[Seasonal variation of blood pressure and related factors in Chinese adults: a survey of over 50 000 people in Suzhou, China].
OBJECTIVE
Seasonal variation in blood pressure had been observed in several studies on Western populations, but uncertainty remains about the strength of the relationship in other populations and the extent to which it was modified by other factors.


METHODS
This study was based on cross-sectional data from the China Kadoorie Biobank study with 53 260 men and women from the Suzhou area involved. Linear regression model was used to analyze the association of blood pressure with outdoor temperature-overall and in various subgroups.


RESULTS
Blood pressure varied with the seasons, ascending in winter and descending in summer. The difference in systolic blood pressure (SBP) between summer and winter was 8.8 mm Hg in men and 7.0 mm Hg in women. SBP was inversely correlated with outdoor temperature, especially above 10°C, with every 10°C colder temperature causing 6.1 mm Hg increase of SBP. The seasonal variation in SBP was more obviously seen in older people and in those with lower body mass index.


CONCLUSIONS
Blood pressure was strongly and inversely associated with outdoor temperature in the population in Suzhou area. Seasonal variation of blood pressure should be considered when the hypertension screening programs, clinical management and data management on hypertensive patients.
Suzhou Center of Disease Control and Prevention, Suzhou 215004, China.
Zheng-ji
ZJ
Zhang
Qiu-li
QL
Zhang
Yi-he
YH
Hu
Huai-dong
HD
DU
Sarah
S
Lewington
Yu
Y
Guo
Paul
P
Sherliker
Zheng
Z
Bian
Zheng-ming
ZM
Chen
Li-ming
LM
Li
D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012621:Seasons; D013696:Temperature