Relationship Between Obesity, Weight Change and Long-Term Blood Pressure Variability in Patients With Hypertension

Objective: To examine the interaction between obesity, weight change and long term visit-to-visit systolic blood pressure variability (SBPV) in patients with hypertension. Design and method: Study involved 270 randomly selected hypertensive patients (132 men and 138 women, average age 67.54±9.64y). At first visit appropriate diet was recommended, and patients were followed for 60 months. The study comprised three visits during the follow up period. Obesity was evaluated through body weight (BW), body mass index (BMI), and waist circumference (WC). Visit-to-visit SBPV for each patient was defined using the standard deviation from 3 values of systolic blood pressure (SBP). High SBPV was defined as standard deviation of SBP (SBP-SD) above the 4th quartile. Results: Values of SBP and SBPV were significantly higher (p< 0,009 and p<0,002) in the group of obese (n= 61 pts), than in the group of non-obese patients (n=209 pts). During follow-up period of 60 months, average decrease of BP for 31/3 mmHg, SBPV for 8.2 mmHg, BMI for 3.8 kg/m2, WC for 10.2 cm and BW for 10.7 kg in examined hypertensive pts were recorded, but the reduction in BW and SBPV was higher in obese than in non-obese group: BW 12,28 vs 9,24kg; SBPV 8,92 vs 7,74 mmHg (P<0,05 for both). The highest SBPV, was recorded in the 4th quartile of distributions of SBP-SD in the group of obese patients compared to the non-obese patients (41.02±5.76 vs 35.48±0; p<0,001). There was statistically stronger correlation between SBP-SD and BMI as parameter of total obesity compared to large waist circumference as parameter of central obesity (p<0.01). Conclusions: Results of the study, showed that obesity is strongly associated with higher SBPV across study visits. During 60-months follow-up, reduction of body weight was associated with reduction of blood pressure values and long term visit-to-visit systolic blood pressure variability.