Seasonal variation of ambulatory blood pressure in Chinese hypertensive adolescents

Abstract

BackgroundBlood 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.MethodsFrom 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.ResultsMean 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.ConclusionHypertensive 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.

Seasonal variation in blood pressure: what is still missing?

“…Likewise, an ambulatory BP monitoring study (18) including 1,075 Japanese patients with chronic kidney disease evidenced that MH was more common in the winter, while WCH was more prevalent in the summer. By contrast, a Chinese study evaluating 649 adolescents assessed by ambulatory BP monitoring reported that both WCH and MH were more frequently detected in the summer (17). Furthermore, Narita et al ( 19) found a higher prevalence of nocturnal masked hypertension in the summer among 2,544 Japanese individuals assessed by home BP monitoring.…”

“…Because both office BP and out-of-office BP increase in colder seasons, the prevalence of SH is markedly greater in the winter when compared to the summer ( 8 , 16 , 17 ). Conversely, little is known regarding the impact of the seasons on MH and WCH.…”