Uric acid and other renal function parameters in patients with stable angina pectoris participating in the ACTION trial: impact of nifedipine GITS (gastro-intestinal therapeutic system) and relation to outcome

Serum uric acid change in relation to antihypertensive therapy with the dihydropyridine calcium channel blockers

PURPOSE

We investigated serum uric acid changes in relation to the achieved clinic and ambulatory blood pressure after 8 weeks of antihypertensive therapy with two dihydropyridine calcium channel blockers.

MATERIALS AND METHODS

The study participants were patients with clinic and ambulatory hypertension, enrolled in a randomised controlled trial that compared amlodipine (5-10 mg, n = 215) and nifedipine gastrointestinal therapeutic system (GITS, 30-60 mg, n = 203). Hyperuricaemia was defined as a serum uric acid concentration of ≥420 µmol/L in men and ≥360 µmol/L in women. Analysis of covariance and multiple regression analyses were performed to study the associations between serum uric acid changes and the achieved clinic and ambulatory blood pressure during follow-up.

RESULTS

At baseline, 67 (16.0%) of the 418 patients had hyperuricaemia. Antihypertensive treatment reduced clinic and 24-h daytime and night-time systolic/diastolic blood pressure by a mean (±standard error [SE]) change of -17.4 ± 0.6/-8.6 ± 0.4 mm Hg and -13.7 ± 0.5/-8.3 ± 0.3 mm Hg, -13.8 ± 0.6/-8.4 ± 0.4 mm Hg, and -12.7 ± 0.7/-8.0 ± 0.4 mm Hg, respectively. Antihypertensive treatment reduced serum uric acid by a mean (±SE) change of -9.3 ± 2.8 μmol/L. The serum uric acid changes differed according to the achieved clinic and ambulatory blood pressure, and were statistically significant (mean ± SE -20.6 ± 6.6 to -10.7 ± 2.9 μmol/L, p ≤ 0.04) at the systolic/diastolic ranges of 130-139/≥90 mm Hg in clinic pressure, and <130/75-84 mm Hg, <145/80-84 mm Hg and <120/65-69 mm Hg in 24-h, daytime and night-time ambulatory pressure.

CONCLUSION

Our study showed that antihypertensive therapy with a dihydropyridine calcium channel blocker was associated with reduced serum uric acid, especially when 24-h ambulatory systolic blood pressure was controlled.

Survey on uric acid in Chinese subjects with essential hypertension (SUCCESS): a nationwide cross-sectional study

Background

Hyperuricemia (HUA) is associated with hypertension and increased cardiovascular risk. Current data regarding the prevalence of HUA in Chinese hypertensive patients are lacking. Our study aims to explore the prevalence and determinants of HUA in Chinese hypertensive adults.

Methods

Treatment-naive hypertensive adults or those taking single antihypertensive agent were included in a nationwide cross-sectional study. Basic demographics, antihypertensive medications, serum uric acid (UA), and other parameters were documented.

Results

The overall prevalence rate of HUA was 38.7% among 33,785 valid cases, 35.1% for males (UA >420 µmol/L), and 45.2% for females (UA >360 µmol/L). A multiple logistic regression analysis, adjusted for demographic and clinical factors (model 1), revealed that female sex [odds ratio (OR), 95% CI, 1.43, 1.36–1.51], age of ≥65 years (1.12, 1.05–1.19), low evaluated glomerular filtration rate [eGFR; 2.06, 1.91–2.23, the lowest [Q1] vs. the highest quartile (Q4)], unmarried (1.58, 1.10–2.27), Western China residency (3.21, 3.33–3.91), longer hypertension duration (1.97, 1.78–2.12, Q4 vs. Q1) and aspirin use (1.21, 1.14–1.29) were associated with HUA. In a multiple logistic regression analysis adjusted for clinical and metabolic parameters (model 2), female sex (OR, 95% CI, 1.34, 1.27–1.41), age of ≥65 years (1.09, 1.03–1.16), low eGFR (2.35, 2.19–2.52, Q1 vs. Q4), new–onset hypertension (2.01, 1.73–2.33), higher quartile of fasting blood glucose (FBG), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) levels, and body mass index (BMI) were associated with higher risk of HUA (1.89, 1.76–2.03; 2.15, 1.99–2.31; 2.86, 2.67–3.06; 1.27, 1.27–1.36, respectively, Q4 vs. Q1). Losartan, valsartan, and nifedipine were associated with lower risk of HUA (OR, 95% CI, 0.77, 0.67–0.88, 0.68, 0.60–0.77; 0.87, 0.77–0.99, 0.79, 0.70–0.89 and 0.80, 0.70–0.91, 0.82, 0.72–0.92), respectively, in models 1 and 2.

