Elevated blood pressure in primary care varies in relation to circadian and seasonal changes

Thomas, Caroline Bedell; Wood, G. Craig; Langer, Róbert; Stewart, Walter F.

doi:10.1038/jhh.2008.44

Cited by 14 publications

(9 citation statements)

References 8 publications

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“…The blood pressure data are concordant with most other studies [7–14], showing maximum blood pressure in the winter months and minimum blood pressure in the summer months.…”

Section: Discussionsupporting

confidence: 90%

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Seasonal variation in prostate‐specific antigen levels: a large cross‐sectional study of men in the UK

Down

Metcalfe²,

Martin³

et al. 2011

BJU International

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• The proportion of participants who would be considered clinically at risk according to their PSA or blood pressure measurement, by month, was also assessed.• The strength of associations between time of year and blood pressure were used to reinforce conclusions from the PSA models. RESULTS• There was no relationship between time of year and PSA levels ( P = 0.11) or between climate and PSA levels ( P = 0.42).• No difference was found in the prevalence of clinically raised PSA content by month ( P = 0.50).• This lack of an association with PSA content was despite our data being sufficient to provide clear evidence of an association between blood pressure and time of year (systolic P < 0.001; diastolic P < 0.001), and to show that this association was largely explained by climatic factors (temperature and sunlight). CONCLUSION• There was no pattern in PSA levels by time of year, air temperature or levels of sunlight in this cohort, so there is no need to take these factors into account when reviewing PSA results. KEYWORDSprostate-specific antigen, blood pressure, season, sunlight, temperature, climate, cosine What's known on the subject? and What does the study add? Evidence for seasonal or climatic effects on PSA levels is mixed and inconclusive.In this large, long-term study, no seasonal or climatic patterns in PSA levels were identified.Study Type -Aetiology (cohort) Level of Evidence 2b OBJECTIVE• To assess whether a seasonal change in prostate specific antigen (PSA) levels can be detected in men recruited to a large clinical trial. PATIENTS AND METHODS• A total of 66 969 men aged 50-69 years were drawn from a large study conducted at general practices across the UK between 2002 and 2007.• Trigonometric algorithms and regression methods were used to assess the relationship between the time of year and serum PSA and blood pressure measurements.• We obtained local daily mean temperatures and hours of sunlight per day to assess whether these factors were potential mechanisms for seasonal variation in PSA levels or blood pressure.

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“…The blood pressure data are concordant with most other studies [7–14], showing maximum blood pressure in the winter months and minimum blood pressure in the summer months.…”

Section: Discussionsupporting

confidence: 90%

“…An extensive body of evidence supports the presence of seasonal variation in blood pressure. High values tend to be recorded in the winter months, and the lowest values in the summer [7–14]. Our ability to detect this established effect will support our findings in respect of any seasonal pattern in PSA levels.…”

Section: Introductionsupporting

confidence: 83%

Seasonal variation in prostate‐specific antigen levels: a large cross‐sectional study of men in the UK

Down

Metcalfe²,

Martin³

et al. 2011

BJU International

View full text Add to dashboard Cite

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“…Firstly, we aimed to quantify visit-to-visit variability, to determine its relationship with mean BP levels and to explore potentially confounding factors associated with variability. BP levels are known to vary according to both season [11] and day of the week [12]. We therefore aimed to determine the extent to which these factors contributed to observed levels of visit-to-visit variability.…”

Section: Introductionmentioning

confidence: 99%

Reproducibility of Measures of Visit-to-Visit Variability in Blood Pressure after Transient Ischaemic Attack or Minor Stroke

