Utility of a surrogate measure of insulin resistance in American Indians: the Strong Heart Study.
OBJECTIVE
1) Determine in a sample of American Indians (AI) how well insulin sensitivity (SI) measured by the frequently sampled intravenous glucose test (FSIGT) correlates with a simpler measure of insulin resistance (IR) measured by the homeostasis assessment (HOMA) model; (2) compare insulin sensitivity in a sample of diabetic and non-diabetic Al in the Strong Heart Study (SHS) with that of White, Black, and Hispanic Americans in the Insulin Resistance Atherosclerosis Study (IRAS).


METHODS
Cross sectional


METHODS
Community


METHODS
Sixty-one Al participants in SHS MAIN OUTCOME MEASURES: Mean SI measured by FSIGT, a complex protocol to evaluate insulin sensitivity, and mean IR measured by the HOMA model, a method based on measures of fasting glucose and fasting insulin.


RESULTS
Although 70% of sample participants were non-diabetic, only 18% were insulin sensitive by SI. Diabetes status strongly confounded Si among Al in SHS. At non-diabetic levels of fasting glucose (< 126 mg/dL), SI correlated well with HOMA IR (rho = -0.49, P = .0009), but SI did not reflect HOMA IR at levels of fasting glucose that are diagnostic of diabetes (> or = 126 mg/dL; rho = -0.13, P = n.s.). With the exception of some Hispanic participants in IRAS, mean SI of non-diabetic Al in SHS was lower than that of their non-diabetic IRAS counterparts. Diabetic Al participants in SHS had markedly lower mean SI than all diabetic participants in IRAS.


CONCLUSIONS
The HOMA model may be a useful tool to identify non-diabetic American Indians who might benefit from early CVD risk factor modification.
Resnick
Helaine E
HE
MedStar Research Institute, Washington, DC, USA. helaine.e.resnick@medstar.net
Bergman
Richard N
RN
Henderson
Jeffrey A
JA
Nez-Henderson
Patricia
P
Howard
Barbara V
BV
D002318:Cardiovascular Diseases / Q000208:ethnology* / Q000209:etiology / Q000517:prevention & control; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000188:drug therapy / Q000208:ethnology* / Q000378:metabolism*; D005260:Female; D005947:Glucose; D005951:Glucose Tolerance Test; D006801:Humans; D007198:Indians, North American; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D015205:Northwestern United States / Q000453:epidemiology; D015206:Southwestern United States / Q000453:epidemiology
D005947:Glucose