Conclusions

The prevalence rate of HUA in Chinese hypertensive patients was 38.7%. Female sex, aging (≥65 years), and low eGFR were independent predictors of HUA. HUA was lower among the patients who were taking losartan, valsartan, and nifedipine. Western region residents, new-onset hypertension, longer hypertension duration, aspirin use, higher FBG, TG, LDL-C levels and BMI were potential risk factors for HUA.

The effects of antihypertensive class on gout in older adults: secondary analysis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial

OBJECTIVES

Gout is a common complication of blood pressure management and a frequently cited cause of medication nonadherence. Little trial evidence exists to inform antihypertensive selection with regard to gout risk.

METHODS

The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) was a randomized clinical trial on the effects of first-step hypertension therapy with amlodipine, chlorthalidone, or lisinopril on fatal coronary heart disease or nonfatal myocardial infarction (1994-2002). Trial participants were linked to CMS and VA gout claims (ICD9 274.XX). We determined the effect of drug assignment on gout with Cox regression models. We also determined the adjusted association of self-reported atenolol use (ascertained at the 1-month visit for indications other than hypertension) with gout.

RESULTS

Claims were linked to 23 964 participants (mean age 69.8 ± 6.8 years, 45% women, 31% black). Atenolol use was reported by 928 participants at the 1-month visit. Over a mean follow-up of 4.9 years, we documented 597 gout claims. Amlodipine reduced the risk of gout by 37% (hazard ratio 0.63; 95% CI 0.51--0.78) compared with chlorthalidone and by 26% (hazard ratio 0.74; 95% CI 0.58--0.94) compared with lisinopril. Lisinopril nonsignificantly lowered gout risk compared with chlorthalidone (hazard ratio 0.85; 95% CI 0.70--1.03). Atenolol use was not associated with gout risk (adjusted hazard ratio 1.18; 95% CI 0.78--1.80). Gout risk reduction was primarily observed after 1 year of follow-up.

CONCLUSION

Amlodipine lowered long-term gout risk compared with lisinopril or chlorthalidone. This finding may be useful in cases where gout risk is a principal concern among patients being treated for hypertension.This trial is registered at clinicaltrials.gov, number: NCT00000542.

The uricosuric effects of dihydropyridine calcium channel blockers in vivo using urate under-excretion animal models

The purpose of this study was to create novel urate under-excretion animal models using pyrazinamide and to evaluate whether dihydropyridine calcium channel blockers (CCBs) have uricosuric effects in vivo. Adult male ICR mice were treated with pyrazinamide, vehicle (dimethyl sulfoxide: DMSO), or tap water. Thirty minutes later, pyrazinamide-treated mice were given benzbromarone, losartan, nilvadipine, nitrendipine, nifedipine or azelnidipine. Six hours after the second administration, urine (by urinary bladder puncture) and plasma were collected to measure uric acid and creatinine levels, and fractional excretion of uric acid (FEUA) and creatinine clearance (Ccr) were calculated and evaluated. There was no significant difference in the levels of plasma uric acid, plasma creatinine, Ccr, urinary N-acetyl-β-d-glucosaminidase (NAG) and urinary NAG-creatinine ratio between water, DMSO, and pyrazinamide-treated mice. But the FEUA of pyrazinamide-treated mice was significantly lower than water mice. The FEUA was significantly higher in mice taking the dihydropyridine CCBs (nilvadipine, nitrendipine, nifedipine, and high-dose azelnidipine) than in pyrazinamide-treated mice. There was no significant difference in Ccr. Thus, a novel animal model created with PZA administration was useful as a urate under-excretion animal model that was probably URAT1-mediated, and the uricosuric effects of dihydropyridine CCBs were confirmed in vivo.

Metoprolol Increases Uric Acid and Risk of Gout in African Americans With Chronic Kidney Disease Attributed to Hypertension

BACKGROUND

There is little evidence guiding selection of nondiuretic, antihypertensive agents with a goal of lowering uric acid (SUA) and minimizing gout risk.

METHODS

In the African American Study of Kidney Disease and Hypertension (AASK) trial, African Americans with chronic kidney disease were randomly assigned to metoprolol (a beta-blocker), ramipril (an angiotensin-converting enzyme inhibitors [ACEi]), or amlodipine (a dihydropyridine calcium-channel blocker). SUA was measured at baseline and 12 months. Gout-related hospitalizations were based on ICD9 codes. Gout-related medication use (GRMs) was based on active prescriptions of allopurinol, colchicine, or probenecid during the baseline visit of the AASK cohort phase. We examined the effect of drug assignment on 12-month SUA (linear regression), gout-related hospitalization (Cox regression), and GRM (logistic regression).

