Blood pressure reference intervals for healthy adult chimpanzees (Pan troglodytes)

Abstract

Cardiovascular disease is the primary cause of morbidity and mortality among captive chimpanzees. But there are no clinical definitions of normotension or hypertension in chimpanzees. We analyzed 1 year of blood pressure (BP) data from a population of 261 healthy captive adult chimpanzees using a consistent set of criteria to ascertain health. Systolic BP varied by body weight. Diastolic BP varied by age. Median normotension was 126/63 mmHg, with an upper limit of 147/84 mmHg. We defined categories of pre-hypertension (148/85-153/88 mmHg) and hypertension (≥154/89 mmHg). The prevalence of elevated BP was 15%. The relative risk of mortality was 2.60, compared to normotensive animals. We used contemporary methods from human laboratory medicine to define reliable reference intervals for chimpanzee BP. Results allow accurate diagnosis of hypertension and pre-hypertension, and demonstrate an effect of elevated BP on mortality.