Abstract
Objectives
The present study aimed to investigate whether nitric oxide synthase (NOS) enzyme gene variants (iNOS rs1060826, eNOS rs1799983, eNOS 27-bp VNTR) play a role in the etiopathogenesis of nonalcoholic fatty liver (NAFLD) in adolescents.
Methods
This cross-sectional study was conducted with obese adolescents [body mass index (BMI) standard deviation score (SDS) ≥2] aged 10–19 years (104 individuals) and age- and sex-matched healthy individuals (64 individuals) whose presence of NAFLD was determined by ultrasound. The iNOS rs1060826 and eNOS rs1799983 variants were performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, and the eNOS 27-bp VNTR variant was analyzed using the PCR method. The genotypes detected were compared between the patient group and the healthy controls and with the clinical parameters of the patients.
Results
iNOS rs1060826 and eNOS rs1799983 were independent of obesity, whereas eNOS 27-bp VNTR was independent of NAFLD. However, in the obese group, especially in those with NAFLD (+), the iNOS rs1060826 GG genotype was found to be associated with lower diastolic blood pressure (DBP) (p=0.011). Compared with the clinical parameters, insulin resistance (HOMA-IR) was higher in those carrying the eNOS rs1799983 gene variant-TT genotype in the NAFLD (+) group (p=0.051).
Conclusions
While the three functional gene variants of the NOS enzyme did not show a significant difference in terms of genotype between patients and healthy controls, it was determined that both the iNOS rs1060826 gene variant-GG allele was associated with low DBP and HOMA-IR may be higher in those carrying the eNOS rs1799983 gene variant TT genotype in NAFLD (+) patients. The iNOS rs1060826 polymorphism is a potentially important genetic variant that may influence DBP regulation through its effects on nitric oxide production.
-
Research ethics: Ethical approval for this study was obtained from the Ethics Committee of Istanbul University Faculty of Medicine (Approval No: 2023-594).
-
Informed consent: Written informed consent was obtained from both the adolescents and their parents.
-
Author contributions: SHS contributed to writing and data organization, IK contributed to statistical analysis, YO contributed to laboratory analysis and validation, SK contributed to data collection, MŞ and AYŞ contributed to manuscript writing and editing, and SP contributed to data analysis.
-
Use of Large Language Models, AI and Machine Learning Tools: None declared.
-
Conflict of interest: The authors state no conflict of interest.
-
Research funding: None declared. This study was carried out with the researchers’ own financial means.
-
Data availability: Istanbul University Pediatrics Department.
References
1. de Alwis, NM, Day, CP. Non-alcoholic fatty liver disease: the mist gradually clears. J Hepatol 2008;48:104–12. https://doi.org/10.1016/j.jhep.2008.01.009.Search in Google Scholar PubMed
2. Han, SK, Baik, SK, Kim, MY. Non-alcoholic fatty liver disease: definition and subtypes. Clin Mol Hepatol 2023;29:5–16. https://doi.org/10.3350/cmh.2022.0424.Search in Google Scholar PubMed PubMed Central
3. Yu, EL, Schwimmer, JB. Epidemiology of pediatric nonalcoholic fatty liver disease. Clin Liver Dis 2021;17:196–9. https://doi.org/10.1002/cld.1027.Search in Google Scholar PubMed PubMed Central
4. Mann, JP, Valenti, L, Scorletti, E, Byrne, CD, Nobili, V. Nonalcoholic fatty liver disease in children. Semin Liver Dis 2018;38:1–13. https://doi.org/10.1055/s-0038-1627456.Search in Google Scholar PubMed
5. Khalifa, O, Errafii, K, Al-Akl, NS, Arredouani, A. Noncoding RNAs in nonalcoholic fatty liver disease: potential diagnosis and prognosis biomarkers. Dis Markers 2020;2020:8822859. https://doi.org/10.1155/2020/8822859.Search in Google Scholar PubMed PubMed Central
