Release from glomerular overload by the addition of low-dose thiazide in patients with angiotensin receptor blocker-resistant hypertension

Triple combination therapy with telmisartan, amlodipine, and hydrochlorothiazide ameliorates albuminuria in a normotensive rat remnant kidney model

Background

Some types of antihypertensive drugs may have pleiotropic effects in patients with chronic kidney disease (CKD). However, whether triple combination therapy with angiotensin II receptor blockers (ARBs), calcium channel blockers (CCBs), and thiazide diuretics (TZD) confer renoprotective effects in normotensive CKD remains unknown. Thus, we explored this issue using a normotensive rat remnant kidney model.

Methods

Sprague-Dawley rats were randomly allocated into four groups: sham (n = 10), 5/6 nephrectomy (NTx) (n = 9), NTx treated with telmisartan and amlodipine (dual) (n = 8), and NTx treated with telmisartan, amlodipine, and hydrochlorothiazide (triple) (n = 7), and followed for 4 weeks. Blood pressure (BP), blood chemistry including renal function, urinary albumin excretion (UAE), and renal pathology were evaluated in all groups.

Results

There was no significant change in systolic BP among the four groups during the study period. Serum blood urea nitrogen (BUN) was significantly higher, and 24-h creatinine clearance (Ccr) was lower in all NTx groups (p < 0.001). Dual therapy further increased the glomerular diameter in NTx rats (p < 0.001), which was significantly ameliorated by triple therapy (p < 0.001). Triple therapy, but not dual therapy, significantly reduced NTx-induced UAE levels (p < 0.05), whereas BUN, 24-h Ccr, and tubulointerstitial injury scores were comparable among all the NTx groups.

Conclusions

Our results suggest that triple combination therapy with telmisartan, amlodipine, and hydrochlorothiazide could ameliorate glomerular hypertrophy and albuminuria in normotensive CKD rats in a BP-lowering independent manner.

Antialbuminuric effect of eplerenone in comparison to thiazide diuretics in patients with hypertension

This study investigated the effects and safety of eplerenone or thiazide diuretics in patients with hypertension and albuminuria (pretreatment urinary albumin/creatinine ratio ≥10 mg/gCr) treated with an angiotensin II receptor blocker. The primary end point was the mean percent change in the urinary albumin/creatinine ratio from baseline to 48 weeks. An efficacy analysis was performed in 195 patients (98 in the eplerenone group and 97 in the thiazide group). Systolic and diastolic blood pressures at 48 weeks were similar in the two groups. The mean percent change in the urinary albumin/creatinine ratio from baseline to 48 weeks was similar in the two groups (P=.804). In the safety analysis, the withdrawal rates for adverse events were similar in both groups. The antialbuminuric effects and safety of eplerenone therapy were similar to those of thiazide diuretics when combined with an angiotensin II receptor blocker in patients with hypertension and albuminuria.

The Combined Effect of High Ambient Temperature and Antihypertensive Treatment on Renal Function in Hospitalized Elderly Patients

Background

The aging kidney manifests structural, functional as well as pharmacological changes, rendering elderly patients more susceptible to adverse environmental influences on their health, dehydration in particular.

Hypothesis

Higher temperature is associated with renal function impairment in patients 65 years and older who routinely take thiazide and/or ACE-inhibitors/ARBs.

Methods

We obtained health data of patients older than 65 who were admitted to a large tertiary center during the years 2006–2011, with a previous diagnosis of hypertension, and treated with thiazide, ACE-inhibitors/ARBs or both. We collected environmental data of daily temperature, available from collaborative public and governmental institutions. In order to estimate the effect of daily temperature on renal function we performed linear mixed models, separately for each treatment group and creatinine change during hospital admission.

Results

We identified 26,286 admissions for 14, 268 patients with a mean age of 75.6 (±6.9) years, of whom 53.6% were men. Increment in daily temperature on admission of 5°C had significant effect on creatinine increase in the no treatment (baseline creatinine adjusted 0.824 mg/dL, % change 1.212, % change 95% C.I 0.082–2.354) and dual treatment groups (baseline creatinine adjusted 1.032mg/dL, % change 3.440, % change 95% C.I 1.227–5.700). Sub-analysis stratified by advanced age, chronic kidney disease and primary diagnosis on hospital admission, revealed a significant association within patients admitted due to acute infection and treated with dual therapy.

Conclusion

Whereas previous studies analyzed sporadic climate effects during heat waves and/or excluded older population taking anti-hypertensive medications, the present study is novel by showing a durable association of temperature and decreased renal function specifically in elderly patients taking anti-hypertensive medications.