Hematocrit and incidence of venous thromboembolism

Abstract

Background Patients with polycythemia vera with high hematocrit have increased risk of venous thromboembolism (VTE). Objective To determine whether high hematocrit in the general population is also associated with elevated VTE risk. Methods The prospective Atherosclerosis Risk in Communities Study performed a complete blood count in 13 891 adults aged 45 to 64 in 1987 to 1989. We identified incident hospitalized VTEs through 2015 and performed proportional hazards regression analyses using race‐sex–specific categorization of hematocrit percentiles (ie, <5th, 5th to <25th, 25th to <75th, 75th to <95th, and 95th‐100th percentiles, with the 25th to <75th percentile serving as the reference). Results Over a median follow‐up of 26 years, 800 participants had an incident venous thrombosis of the leg and/or a pulmonary embolism. There was a nonlinear association of hematocrit with VTE incidence, with risk elevated 72% for participants above the 95th percentile of hematocrit compared with the reference. Specifically, hazard ratios (95% confidence intervals) of incident VTE were 1.27 (0.91‐1.76), 1.06 (0.87‐1.28), 1 (reference), 1.17 (0.98‐1.40) and 1.72 (1.30‐2.27) across the 5 hematocrit percentiles, adjusted for age, race, sex, body mass index, smoking status and pack‐years, and other confounding variables. The association of high hematocrit with VTE was limited to provoked VTE, with little evidence for unprovoked VTE. Hemoglobin above the 95th percentile also was associated with an increased risk of VTE. In contrast, there were no significant associations of platelet, leukocyte, neutrophil, or lymphocyte counts with VTE incidence. Conclusion High hematocrit and hemoglobin in a general middle‐aged population sample were associated with increased long‐term risk of VTE, particularly provoked VTE.

Hemostatic markers and polymorphisms in three families with Legg-Calvé-Perthes disease

“…Regarding laboratory studies, all our patients presented high hemoglobin levels, a factor linked to increased blood viscosity and, probably, to subsequent thrombotic events [30][31][32]. In addition, our results show different hemostatic alterations in every individual analyzed, presenting out-of-range values in one or more parameters.…”

Risk stratification of in-hospital VTE associated with urinary cancer

“…The hemoglobin level is a key measure to assess whether a patient is anemic, and Khorana et al identi ed a hemoglobin level of less than 100g per liter as signi cantly associated [6] with VTE in the study of patients with malignancies. In contrast, the study by Folsom et al suggests that elevated hemoglobin levels are associated [7] with long-term risk for VTE. Anemia is a common complication in patients with malignant tumors.…”

Association of the neutrophil-to-lymphocyte ratio with the occurrence of venous thromboembolism and arterial thrombosis

“…Some studies have indicated that a high hemoglobin level is a risk factor for VTE; however, no study has shown a difference between VTE subgroups. [35][36][37] In general, studies on the value of a high NLR in increasing the risk of VTE are controversial. There is still a long distance from mouse model study results to their clinical application.…”