title: Blood pressure response to patterns of weather fluctuations and effect on mortality.
abstract: Very few studies have looked at longitudinal intraindividual blood pressure responses to weather conditions. There are no data to suggest that specific response to changes in weather will have an impact on survival. We analyzed >169 000 clinic visits of 16 010 Glasgow Blood Pressure Clinic patients with hypertension. Each clinic visit was mapped to the mean West of Scotland monthly weather (temperature, sunshine, rainfall) data. Percentage change in blood pressure was calculated between pairs of consecutive clinic visits, where the weather alternated between 2 extreme quartiles (Q(1)-Q(4) or Q(4)-Q(1)) or remained in the same quartile (Q(n)-Q(n)) of each weather parameter. Subjects were also categorized into 2 groups depending on whether their blood pressure response in Q(1)-Q(4) or Q(4)-Q(1) were concordant or discordant to Q(n)-Q(n). Generalized estimating equations and Cox proportional hazards model were used to model the effect on longitudinal blood pressure and mortality, respectively. Q(n)-Q(n) showed a mean 2% drop in blood pressure consistently, whereas Q(4)-Q(1) showed a mean 2.1% and 1.6% rise in systolic and diastolic blood pressure, respectively. However, Q(1)-Q(4) did not show significant changes in blood pressure. Temperature-sensitive subjects had significantly higher mortality (1.35 [95% confidence interval, 1.06-1.71]; P=0.01) and higher follow-up systolic blood pressure (1.85 [95% confidence interval, 0.24-3.46]; P=0.02) compared with temperature-nonsensitive subjects. Blood pressure response to temperature may be one of the underlying mechanisms that determine long-term blood pressure variability. Knowing a patient's blood pressure response to weather can help reduce unnecessary antihypertensive treatment modification, which may in turn increase blood pressure variability and, thus, risk.
authors: BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors: Louise
authors: L
authors: Aubinière-Robb
authors: Panniyammakal
authors: P
authors: Jeemon
authors: Claire E
authors: CE
authors: Hastie
authors: Rajan K
authors: RK
authors: Patel
authors: Linsay
authors: L
authors: McCallum
authors: David
authors: D
authors: Morrison
authors: Matthew
authors: M
authors: Walters
authors: Jesse
authors: J
authors: Dawson
authors: William
authors: W
authors: Sloan
authors: Scott
authors: S
authors: Muir
authors: Anna F
authors: AF
authors: Dominiczak
authors: Gordon T
authors: GT
authors: McInnes
authors: Sandosh
authors: S
authors: Padmanabhan
mesh_terms: D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000401:mortality / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012606:Scotland / Q000453:epidemiology; D015996:Survival Rate / Q000639:trends; D014887:Weather
keywords: blood pressure; hypertension; mortality; temperature; weather