Hepatic steatosis and low cardiorespiratory fitness in youth with type 2 diabetes.
The purpose of this study was to examine the association between cardiorespiratory fitness, ectopic triglyceride accumulation, and insulin sensitivity among youth with and without type 2 diabetes. Subjects included 137 youth ages 13-18 years including 27 with type 2 diabetes, 97 overweight normoglycemic controls, and 13 healthy weight normoglycemic controls. The primary outcome measure was cardiorespiratory fitness defined as peak oxygen uptake indexed to fat free mass. Secondary outcomes included liver and muscle triglyceride content determined by (1)H-magnetic resonance spectroscopy and insulin sensitivity determined by frequently sampled intravenous glucose tolerance test. Despite similar measures of adiposity, peak oxygen uptake was 11% lower (38.9 ± 7.9 vs. 43.9 ± 6.1 ml/kgFFM/min, P = 0.002) and hepatic triglyceride content was nearly threefold higher (14.4 vs. 5.7%, P = 0.001) in youth with type 2 diabetes relative to overweight controls. In all 137 youth, cardiorespiratory fitness was negatively associated with hepatic triglyceride content (r = -0.22, P = 0.02) and positively associated with insulin sensitivity (r = 0.29, P = 0.002) independent of total body and visceral fat mass. Hepatic triglyceride content was also negatively associated with insulin sensitivity (r = -0.35, P < 0.001), independent of adiposity, sex, age, and peak oxygen uptake. This study demonstrated that low cardiorespiratory fitness and elevated hepatic triglyceride content are features of type 2 diabetes in youth. Furthermore, cardiorespiratory fitness and hepatic triglyceride are associated with insulin sensitivity in youth. Taken together, these data suggest that cardiorespiratory fitness and hepatic steatosis are potential clinical biomarkers for type 2 diabetes among youth.
Manitoba Institute of Child Health, University of Manitoba, Winnipeg, Manitoba, Canada.
Kristy D M
KD
Wittmeier
Brandy A
BA
Wicklow
Andrea C
AC
MacIntosh
Elizabeth A C
EA
Sellers
Lawrence N
LN
Ryner
Hacene
H
Serrai
Philip F
PF
Gardiner
Heather J
HJ
Dean
Jonathan M
JM
McGavock
D000293:Adolescent; D001823:Body Composition; D015992:Body Mass Index; D002170:Canada / Q000453:epidemiology; D002320:Cardiovascular Physiological Phenomena; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology*; D005234:Fatty Liver / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D009765:Obesity / Q000097:blood / Q000503:physiopathology*; D010809:Physical Fitness; D012143:Respiratory Physiological Phenomena; D014280:Triglycerides / Q000097:blood*
D014280:Triglycerides