detoxification may increase the risk for oxidative stress and insulin resistance.

• the skin
• antioxidant defense
• xenobiotic
• lipid homeostasis
• sedentary lifestyle
• metabolic syndrome
• acanthosis nigricans
• acne

It is well-recognized that vitamin D₃ has immune-modulatory properties and that the variation in ultraviolet (UV) exposure affects vitamin D₃ status. Here, we investigated if and to what extent seasonality of vitamin D₃ levels are associated with changes in T cell numbers and phenotypes. Every three months during the course of the entire year, human PBMC and whole blood from 15 healthy subjects were sampled and analyzed using flow cytometry. We observed that elevated serum 25(OH)D₃ and 1,25(OH)₂D₃ levels in summer were associated with a higher number of peripheral CD4⁺ and CD8⁺ T cells. In addition, an increase in naïve CD4⁺CD45RA⁺ T cells with a reciprocal drop in memory CD4⁺CD45RO⁺ T cells was observed. The increase in CD4⁺CD45RA⁺ T cell count was a result of heightened proliferative capacity rather than recent thymic emigration of T cells. The percentage of Treg dropped in summer, but not the absolute Treg numbers. Notably, in the Treg population, the levels of forkhead box protein 3 (Foxp3) expression were increased in summer. Skin, gut and lymphoid tissue homing potential was increased during summer as well, exemplified by increased CCR4, CCR6, CLA, CCR9 and CCR7 levels. Also, in summer, CD4⁺ and CD8⁺ T cells revealed a reduced capacity to produce pro-inflammatory cytokines. In conclusion, seasonal variation in vitamin D₃ status in vivo throughout the year is associated with changes in the human peripheral T cell compartment and may as such explain some of the seasonal variation in immune status which has been observed previously. Given that the current observations are limited to healthy adult males, larger population-based studies would be useful to validate these findings.