The structural arteriolar changes in diabetes mellitus and essential hypertension The relative contribution of ageing and high blood pressure

Aim To evaluate the relative contribution of blood pressure, non-insulin dependent diabetes mellitus and ageing on arteriolar structural changes in essential hypertension and diabetes mellitus. Population and methods One hundred subjects, 25 with hypertension (A), 25 with hypertension and diabetes (B), 25 with diabetes (C) and 25 healthy subjects (D). Blood pressure average values, obtained with non-invasive monitoring, and minimal vascular resistance, calculated with strain-gauge plethysmography, were statistically correlated. Multiple regression analysis was performed to assess the contribution of blood pressure and age. Results Minimal vascular resistance was higher in A, B and C than in D, and higher in B than in A and C. The coefficient of blood pressure in the multiple regression analysis was significant for all the parameters in A and B but not in C and D; that of age was significant only in A and only for the average values of mean and diastolic blood pressure. Conclusion Hypertension and diabetes show arteriolar structural changes of similar gravity. Age does play a role in hypertension but a smaller one than that played by blood pressure. In hypertension and diabetes the lack of significance of the contribution of age to the correlation between minimal vascular resistance and pressure could be ascribed to other neurohumoral factors. These factors play a much more important role in diabetes, where neither blood pressure nor age show any correlation with high vascular resistance.