Seasonal Variation In Blood Pressure Research Articles

BLOOD PRESSURE CONTROL IN TERTIARY-CARE HYPERTENSIVE PATIENTS DURING COVID-19 PANDEMIC

Objective: Cardiovascular risk factors distribution during the pandemic suggests worsening of the cardiovascular risk profile of hypertensive patients. At the same time, data on quality of hypertension control during the COVID-19 pandemic are scarce, in Poland. The aim of the study was to analyse the quality of blood pressure (BP) control in a group of patients who required regular control in tertiary care. Design and method: The study included hypertensive patients regularly monitored in tertiary-care out-patient clinic for at least 4 years with at least 2 visits a year prior the analysis. The size of the group was calculated based on the original data of first 50 consecutive records of patients (power of 90%). Records were retrospectively analysed with respect to office blood pressure (oBP) control. Additionally, within-visit BP variability was calculated (difference of maximum and minimum BP from 3 measurements); body weight, age, sex, duration of hypertension, number of visits per year, seasonal BP variability, use of telemedical services, comorbidities and BP-lowering treatment were recorded. Results: The study enrolled 220 patients. The values of systolic BP (sBP) before and after the break in the whole group were 135.8 ± 17.1 mm Hg vs. 137.9 ±19.5 mm Hg; P=0.08, and a diastolic BP (dBP) of 80.3 ±11.4 mm Hg vs. 82.6 ±12.2 mm Hg; p = 0.001. After adjusting for seasonal variation of BP, the respective differences were: sBP: 134.8 ± 16.5 vs. 138.0 ± 19.4; p = 0.03, and dBP: 79.4 ±10.9 vs. 82.2 ± 11.9; p = 0.004. Before 2020, 61.4% of patients were controlled (BP < 140/90 mm Hg), whereas after the pandemic-driven break in regular visits the control rate decreased to 55.5% (p = 0.21). Conclusions: BP control worsened during the COVID-19 pandemic in a group of patients requiring tertiary care for hypertension.

Abstract MP74: Ambient Temperature and Blood Pressure Are Associated in the Jackson Heart Study

Extreme temperature events related to climate change may impact blood pressure (BP). Communities of color, especially African-American populations, are disproportionately affected by temperature extremes due to structural inequities. We assessed the association between ambient outdoor temperature and BP among participants in the Jackson Heart Study (JHS), a cohort of African American adults residing in the tri-county area of Jackson, Mississippi. We hypothesized that higher outdoor ambient temperatures would be associated with lower BP. The exposure was average outdoor ambient temperature in degrees Fahrenheit, obtained from Daymet Daily Surface Weather dataset for North America accurate to 1km of Jackson, MS. The two outcomes were systolic and diastolic blood pressure (SBP and DBP). A total of 5309 participants were included across 3 visits: Visit 1 (2000-2004), Visit 2 (2005- 2008), Visit 3 (2009-2013). We used a linear mixed effects model to determine the relationship between ambient temperature and SBP/DBP at three visits. Cardiovascular disease, diabetes, BP medication and visit number were included as adjustment variables. Age, sex, socioeconomic status (captured by level of education, income, and occupation), physical activity, history of cardiovascular disease, BP medications and perceived stress were conceptualized as effect modifiers. To account for non-temperature related seasonal variation in BP, we added season specific coefficients to SBP and DBP readings. The average temperature at each visit was 63.8°F (range: 24.5, 85.6), 64.3°F (range: 30.5, 87.8), 66.3°F (range: 21.9, 90.0), respectively. The average age at baseline was 55.3 years and 63% of the study population was female. For every 10 degrees higher temperature in Fahrenheit, SBP was 0.87 mm Hg (standard error: 0.097, p<0.001) and 0.83 mm Hg (standard error: 0.104, p<0.001) lower in unadjusted and adjusted models respectively. DBP was 0.49 mm Hg (standard error: 0.054, p<0.001) and 0.46 mm Hg (SE: 0.058, p<0.001) lower for every 10 degrees Fahrenheit higher temperature, in unadjusted and adjusted models, respectively. We did not find any significant interactions between the effect modifiers listed and ambient temperature. In conclusion, there was an association between higher ambient temperature and lower blood pressure, independent of season. This study is crucial in understanding how ambient temperature affects BP among African American adults. Greater temperature extremes could lead to greater fluctuation in BP levels with uncertain short and long-term health effects.

