Increased sympathetic activity in normotensive offspring of malignant hypertensive parents compared to offspring of normotensive parents.

Malignant hypertension seems to be the consequence of very high blood pressure. Furthermore, an increase in sympathetic and renin-angiotensin system activity is considered to be the main mechanisms producing malignant hypertension. In the present study, 10 offspring of malignant hypertensive (OMH) parents (age 28 +/- 5 years, 7 males, 3 females, 2 white and 8 non-white) and 10 offspring of normotensive (ONT) parents (age 28 +/- 6 years, 2 males, 8 females, 3 white and 7 non-white) were evaluated. The OMH group had significantly higher (P < 0.05) casual blood pressure (125 +/- 10/81 +/- 5 mmHg) compared with ONT (99 +/- 13/67 +/- 5 mmHg). The increase in blood pressure was greater in OMH (Delta SBP = 17 +/- 2 vs Delta SBP = 9 +/- 1 mmHg in ONT) during cold pressor testing, but they had a lower increase in heart rate (Delta HR = 13 +/- 2 vs Delta HR = 20 +/- 3 bpm in ONT) during isometric exercise(handgrip test). Sympathetic activity, measured by microneurography, was significantly higher (P < 0.05) before exercise in OMH (17 +/- 6 vs 11 +/- 4 burst/min in ONT) and exhibited a greater increase (Delta = 18 +/- 10 vs Delta = 8 +/- 3 burst/min in ONT) during isometric exercise. This study showed increased sympathetic activity in OMH before exercise and a greater response during isometric exercise, suggesting an autonomic abnormality before exercise and a greater sympathetic response to physical stress in OMH compared to ONT.

Increased sympathetic activity in normotensive offspring of malignant hypertensive parents compared to offspring of normotensive parents

Malignant hypertension seems to be the consequence of very high blood pressure. Furthermore, an increase in sympathetic and renin-angiotensin system activity is considered to be the main mechanisms producing malignant hypertension. In the present study, 10 offspring of malignant hypertensive (OMH) parents (age 28 ± 5 years, 7 males, 3 females, 2 white and 8 non-white) and 10 offspring of normotensive (ONT) parents (age 28 ± 6 years, 2 males, 8 females, 3 white and 7 non-white) were evaluated. The OMH group had significantly higher (P < 0.05) casual blood pressure (125 ± 10/81 ± 5 mmHg) compared with ONT (99 ± 13/67 ± 5 mmHg). The increase in blood pressure was greater in OMH (Ä SBP = 17 ± 2 vs Ä SBP = 9 ± 1 mmHg in ONT) during cold pressor testing, but they had a lower increase in heart rate (Ä HR = 13 ± 2 vs Ä HR = 20 ± 3 bpm in ONT) during isometric exercise (handgrip test). Sympathetic activity, measured by microneurography, was significantly higher (P < 0.05) before exercise in OMH (17 ± 6 vs 11 ± 4 burst/min in ONT) and exhibited a greater increase (Ä = 18 ± 10 vs Ä = 8 ± 3 burst/min in ONT) during isometric exercise. This study showed increased sympathetic activity in OMH before exercise and a greater response during isometric exercise, suggesting an autonomic abnormality before exercise and a greater sympathetic response to physical stress in OMH compared to ONT.

Lipid profiles in untreated severe congenital isolated growth hormone deficiency through the lifespan.

OBJECTIVE: Growth hormone deficiency (GHD) is associated with adverse changes in lipid profile. However, changes in lipids through life in a homogeneous group of GHD subjects have not been defined. PATIENTS AND MEASUREMENTS: We examined lipid levels in a group of untreated severely GHD patients with a mutation in the GHRH receptor gene from a rural community in North-east Brazil. Lipid profiles in 15 GHD subjects [eight children and adolescents (one male), age (median [range]) 13.2 (5.4-19.9) years; seven adults (one male), age 47 (33-66) years] were compared with those in 29 indigenous controls from the same extended kindred [17 children and adolescents (six male), age 10.2 (5.3-18.4) years; 12 adults (eight male), age 54.5 (33-80) years]. All GHD subjects had a peak GH response of < 0.5 ng/ml in response to an insulin tolerance test and extremely reduced IGF-1 levels (median 5.5 ng/ml). Data were compared between cohorts and with an age- and sex-matched white American reference population. RESULTS: Abnormalities were confined to plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels. More GHD children had levels of plasma TC and LDL-C above the 95th percentile for our reference population (3/8 and 4/7, respectively) compared to controls (0/17 and 1/15, respectively) (P < 0.05). In the adults, median TC and LDL-C levels were higher in the GHD than controls (P < 0.05) (6.3 vs. 4.1 mmol/l; 4.4 vs. 2.7 mmol/l, respectively). Median Z-scores, calculated using values from the reference population, were not different between GHD children and adults for both TC (+0.8 vs.+0.4) and LDL-C (+1.4 vs.+0.7). CONCLUSIONS: The lipid profile in children as well as in adults with very severe GHD is adversely modified. There would appear to be no significant worsening of the lipid abnormality with duration of GHD or achievement of adulthood.

Autonomic abnormalities demonstrable in young normotensive subjects who are children of hypertensive parents

Although a slightly elevated office blood pressure (BP) has been reported in several studies, little is known about the prolonged resting blood pressure, heart rate (HR) and baroreflex sensitivity (BRS) of prehypertensive subjects with a family history of hypertension. Office blood pressure, prolonged resting (1 h) BP and HR were measured in 25 young normotensives with a positive family history of hypertension (FH+) and 25 young normotensives with a negative family history of hypertension (FH-), matched for age, sex, and body mass index. After BP and HR measurements, blood samples were collected for the determination of norepinephrine, plasma renin activity and aldosterone levels, and baroreflex sensitivity was then tested. Casual BP, prolonged resting BP and heart rate were significantly higher in the FH+ group (119.9 + or - 11.7/78.5 + or - 8.6 mmHg, 137.3 + or - 12.3/74.4 + or - 7.9 mmHg, 68.5 + or - 8.4 bpm) compared to the FH- group (112.9 + or - 11.4/71.2 + or - 8.3 mmHg, 128.0 + or - 11.8/66.5 + or - 7.4 mmHg, 62.1 + or - 6.0 bpm). Plasma norepinephrine level was significantly higher in the FH+ group (220.1 + or - 104.5 pg/ml) than in the FH- group (169.1 + or - 63.3 pg/ml). Baroreflex sensitivity to tachycardia (0.7 + or - 0.3 vs 1.0 + or - 0.5 bpm/mmHg) was depressed in the FH+ group (P<0.05). The FH+ group exhibited higher casual blood pressure, prolonged resting blood pressure, heart rate and plasma norepinephrine levels than the FH- group (P<0.05), suggesting an increased sympathetic tone in these subjects. The reflex tachycardia was depressed in the FH+ group