Herlitz H, Widgren B, Wikstrand J, Aurell M, Abnormalities in the renin–angiotensin–aldosterone system in normotensive subjects with a positive family history of hypertension. Eur J Endocrinol 1994:131:179–83. ISSN 0804–4643
Non-hypertensive men with a positive family history of hypertension in two generations (N = 16) were compared with weight-matched (N = 13) and lean (N = 12) control groups with a negative family history of hypertension with respect to the activity of the renin–angiotensin–aldosterone system at baseline and during an oral glucose tolerance test. Blood pressure was measured phonographically after 30 min of semirecumbent rest and the oral glucose tolerance test was performed after a 10-h overnight fast with 100 g of glucose given orally. Blood samples were drawn from a peripheral catheter at baseline, 30 and 120 min after the glucose challenge. Systolic and diastolic blood pressures did not differ between subjects with a positive or a negative family history of hypertension. At baseline, blood glucose and plasma insulin were similar in the three groups while the group with a positive family history of hypertension had a significantly lower plasma renin activity (PRA) (0.85 ± 0.09 compared with the weight-matched but not with the lean control group (1.36 ± 0.13 and 1.06 ± 0.15 ng AI·ml−1 · h−1; p < 0.01 and NS, respectively). The PRA increased significantly after the glucose challenge in all groups (p < 0.01), while the plasma aldosterone concentration decreased after 30 min and then showed an increase at 120 min. The PRA response was less pronounced in the group with a positive family history of hypertension compared with the weight-matched and lean control groups (p < 0.05 and p < 0.01, respectively). Serum potassium did not change significantly in either group after the glucose challenge. Urinary sodium excretion was similar in the three groups. In conclusion, non-hypertensive subjects with a positive family history of hypertension are characterized by a lower activity of the renin–angiotensin–aldosterone system at baseline and a diminished PRA response during hyperinsulinemia compared with normotensive individuals without such heredity. Whether this is due to volume expansion or to a tendency to a higher blood pressure remains to be clarified.
Hans Herlitz, Department of Nephrology, Sahlgrenska sjukhuset, S-413 45 Göteborg, Sweden
Increased Blood Pressure Response to Treadmill Exercise Test in Healthy Normotensive Subjects with a Family History of Hypertension.