SOURCE: McMullan CJ, et al. Racial impact of diurnal variations in blood pressure on cardiovascular events in chronic kidney disease. J Am Soc Hypertens 2015;9:299-306.
The circadian rhythm of blood pressure (BP) in healthy individuals, as well as most persons with hypertension, is characterized by a 10-20% decline in BP overnight, followed by an early (pre-awakening) rise maintained through much of the day. The change from lowest overnight BP to sustained morning BP is called the morning “surge,” remembering that timing of BP changes is actually relative to sleep cycle rather than time of day.
It has been noted that deviations from the “typical” circadian BP pattern of healthy individuals — for instance, failure to experience a dip in overnight BP (non-dipping) — is associated with increased risk of cardiovascular (CV) endpoints. Additionally, CV events tend to cluster with the morning surge in BP in the population at large, including those with hypertension.
McMullan examined diurnal variations in BP among patients with chronic kidney disease, to see whether ethnicity factors into outcomes. Their study population included Japanese (n = 197) and African-American (n = 197) men.
McMullan determined the morning BP surge was associated with increase CV risk in Japanese, but not African-American, men. Whether BP treatment that specifically affects morning BP surge might provide specific risk reduction independent of overall BP control remains to be determined.