Journal: Diabetes

Article Title: Insulin Resistance is Associated with Reduced Mitochondrial Oxidative Capacity Measured by 31P Magnetic Resonance Spectroscopy in Non-Diabetic Participants from the Baltimore Longitudinal Study of Aging.

PMID/MRN: 27737951

Publication Date: 2016-Oct-13

Abstract:

Whether individuals with insulin resistance but without criteria for diabetes exhibit reduced mitochondrial oxidative capacity is unclear; addressing this question could guide research for new therapeutics. We investigated 248 non-diabetic participants from the Baltimore Longitudinal Study of Aging (BLSA) to determine whether impaired mitochondrial capacity is associated with prediabetes, insulin resistance, duration and severity of hyperglycemia exposure. Mitochondrial capacity was assessed as post-exercise phosphocreatine recovery time constant (? PCr ) by 31 P-magnetic resonance spectroscopy, with higher ? PCr reflecting reduced capacity. Prediabetes was defined using the American Diabetes Association criteria from fasting and 2-hr glucose. Insulin resistance and sensitivity were calculated using HOMA-IR and Matsuda Indices. Duration and severity of hyperglycemia exposure were estimated as number of years from prediabetes onset and average oral glucose tolerance test (OGTT) 2h-glucose over previous BLSA visits. Covariates included age, sex, body composition, physical activity and other confounders. Higher likelihood of prediabetes, higher HOMA-IR and lower Matsuda Index were associated with longer ? PCr. Among 205 participants with previous OGTT data, greater severity and longer duration of hyperglycemia were independently associated with longer ? PC In conclusion, in non-diabetic individuals a more impaired mitochondrial capacity is associated with greater insulin resistance and higher likelihood of prediabetes. © 2016 by the American Diabetes Association.