Antihypertensive effect of a fixed-dose combination of losartan/hydrochlorothiazide in patients with uncontrolled hypertension: a multicenter study.

BACKGROUND: Achieving adequate blood pressure (BP) control often requires more than one antihypertensive agent. The purpose of this study was to determine whether a fixed-dose formulation of losartan (LOS) plus hydrochlorothiazide (HCTZ) (LOS/HCTZ) is effective in achieving a greater BP lowering in patients with uncontrolled hypertension. METHODS: The study was a prospective, multicenter, observational trial exploring the antihypertensive effect of a single tablet of LOS 50 mg/HCTZ 12.5 mg. A total of 228 patients whose BP had previously been treated with more than one antihypertensive agents without having achieved BP goal below 130/80 mmHg enrolled in the study. RESULTS: A significant decrease in systolic and diastolic BP was observed in both clinic and home measurement after switching from the previous treatment to LOS/HCTZ. There was a significant decrease in both B-type natriuretic peptide (BNP) and urinary albumin creatinine (Cr) excretion ratio (ACR), especially in patients with elevated values. In contrast, there was a significant increase in serum Cr concentration in conjunction with a decrease in estimated glomerular filtration rate (eGFR). Overall serum uric acid (UA) concentration increased, whereas in patients with hyperuricemia there was a significant reduction in this value. CONCLUSION: Switching to LOS/HCTZ provides a greater reduction in clinic and home BP in patients with uncontrolled hypertension. This combination therapy may lead to cardio-, reno protection and improve UA metabolism.

[Renoprotective effect of triple therapy with low-dose angiotensin receptor blocker, low-dose diuretic and Ca-antagonist in hypertensive type 2 diabetic patients with overt nephropathy].

Combination therapy with angiotensin receptor antagonist(ARB) plus angiotensin converting enzyme inhibitor(ACE-I) (ARB/ACE-I) was efficacious in reducing proteinuria in patients with progressive renal disease. However, this therapy may be associated with the worsening of anemia and hyperkalemia. The present study addressed whether or not triple therapy with low-dose ARB, low-dose diuretic (D) and calcium channel blocker(CCB) (ARB/D/CCB) is as effective as therapy with low-dose ARB/ACE-I in retarding the progression of overt diabetic nephropathy. In the triple therapy, the patients were initially subjected to monotherapy with CCB for 24 weeks. Low-dose ARB and low-dose D were added to the treatment for an additional 24-week period. In parallel, patients undergoing double therapy were initially treated with low-dose ACE-I alone for 24 weeks, and then low-dose ARB was added for an additional 24-week period. The results were as follows: 1) In the triple therapy, blood pressure was reduced by 9 mmHg in systole and 5 mmHg in diastole (not significant) compared to monotherapy with CCB. There was a significant decline in proteinuria (3.3 +/- 1.2 g/day in the CCB-treated period vs. 2.1 +/- 1.0 g/day in the ARB/D/CCB-treated period, n = 12, p = 0.0143). Furthermore, a significant improvement in the slope of reciprocal serum creatinine concentration(1/Cr) was found in response to triple therapy(1/Cr: -0.0118 +/- 0.0009 in the CCB-treated vs. -0.0035 +/- 0.0028(I/mg/dl/month) in the ARB/D/CCB-treated period, n = 12, p < 0.001). There was neither a worsening of anemia nor an increase in the serum potassium(K) concentration. 2) In the double therapy, blood pressure was reduced by 12 mmHg in systole(p = 0.0079, n = 11) and 6 mmHg in diastole(n = 11, p = 0.0037) compared to the monotherapy with ACE-I. A significant improvement in the slope of 1/Cr was found in the double therapy(1/Cr: -0.0095 +/- 0.0052 in the ACE-I treated period vs. -0.0029 +/- 0.0028(I/mg/dl/month) in the ARB/ACE-I, n = 11, p < 0.001). In addition, there was a substantial reduction in hematocrit and increase in serum K concentration. The present result suggests that triple therapy consisting of ARB/D/CCB is as efficacious as double therapy with ARB/ACE-I in protecting the kidney from the progression in patients with diabetic overt nephropathy. The former may be expected to have less adverse effects.

