Stress, Cortisol, and Nighttime Blood Pressure Dipping in Nonhypertensive Black American Women

Black American women have among the highest hypertension (HTN) rates in the world. Research suggests that nighttime might be a critical period of vulnerability for the development of HTN in Blacks. In the present study, personal factors (age, body fat, income, family history), psychological factors (stress, emotions, and John Henryism), and physiological factors (salivary cortisol and blood pressure [BP]) were explored in 30 Black women, ages 26-51 years. Data were collected in participants' homes. BP was monitored while participants were awake and asleep. Cortisol samples were obtained within the first hour after awakening. The usual pattern for BP is a drop or dipping of 10-20% during sleep; however, the BP for about a third of the subjects did not dip adequately during sleep. Though not statistically significant, this nondipping was clinically relevant and was associated with positive family history of HTN, more stress, lower positive and higher negative affect scores, and higher early morning cortisol levels. These findings add to the HTN risk profile and support the need to further explore the relationship between nondipping nighttime BP and cardiovascular disease in Black women.