Howard

Rothwell²

2009

Cerebrovasc Dis

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Background: In certain patients in routine practice, blood pressure (BP) measurements differ substantially from week to week or month to month. Although often assumed to be random, such variability could provide information on underlying pathology or prognosis. In order to be informative, however, visit-to-visit BP variability would have to be neither random (i.e. it should be reproducible over time within individuals) nor artefactual (i.e. it should not be an artefact of the method/timing of measurement, for example). Methods: We quantified visit-to-visit variability in BP and explored potential confounding factors by analysing repeat measurements obtained every few months during follow-up in two large trials in patients with a transient ischaemic attack (TIA) or minor ischaemic stroke: the UK-TIA Aspirin Trial (effect of aspirin, effect of season and day of the week of measurement) and the European Carotid Surgery Trial (ECST – effect of carotid endarterectomy). By comparing different periods of follow-up, we also determined the reproducibilities of mean and several different measures of variability for both systolic (SBP) and diastolic BP (DBP). Results: The mean absolute difference between adjacent SBP readings was 14.7 mm Hg in the UK-TIA Trial and 16.0 mm Hg in ECST. Visit-to-visit variability in both SBP and DBP were independent of the potentially confounding factors studied, but reproducibility of all the variability measures was statistically significantly greater than zero. Reproducibility (intraclass correlation) of standard deviation of SBP was 0.32 (p < 0.0001) in the UK-TIA Trial and 0.18 (p = 0.0007) in ECST. Consequently, classification of patients with high (top quintile) or low (bottom quintile) variability was consistent over time (observed/expected = 2.21, 95% confidence interval 1.71–2.85, p < 0.0001, and 1.65, 1.23–2.21, p = 0.0007, respectively). Reproducibility increased with the number of measurements used to calculate variability, and was independent of any correlation with mean BP. Conclusions: Visit-to-visit variability in BP in these populations was reproducible, independently of any correlation with mean BP, demonstrating that visit-to-visit intra-individual BP variability is not random.

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“…These mechanisms may converge and lead to hypertension, atherosclerotic cardiovascular disease, and heart failure [2,3,[29][30][31]. Hypertension may be worsened in a cold environment [5,[32][33][34][35][36], elevating the myocardial workload and myocardial oxygen demand, or exacerbating functional valve insu ciencies. In addition to these mechanisms, viral infections [37] and/or vitamin de ciency [38] may also be involved.…”

Section: Discussionmentioning

confidence: 99%

Seasonal Changes in Incidence of Patients With Diabetes Undergoing Cardiac Surgery

Kovács¹,

Peták²,

Agócs³

et al. 2020

Preprint

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Background: To evaluate the monthly incidence rate of patients with diabetes requiring heart surgery at a tertiary-care university hospital in East-Central Europe with a temperate climate zone. We also assessed whether additional factors affecting small blood vessels (smoking, aging, and diabetes) modulate the seasonal variability of diabetes.Methods: Medical records were retrospectively analyzed for all 9837 consecutive adult patients who underwent surgery at our institution between 2007 and 2018. Individual seasonal variations of diabetes, smoking, and elderly patients were analyzed monthly. Potential additive or subtractive effects of the coexistence of these factors in seasonal changes in incidence rates were also examined. In the absence of a waiting list, incidence rates accurately reflect the frequency of exacerbation of cardiovascular symptoms requiring surgical intervention.Results: Significant seasonal variations in the monthly incidence rate of diabetes (p < 0.02), smoking (p < 0.001), and elderly (p < 0.001) patients were observed at the cardiac surgery unit. The peak incidence of non-elderly and smoking patients with diabetes was during winter, whereas heart surgery in elderly patients without diabetes and smoking was most frequently required in summer. Concomitant occurrence of diabetes and smoking had an additive effect on the relative incidence rate of requirement for cardiac surgery (p < 0.001), while the simultaneous presence of older age and diabetes or smoking eliminated seasonal variations.Conclusions: Scheduling regular cardiovascular control in accordance with periodicities in diabetes, elderly, and smoking patients more than once a year may improve patient health and social consequences.Trial registration: NCT03967639

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Elevated blood pressure in primary care varies in relation to circadian and seasonal changes

Cited by 14 publications

References 8 publications

Seasonal variation in prostate‐specific antigen levels: a large cross‐sectional study of men in the UK

Seasonal variation in prostate‐specific antigen levels: a large cross‐sectional study of men in the UK

Reproducibility of Measures of Visit-to-Visit Variability in Blood Pressure after Transient Ischaemic Attack or Minor Stroke

Seasonal Changes in Incidence of Patients With Diabetes Undergoing Cardiac Surgery

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