RESULTS

Of the 630 participants, 40% were female with a mean age of 55 years (SD, 10), mean SUA of 8.2 mg/dl (2.0), and mean serum creatinine of 1.8 mg/dl (0.6). After 12 months, metoprolol increased SUA by 0.3 mg/dl, while ramipril or amlodipine had no effect on SUA. Compared to ramipril, metoprolol significantly increased 12-month SUA (0.40; 0.10, 0.70 mg/dl; P = 0.009), nonsignificantly increased risk of gout-related hospitalization (hazard ratio: 3.87; 0.82, 18.26; P = 0.09), and significantly increased the odds of GRM (odds ratio: 1.62; 1.03, 2.54; P = 0.04). While metoprolol was associated with a higher 12-month SUA compared with amlodipine (0.57; 0.18, 0.95; P = 0.004), there was no difference in gout-related hospitalizations or GRM.

CONCLUSIONS

Metoprolol increased SUA and GRM in African American adults. Health professionals treating patients with kidney disease at risk for gout should avoid metoprolol and possibly consider an ACEi.

CLINICAL TRIALS REGISTRATION

Trial Number NCT00582777.

Effect of losartan combined with amlodipine or with a thiazide on uric acid levels in hypertensive patients

Hyperuricemia leads to endothelial dysfunction and insulin resistance, and has been associated with diseases such as hypertension. Antihypertensive drugs modify serum uric acid levels, however, few data are available about their combinations on uricemia. In this study we evaluate the effect of two combinations of losartan, with amlodipine or with hydrochlorothiazide, on serum uric acid levels in hypertensive patients.

METHODS

A total of 60 hypertensive patients were randomized in two groups; group LA received losartan/amlodipine (100/5 mg) once a day, whereas LH group received losartan hydrochlorothiazide (100/12.5 mg) once a day for 3 months. In both groups serum uric acid levels were measured at the beginning and end of the study. Patients were evaluated monthly for blood pressure (BP) and adverse events. Statistical analysis was performed with a two-way analysis of variance (ANOVA) for repeated measures.

RESULTS

All patients experienced a significant reduction of BP to the same extent (LA 155/94 to 123/79, LH 157/92 to 124/78 mmHg, p > 0.05). In the LA group, serum uric acid decreased from 6.5 ± 1.6 to 4.6 ± 1.3 mg/ml ( p = 0.0001), whereas in the LH group there was a nonsignificant increase from 5.82 ± 1.4 to 5.85 ± 1.5 mg/ml, ( p = 0.936). When both groups were compared, we found a significant reduction ( p < 0.00013) on serum uric acid levels in the LA group.

CONCLUSIONS

Both combinations decrease BP values to the same extent, however, LA combination showed a reduction on serum uric acid levels, which may contribute to a reduction in the metabolic risk in hypertensive patients.

Update in Hypertension Therapy

Hypertension is the leading cause of early mortality in the world, and reduction of blood pressure can help to reduce that burden. There is an enormous and ever-expanding body of literature on hypertension, with a 2016 Medline search for hypertension retrieving more than 113,000 publications. Recent guidelines from major societies have been published, and often present conflicting recommendations based on the same data. Using a question-and-answer format, this article reviews some of the recent developments and opinions on management of blood pressure and provides practical suggestions for management in the clinical arena.

Hypertension, its treatment, hyperuricaemia and gout

PURPOSE OF REVIEW

Gout is increasing worldwide. An appreciation that hyperuricaemia and gout are associated with hypertension and chronic kidney disease is well established, but the cause and effect relationships are controversial. Studies which address this conundrum have been reviewed.

RECENT FINDINGS

Epidemiological surveys have confirmed the strong relationship of gout and hyperuricaemia with hypertension and diuretic treatment. There are multiple confounders such as obesity and alcohol consumption which despite adjustments make interpretation of the epidemiology difficult. There are data to suggest that hyperuricaemia itself causes hypertension and renovascular disease, and that lowering of serum urate may assist in control of hypertension. The mechanism for diuretic-induced hyperuricaemia may operate through volume depletion and reduced secretion of uric acid. The latter effect may be genetically influenced.

SUMMARY

Recent population surveys have strongly supported the association of gout and hyperuricaemia with hypertension. The prevailing explanation that renal dysfunction causes both phenomena or that they are caused by shared factors is challenged by the evidence that hyperuricaemia drives hypertension. A confounder of epidemiology studies is the use of diuretics for treating hypertension. A closer understanding of the mechanisms of diuretic-induced hyperuricaemia may lead to the creation of uricosuric diuretics. Losartan is exceptional amongst antihypertensive drugs in possessing mild uricosuric properties and therefore has a role in treating hypertensive patients with gout. Overcoming diuretic-induced hyperuricaemia is difficult and there is need for a uricosuric diuretic.

