Calcium channel blockers, losartan best for patients at risk for gout
MedWire News: Calcium channel blockers (CCBs) and the angiotensin receptor blocker (ARB) losartan may be the best antihypertensive drugs to prescribe to patients at risk for developing gout, research suggests.
The study found that patients with hypertension currently using CCBs had a 13% lower risk for gout relative to those who never used CCBs, while those currently using losartan had a 19% lower risk relative to never-users.
Furthermore, these associations were also seen in patients without hypertension and independent of use of other antihypertensive drugs and other risk factors for gout, such as age, body mass index, smoking, alcohol use, and the presence of ischemic heart disease, hyperlipidemia, and renal failure.
In addition, the associations were stronger with both a longer duration and a higher dose of use, report Hyon Choi (Boston University School of Medicine, Massachusetts, USA) and team in the British Medical Journal.
The authors say these findings are compatible with the documented urate lowering properties of these drugs; by contrast, beta blockers, angiotensin converting enzyme (ACE) inhibitors, and ARBs other than losartan were all associated with increased risks for gout.
For the study, Choi and team analysed data on a cohort of 24,768 people aged 20-79 years with newly diagnosed gout, and a random sample of 50,000 matched control individuals, taken from the UK general practice health improvement network database.
Multivariate analysis showed that compared with no use of CCBs, current CCB use among patients with hypertension was associated with a relative risk for gout of 0.87, after adjusting for other covariates and antihypertensive drugs. For individual CCBs, the multivariate relative risks were 0.79 for amlodipine, 0.87 for nifedipine, and 0.86 for diltiazem.
Further analysis showed that the relative risk for gout was associated with duration of CCB use, at 1.04 for less than 1 year, 0.89 for 1-1.9 years, and 0.77 for 2 years or more. And the association was stronger with high-dose than with medium or low-dose use of CCBs, at a relative risk of 0.80 versus 0.90.
For losartan, the multivariate relative risk for gout associated with current use compared with no use was 0.81; again it was lower the longer the duration of losartan use, at 0.97 for less than a year, 0.86 for 1-1.9 years, and 0.70 for 2 or more years, and at high than at lower doses, at 0.66 versus 0.88.
By contrast, current use of diuretics, beta blockers, ACE inhibitors, and non-losartan ARBs in patients with hypertension was associated with an increased gout risk compared with no use of each, at multivariate relative risks of 2.36, 1.48, 1.24, and 1.29, respectively.
All the associations were similar among patients without hypertension, although the frequency of losartan use in particular in the group of patients without hypertension was low, Choi et al note.
The team also reports that the direction and magnitude of associations seen with commonly used combinations were consistent with those for monotherapy. For instance, in commonly used dual therapy combinations including diuretics, the gout risk was greater with ACE inhibitors and with beta blockers than with CCBs, and in combined use of beta blockers the risk was higher with ACE inhibitors than with CCBs, while the risk was nonsignificant for the combination of ACE inhibitors and CCBs.
"Our findings suggest that calcium channel blockers and losartan may be protective against the risk of gout among people with hypertension," conclude the researchers.
"These data may have practical implications for choosing the appropriate antihypertensive drugs in patients with hypertension, a common comorbidity of gout."
By Caroline Price