Association of Hematocrit and Pre-hypertension Among Chinese Adults: The CRC Study

Abstract

Elevated blood pressure is regarded as an independent risk factor for cardiovascular diseases and diabetes. We examined the relation between hematocrit and pre-hypertension as well as the effect of sex, obesity, fasting glucose, and lipids in Chinese adults. The study samples were from a community-based health examination survey in China and included a total of 2,3691 patients with blood pressure in normal range. The odds ratios [ORs, 95 % confidence interval (CI)] of pre-hypertension across increasing quartiles of hematocrit were 1.000, 1.176 (1.050-1.318), 1.213 (1.081-1.363), and 1.364 (1.209-1.540) (P for trend < 0.001), when adjusted for age, sex, body mass index, glutamic-pyruvic transaminase, glutamic-oxalocetie transaminase, serum uric acid, glucose, and lipids. Associations were significant in both men and women, but not in individuals older than 60 years. In addition, low-density lipoprotein cholesterol significantly interacted with hematocrit (P for interaction <0.024). The associations were more evident in patients with low (P < 0.001) and median LDL-C levels (P < 0.013) than those with high glucose levels. Hematocrit was associated with pre-hypertension, and was independent of metabolic risk factors. These associations were not significant in older individuals and low-density lipoprotein cholesterol may modify these associations.

Association of hematocrit with blood pressure and hypertension

“…Moreover, in another study Liu et al. in a large cross‐sectional study found an independent association between HCT and pre‐hypertension in Chinese population . Tripolino et al.…”

“…Moreover, high levels of red cell distribution width (RDW), variability in the size of circulating erythrocytes, is associated with hypertension . Consistent with these findings, hematocrit (HCT), a major determinant of blood viscosity, is associated with the risk of high blood pressure and is considered as a risk factor for HTN . Furthermore, the association of hemoglobin (HGB) level in the pathogenesis of hypertension related diseases has been investigated …”

Cross-sectional and longitudinal association between hemoglobin concentration and hypertension

“…[ 2 – 6 ] However, a Chinese study recently suggested that increasing hematocrit was not associated with prehypertension in individuals older than 60 years. [ 7 ] According to several previous studies, high hemoglobin can cause vasoconstriction and then elevate the blood pressure. [ 8 , 9 ] However, other studies reported that blood pressure is not correlated with blood viscosity in healthy individuals.…”

Higher blood hematocrit predicts hyperuricemia: a prospective study of 62897 person-years of follow-up

“…In addition to the studies directly suggested a positive association between Hct and serum uric acid 33 34 35 , some other researches indicated a positive trend between Hct and serum uric acid in a variety of settings, such as screen-based cohorts 42 43 , subjects with intact kidney function in community-based cohorts 44 , screen-based cross-sectional survey 45 , slightly reduced glomerular filtration rate 46 , and angiographically near normal coronary arteries 47 , even though the significance of difference remained unclear. The present study was the first one demonstrating that higher Hct level at baseline is associated with an increased risk of HU during the follow-up period.…”