Mitochondrial Impairment in Muscle Insulin Resistance

Recent research from our laboratory has detected novel findings concerning damage to mitochondria within skeletal muscle in type 2 diabetes (type 2 DM), damage that is evident morphologically and by functional criteria. In this project, we propose, firstly, to more fully test this hypothesis of an impaired bio-energetic capacity, and to begin to examine the pathogenesis of damage to mitochondria in type 2 DM. We are also interested in assessing the potential for reversing damage, and improving functional capacity of mitochondria through a weight loss or a combined exercise and weight loss intervention.

The first specific aim is to measure the functional capacity of mitochondria in human skeletal muscle in type 2 DM and in those at apparent risk for type 2 DM (obese, sedentary, non-diabetic adults with the Metabolic Syndrome and/or impaired glucose tolerance). The second specific aim is to examine the morphology of mitochondria in human skeletal muscle in type 2 DM and in those at apparent risk for type 2 DM. The third specific aim is to examine the pathogenesis of mitochondrial damage in type 2 DM and in those at apparent risk for type 2 DM. The fourth specific aim is to assess whether exercise and diet can improve mitochondrial function and morphology in type 2 DM and in those at apparent risk for type 2 DM.

Inclusion criteria

• AGE 30 to 55 years old BMI 28 to 38 kg/m2 BLOOD PRESSURE Systolic < 150 ; Diastolic < 95 SEDENTARY Currently not engaged in a regular exercise program and a VO2 max pre-training value < 55 ml/kg-fat free mass-min HEALTH (Group 1) Type 2 diabetes mellitus for < 10 years and independent in SBGM HEALTH (Group 2) Non-diabetic with impaired glucose tolerance (as per ADA) or with Metabolic Syndrome (as per NCEP-ATP III)

HEALTH Must be in good general health with no known h/o the following:

liver disease, kidney disease, PVD (including diminished pulses, or H/O thrombophlebitis), heart disease (including any h/o MI), neuromuscular disease, neurological disease (including peripheral neuropathy or muscle wasting), paresis, edema , current malignancy, or any drug or alcohol abuse, LAB VALUES Enroll if: No Proteinuria (defined as < 1+ protein on routine dipstick) Hct > 34% ALT < 80, AST < 80, Alk Phos < 240 sTSH < 8 (Group 2) 2 hr glucose on OGTT >140mg/dl but < 200mg/dl or NCEP-ATP III criteria) Triglyceride < 450 Cholesterol < 300 Negative Urine Pregnancy

Exclusion criteria

• (Group 1) anti-hypertensives, "statin" hypolipemics, and diabetic medications okay but exclude if taking: insulin, or a hypolipemic that is not a "statin" (Group 2) "statin" hypolipemic medications are okay. A hypolipemic that is not a "statin" will exclude.

Inability and / or unwillingness to comply with the protocol as written Previous difficulty with lidocaine or other local anesthetic Claustrophobia Wt gain or loss of > 3 kg during past 4 weeks