6. Nassir, F, Ibdah, JA. Role of mitochondria in nonalcoholic fatty liver disease. Int J Mol Sci 2014;15:8713–42. https://doi.org/10.3390/ijms15058713.Search in Google Scholar PubMed PubMed Central
7. Fan, Z, Liu, T, Na, W. Association of nitric oxide synthase gene polymorphism with asthma: a systematic review and meta-analysis. Clin Respir J 2023;17:516–26. https://doi.org/10.1111/crj.13617.Search in Google Scholar PubMed PubMed Central
8. Sansbury, BE, Hill, BG. Antiobesogenic role of endothelial nitric oxide synthase. Vitam Horm 2014;96:323–46. https://doi.org/10.1016/b978-0-12-800254-4.00013-1.Search in Google Scholar PubMed PubMed Central
9. Sheldon, RD, Padilla, J, Jenkins, NT, Laughlin, MH, Rector, RS. Chronic NOS inhibition accelerates NAFLD progression in an obese rat model. Am J Physiol Gastrointest Liver Physiol 2015;308:G540–9. https://doi.org/10.1152/ajpgi.00247.2014.Search in Google Scholar PubMed PubMed Central
10. Hancock, DB, Martin, ER, Vance, JM, Scott, WK. Nitric oxide synthase genes and their interactions with environmental factors in Parkinson’s disease. Neurogenetics 2008;9:249–62. https://doi.org/10.1007/s10048-008-0137-1.Search in Google Scholar PubMed PubMed Central
11. Jiao, J, Wu, J, Huang, D, Liu, L. Lack of association of the iNOS gene polymorphism with risk of cancer: a systematic review and meta-analysis. Sci Rep 2015;5:9889. https://doi.org/10.1038/srep09889.Search in Google Scholar PubMed PubMed Central
12. Chai, J, Wang, Q, Qin, B, Wang, S, Wang, Y, Shahid, M, et al.. Association of NOS2A gene polymorphisms with susceptibility to bovine tuberculosis in Chinese holstein cattle. PLoS One 2021;16:e0253339. https://doi.org/10.1371/journal.pone.0253339.Search in Google Scholar PubMed PubMed Central
13. Li, R, Zhao, A, Diao, X, Song, J, Wang, C, Li, Y, et al.. Polymorphism of NOS3 gene and its association with essential hypertension in Guizhou populations of China. PLoS One 2023;18:e0278680. https://doi.org/10.1371/journal.pone.0278680.Search in Google Scholar PubMed PubMed Central
14. Shi, J, Liu, S, Guo, Y, Liu, S, Xu, J, Pan, L, et al.. Association between eNOS rs1799983 polymorphism and hypertension: a meta-analysis involving 14,185 cases and 13,407 controls. BMC Cardiovasc Disord 2021;21:385. https://doi.org/10.1186/s12872-021-02192-2.Search in Google Scholar PubMed PubMed Central
15. Say, YH. The association of insertions/deletions (INDELs) and variable number tandem repeats (VNTRs) with obesity and its related traits and complications. J Physiol Anthropol 2017;36:25. https://doi.org/10.1186/s40101-017-0142-x.Search in Google Scholar PubMed PubMed Central
16. Nasr, HB, Dimassi, S, M’hadhbi, R, Debbabi, H, Kortas, M, Tabka, Z, et al.. Functional G894T (rs1799983) polymorphism and intron-4 VNTR variant of nitric oxide synthase (NOS3) gene are susceptibility biomarkers of obesity among Tunisians. Obes Res Clin Pract 2016;10:465–75. https://doi.org/10.1016/j.orcp.2015.04.008.Search in Google Scholar PubMed
17. Dasarathy, S, Dasarathy, J, Khiyami, A, Joseph, R, Lopez, R, McCullough, AJ. Validity of real time ultrasound in the diagnosis of hepatic steatosis: a prospective study. J Hepatol 2009;51:1061–7. https://doi.org/10.1016/j.jhep.2009.09.001.Search in Google Scholar PubMed PubMed Central
18. Neyzi, O, Bundak, R, Gökçay, G, Günöz, H, Furman, A, Darendeliler, F, et al.. Reference values for weight, height, head circumference, and body mass index in Turkish children. J Clin Res Pediatr Endocrinol 2015;7:280–93. https://doi.org/10.4274/jcrpe.2183.Search in Google Scholar PubMed PubMed Central
19. Flynn, JT, Kaelber, DC, Baker-Smith, CM, Blowey, D, Carroll, AE, Daniels, SR, et al.. Clinical practice guideline for screening and management of high blood pressure in children and adolescents. Pediatrics 2017;140:e20171904. https://doi.org/10.1542/peds.2017-1904.Search in Google Scholar PubMed
