ABSTRACT
Purpose: A study among Filipinos revealed that only 15% of patients with diabetes achieved glycemic control, and poor response to metformin could be one of the possible reasons. Recent studies demonstrate how genetic variations influence response to metformin. Hence, the present study aimed to determine genetic variants associated with poor response to metformin. Methods: Using a candidate variant approach, 195 adult Filipino participants with newly diagnosed type 2 diabetes mellitus (T2DM) were enrolled in a case-control study. Genomic DNA from blood samples were collected. Allelic and genotypic associations of variants with poor response to metformin were determined using exact statistical methods. Results: Several polymorphisms were nominally associated with poor response to metformin (P uncorrâ <â 0.05). The most notable is the association of multiple variants in the SLC2A10 gene-rs2425911, rs3092412, and rs2425904-with common additive genetic mode of inheritance. Other variants that have possible associations with poor drug response include rs340874 (PROX-AS1), rs815815 (CALM2), rs1333049 (CDKN2B-AS1), rs2010963 (VEGFA), rs1535435 and rs9494266 (AHI1), rs11128347 (PDZRN3), rs1805081 (NPC1), and rs13266634 (SLC30A8). Conclusion: In Filipinos, a trend for the association for several variants was noted, with further observation that several mechanisms may be involved. The results may serve as pilot data for further validation of candidate variants for T2DM pharmacotherapy.
ABSTRACT
Objective. Previous studies have demonstrated the role of genetic susceptibility in the pathogenesis of diabetic nephropathy. The study aimed to determine the frequencies of angiotensin I-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism in a pilot population of Filipino type 2 diabetic patients and normal controls. Methods. An analysis of the ACE gene polymorphism was performed in 42 diabetic patients with and without nephropathy, and 24 normal controls. The analysis was done using polymerase chain reaction, restriction enzyme digestion, and gel electrophoresis techniques to determine the polymorphism (II, DD or ID). Independent T-tests and chi-square tests were used to compare clinical characteristics, and logistic regression analysis was done to determine odds ratio for development of nephropathy. Results. The ID polymorphism of the ACE gene was more frequent (52.4%) in patients with diabetic nephropathy (n=21). In those without nephropathy (n=21), II was more common (61.9%). ID was the more frequent genotype in the normal controls (n=24) (58.3%). The odds of developing diabetic nephropathy were increased by 4.8 times in those with ID polymorphism, and 2.9 times in those with DD. Conclusion. The D allele was more common in patients with diabetic nephropathy, similar to the observation in South Indian patients. Since the study involved only a small pilot group, studies on a larger population is needed to establish the hypothesized role of the D allele in susceptibility to diabetic nephropathy in Filipinos.