Changes in serum uric acid levels and cardiovascular events: a meta-analysis

BACKGROUND AND AIMS

The association between serum uric acid (SUA) levels and cardiovascular (CV) risk or all-cause death has been repeatedly reported. However, it has not been assessed whether reduction of SUA levels is associated with reduced CV risk. The aim of the current study was to evaluate the relationship between changes of SUA levels and CV events as well as all-cause death.

METHODS AND RESULTS

Randomised trials reporting SUA at baseline and at the end of follow-up and clinical end-points (all-cause death, myocardial infarction (MI), stroke, heart failure (HF) and CV death) were included in the study. Meta-regression analysis was performed to test the relationship between SUA changes and clinical end-points. Eleven trials enrolling 21,373 participants followed up for 2.02 ± 1.76 years and reporting 4533 events were included. In meta-regression analysis, no relationship between SUA changes from baseline to end of follow-up and the composite outcome including CV death, stroke, MI and HF was found (change in Tau(2) (t) = -0.64; p Tau (p) = 0.541). Similarly, no relationship was found between SUA changes and single components of the composite outcome (MI: t = -0.83; p = 0.493; stroke: t = 0.46; p = 0.667; HF: t = 2.44; p = 0.162; CV death: t = -0.54; p = 0.614) and all-cause death (t = -0.72; p = 0.496). Results were confirmed by sensitivity analysis. No heterogeneity among studies or publication bias was detected.

CONCLUSIONS

Changes in SUA levels observed during pharmacologic treatments do not predict the risk of all-cause death or CV events. As SUA levels are associated with increased CV risk, additional studies with direct xanthine-oxidase inhibitors are requested.

Antihypertensive drugs and risk of incident gout among patients with hypertension: population based case-control study

OBJECTIVE

To determine the independent associations of antihypertensive drugs with the risk of incident gout among people with hypertension.

DESIGN

Nested case-control study.

SETTING

UK general practice database, 2000-7.

PARTICIPANTS

All incident cases of gout (n = 24,768) among adults aged 20-79 and a random sample of 50,000 matched controls.

MAIN OUTCOME MEASURE

Relative risk of incident gout associated with use of antihypertensive drugs.

RESULTS

After adjusting for age, sex, body mass index, visits to the general practitioner, alcohol intake, and pertinent drugs and comorbidities, the multivariate relative risks of incident gout associated with current use of antihypertensive drugs among those with hypertension (n = 29,138) were 0.87 (95% confidence interval 0.82 to 0.93) for calcium channel blockers, 0.81 (0.70 to 0.94) for losartan, 2.36 (2.21 to 2.52) for diuretics, 1.48 (1.40 to 1.57) for β blockers, 1.24 (1.17 to 1.32) for angiotensin converting enzyme inhibitors, and 1.29 (1.16 to 1.43) for non-losartan angiotensin II receptor blockers. Similar results were obtained among those without hypertension. The multivariate relative risks for the duration of use of calcium channel blockers among those with hypertension were 1.02 for less than one year, 0.88 for 1-1.9 years, and 0.75 for two or more years and for use of losartan they were 0.98, 0.87, and 0.71, respectively (both P<0.05 for trend).

CONCLUSIONS

Compatible with their urate lowering properties, calcium channel blockers and losartan are associated with a lower risk of incident gout among people with hypertension. By contrast, diuretics, β blockers, angiotensin converting enzyme inhibitors, and non-losartan angiotensin II receptor blockers are associated with an increased risk of gout.

Effective management of hypertension with dihydropyridine calcium channel blocker-based combination therapy in patients at high cardiovascular risk

The increasing prevalence of hypertension, owing to modern lifestyles and the increasing elderly population, is contributing to the global burden of cardiovascular (CV) disease. Although effective antihypertensive therapies are available, blood pressure (BP) is generally poorly controlled. In addition, the full benefits of antihypertensive therapy can only be realised when target BP is achieved. International guidelines and clinical trial evidence support the use of combination therapy to manage hypertension. In high-risk patients, such as those with coronary artery disease, diabetes and renal dysfunction, BP targets are lower and there is a need for intensive management with combination therapy to control BP and provide additional CV risk reduction benefits. Combinations of antihypertensive agents with different but complementary modes of action improve BP control and may also provide vascular-protective effects. Calcium channel blockers (CCBs) have been shown to be effective in combination with a range of antihypertensive drugs and in different patient populations. As part of a first-line combination strategy, CCBs can provide CV benefits beyond BP control, even in patients at increased CV risk. Benefits include protection against end-organ damage and serious CV events. Indeed, in major intervention trials, these benefits have already been clearly demonstrated. Ongoing studies will provide further data to support the clinical benefits of combination therapy as a first-line treatment approach. Implementation of this approach in clinical practice, together with adherence to global hypertension management guidelines will help ensure patients achieve and sustain BP targets, and reduce the risk of CV events.