20. Singh, R, Ghoshal, UC, Misra, A, Mittal, B. Achalasia is associated with eNOS4a4a, iNOS22GA, and nNOS29TT genotypes: a case-control study. J Neurogastroenterol Motil 2015;21:380–9. https://doi.org/10.5056/jnm14123.Search in Google Scholar PubMed PubMed Central
21. Şenkal, N, Oyacı, Y, Cebeci, T, Konyaoğlu, H, Chahed, K. Associating eNOS gene variants with COVID-19 susceptibility in the Turkish population. J Istanb Fac Med 2023;86:1–6.10.26650/IUITFD.1211888Search in Google Scholar
22. Nozaki, Y, Fujita, K, Wada, K, Yoneda, M, Shinohara, Y, Imajo, K, et al.. Deficiency of eNOS exacerbates early-stage NAFLD pathogenesis by changing the fat distribution. BMC Gastroenterol 2015;15:177. https://doi.org/10.1186/s12876-015-0409-9.Search in Google Scholar PubMed PubMed Central
23. Persico, M, Masarone, M, Damato, A, Ambrosio, M, Federico, A, Rosato, V, et al.. Nonalcoholic fatty liver disease and eNOS dysfunction in humans. BMC Gastroenterol 2017;17:35. https://doi.org/10.1186/s12876-017-0592-y.Search in Google Scholar PubMed PubMed Central
24. Nasyrova, RF, Moskaleva, PV, Vaiman, EE, Shnayder, NA, Blatt, NL, Rizvanov, AA. Genetic factors of nitric oxide’s system in psychoneurologic disorders. Int J Mol Sci 2020;21:1604. https://doi.org/10.3390/ijms21051604.Search in Google Scholar PubMed PubMed Central
25. Qidwai, T, Jamal, F. Inducible nitric oxide synthase (iNOS) gene polymorphism and disease prevalence. Scand J Immunol 2010;72:375–87. https://doi.org/10.1111/j.1365-3083.2010.02458.x.Search in Google Scholar PubMed
26. Levinsson, A, Olin, AC, Bjorck, L, Rosengren, A, Nyberg, F. Nitric oxide synthase (NOS) single nucleotide polymorphisms are associated with coronary heart disease and hypertension in the INTERGENE study. Nitric Oxide 2014;39:1–6. https://doi.org/10.1016/j.niox.2014.03.164.Search in Google Scholar PubMed
27. Dong, J, Ping, Y, Wang, Y, Zhang, Y. The roles of endothelial nitric oxide synthase gene polymorphisms in diabetes mellitus and its associated vascular complications: a systematic review and meta-analysis. Endocrine 2018;62:412–22. https://doi.org/10.1007/s12020-018-1683-4.Search in Google Scholar PubMed
28. Kamanaka, Y, Kawabata, A, Matsuya, H, Taga, C, Sekiguchi, F, Kawao, N. Effect of a potent iNOS inhibitor (ONO-1714) on acetaminophen-induced hepatotoxicity in the rat. Life Sci 2003;74:793–802. https://doi.org/10.1016/j.lfs.2003.09.036.Search in Google Scholar PubMed
29. Higashi, Y. Endothelial function in dyslipidemia: roles of LDL-cholesterol, HDL-cholesterol and triglycerides. Cells 2023;12:1293. https://doi.org/10.3390/cells12091293.Search in Google Scholar PubMed PubMed Central
30. Kim, B, Zhao, W, Tang, S, Levin, MG, Ibrahim, A, Yang, Y, et al.. Endothelial lipid droplets suppress eNOS to link high fat consumption to blood pressure elevation. J Clin Investig 2023;133:e173160. https://doi.org/10.1172/jci173160.Search in Google Scholar
31. Higashibata, T, Hamajima, N, Naito, M, Kawai, S, Yin, G, Suzuki, S, et al.. eNOS genotype modifies the effect of leisure-time physical activity on serum triglyceride levels in a Japanese population. Lipids Health Dis 2012;11:150. https://doi.org/10.1186/1476-511x-11-150.Search in Google Scholar
32. Chaichanabut, C, Sritara, P, Sirivarasai, J. Genetic polymorphisms of endothelial nitric oxide synthase associated with hypertension and blood homocysteine levels. Int J Gen Med 2024;17:1509–19. https://doi.org/10.2147/ijgm.s456519.Search in Google Scholar
© 2025 Walter de Gruyter GmbH, Berlin/Boston
Articles in the same Issue
- Frontmatter
- Original Articles
- Spatiotemporal associations between incidence of type 1 diabetes and COVID-19 vaccination rates in children in Germany – a population-based ecological study