Acknowledging the impact of seasonal blood pressure variation in hypertensive CKD and non-CKD patients living in a Mediterranean climate

Background This study aims to assess seasonal blood pressure (BP) variation in chronic kidney disease (CKD) and non-CKD patients living in a Mediterranean climate, and to find out if this variation entails significant adjustment of treatment and if it impacts renal outcomes and mortality. Methods This retrospective study included all hypertensive patients seen between February 2006 and April 2020 in two Lebanese clinics. Regression analyses were used to assess the association of seasonal BP variability and treatment adjustment with eGFR change from baseline, dialysis initiation and death. Results A total of 398 patients of 64.2 ±13.9 years were followed for 51.1 ±44.3 months, 67% had eGFR< 60 mL/min. Mean systolic and diastolic BP was 137.7 ±14.7 and 76.5 ±9.5 mmHg respectively. Systolic and diastolic BP were significantly lower in the warm season in CKD and non-CKD patients (P<0.001). The majority (91.4%) needed seasonal treatment modifications. After adjustment to age, sex, baseline eGFR, BP and number of antihypertensive drugs, we found a significant loss of eGFR with treatment modifications in both seasons, double risk of dialysis with the increase of antihypertensive treatment in both seasons and a 2.5 more risk of death with reduced treatment in the warm season. Conclusion This study confirmed the seasonal BP variability in CKD and non-CKD patients from a Mediterranean climate. All types of treatment adjustment were associated with eGFR loss. Low BP in the warm season was highly associated with death.

Seasonal variation in blood pressure: what is still missing?

Seasonal variation of blood pressure (BP) is a topic in cardiology that has gained more attention throughout the years. Although it is extensively documented that BP increases in seasons coupled with lower temperatures, there are still many gaps in this knowledge field that need to be explored. Notably, seasonal variation of BP phenotypes, such as masked and white coat hypertension, and the impact of air pollution, latitude, and altitude on seasonal variation of BP are still poorly described in the literature, and the levels of the existing evidence are low. Therefore, further investigations on these topics are needed to provide robust evidence that can be used in clinical practice.

Seasonal Variations in Blood Pressure and Increased Incidence of Intracerebral Hemorrhage in Cold Months of the Year

Objective: To assess the Seasonal variations in Blood Pressure and increased incidence of Intracerebral Hemorrhage in cold months of the year Methods: This cross sectional study was conducted at KGN hospital, during the time period of one year. The months of the year was divided as cold months (November-February) and all other months (March-October) of the year. Ischemic stroke and intracerebral hemorrhagic stroke were the two main categories used to categorize individuals with stroke based on non contrast brain CT scan along with clinical characteristics. Results: In cold months, the incidence of Intracerebral hemorrhage, 98 (65.3%) was significantly greater at p < 0.05 as compared to all other months of the year, 52 (34.7%). Both systolic and diastolic blood pressure of intracerebral hemorrhage patients was higher in cold months as compared to all other months of the year Conclusion: The good reason for increase in both systolic and diastolic blood pressure of intracerebral hemorrhage patients is the peripheral vasoconstriction of the vessels in cold weather. Keywords: Intracerebral hemorrhage, seasonal variations, Ischemic stroke, cholesterol, blood pressure.

Seasonal variation in blood pressure and its impact on target organ damage and cardiovascular disease incidence.

Seasonal variation in blood pressure and its impact on target organ damage and cardiovascular disease incidence.

Seasonal variation in blood pressure control across US health systems.

We aimed to characterize seasonal variation in US population-based blood pressure (BP) control and BP-related metrics and evaluate the association between outdoor temperature and BP control variation. We queried electronic health records (EHRs) from 26 health systems, representing 21 states, to summarize BP metrics by quarters of 12-month periods from January 2017 to March 2020. Patients with at least one ambulatory visit during the measurement period and a hypertension diagnosis during the first 6 months or prior to the measurement period were included. Changes in BP control, BP improvement, medication intensification, average SBP reduction after medication intensification across quarters and association with outdoor temperature were analyzed using weighted generalized linear models with repeated measures. Among 1 818 041 people with hypertension, the majority were more than 65 years of age (52.2%), female (52.1%), white non-Hispanic (69.8%) and had stage 1/2 hypertension (64.8%). Overall, BP control and process metrics were highest in quarters 2 and 3, and lowest in quarters 1 and 4. Quarter 2 had the highest percentage of improved BP (31.95 ± 0.90%) and average SBP reduction after medication intensification (16 ± 0.23 mmHg). Quarter 3 had the highest percentage of BP controlled (62.25 ± 2.55%) and lowest with medication intensification (9.73 ± 0.60%). Results were largely consistent in adjusted models. Average temperature was associated with BP control metrics in unadjusted models, but associations were attenuated following adjustment. In this large, national, EHR-based study, BP control and BP-related process metrics improved during spring/summer months, but outdoor temperature was not associated with performance following adjustment for potential confounders.

