Blood pressure at diagnosis of type 2 diabetes correlates with plasma insulin concentration but not during the next 5 years.

At diagnosis of non-insulin-requiring diabetes, in 215 patients, systolic and diastolic (Korotkow 4) blood pressures, corrected for arm circumference, correlated with fasting plasma insulin concentration (r = 0.29, p less than 0.001), body mass index (BMI) (W/H2), and age (p less than 0.05 in all cases for both systolic and diastolic pressures). Women had higher pressures but were also heavier than men. Systolic pressure fell by 13 +/- SD 11%, diastolic by 8 +/- 15%, over 1 month and remained decreased over 5 yr. The fall was greater with high initial pressure (r = 0.6-0.7, p less than 0.001 all years). The correlation of initial pressure with plasma insulin remained significant even when allowing for age, surface area, BMI, and plasma concentrations of glucose, urea, creatinine, sodium and urate. Neither gender nor treatment with sulphonylureas or hypotensives influenced this relationship. During the first 5 yr after diagnosis the correlation between blood pressure and insulin weakened, particularly when allowing for the factors above (at 5 yr, systolic p = 0.025, diastolic NS).