Consistency of genetic inheritance mode and heritability patterns of triglyceride vs. high density lipoprotein cholesterol ratio in two Taiwanese family samples.
BACKGROUND
Triglyceride/HDL cholesterol ratio (TG/HDL-C) is considered as a risk factor for cardiovascular events. Genetic components were important in controlling the variation in western countries. But the mode of inheritance and family aggregation patterns were still unknown among Asian-Pacific countries. This study, based on families recruited from community and hospital, is aimed to investigate the mode of inheritance, heritability and shared environmental factors in controlling TG/HDL-C.


RESULTS
Two populations, one from community-based families (n = 988, 894 parent-offspring and 453 sibling pairs) and the other from hospital-based families (n = 1313, 76 parent-offspring and 52 sibling pairs) were sampled. The population in hospital-based families had higher mean age values than community-based families (54.7 vs. 34.0). Logarithmic transformed TG/ HDL-C values, after adjusted by age, gender and body mass index, were for genetic analyses. Significant parent-offspring and sibling correlations were also found in both samples. The parent-offspring correlation coefficient was higher in the hospital-based families than in the community-based families. Genetic heritability was higher in community-based families (0.338 +/- 0.114, p = 0.002), but the common shared environmental factor was higher in hospital-based families (0.203 +/- 0.042, p < 0.001). Commingling analyses showed that more than one-component distribution models were the best-fit models to explain the variance in both populations. Complex segregation analysis by regressive models revealed that in both samples the best-fit model of TG/HDL-C was the model of environmental effects plus familial correlation, in which significant parent-offspring and sibling correlations were demonstrated. Models of major gene effects were rejected in both samples.


CONCLUSIONS
Variations of TG/HDL-C in the normal ranges were likely to be influenced by multiple factors, including environmental and genetic components. Higher genetic factors were proved in younger community-based families than in older hospital-based families.
Chien
Kuo-Liong
KL
Graduate Institute of Preventive Medicine, School of Public Health, National Taiwan University, Taipei, TAIWAN. klchien@ha.mc.ntu.edu.tw
Hsu
Hsiu-Ching
HC
Su
Ta-Chen
TC
Yang
Chi-Yu
CY
Lee
Yuan-Teh
YT
D000328:Adult; D000367:Age Factors; D015992:Body Mass Index; D008076:Cholesterol, HDL / Q000097:blood* / Q000235:genetics*; D003151:Community Health Centers / Q000706:statistics & numerical data; D005260:Female; D005799:Genes, Dominant / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics; D005828:Genetics, Population / Q000379:methods / Q000706:statistics & numerical data; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D040582:Inheritance Patterns / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009679:Nuclear Family; D012737:Sex Factors; D035781:Siblings; D013624:Taiwan; D014280:Triglycerides / Q000097:blood* / Q000235:genetics*
D008076:Cholesterol, HDL; D014280:Triglycerides