Long-term blood pressure variability, incidence of hypertension and changes in renal function in type 2 diabetes

OBJECTIVES: Long-term visit-to-visit SBP variability (VVV) predicts cerebro-cardiovascular and renal events in patients with hypertension. Whether VVV predicts hypertension and/or chronic kidney disease is currently unknown. We assessed the role of VVV on the development of hypertension and changes in renal function in patients with type 2 diabetes and normal blood pressure (NBP) in a real-life clinical setting. METHODS: Clinical records from 8998 patients with type 2 diabetes, NBP, and normal estimated glomerular filtration rate (eGFR) were analyzed. VVV was measured by SD of the mean SBP recorded in at least four visits during 2 consecutive years before follow-up. Hypertension was defined as SBP at least 140 mmHg and DBP at least 90 mmHg or the presence of antihypertensive treatment. Renal function was defined as worsening of albuminuria status and/or a reduction in eGFR at least 30% from baseline. RESULTS: After a mean follow-up time of 3.5 ± 2.8 years, 3795 patients developed hypertension (12.1 per 100 person-years). An increase of 5 mmHg VVV was associated with a 19% (P < 0.0001) and a 5% (P = 0.008) independent increased risk of developing hypertension and worsening of albuminuria, respectively. We found no association between VVV and eGFR decrease from baseline. Patients with VVV in the upper quartile (>12.8 mmHg) showed a 50% increased risk of developing hypertension (P < 0.0001) and an almost 20% increased risk of worsening albuminuria (P = 0.004) as compared with those in the lower one (<6.9 mmHg). CONCLUSION: Increased VVV independently predicts incident hypertension and albuminuria worsening in type 2 diabetes and NBP.