There was a borderline significant reduction in retinopathy with more intensive BP lowering (RR 0.81, 95% CI 0.66–1.00, p = 0.051) but substantial heterogeneity in the magnitude of the effect across the included studies ( I 2 = 65.5%, p = 0.033) ( Figure 4 ) mostly attributable to the ACCORD result.
Four trials [16] , [17] , [29] , [33] reported hypotension outcomes (5,118 participants, with 76 versus 16 events) with more intensive BP control greatly increasing the risk of hypotension (RR 4.16, 95% CI 2.25–7.70, p <0.001) and showing an adverse trend towards severe hypotension (RR 2.19, 95% CI 0.03–164.77, p = 0.723) although the annual rate of severe hypotension was very low (0%–0.15%) [16] , [33] .