Insulin sensitivity, body fat distribution, and family diabetes history: the IRAS Family Study.
OBJECTIVE
Markers of insulin resistance are often apparent in nondiabetic relatives of subjects with type 2 diabetes. Whether diabetes family history (FH) also predicts visceral fat accumulation and, if so, whether the increased insulin resistance in relatives of diabetic subjects occurs independently of visceral fat accumulation are not known.


METHODS
To examine this issue, we studied the relationship of diabetes FH with insulin sensitivity and fat measures, measured by minimal model analysis and computed tomography, respectively, in families participating in the Insulin Resistance Atherosclerosis (IRAS) Family Study. FH scores were based on the diabetes status of the participants' parents and older siblings.


RESULTS
FH scores were significantly correlated with reduced insulin sensitivity (p < 0.05) and increased subcutaneous (p < 0.05) and visceral (p < 0.05, San Antonio only) fat in families from San Antonio and Los Angeles but not in the leaner Hispanic families from San Luis Valley. There was no evidence for a stronger association of FH score with visceral fat accumulation than with subcutaneous fat or insulin resistance.


CONCLUSIONS
The absence of an association between FH score and insulin resistance/fat accumulation in San Luis Valley is consistent with the idea that the expression of transmitted diabetes genes may be suppressed in leaner, more physically active populations.
Mitchell
Braxton D
BD
University of Maryland School of Medicine, Division of Endocrinology, Diabetes, and Nutrition, 660 W. Redwood Street, Room 492, Baltimore, MD 21201, USA. bmitchel@medicine.umaryland.edu
Zaccaro
Daniel
D
Wagenknecht
Lynne E
LE
Scherzinger
Ann L
AL
Bergman
Richard N
RN
Haffner
Steven M
SM
Hokanson
John
J
Norris
Jill M
JM
Rotter
Jerome I
JI
Saad
Mohammed F
MF
D000273:Adipose Tissue; D001741:Black or African American; D001161:Arteriosclerosis / Q000235:genetics*; D001823:Body Composition; D015992:Body Mass Index; D003920:Diabetes Mellitus / Q000235:genetics*; D005190:Family; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D007333:Insulin Resistance / Q000235:genetics*; D015141:Los Angeles; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D013781:Texas; D014057:Tomography, X-Ray Computed