ARTERIAL HYPERTENSION, HEART RATE, AND ARTERIAL STIFFNESS IN OVERWEIGHT AND OBESE PATIENTS

Objective: Obesity and overweight represent a global public health crisis, due to the increased risk of cardiovascular diseases consequent to many factors such as metabolic dysregulation and chronic inflammation. This study aimed to compare the Heart Rate variability (HRV) between obese and non-obese hypertensive patients. Design and method: A cross-sectional study included 76 hypertensive patients, referred to the Functional Explorations department. Anthropometric and clinical data were collected. All patients underwent 24-hour Ambulatory Blood Pressure (BP) Monitoring. HRVs were measured (standard deviation in percentage) during 24-hour, diurnal and nocturnal periods. Patients were divided into two groups, according to their body mass index (BMI, whether < 30 kg/m 2 or = 30 30 kg/m 2 and more): G1 (obese, n=39) and G2 (non-obese, n=37). Results: Mean age was 55±10 vs. 52±15 years and mean BMI was 34±4 vs. 26±2 kg/m 2 in G1 and G2, respectively. Both groups were matched for sex (66.7% of females in G1 vs. 48.6% of females in G2) and comorbidities (mainly diabetes and dyslipidemia), but G1 included a higher proportion of metabolic syndrome (p<0.05). Mean values of 24-hour Systolic and Diastolic BPs were 136±10 mmHg vs. 130±11 mmHg (p=0.022), and 84±9 mmHg vs. 80±9 mmHg (p=0.066), respectively in G1 and in G2. Mean values of 24-hour, diurnal and nocturnal HRVs were 14±3% vs. 16±3%; 14±3% vs. 16±3%; 7±3% vs. 9±6%, respectively in G1 and in G2. Diurnal and 24-hour HRVs were statistically lower in G1 (p=0.010 and 0.035, respectively). However, no significant difference was observed in nocturnal HRV (p=0.279) between the two groups. Conclusions: This study revealed lower HRVs among obese patients which highlights a clear association between obesity and reduced autonomic nervous system function, particularly with diminished parasympathetic activity. This HRV reduction, resulting in an imbalance in autonomic regulation, increases cardiovascular risk. Managing weight seems to be the key to minimize these negative impacts.