JS-HR-7: BLOOD PRESSURE VARIABILITY; THERAPEUTIC TARGET FOR THE PREVENTION OF CARDIOVASCULAR DISEASE

In the past three decades, there have been many reports on the associations of various parameters of blood pressure (BP) variability with increased risk of cardiovascular disease (CVD) events; these parameters include short term BP variability (BPV), i.e., beat-by-beat BPV and ambulatory BPV, abnormality of nocturnal BP dipping pattern, and mid- to long-term BPV, i.e., day-by-day BPV, visit-to-visit BPV, and seasonal variations in BP. Several factors that are associated with abnormal BPV, as well as environmental factors such as cold or warm temperatures and seasonal changes in climate, increase fluctuations in BP. Individual intrinsic factors such as sympathetic nervous tone, arterial stiffness, physical activity, and mental stress also contribute to elevated BPV. According to evaluations of BPV abnormalities, out-of-office BP measurements such as ambulatory and home BP monitoring are needed. Although there are issues regarding measurement accuracy, cuffless BP monitoring devices, for example, those using pulse transit time, may be used to estimate nighttime BP levels. Such cuffless BP devices can also evaluate beat-by-beat BPV. Moreover, by using the multisensor-equipped ambulatory BP monitoring device developed by our research group, it is possible to evaluate BPV associated with changes in temperature, physical activity, and/or atmospheric pressure. Based on the mechanism(s) behind a given patients BPV abnormality, several methods may be considered for the management of that abnormality (Figure). For example, improving excessive sympathetic nervous system activation may be useful in the management of BPV abnormality, and renal denervation has been reported to decrease ambulatory BPV. Abnormal nocturnal BP dipping may be treated by decreasing nighttime BP. Moreover, early adjustment of antihypertensive drugs has been reported to be useful in suppressing seasonal variations in BP, leading to a decreased risk of CVD events. Furthermore, housing conditions and room temperature are closely related to BP levels, and adaptive control of room temperature would be useful to suppress winter increases in BP. In clinical practice, we must not forget that BPV parameters are interrelated. For instance, frequent evaluation of BP levels and adjustment of antihypertensive drugs can suppress visit-to-visit BPV, which in turn leads to the suppression of seasonal variations in BP. Over the next decade, greater data on how to manage and control BPV need to be accumulated. Additionally, future studies should be conducted to verify whether the different types of BVP management are useful in preventing CVD events.

JS-ISH-ESH-4: SEASONAL VARIATION IN BLOOD PRESSURE AND THE RISK OF CARDIOVASCULAR DISEASES

Blood pressure exhibits seasonal variation with lower levels at higher environmental temperatures and higher at lower temperatures. The seasonal blood pressure variation can be confirmed by repeated office measurements. However, long term home blood pressure measurement under stable condition is the best tool to access seasonal blood pressure variation because it is highly reproducible and reliable. In this lecture, I would like to talk about evidences on the prognostic significance of seasonal blood pressure variation and some recommendations for clinical practice.

Potential Role of TRPM8 in Cold-Induced Hypertension and Its Clinical Implications.

