Background: Taxi-motorbike drivers (TMDs) in Cotonou are occupationally exposed to high levels of air pollution, which may contribute to metabolic dysfunction, including insulin resistance (IR). This study evaluated the associations between vitamin B12 levels, lifestyle factors, and IR in this high-risk population. Methods: A cross-sectional study was conducted among 139 TMDs in Cotonou, Benin. Fasting blood samples were collected to measure glucose, insulin, and vitamin B12 levels. Insulin resistance was assessed using HOMA-IR (>2.9). Participants were stratified by vitamin B12 quartiles, and logistic regression identified factors associated with IR. Results: The median age was 39.6 years (IQR: 34.0 - 44.0), and the median BMI was 22.8 kg/m2 (IQR: 20.8 - 25.8). IR prevalence was 67.6% (94/139), with a median HOMA-IR of 3.6 (IQR: 2.6 - 6.1). Vitamin B12 levels were adequate (>221 pmol/L) in 90.6% of participants. Participants in the third quartile (381 - 482 pM) had significantly lower glucose (4.1 nmol/L, p = 0.013), insulin (14.7 μM/mL, p = 0.014), and HOMA-IR (2.6, p = 0.009) compared to lower quartiles. Logistic regression identified BMI (OR = 1.28, 95% CI: 1.11 - 1.48, p = 0.001) and alcohol use (OR = 2.41, 95% CI: 1.02 - 5.72, p = 0.046) as risk factors for IR, while vitamin B12 levels between 381 - 482 pM were protective (OR = 0.19, 95% CI: 0.06 - 0.59, p = 0.004). Conclusions: This study reveals a high prevalence of IR among TMDs in Cotonou, with BMI and alcohol consumption identified as key modifiable risk factors. Notably, vitamin B12 levels within the 381 - 482 pM range, a moderate concentration exceeding standard deficiency thresholds, demonstrated a protective association against IR, potentially reflecting optimal bioavailability for mitigating oxidative stress and epigenetic dysregulation linked to air pollution exposure. Implementing tailored interventions to address nutritional and lifestyle factors, such as targeted vitamin B12 supplementation for TMDs with suboptimal levels (<381 pmol/L) and structured weight management programs, could reduce metabolic risks in this occupationally high-risk population.
References
[1]
Avogbe, P.H., Ayi-Fanou, L., Autrup, H., Loft, S., Fayomi, B., Sanni, A., et al. (2004) Ultrafine Particulate Matter and High-Level Benzene Urban Air Pollution in Relation to Oxidative DNA Damage. Carcinogenesis, 26, 613-620. https://doi.org/10.1093/carcin/bgh353
[2]
Ayi Fanou, L., Mobio, T.A., Creppy, E.E., Fayomi, B., Fustoni, S., Møller, P., et al. (2006) Survey of Air Pollution in Cotonou, Benin—Air Monitoring and Biomarkers. Science of the Total Environment, 358, 85-96. https://doi.org/10.1016/j.scitotenv.2005.03.025
[3]
Ayi‐Fanou, L., Avogbe, P.H., Fayomi, B., Keith, G., Hountondji, C., Creppy, E.E., et al. (2011) DNA‐Adducts in Subjects Exposed to Urban Air Pollution by Benzene and Polycyclic Aromatic Hydrocarbons (PAHs) in Cotonou, Benin. