Abstract
Background: Nitric oxide (NO) is one of the major signaling messengers in the cardiovascular system. A sufficient level of endothelial NO is necessary to preserve normal vascular physiology and is one of the regulators of pulse pressure. Aging is linked to a gradual decrease of NO activity in the vessel wall. Hence, we tried to find a relationship between serum NO levels and pulse pressure in aging.

Aims and Objective: The aim and objective of this study are to estimate serum NO levels and pulse pressure in normal aging.

Materials and Methods: A total of 90 healthy male subjects aged between 70 and 80 otals were randomly selected. Fasting blood samples of the subjects were obtained for the estimation of serum NO levels (Griess method). NO concentration is indirectly measured by means of accurately quantifying the levels of nitrite (NO2-). The resting pulse pressure of the subjects was recorded on 3 consecutive days, and the average of the three values was recorded.

Results: The mean pulse pressure of the study population was 60.6 ± 6.2 mm Hg, and the mean serum NO level was 27.9 ± 9.9 (μM). A negative correlation was observed between serum NO levels and pulse pressure. The Pearson’s coefficient of correlation was r = −0.398 which is statistically significant at the 0.05 level (one-tailed).

Conclusion: In our study population of 90 urban dwelling elderly men (mean age 74 ± 3 years), we observed that higher levels of serum NO levels were associated with lower pulse pressures.

Key words: Nitric Oxide; Pulse Pressure; Nitrite (NO2-); Griess Method