Sample

Observation

Ref.

T2D Patients

Mitochondrial enzyme activity is reduced to 30–40%.

[32]

Obese individuals

Reduction in mitochondrial content, smaller mitochondrial size and alteration in the performance of mitochondria.

[28]

Healthy lean elderly

Decreased mitochondrial oxidative capacity and ATP synthesis, severe insulin resistance in skeletal muscle, high TG level in liver and muscle.

[33]

T2D and insulin resistant individuals

Mitochondrial density is reduced to 30%.

[34]

Young-insulin resistant offspring of parents with T2D

Decreased oxidative and glycolytic fibers in muscle, increased intramyocellular FA and reduced mitochondrial activity.

[35]

Obese Caucasians with IGT and T2D

Reduced expression of nuclear-encoded genes regulating mito biogenesis.

[29]

Obese and overweight nondiabetic Mexican-Americans

Lower expression of PGC-1α, PGC-1β and nuclear OXPHOS genes.

[36]