[Salt intake and the progression of chronic renal diseases].

To what extent dietary salt intake is involved in the pathogenesis of progressive renal diseases has never been fully understood in humans. To this aim, we investigated the relationship between urinary sodium excretion (under a low salt & low protein diet) and urinary protein excretion/renal function in patients with three major renal diseases: chronic glomerulonephritis(GN), diabetic nephropathy(DN) and nephrosclerosis(NS). The results were as follows; 1) A significant positive correlation was found between urinary sodium excretion (equivalent to the daily salt intake) and daily urinary protein excretion in patients with a GN and DN. However, no relationship was found between the two parameters in patients with NS. 2) Reduction in salt intake led to a significant decrease in daily protein excretion, the effect of which was prominent in patients with GN and DN. 3) A significant positive correlation was found between urinary sodium excretion and estimated protein intake(EPI) in all three groups. 4) There was a significant positive correlation between EPI and urinary protein excretion in DN, but not in GN. 5) Reduction in salt and protein intake(calculated as an EPI) ameliorates the slope of reciprocal creatinine concentration(1/Cr) in patients with GN and DN. These results indicate that slat restriction is strongly associated with the preservation of renal function in patients with GN and DN, suggesting that this dietary strategy can be a useful measure for retarding the progressive nature of these diseases. Of note is that both salt and protein restriction was renoprotective only in patients with DN. Thus, patients with GN and DN must be followed-up on the basis of a salt-restricted diet throughout their clinical course.

Antiproteinuric effects of combined antihypertensive therapies in patients with overt type 2 diabetic nephropathy.

Combined antihypertensive therapy plays a crucial role in achieving targeted blood pressure reductions and renoprotection. We therefore compared the antihypertensive and antiproteinuric effects of combined therapy with either a calcium channel blocker (CCB) plus an angiotensin II receptor blocker (ARB) or an angiotensin converting enzyme inhibitor (ACE-I) plus an ARB in patients with type 2 diabetes mellitus complicated by overt nephropathy and mild to moderate hypertension. After a 12-week dietary control period, diabetic patients with mildly to moderately impaired renal function were randomly assigned to either a CCB (amlodipine 5 mg once daily) or an ACE-I (temocapril 2 mg once daily) for 12 weeks (monotherapy period). Both groups then received add-on therapy with an ARB (candesartan 4 mg once daily) for an additional 12 weeks. During the monotherapy period, blood pressure was decreased equally well in both groups. Daily urinary protein excretion remained unchanged in the CCB-treated group (control period, 4.0 +/- 1.8 g/day vs. CCB period, 4.1 +/- 1.9 g/day; ns; n = 8), but decreased in the ACE-I-treated group (control period, 4.3 +/- 1.8 g/day vs. ACE-I period, 3.5 +/- 1.7 g/day; p < 0.05; n = 9). After the combined therapy period, blood pressure was decreased to the same degree in both groups. Although ARB plus CCB significantly reduced urinary protein excretion (to 3.5 +/- 1.5 g/day; p < 0.05 vs. control period; n = 8), a more profound reduction was achieved with ARB plus ACE-I (to 2.6 +/- 1.3 g/day; p < 0.01 vs. control period; n = 9). Monotherapy with the ACE-I increased the serum potassium concentration, and this elevation was sustained after addition of the ARB. In contrast, the serum potassium concentration was not influenced by monotherapy with the CCB, but was significantly increased after addition of the ARB. A decreased hematocrit was observed in the ARB plus ACE-I group. The present study suggests that combined antihypertensive therapy with either a CCB plus an ARB or an ACE-I plus an ARB exerts an antiproteinuric effect in patients with type 2 diabetic nephropathy with mildly impaired renal function. Although the latter combination had a more profound effect, it was associated with an increased serum potassium concentration and worsening of renal anemia. Thus, the combination of a CCB and an ARB should be the first line antihypertensive therapy in those with overt diabetic nephropathy. The long-term efficacy of these combined antihypertensive therapies will need to be further addressed in a future study.