TY - JOUR
T1 - Mean arterial blood pressure and serum levels of the molar ratio of insulin-like growth factor-1 to its binding protein-3 in healthy centenarians
AU - Paolisso, Giuseppe
AU - Tagliamonte, Maria Rosaria
AU - Rizzo, Maria Rosaria
AU - Rotondi, Mario
AU - Gualdiero, Pasquale
AU - Gambardella, Antonio
AU - Barbieri, Michelangela
AU - Carella, Carlo
AU - Giugliano, Dario
AU - Varricchio, Michele
PY - 1999
Y1 - 1999
N2 - Objective. Healthy centenarians have a greater molar ratio of plasma insulin-like growth factor-1 to insulin-like growth factor binding protein-3 than that of aged subjects. We investigated the question of whether differences in mean arterial pressure and in this plasma ratio were related in healthy centenarians. Subjects and methods. We studied 52 subjects in total, 30 aged subjects (70-99 years) and 22 healthy centenarians (> 100 years) to determine differences in mean arterial pressure, endothelial function and intracellular cation levels. Results. In the healthy centenarians, the molar ratio of fasting plasma insulin-like growth factor-1 to its binding protein-3 was significantly correlated with mean arterial pressure (r = -0.66, P <0.001). Baseline (19.3 ± 1.5 versus 27.6 ± 2.2 μmol/l, P <0.05) and L-arginine-stimulated percentage increases in the plasma total nitrate:nitrite ratio (67 ± 3.4 versus 48 ± 4.5%, P <0.03) were greater in the healthy centenarians than in the aged subjects. An L-arginine bolus elicited an increase in forearm blood flow which was correlated with the percentage increase in the plasma total nitrate:nitrite ratio (r = 0.79, P <0.001) and with the fasting erythrocyte magnesium concentration (r = 0.80, P <0.001) in healthy centenarians. Both correlations remained significant (P <0.01) after adjustment for sex, body mass index and the waist:hip ratio. Moreover, the fasting plasma molar ratio of insulin-like growth factor-1 to its binding protein-3 was correlated with the percentage increase in forearm blood flow (r = 0.59, P <0.005) and with the percentage increase in the plasma total nitrate:nitrite ratio (r = 0.54, P <0.009) in healthy centenarians. The centenarians had higher baseline total erythrocyte magnesium and lower calcium concentrations than the aged subjects. The addition of insulin growth factor-1 to the incubation medium increased the total intracellular erythrocyte magnesium content and decreased the calcium content in both groups of subjects. Nevertheless, the percentage increase in total erythrocyte magnesium (33 ± 3.8 versus 12 ± 3.4%, P <0.03) and decline in intracellular calcium (17 ± 2.8 versus 8 ± 3.1%, P <0.02) concentrations were greater in the healthy centenarians than the aged subjects. Conclusion. In healthy centenarians, insulin-like growth factor-1 may preserve endothelial function and modulate the intracellular cation content, thus contributing to a lower mean arterial pressure than that in aged subjects.
AB - Objective. Healthy centenarians have a greater molar ratio of plasma insulin-like growth factor-1 to insulin-like growth factor binding protein-3 than that of aged subjects. We investigated the question of whether differences in mean arterial pressure and in this plasma ratio were related in healthy centenarians. Subjects and methods. We studied 52 subjects in total, 30 aged subjects (70-99 years) and 22 healthy centenarians (> 100 years) to determine differences in mean arterial pressure, endothelial function and intracellular cation levels. Results. In the healthy centenarians, the molar ratio of fasting plasma insulin-like growth factor-1 to its binding protein-3 was significantly correlated with mean arterial pressure (r = -0.66, P <0.001). Baseline (19.3 ± 1.5 versus 27.6 ± 2.2 μmol/l, P <0.05) and L-arginine-stimulated percentage increases in the plasma total nitrate:nitrite ratio (67 ± 3.4 versus 48 ± 4.5%, P <0.03) were greater in the healthy centenarians than in the aged subjects. An L-arginine bolus elicited an increase in forearm blood flow which was correlated with the percentage increase in the plasma total nitrate:nitrite ratio (r = 0.79, P <0.001) and with the fasting erythrocyte magnesium concentration (r = 0.80, P <0.001) in healthy centenarians. Both correlations remained significant (P <0.01) after adjustment for sex, body mass index and the waist:hip ratio. Moreover, the fasting plasma molar ratio of insulin-like growth factor-1 to its binding protein-3 was correlated with the percentage increase in forearm blood flow (r = 0.59, P <0.005) and with the percentage increase in the plasma total nitrate:nitrite ratio (r = 0.54, P <0.009) in healthy centenarians. The centenarians had higher baseline total erythrocyte magnesium and lower calcium concentrations than the aged subjects. The addition of insulin growth factor-1 to the incubation medium increased the total intracellular erythrocyte magnesium content and decreased the calcium content in both groups of subjects. Nevertheless, the percentage increase in total erythrocyte magnesium (33 ± 3.8 versus 12 ± 3.4%, P <0.03) and decline in intracellular calcium (17 ± 2.8 versus 8 ± 3.1%, P <0.02) concentrations were greater in the healthy centenarians than the aged subjects. Conclusion. In healthy centenarians, insulin-like growth factor-1 may preserve endothelial function and modulate the intracellular cation content, thus contributing to a lower mean arterial pressure than that in aged subjects.
KW - Endothelial function
KW - Healthy centenarians
KW - Insulin-like growth factor
KW - Insulin-mediated glucose uptake
KW - Intracellular magnesium
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M3 - Article
C2 - 10100096
AN - SCOPUS:0033044163
VL - 17
SP - 67
EP - 73
JO - Journal of Hypertension
JF - Journal of Hypertension
SN - 0263-6352
IS - 1
ER -