# Comparative Analysis of Serum Lipid Profiles in Sanctuary-Housed Chimpanzees (Pan troglodytes verus) at Tacugama Chimpanzee Sanctuary

## TL;DR

This study compares serum lipid levels in sanctuary-housed chimpanzees to managed populations, finding unique patterns that may affect health assessments.

## Contribution

The study provides the first detailed serum lipid data for sanctuary-housed Western chimpanzees in a range country.

## Key findings

- Male chimpanzees had higher total cholesterol and LDL levels compared to females.
- HDL levels varied by housing group, suggesting environmental and activity influences.
- Lipid values at TCS differed from managed chimpanzee and human reference ranges.

## Abstract

Data on the normal concentration of serum lipids in chimpanzees and how these vary among populations, such as human care versus free-ranging, are sparse. This lack of information makes it difficult to understand the relationship between serum lipid dynamics and health problems such as cardiovascular disease in chimpanzees, a prominent cause of death in great apes. Additional data on baseline serum lipids will further our understanding of this relationship. Five lipid biomarkers were evaluated in chimpanzees at Tacugama Chimpanzee Sanctuary (TCS) and compared to managed chimpanzee values (ZIMS). Lipid values from TCS were also compared by age, body condition score, housing group, and sex for the five lipid biomarkers. Blood samples from 75 chimpanzees were collected, centrifuged, and were analyzed within 24 h. Total cholesterol was higher in males than in females and low-density lipoproteins tended to be higher in males. Average very-low-density lipoprotein and triglyceride concentrations exceeded ZIMS values. High-density lipoproteins varied by housing group, possibly due to environment, physical activity, and age. Differences from data published on managed chimpanzees and human reference intervals suggest that chimpanzees at TCS are unique with respect to their lipid values. Future studies are needed to assess whether these differences are healthy variations in the lipid metabolites or represent a higher disease risk.

Cholesterol, triglycerides, high-density lipoproteins (HDLs), low-density lipoproteins (LDLs), and very-low-density lipoproteins (VLDLs) were evaluated in chimpanzees at Tacugama Chimpanzee Sanctuary, Sierra Leone. Blood from 75 visually healthy chimpanzees was collected, centrifuged within one hour of collection, and analyzed at Choithram Hospital within 24 h. Statistical analyses assessed differences and interactions based on age, body condition score (BCS), housing group, and sex. HDLs varied widely by housing group; HDLs and LDLs were higher in males than in females. Cholesterol and LDLs were higher in prepubertal individuals while VLDLs and triglycerides were higher in postpubertal individuals. Lipid biomarker differences by age and age ∗ sex statistical interactions were not observed. These data represent a novel compilation of serum lipid biomarkers from a large population of sanctuary-housed Western chimpanzees (Pan troglodytes verus) within a range country, a population not previously studied with regard to serum lipid biomarkers. This study has documented significant differences compared to known values from managed chimpanzees and human reference ranges. The relationship of serum lipid biomarkers with health and disease in great apes remains understudied, but the present data set provides a basis for future studies to ascertain whether these differences are healthy biomarker variations or represent an elevated risk factor for disease.