Seasonal variation in blood pressure that is higher in winter and lower in summer has been attributed to several factors that include changes in the activity of autonomic nervous system, vasopressin and expression of endothelial nitric oxide synthase (eNOS). Transient receptor potential melastatin 8 (TRPM8), a non-selective Ca2+-permeable cationic channel, serves as a molecular transducer to sense cold by the somatosensory system. TRPM8 is sensitive to protein kinase C (PKC) and phosphatidyl inositol-4,5-biphosphate [PI(4,5)P2] suggesting that TRPM8 is stimulated by phospholipase C (PLC)-coupled receptors. Activated PLC inhibits TRPM8 by reducing cellular PI(4,5)P2 levels and by activating PKC via diacyl glycerol. Bradykinin and prostaglandin E2 (PGE2), which are pro-inflammatory molecules, reduce the responses to cold, suggesting that phospholipase A2 (PLA2), which releases polyunsaturated fatty acids (PUFAs), the precursors of various eicosanoids, from the cell membrane lipid pool can modulate the function of TRPM8. TRPM8 functions as a nociceptor and modulates immune response. These and other studies indicate that cold-induced activation of transient receptor potential melastatin 8 (TRPM8) plays a role in the pathobiology of hypertension, preeclampsia and in the regulation of inflammation and immunity.

PS-C19-10: SEASONAL VARIATION IN THE EFFECT OF ANTIHYPERTENSIVE TREATMENT WITH THE IRBESARTAN/HYDROCHLOROTHIAZIDE COMBINATION

Objective: There is increasing awareness of seasonal variation in blood pressure. In the present analysis, we investigated seasonal variation in antihypertensive treatment effect of the irbesartan/hydrochlorothiazide combination in patients with stage 2 and 3 hypertension. Design and Methods: The study participants were hypertensive patients enrolled in a 12-week therapeutic study. Antihypertensive treatment was initiated with the irbesartan/hydrochlorothiazide 150/12.5 mg/day, with the possible up-titration to 300/12.5 mg/day and 300/25 mg/day at 4 and 8 weeks of follow-up. The month of treatment commencement was classified as spring/summer (May to August) and autumn/winter (September to December). Results: Of the 501 enrolled patients, 313 and 188 commenced antihypertensive treatment in spring/summer and autumn/winter, respectively. The mean changes in systolic/diastolic blood pressure at 8 and 12 weeks of follow-up were greater in patients who commenced treatment in autumn/winter (-32.3/-16.5 and -34.2/-16.7 mmHg, respectively) than those in spring/summer (-28.4/-13.9 and -27.1/-12.8 mmHg, respectively), with a between-season difference of 3.9 (95% confidence interval [CI], 1.4–6.4, P = 0.002)/2.6 (95% CI, 0.9–4.2, P = 0.002) mmHg and 7.0 (95% CI, 4.7–9.3, P < 0.0001)/3.9 (95% CI, 2.4–5.4, P < 0.0001) mmHg, respectively. Further subgroup analyses showed a greater between-season difference in the changes in systolic blood pressure in patients aged 55 years and older (n = 255) than those < 55 years (n = 246, 12.6 vs. 6.9 mmHg, P = 0.02), and in patients with chronic kidney disease (n = 175) than those with normal renal function (n = 326, 12.1 vs. 7.4 mmHg, P = 0.06). Conclusions: There is indeed seasonality in antihypertensive treatment effect, with a greater blood pressure reduction in patients who commenced treatment in cold than warm seasons.

Interaction of Vitamin D with Peptide Hormones with Emphasis on Parathyroid Hormone, FGF23, and the Renin-Angiotensin-Aldosterone System.

The seminal discoveries that parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) are major endocrine regulators of vitamin D metabolism led to a significant improvement in our understanding of the pivotal roles of peptide hormones and small proteohormones in the crosstalk between different organs, regulating vitamin D metabolism. The interaction of vitamin D, FGF23 and PTH in the kidney is essential for maintaining mineral homeostasis. The proteohormone FGF23 is mainly secreted from osteoblasts and osteoclasts in the bone. FGF23 acts on proximal renal tubules to decrease production of the active form of vitamin D (1,25(OH)2D) by downregulating transcription of 1α-hydroxylase (CYP27B1), and by activating transcription of the key enzyme responsible for vitamin D degradation, 24-hydroxylase (CYP24A1). Conversely, the peptide hormone PTH stimulates 1,25(OH)2D renal production by upregulating the expression of 1α-hydroxylase and downregulating that of 24-hydroxylase. The circulating concentration of 1,25(OH)2D is a positive regulator of FGF23 secretion in the bone, and a negative regulator of PTH secretion from the parathyroid gland, forming feedback loops between kidney and bone, and between kidney and parathyroid gland, respectively. In recent years, it has become clear that vitamin D signaling has important functions beyond mineral metabolism. Observation of seasonal variations in blood pressure and the subsequent identification of vitamin D receptor (VDR) and 1α-hydroxylase in non-renal tissues such as cardiomyocytes, endothelial and smooth muscle cells, suggested that vitamin D may play a role in maintaining cardiovascular health. Indeed, observational studies in humans have found an association between vitamin D deficiency and hypertension, left ventricular hypertrophy and heart failure, and experimental studies provided strong evidence for a role of vitamin D signaling in the regulation of cardiovascular function. One of the proposed mechanisms of action of vitamin D is that it functions as a negative regulator of the renin-angiotensin-aldosterone system (RAAS). This finding established a novel link between vitamin D and RAAS that was unexplored until then. During recent years, major progress has been made towards a more complete understanding of the mechanisms by which FGF23, PTH, and RAAS regulate vitamin D metabolism, especially at the genomic level. However, there are still major gaps in our knowledge that need to be filled by future research. The purpose of this review is to highlight our current understanding of the molecular mechanisms underlying the interaction between vitamin D, FGF23, PTH, and RAAS, and to discuss the role of these mechanisms in physiology and pathophysiology.

