Myocardial Changes in Diabetic and Nondiabetic Nonhuman Primates

Area of Science:

• Cardiovascular Science
• Metabolic Disease Research
• Primate Models in Aging Studies

Background:

• Diabetic patients face higher heart failure risks than healthy individuals.
• Understanding diabetes-induced cardiac dysfunction mechanisms requires well-characterized animal models.
• Aging rhesus monkeys offer a relevant model for studying diabetes complications.

Purpose of the Study:

• To evaluate myocardial alterations in aging rhesus monkeys with and without diabetes.
• To investigate the relationship between diabetes and cardiac pathology in this primate model.

Main Methods:

• Histological examination of left ventricular myocardial samples from diabetic and non-diabetic rhesus monkeys.
• Semiquantitative assessment of myocardial fibrosis and fat infiltration.
• Digital quantification of collagen, lipofuscin, nuclear area, and cardiomyocyte diameter.

Main Results:

• Histological analysis revealed lipofuscin, large nuclei, fibrosis (interstitial, replacement, vascular), adipocyte infiltration, and vacuolar degeneration with cardiomyocyte atrophy.
• No significant differences were observed between diabetic and non-diabetic groups in fibrosis, fat infiltration, cardiomyocyte size, collagen, nuclear, or lipofuscin area fractions.
• Lipofuscin accumulation correlated with plasma insulin, triglyceride, total cholesterol, and HDL cholesterol levels.

Conclusions:

• Myocardial pathological changes are present in aged rhesus monkeys, irrespective of diabetes status.
• The observed cardiac changes may be independent of diabetes duration in this model.
• Further research is needed to elucidate the precise mechanisms and timelines of diabetes-related cardiac dysfunction.