Insulin resistance and endothelial dysfunction in hypertensive and atherosclerotic non diabetic subjects

Atherosclerosis and hypertension show both endothelial dysfunction and impaired insulin action. However, a direct association between insulin resistance and endothelial dysfunction is not fully demonstrated. To esplorate this relationship, the transcapillary escape rate of albumin (TERalb) and insulin resistance have been measured in 55 non diabetic males: 10 healthy controls (C), 10 essential hypertensives (EH), 24 atherosclerotic subjects (ATH) and 11 hypertensive-atherosclerotics (EH/ATH). Atherosclerotic groups (ATH, EH/ATH) had higher total- and LDL-cholesterol, ApoB, triglycerides and fibrinogen compared with C and EH. Systolic and diastolic 24 hour ambulatory BP were higher (p<0.001) in EH and EH/ATH, and similar in C and ATH. TERalb was 7.1+/-1.5 %/h in controls and significantly higher (p=0.005) in EH(10.4+/-3.2 %/h) in ATH(10.2+/-2.5) and EH/ATH (11.0+/-2.8). HOMA IR was 1.71+/-0.20 in controls and higher (p=0.06) in EH (2.23+/-0.39), ATH (2.40+/-0.31) and EH/ATH (2.45+/-0.34). Positive linear regression were found between TERalb and both BMI (r=0.37, p=0.006) and HOMA IR (r=0.34, p=0.01). Stepwise regression analysis showed that (model 1) BMI (r=0.400), atherosclerosis (cumulative r=0.473) and hypertension (r=0.537) and (model 2) HOMA IR (r=0.350), atherosclerosis (r=0.415) and hypertension (r=0.466) independently contribute to TERalb. These data suggest a relationship between widespread endothelial dysfunction and insulin action and provide Further evidence for a relationship with one of the main features (increased body weight) of the insulin resistance syndrome.