Seasonal variation in the effect of antihypertensive treatment with the irbesartan/hydrochlorothiazide combination.

There is increasing awareness of seasonal variation in blood pressure (BP). In the present analysis, we investigated seasonal variation in the antihypertensive treatment effect of the irbesartan/hydrochlorothiazide combination in patients with stage 2 and 3 hypertension. The study participants were hypertensive patients enrolled in a 12-week therapeutic study. Antihypertensive treatment was initiated with irbesartan/hydrochlorothiazide 150/12.5 mg/day, with possible uptitration to 300/12.5 mg/day and 300/25 mg/day at 4 and 8 weeks of follow-up, respectively. The month of treatment commencement was classified as spring/summer (May to August) and autumn/winter (September to December). Of the 501 enrolled patients, 313 and 188 commenced antihypertensive treatment in spring/summer and autumn/winter, respectively. The mean changes in systolic/diastolic BP at 8 and 12 weeks of follow-up were greater in patients who commenced treatment in autumn/winter (-32.3/-16.5 and -34.2/-16.7 mmHg, respectively) than those who commenced treatment in spring/summer (-28.4/-13.9 and -27.1/-12.8 mmHg, respectively), with a between-season difference of 3.9 (95% confidence interval [CI], 1.4-6.4, P = 0.002)/2.6 (95% CI, 0.9-4.2, P = 0.002) mmHg and 7.0 (95% CI, 4.7-9.3, P < 0.0001)/3.9 (95% CI, 2.4-5.4, P < 0.0001) mmHg, respectively. Further subgroup analyses according to several baseline characteristics showed a greater between-season difference in the changes in systolic BP in patients aged ≥55 years than in those <55 years (n = 255, 12.6 mmHg vs. n = 246, 6.9 mmHg, P = 0.02), especially in patients who did not use antihypertensive medication at baseline (n = 94, 15.4 mmHg vs. n = 132, 5.4 mmHg, P = 0.006). In conclusion, there is indeed seasonality in the antihypertensive treatment effect, with a greater BP reduction in patients who commenced treatment in cold than warm seasons.

Seasonal variation of ambulatory blood pressure in Chinese hypertensive adolescents.

Blood pressure (BP) exhibits seasonal variation with lower levels at higher temperatures and vice versa. This phenomenon affects both sexes and all age groups. So far, only a few research studies have investigated this condition in adolescents and none of them were based on hypertensive population or ever applied ambulatory blood pressure monitor (ABPM). Therefore, we carried out the first study that used ABPM to record seasonal variation of blood pressure in hypertensive adolescents. From March 2018 to February 2019, 649 ABPMs from hypertensive adolescents between 13 and 17 years who were referred to wear an ABPM device in Beijing and Baoding were extracted. Seasonal change in ambulatory BP value, dipping status, and prevalence of different BP phenotypes were analyzed and compared. Mean age of participants was 14.9 ± 1.5 years and 65.8% of them were boys. Of the participants, 75.3% met the criteria of overweight or obesity. From summer to winter, average 24-hour, day-time, and night-time BP showed significant rise, which was 9.8/2.8, 9.8/3.0, and 10.9/3.4 mmHg, respectively. This seasonal effect on BP was not dependent on the obesity degree. In addition, higher prevalence of nondippers and risers existed in winter while white coat hypertension was more frequent in warmer seasons. Hypertensive adolescents showed evident seasonal change in their ABPM results, which was featured by elevated BP level and more frequent abnormal dipping patterns in winter. On the contrary, higher prevalence of white coat hypertension was found in warmer seasons. Physicians should take seasonal variation into consideration when managing adolescent hypertension.

