Int J Med Sci 2018; 15(10):1035-1042. doi:10.7150/ijms.25742 This issue
1. The Ph.D. Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.
2. Division of Biostatistics and Bioinformatics, Institute of Population Health Sciences, National Health Research Institutes, Taiwan.
3. Section of Endocrinology and Metabolism, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
4. Faculty of Medicine, National Yang-Ming University School of medicine, Taipei, Taiwan.
5. Division of Endocrinology and Metabolism, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
6. School of Medicine, Chung Shan Medical University, Taichung, Taiwan.
7. School of Medicine, National Yang-Ming University, Taipei, Taiwan.
8. Division of Endocrine and Metabolism, Tri-Service General Hospital, Taipei, Taiwan.
9. Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan.
10. Graduate Institute of Medical Genomics and Proteomics, National Taiwan University, Taiwan.
11. Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
12. Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan.
13. Division of Cardiovascular Medicine, Falk Cardiovascular Research Building, Stanford University School of Medicine, Stanford, CA, USA.
14. Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center, Torrance, California, USA.
Chromosome 12q23-q24 has been linked to triglyceride (TG) levels by previous linkage studies, and it contains the Insulin-like growth factor 1 (IGF1) gene. We investigated the association between IGF1 and TG levels using two independent samples collected in Taiwan. First, based on 954 siblings in 397 families from the Stanford Asian Pacific Program in Hypertension and Insulin Resistance (SAPPHIRe), we found that rs978458 was associated with TG levels (β = -0.049, p = 0.0043) under a recessive genetic model. Specifically, subjects carrying the homozygous genotype of the minor allele had lower TG levels, compared with other subjects. Then, a series of stratification analyses in a large sample of 13,193 unrelated subjects from the Taiwan biobank (TWB) project showed that this association appeared in subjects with a family history (FH) of hypertension (β = -0.045, p = 0.0000034), but not in subjects without such an FH. A re-examination of the SAPPHIRe sample confirmed that this association appeared in subjects with an FH of hypertension (β = -0.068, p = 0.0025), but not in subjects without an FH. The successful replication in two independent samples indicated that IGF1 is associated with TG levels in subjects with an FH of hypertension in Taiwan.
Keywords: Family history of hypertension, IGF1, Insulin-like growth factor 1, Single-nucleotide polymorphism, Triglyceride