Blockade of renin-angiotensin system does not prevent diabetic nephropathy

A long term placebo controlled trial has overturned the prevailing wisdom that blocking the renin-angiotensin system helps protect renal function in patients with type 1 diabetes. Five years of treatment with either losartan or enalapril did not prevent the renal structural damage that underlies nephropathy, and it made no difference to glomerular filtration rates (which fell) in 285 adults who began the trial with normal blood pressure and renal function. Losartan actually increased albumin excretion relative to placebo, a result that surprised both the researchers and the authors of an accompanying editorial (p 83).

Both agents were more effective than placebo at halting retinopathy, however. Enalapril reduced the odds of clinically important progression by 65% (odds ratio 0.35, 95% CI 0.14 to 0.85), losartan reduced the odds by a comparable 70% (0.3, 0.12 to 0.73).⇑ Both effects were independent of changes in blood pressure. One third of the participants had no retinopathy when randomised, and most of the rest had minimal disease.

Blockade of the renin-angiotensin system seems to have very different effects in the early and late stages of diabetic complications, says the editorial. This early stage trial suggests it is good for retinopathy but not for nephropathy. Trials in patients with more severe complications have suggested precisely the opposite.

Swine flu had the hallmarks of a pandemic from the start

The epidemiology of swine flu is still emerging, but early surveillance data from Mexico show that the first wave of serious infections looked very much like the initial phases of previous influenza pandemics—a new virus, a spike of cases outside the usual influenza season, and a clear shift in the age distribution of illness and death.⇑

Between 24 March and 29 April this year, healthcare providers in Mexico reported 2155 cases of severe pneumonia, including 100 deaths, to the Ministry of Health. Most (71%) of the cases …