Seasonal Variation in 24-h Blood Pressure Pattern of Young Normotensive Women.

Abstract

To investigate the seasonal variations in ambulatory blood pressure patterns, 24-h blood pressure was measured every 15 minutes noninvasively in ten young normotensive women. Urine was collected every 4 hours. The examinations were repeated in spring, summer, autumn, and winter in a standardized living environment.The 24-h average systolic and diastolic blood pressures did not differ significantly among the seasons. Similarly, there were no significant differences in the average values of either daytime or nighttime blood pressure. In contrast, the average pulse rate during nighttime was significantly higher in winter than in summer (64 ± 2 beats/min vs. 59 ± 2 beats/min, p < 0.05). The variabilities of either blood pressure or pulse rate did not change significantly among the seasons. The mesors and acrophases of both systolic and diastolic blood pressures, determined by a single cosinor method, were not significantly different among the seasons. On the other hand, the acrophase of pulse rate appeared significantly later in winter (16:19) compared with those in spring (14:54), summer (14:42), and autumn (14:21). Urine volume and urinary excretion of norepinephrine were significantly greater in winter than in summer. These results indicate that the 24-h pattern of blood pressure is reproducible and shows no seasonal difference in young normotensive women. (Hypertens Res 1995; 18: 209-214)

Dynamic Blood Pressure Changes and Recovery Under Different Work Shifts in Young Women

“…To control for potential seasonal effects, this study was conducted from March to June 2005, a time of year that Taipei temperatures range between 18 and 24 °C. 16,17 Twenty-four hour monitoring of arterial BP. The ABPM was recorded with a noninvasive, automated oscillometric device, Dynapulse 5000A (Pulse Metric, San Diego, CA).…”

Reproducibility of salt sensitivity testing using a dietary approach in essential hypertension

“…Previous studies have also reported a seasonal variation in casual, home and 24-h BP with a 2-4 mm Hg higher BP during winter, and a trend towards higher BP during winter was also found in our study. [32][33][34][35][36][37][38][39][40] However, no seasonal effect on BP response to change in dietary salt intake was found. Thus, salt sensitivity classification did not seem to be influenced by season.…”

“…As previously reported by others, a sea-382 sonal effect on daily sodium excretion and diuresis was found. [30][31][32] But time of year did not influence the response of daily sodium excretion following change in dietary salt intake. Previous studies have also reported a seasonal variation in casual, home and 24-h BP with a 2-4 mm Hg higher BP during winter, and a trend towards higher BP during winter was also found in our study.…”

Provisional criteria for the diagnosis of hypertension in pregnancy using home blood pressure measurements

“…These definitions were used because the acrophase of the BP was approximately at 1500 hours. 15 Because some participants measured the HBP twice or more, while others measured it only once, the HBP values of the first measurement were used for the calculations. Data revealing unfitness of the arm-cuff or movement during the measurement were excluded.…”