Time-series analysis of blood pressure changes after the guideline update in 2019 and the coronavirus disease pandemic in 2020 using Japanese longitudinal data.

We assessed blood pressure (BP) changes during fiscal years (April to March of the following year) 2015–2020 to clarify the effect of the state of emergency due to the coronavirus disease 2019 (COVID-19) pandemic in 2020. We then considered BP in 2019 separately, as the Japanese hypertension guidelines were updated in 2019. The present retrospective cohort study extracted data from 157,510 Japanese individuals aged <75 years (mean age: 50.3 years, men: 67.5%) from the annual health check-up data of the DeSC database. The trends in BP were assessed using a repeated measures linear mixed model. After adjusting for the month of health check-ups to exclude seasonal BP variation, systolic BP linearly increased during fiscal years 2015–2018. From the value estimated by the trend in 2015–2018, systolic BP was lower by ≤1 mmHg in fiscal year 2019 among the treated participants. Meanwhile, systolic/diastolic BP (95% confidence interval) increased by 2.11 (1.97–2.24)/1.05 (0.96–1.14) mmHg for untreated women (n = 43,292), 1.60 (1.51–1.70)/1.17 (1.11–1.24) mmHg for untreated men (n = 88,479), 1.92 (1.60–2.23)/0.46 (0.25–0.67) mmHg for treated women (n = 7855), and 1.00 (0.79–1.21)/0.39 (0.25–0.53) mmHg for treated men (n = 17,884) in fiscal year 2020. These increases remained time-dependent covariates after adjustments for age, body mass index, alcohol consumption, smoking, physical activity, and blood sampling indices. Social change due to the pandemic might have increased BP by approximately 1–2/0.5–1 mmHg. Meanwhile, only a slight decrease in BP was observed immediately after the guideline update in Japan.

An Exploration of How Solar Radiation Affects the Seasonal Variation of Human Mortality Rates and the Seasonal Variation in Some Other Common Disorders.

Many diseases have large seasonal variations in which winter overall mortality rates are about 25% higher than in summer in mid-latitude countries, with cardiovascular diseases and respiratory infections and conditions accounting for most of the variation. Cancers, by contrast, do not usually have pronounced seasonal variations in incidence or mortality rates. This narrative review examines the epidemiological evidence for seasonal variations in blood pressure, cardiovascular disease rates and respiratory viral infections in relation to atmospheric temperature and humidity, and solar UV exposure through vitamin D production and increased blood concentrations of nitric oxide. However, additional mechanisms most likely exist by which solar radiation reduces the risk of seasonally varying diseases. Some studies have been reported with respect to temperature without considering solar UV doses, although studies regarding solar UV doses, such as for respiratory infections, often consider whether temperature can affect the findings. More research is indicated to evaluate the relative effects of temperature and sun exposure on the seasonality of mortality rates for several diseases. Since solar ultraviolet-B (UVB) doses decrease to vanishingly small values at higher latitudes in winter, the use of safe UVB lamps for indoor use in winter may warrant consideration.

Seasonal Variation: A Non-negligible Factor Associated With Blood Pressure in Patients Undergoing Hemodialysis.

ObjectiveTo investigate a seasonal variation in blood pressure (BP) for patients undergoing hemodialysis (HD).MethodsIn this retrospective study, we exported all BP measurements from the information system to investigate a seasonal variation of BP. We also investigated a seasonal variation in BP for patients of different gender types, of different age groups, with diabetic nephropathy (DN), and with non-DN having HD. Multiple linear regression models were used to explore the associations between BP and climatic parameters.ResultsIn 2019, a total of 367 patients had received HD therapy in the Longwen HD unit. We included nearly 40,000 pre-dialysis BP measurements. The result of our study demonstrated a clear seasonal variation in pre-dialysis BP in general patients with HD, in male and female patients, and patients with DN and non-DN. December seemed to be a peak in the values of pre-dialysis systolic BP (SBP) and diastolic BP (DBP). The nadir values of pre-dialysis SBP and DBP were observed in June and July, respectively. A difference between peak and nadir values of BP is 3.81/2.20 mmHg in patients undergoing HD. Maximal seasonal variation in BP is 9.03/5.08 mmHg for patients with DN. A significant association of SBP and DBP with climatic parameters was found in this study. Pre-dialysis BP was inversely correlated with outdoor temperature, daytime length, and relative humidity.ConclusionA clear seasonal variation in BP is observed for patients with HD. Pre-dialysis SBP and DBP are inversely associated with outdoor temperature, daytime length, and relative humidity. The magnitude of a seasonal variation in BP increases in patients with DN.

