Pulse pressure and diurnal blood pressure variation: association with micro- and macrovascular complications in type 2 diabetes

BACKGROUND: In nondiabetic subjects pulse pressure (PP) is an independent predictor of cardiovascular disease and microalbuminuria. Reduced circadian blood pressure (BP) variation is a potential risk factor for the development of diabetic complications. We investigated the association between retinopathy, nephropathy, macrovascular disease, PP, and diurnal BP variation in a group of type 2 diabetic patients. METHODS: In 80 type 2 diabetic patients we performed 24-h ambulatory BP (AMBP) and fundus photographs. Urinary albumin excretion was evaluated by urinary albumin/creatinine ratio. Presence or absence of macrovascular disease was assessed by an independent physician. RESULTS: Forty-nine patients had no detectable retinal changes (grade 1), 13 had grade 2 retinopathy, and 18 had more advanced retinopathy (grades 3-6). Compared to patients without retinopathy (grade 1), patients with grades 2 and 3-6 had higher PP and blunted diurnal BP variation: night PP 55 +/- 10 mm Hg, 64 +/- 10 mm Hg, 61 +/- 15 mm Hg, P < .05 and systolic night/day ratio 89.3% +/- 7%, 94.6% +/- 8%, and 92.0% +/- 6%, P < .05 (grade 1, 2, and 3-6, respectively). Comparing nephropathy groups (45 normo-, 19 micro-, and 15 macroalbuminuric patients) results were similar: night PP 54 +/- 9 mm Hg, 57 +/- 10 mm Hg, and 70 +/- 15 mm Hg, P < .001 and systolic night/day ratio 88.9% +/- 7%, 92.0% +/- 7%, and 94.9% +/- 7%, P < .02. Likewise, compared to patients without macrovascular disease (n = 55), patients with this complication (n = 25) had higher AMBP values: night PP 57 +/- 12 mm Hg v 63 +/- 11 mm Hg, P < .05 and systolic night/day ratio 89.2% +/- 6% v 94.1% +/- 9%, P < .01. CONCLUSIONS: Increased PP and blunted diurnal BP variation are hemodynamic abnormalities associated with micro- and macrovascular complications in type 2 diabetes.