Previous studies have shown that hypertension treatment with an angiotensin-converting enzyme (ACE) inhibitor can slow the development of impaired kidney function, as demonstrated by delayed onset of microalbuminuria.
However, studies of whether angiotensin-receptor blockers (ARBs) delay onset of microalbuminuria have not produced consistent results.
Professor Hermann Haller from Hannover Medical School in Germany, and a team including researchers from Japan and the UK, looked at the effect of using an ARB in this setting.
They presented their findings at the European Society of Hypertension meeting in Oslo this week.
The researchers compared the effect of the ARB olmesartan on time to occurrence of first microalbuminuria in 4,447 patients with type-2 diabetes.
They found that, after four years of treatment, olmesartan reduced the risk of patients developing microalbuminuria by 23 per cent: 8.2 per cent of patients given olmesartan developed the condition, compared with 9.8 per cent of those given placebo. The researchers showed most of this effect was independent of the effect of olmesartan on BP.
However, 0.7 per cent of patients in the study given olmesartan died from cardiovascular causes compared with 0.2 per cent of those who were not given the ARB.
Professor Hermann Haller told GP that the low numbers of deaths from cardiovascular disease suggested this was 'not a real outcome but a sign that there may be a problem' in some patients.
He said patients with pre-existing coronary artery disease appeared to be most at risk, and that pushing these patients' BP below recommended levels could cause problems.
Professor Haller said three types of patients would be most likely to benefit from treatment with olmesartan to delay progression of microalbuminuria: those with high systolic BP, low eGFR and existing albumin excretion.
Professor Haller said that, although his study had used olmesartan, other ARBs may be able to delay the development of microalbuminuria, although this has not yet been shown.