Anxiety, home blood pressure monitoring, and cardiovascular events among older hypertension patients during the COVID-19 pandemic

The global coronavirus disease 2019 (COVID-19) pandemic has led to a health crisis. It remains unclear how anxiety affects blood pressure (BP) and cardiovascular risk among older patients with hypertension. In this study, we extracted longitudinal data on home BP monitored via a smartphone-based application in 3724 elderly patients with hypertension from a clinical trial (60–80 years; 240 in Wuhan and 3484 in non-Wuhan areas) to examine changes in morning BP during the COVID-19 outbreak in China. Anxiety was evaluated using Generalized Anxiety Disorder-7 item scores. Changes in morning systolic BP (SBP) were analyzed for five 30-day periods during the pandemic (October 21, 2019 to March 21, 2020), including the pre-epidemic, incubation, developing, outbreak, and plateau periods. Data on cardiovascular events were prospectively collected for one year. A total of 262 individuals (7.0%) reported an increased level of anxiety, and 3462 individuals (93.0%) did not. Patients with anxiety showed higher morning SBP than patients without anxiety, and the between-group differences in SBP change were +1.2 mmHg and +1.7 mmHg during the outbreak and plateau periods (P < 0.05), respectively. The seasonal BP variation in winter among patients with anxiety was suppressed during the pandemic. Anxious patients had higher rates of uncontrolled BP. During the 1-year follow-up period, patients with anxiety had an increased risk of cardiovascular events with a hazard ratio of 2.47 (95% confidence interval, 1.10–5.58; P = 0.03). In summary, COVID-19-related anxiety was associated with a short-term increase in morning SBP among older patients and led to a greater risk of cardiovascular events. (ClinicalTrials. gov number, NCT03015311).

Seasonal changes in blood pressure and related factors among older patients receiving home medical care

We investigated seasonal variations in blood pressure (BP) and factors related to these variations among older patients receiving home medical care. A total 57 patients ≥ 65 years old receiving home medical care who participated in the Osaka Home Care REgistry study (OHCARE), a prospective cohort study, were included. We investigated the seasonal patient characteristics and variations in the BP. In addition, to determine the influence of seasonal variations in the systolic blood pressure (SBP) on the occurrence of clinical events (hospitalization, falls and death), we classified patients into larger- and smaller- change groups based on the median seasonal variations in SBP. About 60% of subjects were very frail or bedridden. The mean BP was higher in winter than in summer (124.7±11/69.5±7 vs.120.5±12/66.9±8 mmHg) (P< 0.01). On comparing the characteristics of the two groups with larger and smaller changes in the SBP, the group with large BP changes had a significantly lower BP in summer than the group with small BP changes. In addition, the incidence of "hospitalization" was significantly higher in the group with large BP changes than in the group with small BP changes (P = 0.03). The present study revealed that there were seasonal changes in the BP in older patients receiving home medical care. It was also suggested that seasonal changes in the BP might be associated with the risk of hospitalization events. Given these BP variations, doctors and visiting nurses should be alert for systemic abnormalities, especially in frail patients receinving home medical care.

Seasonal variation of blood pressure and orthostatic intolerance in Parkinson's disease

Patients with Parkinson's disease (PD) have autonomic dysfunction, for example, orthostatic hypotension (OH). In general, resting blood pressure has seasonal variation and OH may become worsen in summer and ameliorated in winter. It has not yet been studied whether orthostatic intolerance has seasonal changes and it influences on seasonal variation of resting blood pressure in PD. The purpose of this study is to elucidate how orthostatic intolerance in PD is influenced by climatic differences.