Heritability and genetic correlations of insulin resistance and component phenotypes in Asian Indian families using a multivariate analysis.
OBJECTIVE
Insulin resistance and related metabolic disturbances are more common among Asian Indians than European whites. Little is known about the heritability of insulin resistance traits in Asian Indians. Our objective was to estimate heritabilities and genetic correlations in Asian Indian families.


METHODS
Phenotypic data were assembled for 181 UK Asian Indian probands with premature CHD, and their 1,454 first-, second- and third-degree relatives. We calculated (narrow-sense) heritabilities and genetic correlations for insulin resistance traits, and common environmental effects using all study participants and a multivariate model. The analysis was repeated in a subsample consisting of individuals not on drug therapy.


RESULTS
Heritability estimates (SE) for individuals not on drug therapy were: BMI 0.31 (0.04), WHR 0.27 (0.04), systolic BP 0.29 (0.03), triacylglycerol 0.40 (0.04), HDL-cholesterol 0.53 (0.04), glucose 0.37 (0.03), HOMA of insulin resistance (HOMA-IR) 0.22 (0.04), and HbA(1c) 0.60 (0.04). We observed many significant genetic correlations between the traits, in particular between HOMA-IR and BMI. Heritability estimates were lower for all phenotypes when analysed among all participants.


CONCLUSIONS
Genetic factors contribute to a significant proportion of the total variance in insulin resistance and related metabolic disturbances in Asian Indian CHD families.
Zabaneh
D
D
Department of Epidemiology and Public Health, Imperial College London, St Mary's Campus, Norfolk Place, London, W2 1PG, UK. d.zabaneh@imperial.ac.uk
Chambers
J C
JC
Elliott
P
P
Scott
J
J
Balding
D J
DJ
Kooner
J S
JS
D000328:Adult; D017668:Age of Onset; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D008076:Cholesterol, HDL / Q000097:blood; D003327:Coronary Disease / Q000453:epidemiology / Q000235:genetics*; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology; D003971:Diastole; D005190:Family; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D000960:Hypolipidemic Agents / Q000627:therapeutic use; D007194:India / Q000208:ethnology; D007333:Insulin Resistance / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018579:Patient Selection; D013599:Systole; D014280:Triglycerides / Q000097:blood; D006113:United Kingdom; D049629:Waist-Hip Ratio
D001786:Blood Glucose; D008076:Cholesterol, HDL; D006442:Glycated Hemoglobin; D000960:Hypolipidemic Agents; D014280:Triglycerides