Changes in haemostatic and platelet activation markers in non-dipper hypertensive patients.

BACKGROUND

Non-dipper hypertensive patients are at increased risk for cardiovascular disease. Coagulation and fibrinolysis activation factors are considered as risk factors for cardiovascular disease. The aim of this study was to examine the relationship between the haemostatic and platelet activation markers and the non-dipping pattern in treated hypertensive patients.

PATIENTS AND METHODS

Seventy-one treated hypertensive patients (53 with essential and 18 with secondary hypertension, due to chronic kidney disease-stage 4), aged 33 to 81 years (30 men), were classified as dippers and non-dippers, according to the presence or absence, respectively, of a decline of nocturnal average systolic blood pressure (BP) by more than 10% of the diurnal BP (non-dipping pattern) on 24-hour ambulatory BP monitoring. Plasma levels of factors VIII and IX, fibrinogen, prothrombin fragment 1 + 2, thrombin-antithrombin complex, protein C, plasmin-alpha-2 antiplasmin complex, D-dimer and platelet factor 4 were measured in all patients.

RESULTS

Thirty-seven patients were classified as dippers and 34 as non-dippers. The percentages of patients with essential and with secondary hypertension were similar in the dippers and in the non-dippers groups (both P = 0.754). Multivariate analysis of variance showed statistically significant differences in all measured variables between dippers and non-dippers (P = 0.043). Plasma levels of factors VIII and IX, fibrinogen, prothrombin fragment 1 + 2, protein C, plasmin-alpha-2-antiplasmin complex, and D-dimers were significantly higher in non-dippers when compared to dippers (P < 0.05 for all). In contrast, there were no significant differences in plasma levels of thrombin-antithrombin complex (P = 0.955) and platelet factor 4 (P = 0.431) between the two groups.

CONCLUSION

This study provides evidence that non-dipper treated hypertensive patients exhibit alterations in haemostasis, which may affect their cardiovascular risk.