Enhanced left ventricular systolic function early in type 2 diabetic mice: clinical implications

Area of Science:

• Cardiology
• Metabolic Diseases
• Physiology

Background:

• Diabetes mellitus is associated with cardiac dysfunction.
• Early diabetes may present with altered myocardial substrate availability.
• The impact of early diabetes on systolic function before structural changes is not well understood.

Purpose of the Study:

• To investigate if increased substrate availability in early type 2 diabetes enhances left ventricular systolic function.
• To determine if enhanced systolic function precedes myocardial structural changes in diabetes.

Main Methods:

• Utilized BKS.Cg-m +/+ Lepr db (db/db) mice (type 2 diabetes) and wild type controls.
• Determined in situ left ventricular pressure-volume relationships.
• Assessed parameters including power/EDV, positive dP/dt, preload recruitable stroke work, dP/dt--EDV relationship, and end-systolic elastance.

Main Results:

• db/db mice exhibited enhanced left ventricular systolic function compared to controls.
• Specific indicators of enhanced function included increased power/EDV, positive dP/dt, preload recruitable stroke work, dP/dt--EDV relationship, and end-systolic elastance.
• This enhancement occurred despite increased body weight but similar preload and afterload.

Conclusions:

• Early type 2 diabetes in db/db mice is associated with enhanced left ventricular systolic function.
• This enhanced systolic function may be a compensatory mechanism.
• Enhanced cardiac function could potentially explain increased renal glomerular filtration rates in early diabetes.