Gerontological Nursing Interventions Research Center (GNIRC)

Title: Seasonal Variation of Hematocrit, Nitric Oxide & Fatigue in Young & Older Men

Principal Investigator: Deidre Wipke-Tevis, PhD, RN

Study Site: University of Missouri-Columbia

Abstract

Cardiovascular disease is the number one cause of death in the United States and an important public health problem. Blood viscosity and nitric oxide are vital to cardiovascular health and control. Preliminary data in animals suggest that hematocrit, a determinant of viscosity, oscillates throughout the year and that changes in nitric oxide are related to changes in hematocrit. Currently, it is unknown if a relationship exists between hematocrit and nitric oxide in humans. The specific aims of this translational pilot study are: 1) To measure plasma NOx (the stable metabolite of nitric oxide) and hematocrit in healthy young and older men, and 2) To measure fatigue and mood in healthy young and older men. This study will employ a two group, prospective, longitudinal design with repeated measures of hematocrit, plasma NOx, fatigue, and mood. A convenience sample of 5 young (20 to 30 years old) and 5 older (60 to 70 years old) healthy men will be recruited. Subjects will have blood drawn and complete a fatigue and mood questionnaire monthly for one year. Hematocrit will be measured using the microhematocrit method; plasma NOx will be measured using chemiluminescence. Mixed model ANOVA and correlation statistical procedures will be used to analyze the longitudinal data. This study, which is a new research direction for our multidisciplinary team, will assist us to bridge basic and applied science in one area of cardiovascular physiology. One innovative potential outcome of this pilot study is an exercise intervention tailored uniquely to stimulate the cardiovascular system of older men. The intervention developed ultimately may help to decrease the incidence of cardiovascular disease.