Abstract P114: The Impact of Obesity and Weight Loss on Nocturnal Blood Pressure Dipping
In healthy individuals, sleep is associated with at least a 10% dip in Blood Pressure (BP). A lack of nocturnal BP dipping (LND) or a rise of BP nocturnally (RBPN) is associated with an increased risk of many cardiovascular diseases including stroke, heart failure and renal failure. Limited therapies exist for individuals with a LND or a RBPN.
In this study, we examine a potential correlation between obesity and a lack of nocturnal BP dipping as well as the impact of weight loss on nocturnal BP patterns. We assessed the hypothesis that elevated BMI would correlate to LND or RBPN and that weight loss would improve nocturnal BP patterns.
We recruited 30 volunteers with a LND pattern, 30 volunteers with a RBPN pattern and 20 control volunteers, with a healthy nocturnal BP dip. Individuals with sleep apnea were excluded. 24-hour Ambulatory BP Monitor readings and BMI measurements were performed before and after a 2 month dietary and lifestyle intervention to reduce weight, employing the DASH diet and lifestyle program.
At baseline we observed a negative correlation between BMI and nocturnal BP dipping: The average BMI of the control group was 28.1 kg/m2. The average BMI of the LND group was 30.3 kg/m2 (mildly obese). The average BMI of the RBPN group was 35.3 kg/m2 (severely obese) (p<0.0001).
After the 2 month intervention, we observed that individuals who achieved a weight loss of 5% or more (who previously experienced abnormalities in nocturnal dip) had an average 8.4% dip in nocturnal BP, representing a significant improvement in nocturnal BP patterns. Those who did not achieve a 5% weight loss & those who gained weight had blood pressure that rose by 3.2% at night on average (p<0.0001). Figure 1
The findings of this study suggest that obesity may contribute to nocturnal BP abnormalities and weight loss, through diet and lifestyle modifications, may improve nocturnal blood pressure patterns. The clinical implications of this strategy on the development or progression of cardiovascular diseases remain to be determined.
Author Disclosures: A.K. Pandey: None.
- © 2015 by American Heart Association, Inc.