Poor Sleep May Drive Obesity, Hypertension in Black Women

Megan Brooks

September 11, 2018

CHICAGO — Poor sleep may contribute to low levels of physical activity, high blood pressure, and obesity in middle-aged black women, suggesting that efforts to combat obesity and high blood pressure in this population should address sleep quality, researchers say.

Augustine Kang, MSc, a PhD candidate from Brown University, Providence, Rhode Island, presented the study September 6 during the American Heart Association Joint Hypertension 2018 Scientific Sessions.

Augustine Kang

"Sleep is an important component of blood pressure control and weight management, but few studies have explored the relationship between sleep and lifestyle factors associated with hypertension and obesity, such as physical activity," Kang told the heart.org | Medscape Cardiology.

"Even fewer studies have explored these constructs among minority populations. To our knowledge, this is the first study reporting associations between sleep, physical activity, and blood pressure among a population of black women," said Kang.

Kang and coauthor Patricia Markham Risica, DrPH, also from Brown University, studied 391 overweight or obese black women from the SisterTalk at Home study, a randomized controlled trial assessing the efficacy of a church-based weight management program for black women. The mean age of the cohort was 49.9 years, mean body mass index was 34.8 kg/m2, and mean systolic/diastolic blood pressure was 125.9 ± 17.8 / 77.9 ± 9.2 mm Hg.

Based on the Epworth Sleepiness Scale, 49% of the women were short sleepers (<7 hours/night), 46% were optimal sleepers (7 to 9 hours/night), and 5% were long sleepers (>9 hours/night).  Nearly two thirds (62%) of the women reported daytime sleepiness (35% "high normal" and 27% "excessive"), while 38% had normal levels of daytime sleepiness.

In this cohort, the prevalence of short sleepers and excessive daytime sleepiness was higher than in the general population, supporting prior observations that poor sleep quality may be comorbid with obesity, the researchers note.

In adjusted analyses, women with high levels of daytime sleepiness got far less vigorous (P = .028) and moderate (P = .035) physical activity and had higher systolic (P = .009) and diastolic (P = .031) blood pressure compared with those with normal levels of daytime sleepiness.  Moderate physical activity was inversely associated with systolic blood pressure (P = .039). 

"Hence, poor sleep quality may be related to less physical activity, which is in turn related to high blood pressure," said Kang.

"Sleeping enough hours can help us manage our body weight and blood pressure, and our study findings highlight the need for healthcare providers to recognize the important role of sleep for our overall health," said Kang. "We recommend lifestyle counseling that includes sleep and physical activity self-management strategies to better manage one's weight and blood pressure."

"This study highlights a major public health concern," Chandra L Jackson, PhD, from the National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, told the heart.org | Medscape Cardiology.

"Greatly underdiagnosed among African Americans, sleep disorders like obstructive sleep apnea which lead to excessive daytime sleepiness also lead to intermittent hypoxemia, swings in intrathoracic pressure, and nondipping of blood pressure that is likely to increase risk of cardiometabolic dysfunction," she noted.

"While more research is needed with objective sleep measures to corroborate the findings, physicians should consider screening for sleep disorders like obstructive sleep apnea among African American patients as a strategy to combat high blood pressure, which is disproportionately higher in this group," said Jackson, a member of the American Academy of Sleep Medicine.

"The social determinants of health related to where people live, work, and play that contribute to these major disparities by race/ethnicity are also very important to investigate in order to address the fundamental causes of these disparities," she added.

This study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases. The authors and Jackson have disclosed no relevant financial relationships.

American Heart Association Joint Hypertension 2018 Scientific Sessions. Poster #225. Presented September 6, 2018.

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