- Continuous glucose monitoring evidence of celiac disease in type 1 diabetes
- Impact of race and delayed adoption of diabetes technology on glycemia and partial remission in type 1 diabetes
- Immunogenetic profiling of type 1 diabetes in Jordan: a case-control study on HLA-associated risk and protection
- Annual case counts and clinical characteristics of pediatric and adolescent patients with diabetes in Kenyatta National Hospital, Nairobi, Kenya. A 14 year retrospective study
- Real-world effectiveness of sodium glucose transporter 2 inhibitors among youth with type 2 diabetes
- Investigation of the association between nitric oxide synthase gene variants and NAFLD in adolescents with obesity
- Cardiometabolic outcomes in girls with premature adrenarche: a longitudinal analysis of typical vs. exaggerated presentations
- A disease that is difficult to predict: regional distribution and phenotypic, histopathological and genetic findings in McArdle disease
- Causal analysis of uterine artery pulsatility index-related proteins and the risk of precocious puberty in girls: a Mendelian randomization study
- Case Reports
- Understanding rickets in osteopetrosis via a case: mechanisms and treatment implications
- A case of JAGN1 mutation presenting with atypical diabetes and immunodeficiency
- Compound heterozygous ROBO1 gene variants in a neonate with congenital hypopituitarism, dysmorphic features and midline abnormalities: a case report and review of the literature
- Phenotypic variation among four members in a family with DAX1 deficiency
- MMP13-related metaphyseal dysplasia: a differential diagnosis of rickets
- Congress Abstracts
- JA-PED | Annual Meeting of the German Society for Pediatric and Adolescent Endocrinology and Diabetology (DGPAED e. V.)
Articles in the same Issue
- Frontmatter
- Original Articles
- Spatiotemporal associations between incidence of type 1 diabetes and COVID-19 vaccination rates in children in Germany – a population-based ecological study
- Continuous glucose monitoring evidence of celiac disease in type 1 diabetes
- Impact of race and delayed adoption of diabetes technology on glycemia and partial remission in type 1 diabetes
- Immunogenetic profiling of type 1 diabetes in Jordan: a case-control study on HLA-associated risk and protection
- Annual case counts and clinical characteristics of pediatric and adolescent patients with diabetes in Kenyatta National Hospital, Nairobi, Kenya. A 14 year retrospective study
- Real-world effectiveness of sodium glucose transporter 2 inhibitors among youth with type 2 diabetes
- Investigation of the association between nitric oxide synthase gene variants and NAFLD in adolescents with obesity
- Cardiometabolic outcomes in girls with premature adrenarche: a longitudinal analysis of typical vs. exaggerated presentations
- A disease that is difficult to predict: regional distribution and phenotypic, histopathological and genetic findings in McArdle disease
- Causal analysis of uterine artery pulsatility index-related proteins and the risk of precocious puberty in girls: a Mendelian randomization study
- Case Reports
- Understanding rickets in osteopetrosis via a case: mechanisms and treatment implications
- A case of JAGN1 mutation presenting with atypical diabetes and immunodeficiency
- Compound heterozygous ROBO1 gene variants in a neonate with congenital hypopituitarism, dysmorphic features and midline abnormalities: a case report and review of the literature
- Phenotypic variation among four members in a family with DAX1 deficiency
- MMP13-related metaphyseal dysplasia: a differential diagnosis of rickets
- Congress Abstracts
- JA-PED | Annual Meeting of the German Society for Pediatric and Adolescent Endocrinology and Diabetology (DGPAED e. V.)