Investigation of the insulin - blood pressure association

Hypertension and diabetes are strong predictors of cardiovascular (CV) mortality and morbidity. The purpose of the study was to examine the extent to which insulin, glucose, and adiposity were associated with BP and BP reactivity in three ethnic groups and both genders. The sample consisted of 294 male and female participants from the Miami Community Health Study. Three ethnic groups were represented by 115 non-Hispanic Whites (NHWs), 72 African Americans (AAs), and 107 Cuban-Americans (CAs) selected from a county in South Florida. Participants were free of overt CV disease, hypertension, or diabetes. The mean age was 35.2 years (range 25--44 years).A quasi-experimental design was used to test four primary null hypotheses. Relationships were explored among ethnicity and gender in glucose and insulin levels after an oral glucose tolerance test (fasting, 1-hour and 2-hour). Relationships among ethnicity and gender were examined using BP and BP reactivity with and without fasting insulin. BP and BP reactivity were comprised of baseline systolic BP (SBP), diastolic BP (DBP), and percent change after Mirror Star Tracer (MST), Speech Talk (ST), and Foot Immersion Cold Pressor (FICP).Stepwise Multiple Linear Regression demonstrated a relationship among ethnicity, gender, insulin, and BP. Glucose analyses revealed significant findings in fasting (males) and 1-hour (CAs). Insulin analyses revealed significant findings in fasting (males, age and CAs), 1-hour (CAs), and 2-hour (CAs and AAs). BP and BP reactivity analyses revealed significant findings in baseline SBP (BMI beta = .688, p \u3c .0001; males beta = 8.375, p \u3c .0001; CAs beta = 4.647, p = .001), baseline DBP (males beta = 4.903, p \u3c .0001; BMI beta = .263, p .002; CAs beta 2.040, p = .033), and SBP after ST (age beta = .005, p = .002; BMI beta = -.003, p = .033; females beta = -.037, p = .035, AAs beta .041, p = 0.46). Addition of fasting insulin was significant in baseline SPB and DBP maintaining the original model. Insulin did not contribute significantly to reactivity analyses. Recommendations were given for nursing education, research, practice and theory construction