Body condition and adrenal glucocorticoid activity affects metabolic marker and lipid profiles in captive female elephants in Thailand

• Published in: PloS one Vol. 13; no. 10; p. e0204965
• Main Authors: Norkaew, Treepradab, Brown, Janine L., Bansiddhi, Pakkanut, Somgird, Chaleamchat, Thitaram, Chatchote, Punyapornwithaya, Veerasak, Punturee, Khanittha, Vongchan, Preeyanat, Somboon, Nopphamas, Khonmee, Jaruwan
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 02.10.2018; Public Library of Science (PLoS)
• Subjects: Adrenal Glands - metabolism; Analysis; Animals; Biology and Life Sciences; Biomarkers - blood; Body fat; Body weight; Cardiovascular disease; Cholesterol; Density; Earth Sciences; Elephants; Environmental factors; Exercise; Female; Glucocorticoids; Glucocorticoids - blood; Glucose; Health aspects; High density lipoprotein; Hormones; Insulin; Insulin resistance; Lipids; Lipids - blood; Lipoproteins; Lipoproteins test; Low density lipoprotein; Medical technology; Medicine and Health Sciences; Metabolic syndrome; Metabolites; Obesity; Occupational health; Overweight; Physical fitness; Physical Sciences; Physiological aspects; Public health; Rainfall; Rainy season; Regression analysis; Regression models; Seasonal variations; Seasons; Thailand; Triglycerides; Veterinary medicine; Wildlife conservation; Winter; Zoo animals; Thailand; Asia
• DOI: 10.1371/journal.pone.0204965
• ISSN: 1932-6203

Studies in western zoo elephants have found relationships between body condition and physiological function, and identified mitigating management strategies to optimize health and welfare. A similar methodological approach was used in this study, which evaluated a body condition score (BCS; 1 = thinnest, 5 = fattest) every other month and fecal glucocorticoid metabolite (FGM) concentrations twice monthly in 33 tourist camp elephants in Thailand for a 1-year period to assess seasonal variations, and determine how lipid profiles [total cholesterol (TC), low density lipoproteins (LDL), high density lipoproteins (HDL), triglycerides (TG)] and metabolic parameters [insulin, glucose, fructosamine, glucose to insulin ratio (G:I)] related to measures of body condition and adrenal function. The most prevalent BCS was 3-3.5 (60.6%), with 27.3% at BCS = 4 (overweight) and 12.1% at BCS = 4.5-5 (very overweight); no elephants had a BCS <2. BCSs were higher in rainy and winter seasons compared to summer, with FGM, TG, HDL, LDL, and insulin also higher in the rainy and/or winter seasons (p<0.05). By contrast, TC and glucose were lowest in the rainy season. FGM measures were negatively associated with two environmental factors: temperature and rainfall, but not humidity. Positive correlations were found between BCS and TC, LDL, and HDL, and between FGM and TC, HDL, glucose, and insulin (p<0.05), whereas BCS and FGM were both negatively associated with the G:I (p<0.05). However, there was no relationship between BCS and FGM among the camp elephants. Using BCS and FGM measures as outcome variables in separate regression models, this study found high BCS and elevated FGM concentrations were associated with altered lipid profiles and metabolic status in elephants. Furthermore, more work hours/day was associated with better body condition and health measures. Thus, being overweight and exposed to factors that increase adrenal activity could adversely affect health status, requiring alterations in management for some individuals, whereas exercise appears to have a protective effect.