Abstract

Cardiac disease is a major cause of morbidity and mortality for adult gorillas. We analyzed serum and hematology markers with cardiac measures in a large sample of gorillas. Study sample included 44 male (age range 4–50 years, mean 21.4±10.99) and 25 female (age range 5 to 51 years, mean 21.3±7.35) gorillas housed in the United States at AZA-accredited zoos. Serum samples were collected from fasted gorillas during routine health exams and analyzed using enzyme immunoassay using commercially available kits for leptin, adiponectin, IGF-1, insulin, and ferritin. Glucose, triglycerides, and cholesterol were measured using an IDEXX Vettest 8008 Chemistry Autoanalyzer. Cardiac ultrasonography via transthoracic echocardiogram was performed using standard protocols. Three echocardiographic parameters were chosen to assess cardiac disease according to parameters established for captive lowland gorillas: left ventricular internal diameter (LVID), interventricular septum thickness (IVS), and left ventricular posterior wall thickness (LVPW). Spearman’s partial correlation coefficients, i.e., controlling for age, were calculated separately for males and females for the blood parameters as well as the glucose-to- insulin ratio. Principal components analyses with varimax rotation were performed on each Spearman matrix. Principal components analyses revealed that high leptin, low adiponectin, and low cholesterol accounted for the majority of variance in both males and females. These components were significantly and positively correlated with measures of heart thickness and age in males but not females. The association of high leptin and low adiponectin is indicative of increased adiposity. The finding of lowered cholesterol requires further evaluation.

Acknowledgments

The authors would like to thank the Great Ape Heart Project and all zoos participating in this study.