Discriminant Analysis of Transmission of Elevated Blood Pressure in First Generation Offspring of African Green Monkeys

Abstract

A linear discriminant analysis was applied to blood pressure data of 162 first generation colony-born offspring of normotensive (C), hypertensive (H), or borderline hypertensive (B) African green monkeys who were being selectively bred in an attempt to establish a strain of spontaneously hypertensive monkeys. The offspring were classified according to their parents' blood pressures as CC, HH, or Mixed (e.g. HC). Blood pressures were measured by indirect methods from unanesthetized offspring aged 0.5–6 years of age. The discriminant score was used to classify each of the 533 blood pressure measurements of the CC, Mixed, and HH offspring into one of three predicted groups: normotensive, borderline hypertensive, or hypertensive. The group means of the three predicted groups compared without regard to offspring type were significantly different (p<.001). In addition, the percentage of blood pressure measurements predicted to be normal or elevated differed among the three offspring groups (p<.001). 82% of the blood pressure measurements from CC offpring were classified as normotensive, compared with 58% and 40% of the blood pressure measurements from the Mixed and HH groups, respectively. In contrast, 25% of the blood pressure measurements from the HH groups were classified as hypertensive, compared with 10% and 4% from the Mixed and CC groups, respectively. Blood pressures of the normotensive, borderline hypertensive, and hypertensive subgroups derived from the CC group were consistently and significantly lower (p<.001) than their respective counterparts in the Mixed and HH groups. The results of the discriminant analysis indicate a trimodal distribution of blood pressures in the first generation offspring and a significant separation of blood pressures among the offspring after a single generation.

Key Words:

• genetic hypertension
• African green monkeys
• blood pressure
• primates