Hypertension is often associated with insulin resistance or hyperinsulinemia. Metabolism of arachidonic acid by cytochrome P450 to the vasoconstrictor 20-HETE is thought to be involved in the pathogenesis of hypertension, but the relationship of 20-HETE with insulin resistance is not clearly understood. Obesity is a major determinant of insulin resistance, and we have previously demonstrated a positive relationship between BMI and 20-HETE in untreated hypertensive and normotensive individuals. The present analysis sought to determine if this relationship was related to insulin levels or insulin resistance (HOMA). We analysed 24 It urinary excretion of 20-HETE, serum insulin levels and insulin resistance in 66 lean to overweight untreated hypertensive and normotensive individuals. There was a significant positive association between 20-HETE and BMI (p < 0.001), and serum insulin and BMI (p = 0.003). There were no associations between 20-HETE excretion and either serum insulin or insulin resistance, before or after adjustment for age, gender, BMI and BP, or when hypertensive and normotensive individuals were considered separately.The results of the present study suggest that the observed positive association between urinary 20-HETE excretion and BMI may not be related to circulating insulin levels or insulin resistance. (c) 2006 Elsevier Ireland Ltd. All rights reserved.