During the year-long debate over the new NICE guidelines for type 2 diabetes (NG28, published in December 2015), the area of discussion was almost entirely restricted to glycaemic management whilst blood pressure control went under the radar. Indeed, this section of NG28 was entirely ‘lifted’ from the 2009 NICE clinical guideline and can be summarised as follows:
‘Add medications if lifestyle advice does not reduce blood pressure to below 140/80 mmHg (below 130/80 mmHg if there is kidney, eye or cerebrovascular damage). ’
However, the field of blood pressure research is not as stagnant as this might imply. This was reflected by the report from the panel members appointed to the eight joint national committee (JNC8) in 2014, ‘Evidence-based guidelines for the management of high blood pressure in adults’. Recommendation 5 states that ‘in the population aged 18 years or older with diabetes, initiate pharmacologic treatment….and treat to a goal of lower than 140mmHg systolic blood pressure (SBP) and goal DBP lower than 90mmHg’. Note the omission of 130/80mmHg.
A systematic review and meta-analysis of the effect of antihypertensive treatment at different blood pressure levels in patients with diabetes mellitus, published in 2016, also promoted relaxation of SBP targets. The authors concluded that ‘If systolic blood pressure is less than 140 mmHg, further treatment is associated with an increased risk of cardiovascular death, with no observed benefit’.
So, what is my take on current blood pressure management in type 2 diabetes? I feel that SBP control is important but one size doesn’t fit all. I believe that ACE-inhibitors and Angiotensin receptor blockers have been over-hyped and a focus on renin-angiotensin blockade (and ‘treating microalbuminuria’) without reference to SBP is inappropriate. Patients treated with newer glycaemic agents (GLP-1RAs and SGLT-2 inhibitors), may be able to reduce their antihypertensive therapy. And, for many of my patients, especially the elderly and those with co-morbidities, a SBP between 140-150mmHg is appropriate.
Professor Steve Bain