NATURE OF ELEVATED BLOOD-PRESSURE IN NORMOALBUMINURIC TYPE-I DIABETIC-PATIENTS - ESSENTIAL-HYPERTENSION

This study was undertaken to characterize type I diabetic patients with essential hypertension with respect to kidney function, renal hormones, and endothelial function. After 4 weeks without antihypertensive treatment, a cross-sectional study was carried out in the following groups: group 1, 14 healthy controls; group 2, 13 nondiabetic patients with essential hypertension (blood pressure greater-than-or-equal-to 140/90 mm Hg); group 3, 11 type I diabetic patients with hypertension but urinary albumin excretion (UAE) persistently normal (UAE: 10 mg/24 h, range 3 to 18) both before, during, and after discontinuing antihypertensive treatment; group 4, 15 type I diabetic patients with clinical nephropathy (UAE: 611 mg/24 h, range 192 to 3837) and hypertension. Systolic and diastolic blood pressures were similar in the three hypertensive groups: 147/96 +/- 8/6, 150/94 +/- 11/9, and 152/92 +/- 12/6 mm Hg (groups 2, 3, and 4, respectively) but elevated compared with controls (114/74 +/- 9/9 mm Hg, P < .001). The diabetic patients with essential hypertension were hyperfiltering in contrast to patients with nephropathy (glomerular filtration rate 114 +/- 23 v 90 +/- 21 mL/min/173 m2 +/- P < .05). The following parameters were normal in diabetic patients with essential hypertension and elevated only in patients with diabetic nephropathy as compared with controls: total body exchangeable sodium (2752 +/- 257 v 3000 +/- 247 mEq/1.73 m2 +/- P < .05, group 3 v group 4), extracellular volume (14.6 +/- 1.8 v 14.8 +/- 2.3 L/1.73 m2, NS), angiotensin-converting enzyme (28 [14 to 46] v 42 [25 to 60] U/L, P < .001), and inactive renin (105 [35 to 211] v 235 168 to 1070] mIU/L, P < .001). Our data suggest that two different types of hypertension occur in type I diabetic patients with and without proteinuria, respectively.