Underpowered, cut rate head to head studies that prove nothing worlks better than something.. David Nathan's take on NAVIGATOR, a prototype for CER studies that will show no clinical beneift...
http://content.nejm.org/cgi/content/full/NEJMe1002322
http://content.nejm.org/cgi/content/full/NEJMe1002322
The finding that valsartan failed to have an effect on either of the cardiovascular-disease outcomes but had a positive effect on the incidence of diabetes is surprising. Previous studies of ACE inhibitors and ARBs have suggested that these drugs have a beneficial effect on cardiovascular disease in patients with diabetes, and the lower blood pressure achieved would be expected to result in a reduction in cardiovascular disease. In the NAVIGATOR study, the high rates of loss to follow-up (13%), use of off-study ACE inhibitors or ARBs among participants assigned to placebo (24%), and nonadherence to valsartan (34% by study end) could explain the absence of an effect on cardiovascular disease.
The results from the NAVIGATOR study do not support the contention that reducing postprandial hyperglycemia has a specific role in preventing diabetes or reducing cardiovascular disease. Other than increasing the rate of hypoglycemia by a factor of two, nateglinide had little effect. Although the authors suggest that the prevention of diabetes with valsartan might make it a preferred drug as compared with antihypertensive drugs that potentially worsen glycemia, valsartan was relatively weak in preventing diabetes, and it did not lower the rates of cardiovascular disease. The prevention of diabetes remains a critical public health priority, but for now we should steer away from these two drugs and use effective lifestyle interventions and, in selected persons, metformin to combat the epidemic.
