Thursday, November 13, 2008

Mitochondrial Dysfunction and Diabetes

Case described in conference. Young man with DM and hearing loss. Has a history of some muscle weakness and seizures. --> Dx is MELAS Syndrome.

The Mitochondrial Myopathy Encephalopathy, Lactic Acidosis with Stroke-Like Episodes (MELAS) Syndrome

  • weakness that may progress to further deterioration in neuromuscular function.
  • Headaches, nausea or vomiting.
  • Stroke-like episodes (usually occur before 40 years of age).
  • Encephalopathy--> seizures, dementia, or both.
  • Lactic Acidosis (other members of faculty noted that they have had cases present in the cath-lab with severe lactic acidosis)
  • Normal Weight (cases noted to have BMI of 17-20)...many felt that due to mitochondrial dysfunction, these patients have a high REE.
  • Neurosensory deafness (A young man with diabetes, hearing aid, and a mother with diabetes--> what is the mode of inheritance?).
Pathogenesis: Mitochondrial DNA mutation that leads to dysfunction--> inability to generate ATP in response to glucose in beta-cell--> leads to ineffective insulin secretion.

  • Diet: primary mode of therapy
  • Exercise: not as effective since most have some form of myopathy
  • Sulfonylureas: good choice
  • Metformin: should be avoided due to high rate of lactic acidosis
  • TZD: again most faculty would avoid due to high prevalence of cardiomyopathy and risk of further worsening heart failure.
  • Insulin: good choice as well.

  1. MELAS: a review of treatment options. CNS Drugs; 2006, Vol. 20 Issue 6, p443.
  2. Mitochondrial gene defects in NIDDM. Diabetologia 37; 818-825
  3. Mitochondrial Cytopathies; J neurol 250:267-277

1 comment:

  1. I think a previous speaker talked about mitochondria defects in normal type 2 diabetes patient.


Note: Only a member of this blog may post a comment.