The BDNF rs6265 variant may interact with overweight and obesity to influence obesity-related physical, metabolic and behavioural traits in Pakistani individuals.

BACKGROUND: The association of the variant rs6265 (G>A) in the brain-derived neurotrophic factor (BDNF) gene with obesity and other obesity-related parameters is not known for the Pakistani population. Moreover, the effects of interaction between BDNF rs6265 and overweight/obesity on obesity-related traits have never been investigated before. AIM: To find the association of the BDNF rs6265 with obesity and related traits and to explore the effect of rs6265 × obesity interaction on obesity-related traits in Pakistanis. SUBJECTS AND METHODS: The study involved a total of 606 subjects, including 306 overweight and obese (OW/OB) cases and 300 normal weight (NW) controls. The genotyping of the BDNF rs6265 was done and obesity-related anthropometric, physical, behavioural and metabolic parameters were determined. Statistical analyses using SPSS software were performed to find the associations. RESULTS: The study revealed a lack of association of the BDNF rs6265 with obesity and obesity-related traits. On the other hand, the interaction between the BDNF rs6265 and overweight/obesity was found to be significantly associated with some of the obesity-related anomalous traits. However, no association between rs6265 and these anomalous traits was seen in either group when the association test was performed in NW and OW/OB groups separately. CONCLUSION: The BDNF rs6265, in the presence of obesity, may be associated with elevated risk of anomalous metabolic, behavioural and physical traits and obesity-related co-morbidities, but it needs to be validated in a significantly larger Pakistani sample population.

MC4R variant rs17782313 and manifestation of obese phenotype in Pakistani females.

MC4R represents a key player involved in melanocortin-mediated control of energy balance. Recently identified near MC4R variant rs17782313 (T > C) can serve as a contributing factor for obese phenotype but its association with obesity has never been sought in a sample of the Pakistani population. The role of genetic variants as causal factors varies across populations. Association studies in a specific population can help us to distinguish global from local gene-gene and gene-environment interactions. This is the first study that investigated the association of rs17782313 with obesity and various obesity-linked anthropometric, metabolic, physical, and behavioural traits in Pakistani subjects including 306 OW/OB (overweight and obese) and 300 NW (normal weight) individuals. The comparison of various aforementioned obesity-linked continuous and categorical variables between OW/OB and NW subjects revealed that almost all variables were found significantly aberrant (p < 0.05) in OW/OB subjects as compared to their age- and gender-matched NW controls indicating greater risk of developing various cardio-metabolic disorders. The genotyping of rs17782313 showed significant association of this variant with obesity and obesity-linked anthropometric traits in females suggesting the gender-specific effect of this variant in our population. The minor allele C increased the risk of obesity by 1.55 times (95% CI = 1.1-2.18, p = 0.01) whereas homozygous CC genotype increased the risk by 2.43 times (95% CI = 1.19-4.96, p = 0.015) in females. However, no association of rs17782313 was observed with any of the obesity-linked metabolic, physical, and behavioural traits except random eating timings. In conclusion, the current study significantly contributes to the knowledge of the genetic proneness to obesity in Pakistani females. This could also be helpful for forthcoming meta-analysis studies elucidating which variants are truly associated with the susceptibility to develop an obese phenotype.