High Haemoglobin and Haematocrit Are Associated with Triglycerides, Low-density Lipoprotein and High-density Lipoprotein and Negatively Associated with Diabetes, in Patients at High Risk of Coronary Artery Disease

Abstract

Introduction: High haematocrit (HCT) has been associated with increased cardiovascular mortality. The cholesterol content of erythrocytes is susceptible to serum cholesterol and HbA1c is increased in diabetes. However, associations between HCT and haemoglobin (Hb) with dyslipidaemia and diabetes are unclear. We hypothesised that Hb and HCT are associated with serum lipids and diabetes. Methods: Patients from the BRAVEHEART and MINACS studies underwent venepuncture and angiography (n = 824; diabetes: n = 214, no diabetes: n = 559). Multivariate logistic regression was performed to determine associations of Hb and HCT with diabetes, adjusting for cardiovascular risk factors. Multivariate linear regression was performed to determine associations with serum lipid concentrations. Lipids were log transformed and Hb and HCT were divided into tertiles. Results: After adjustment for cardiovascular risk factors, high haematocrit was significantly associated with higher LDL-C (β=0.12; 95% CI: [0.05,0.19]; p = 0.001), higher HDL-C (β=0.047; 95% CI: [0.003, 0.091]; p = 0.038) and less diabetes (OR = 0.49; 95% CI: [0.29-0.83]; p = 0.008) and a trend towards higher TG (β=0.082; 95% CI: [-0.007, 0.171]; p = 0.071). High haemoglobin was significantly associated with higher LDL-C (β=0.10; 95% CI: [0.03,0.18]; p = 0.010), higher TG (β=0.13; 95% CI: [0.03, 0.23]; p = 0.009) and less diabetes (OR = 0.41; 95% CI: [0.23-0.73]; p = 0.003) and a trend towards higher HDL-C (β=0.035; 95% CI: [-0.014, 0.083]; p = 0.164). Conclusion: In high risk patients, higher haemoglobin and haematocrit were associated with higher LDL-C, HDL-C and TG, and less diabetes, after adjusting for other cardiovascular risk factors. We provide further evidence for the relationship between haematocrit or haemoglobin with dyslipidaemia and diabetes.