Effects of Age on Inflammatory Profiles and Nutrition/Energy Metabolism in Domestic Cats

BACKGROUND: Animals tend to increase in body weight and body condition score (BCS) with aging. Serum diagnostic markers related to energy metabolism may show changes even in healthy cats with aging. MATERIALS AND METHODS: Seventy domestic cats were recruited for this study. Based upon the modified AAFP-AAHA Feline Life Stage Guidelines, animals were divided into six groups: Junior (7 months–2 years), Prime (3 −6 years), Mature (7–10 years), Senior (11–14 years), Geriatric-obese (15 years ≤) and Geriatric-thin (15 years ≤). Their body condition scores (BCS) ranged from 3/9 to 9/9. Changes in metabolites, inflammatory markers, hormone concentrations and enzyme activities related to energy metabolism were investigated in serum of 70 domestic cats of various ages. RESULTS: Serum glucose (GLU) concentrations in the Mature, Senior, and Geriatric-obese groups were significantly higher than those in the Junior group. Serum amyloid A (SAA) concentrations in the Geriatric-thin group were significantly increased compared with the Junior group. SAA concentrations in the Geriatric-obese group tended to increase although there were no statistically significant differences. In the Mature, Senior, Geriatric-obese and Geriatric-thin groups, malate dehydrogenase/lactate dehydrogenase (M/L) ratio, an energy metabolic indicator, tended to decrease compared with the Junior group. In the Senior group, triglyceride (TG) concentrations were significantly increased compared with the Junior group. In the Geriatric-obese and Geriatric-thin groups, blood urea nitrogen (BUN) concentrations were significantly increased compared with the Junior group. In the Geriatric-obese group, albumin (ALB) concentrations were decreased compared with the Junior group. CONCLUSION: Aged domestic cats tend to increase in body weight and BCS. In addition, serum GLU, TG, SAA, and BUN concentrations increased and serum ALB concentrations and M/L ratio decreased. These diagnostic markers may be useful to detect small changes related to energy metabolism with aging that may cause obesity with light inflammation in healthy cats.