Doxazosin GITS versus standard doxazosin in mild to moderate hypertension.

BACKGROUND: The selective alpha 1-adrenoceptor antagonist doxazosin in both standard formulation and gastrointestinal therapeutic system (GITS) controlled-release formulation is effective for hypertension without having a negative impact on serum lipids. This study was designed to compare the relative efficacy of these two formulations of doxazosin on clinic and ambulatory blood pressure and serum lipids in patients with mild to moderate hypertension. METHODS: Hypertensive patients aged 18-70 years (n = 335) were evaluated in a multi-center prospective randomized study. Following a 2-week placebo run-in phase, patients were randomized to receive doxazosin 2 or 4 mg, with dose titration, or doxazosin GITS 4 mg, no dose titration, for 9 weeks. RESULTS: Both doxazosin formulations reduced clinic diastolic and systolic blood pressure from baseline (P < 0.0001). Doxazosin GITS and doxazosin 4 mg had similar blood pressure-lowering effects. Doxazosin GITS reduced sitting diastolic and systolic blood pressure compared with doxazosin 2 mg (P < 0.01 for both). A greater proportion of the doxazosin GITS group reached goal blood pressure (< or = 140/90 mm Hg) after 9 weeks compared with the doxazosin 2-mg group. All doses of doxazosin reduced 24-h and daytime (7:00 am to 10:00 pm) ambulatory blood pressure from baseline (all P < 0.01). Doxazosin GITS significantly reduced nighttime (10:00 pm to 7:00 am) ambulatory blood pressure from baseline. A neutral effect on serum lipids was observed with doxazosin. CONCLUSIONS: Doxazosin GITS and doxazosin were effective in reducing clinic and ambulatory blood pressure. The GITS formulation reduced the need for dose titration. Both doxazosin formulations were well tolerated.

Effect of quinapril, quinapril-hydrochlorothiazide, and enalapril on the bone mass of hypertensive subjects: relationship with angiotensin converting enzyme polymorphisms.

BACKGROUND: Many alterations in extracellular metabolism of calcium have been associated to hypertension, but the number of studies relating this disease with osteoporosis is extremely low. This study clarifies the therapeutic effect of three treatments-quinapril, quinapril + hydrochlorothiazide (HCTZ), enalapril-on bone remodeling markers, bone mineral density (BMD) in hypertensive patients, and relationship with angiotensin converting enzyme (ACE) polymorphism. METHODS: This open, prospective study included 134 patients with low-to-moderate hypertension and stable BMD according to Joint National Committee criteria and 96 patients completed the study. After a washout period, patients were randomized to one of the three treatments, which they received for 1 year. Analyses of blood and urine samples and densitometric studies on lumbar spine were performed. RESULTS: Calcium and 25-hydroxyvitamin D levels increased (9.5 +/-0.3 and 9.6 +/-0.3 mg/dL, P =.01 and 46 +/-22 and 58 +/-22 nmol/L, P =.026, respectively) in the quinapril-treated group and calcium levels increased (9.4 +/-0.6 and 9.8 +/-0.4 mg/dL, P =.001) in the quinapril-HCTZ-treated group. The 1, 25-dihydroxyvitamin D levels, calciuria, and calcium/creatinine ratio decreased (64 +/-23 and 43 +/-16 nmol/L, P =.0001;209 +/-93 and 161 +/-93 mg/24 h, P =.0022;0.21 +/-0.09 and 0.17 +/-0.11, P =.04, respectively). In the enalapril-treated group 1, 25-dihydroxyvitamin D levels (61 +/-27 and 42 +/-19 nmol/L, P =.0022) decreased. Only women presented a statistical significance (1.064 +/-0.16 g/cm(2), P =.034) between ID+II polymorphism and BMD decrease, and between DD polymorphism with less BMD under baseline conditions and a BMD increase (1.070 +/-0.16 g/cm(2), P =.017) after ACE inhibitor treatment. CONCLUSIONS: The ACE inhibitors have a beneficial effect on BMD and calcium metabolism alterations in hypertensive subjects. Concerning BMD response, women presenting with the II+ID polymorphism had a poor response to antihypertensive drug treatment, whereas women with the DD polymorphism responded better. This is the first study demonstrating a relationship between ACE polymorphism and BMD response and antihypertensive ACE inhibitor treatment.

Relationship between bone mineral density and angiotensin converting enzyme polymorphism in hypertensive postmenopausal women.

BACKGROUND: The purpose of this study was to assess the relationship between bone mineral density and insertion/deletion (I/D) angiotensin converting enzyme polymorphism (ACE) in hypertensive postmenopausal women. METHODS: Blood and urine samples from the study subjects were analyzed for calcium metabolism related parameters. Densitometry studies were conducted in the lumbar spine (L2 to L4). The ACE polymorphism was analyzed by polymerase chain reaction. RESULTS: Women with II genotype showed a higher intact parathyroid hormone (76 +/- 33 v 55 +/- 27 pg/mL and 52 +/- 26 pg/mL, P =.034) without a decrease in calciuria, and higher bone mineral density than women with ID and homozygotus deletion genotype (1.138 +/- 0.08 v 1.051 +/- 0.16 pg/mL and 1.053 +/- 0.16 pg/mL). CONCLUSIONS: The ACE polymorphism could be one of the factors causing bone mass variations.