Gender-Specific Association of Serum Adiponectin Level with 24-Hour Heart Rate but not Blood Pressure in Female Hypertensive Patients

Objective: Serum adiponectin, an adipocyte-derived plasma protein, could be reduced in patients with cardio-metabolic diseases including essential hypertension. It is not known whether serum adiponectin could be correlated with the alteration of cardiovascular regulation in hypertensive patients. This study aimed to evaluate the association of serum adiponectin level with the various parameters of ambulatory blood pressure (BP) monitoring in patients with never-treated hypertension. Methods: We studied 89 patients with untreated mild to moderate hypertension (29 women and 60 men). BP and heart rate were measured for 24 hours with the SpaceLab 902907 recorder in each patient. The anthropometric and blood test for the metabolic profiles were also conducted. Results: Serum adiponectin level was inversely correlated to plasma insulin and homeostasis model assessmentinsulin resistance index (HOMA-IR) in both male and female patients. Serum adiponectin level was also inversely related to body mass index and serum triglyceride level in male patients, which was not seen in female patients. In female patients, serum adiponectin level was inversely correlated with 24-hour (r=-0.59, P=0.001), daytime (r=-0.59, P=0.001), and nighttime heart rate (r=-0.55, P=0.002) but not with BP. Such association was not seen in male patients, suggesting the gender specific interaction between serum adiponectin and resting heart rate in never-treated hypertensive patients. Conclusions: Though correlated to plasma insulin and HOMA-IR in patients of both genders, serum adiponectin level was inversely correlated to 24-hour heart rate rather than BP in female hypertensive patients, suggesting gender-specific interaction between the regulation of cardiovascular autonomic tone and adipocyte-derived adiponectin.