Influence of night-day blood pressure ratio on erythropoietin concentrations in diabetic patients

The purpose of this study was to investigate the relationships between 24-h BP profil and erythropoietin level in diabetics. Patients and methods: This study included 513 patients (26 women and 32 men, mean age: 58.7+/-14.6 yrs, diabetes duration: 16+/-11.2 yrs). Patients were divided by 24 hrs ABPM into 2 groups, one in which night-time pressures dipped by more than 10% (dippers, n=16) and the other in which pressures dipped by less than 10% (non-clippers, n=42) when compared to daytime pressures. Haemoglobin (Hb) and erythropoietin (EPO) levels where compared between diabetics and a control group (n=110) and between dippers and non-dippers. Results: Fib concentration of diabetics was significantly lower than those of control subjects (13.5+/-1.5 vs 14.5+/-1 g/dL; p<0.0001) but EPO levels did not differ from significant manner between these two groups. EPO concentrations were lower in dippers than in control subjects (13.7+/-5.4 vs 17.9+/-5 mU/mL; p<0.01), but there was not significant difference in Hb levels. Non-dippers had a Fib level lower than dippers (13.1+/-1.5 vs 14.6+/-1.1 g/dL, p<0.0001), but EPO concentrations did not differ from significant manner. Hb was correlated with between daytime and nighttime BP difference (SBP: r=0.262; p<0.05 and DBP: r=0.396; p<0.002). Hb was negatively correlated with albumin excretion rate (r=-0.335, p<0.01) and with creatinine level (r=-0.419; p<0.001). Conclusion: These data indicated that EPO production could be impaired in diabetics with abnormal diurnal BP variation. Nephropathy and cardiac autonomic dysfunction could explain these results.