From our CCG’s review of evidence (Rational Prescribing, Sept 2015):
- On current evidence (which admittedly is somewhat limited), there is no statistically significant benefit from treating Stage 1 hypertension (160/100 or less)
- Aiming for an HbA1c level of 7.0% vs. 7.9% needs a NNT of 200/year to prevent one microvascular (mostly retinal) event. Aiming for 6.3% vs. 7.3% has a NNT of 333/yr ditto.
- In diabetes, getting systolic BP from 134 to 120 prevents about 1 stroke per 500 pts per yr. Getting BP control below 140/90 has an NNT of 57/yr to prevent one major event including MI or death.
- In most cases of CKD, the target BP range should be 120 – 139 systolic, as getting BP <120 systolic is associated with an increase in harm. A striking one, apparently, in both mortality and CV events. Target diastolic should be <90. The two exceptions here are ACR >70, or co-existing diabetes, in both of which groups aiming for a systolic 120 – 129 (note still don’t aim below 120) and diastolic <80; this slows progression to end-stage renal disease, although it doesn’t change cardiovascular outcomes or mortality. (However, much of the evidence in diabetes is for Type 1; doesn’t seem to be strong evidence for Type 2 in CKD.)
- Antimuscarinics for OAB are not, in clinical terms, that effective. It may be better to continue them only if a satisfactory clinical response. In terms of side-effect risks, there is evidence on how some compare in terms of their risk of dry mouth: oxybutynin > oxybutynin SR > tolterodine > solifenacin.
Aaaaaand edited, because a couple of pertinent points just showed up in recent BMJs:
This systematic review found that antihypertensive treatment should only be given to diabetics whose baseline systolic is >140. If it’s less than 140, antihypertensives increase the risk of cardiovascular death, with no apparent benefit.
And an opinion article linked to this study showing that, in the over-50s, trying to get HbA1c lower than 9% (74.9) was associated with ‘at best modest benefits’.