The Influence of Long Term Hydrochlorothiazide Administration on the Relationship between Renin-Angiotensin-Aldosterone System Activity and Plasma Glucose in Patients with Hypertension

Objective. To observe the relationship between changes in renin-angiotensin-aldosterone system (RAAS) activity and blood plasma glucose after administration of hydrochlorothiazide (HCTZ) for one year in patients with hypertension. Methods. 108 hypertensive patients were given 12.5？mg HCTZ per day for one year. RAAS activity, plasma glucose levels, and other biochemical parameters, as well as plasma oxidized low density lipoprotein (oxLDL) levels, were measured and analyzed at baseline, six weeks, and one year after treatment. Results. After one year of treatment, the reduction in plasma glucose observed between the elevated plasma renin activity (PRA) group ( ？mmol/L) and the nonelevated PRA group ( ？mmol/L) was statistically significant ( ). The decrease of plasma glucose in the elevated Ang II group ( ？mmol/L) compared to the nonelevated Ang II group ( ？mmol/L) was statistically significant ( ). The proportion of patients with elevated plasma glucose in the elevated Ang II group (40.5%) was significantly higher than those in the nonelevated Ang II group (16.3%) ( ). The relative oxLDL level was not affected by the treatment. Conclusions. Changes in RAAS activity were correlated with changes in plasma glucose levels after one year of HCTZ therapy. 1. Introduction The renin-angiotensin-aldosterone system (RAAS) is composed of a series of hormones and corresponding enzymes. By controlling the blood volume and peripheral resistance, RAAS helps maintain the balance between human blood pressure, water and electrolytes, and thus homeostasis. Currently, the levels of plasma renin activity (PRA), angiotensin II (Ang II), and aldosterone (ALD) have become the key indicators for diagnosis, treatment, and clinical research about both primary and secondary types of hypertension. Research has demonstrated that RAAS activation not only was an important mechanism for the development of hypertension, but also could modulate insulin resistance [1]. Patients with hypertension usually exhibit insulin resistance and the risk of diabetes is elevated compared to nonhypertensive patients [2]. Consequently, as first-line antihypertensive medications, diuretics may influence RAAS [3]. However, little research has examined the relationship between changes in RAAS and changes in plasma glucose level. Thus, we examined changes in RAAS activity and plasma glucose in primary hypertensive patients taking HCTZ for one year, with the hope of providing new insight into the study of hypertension and its treatment. 2. Materials and Methods 2.1. Patient Enrollment From November 2007 to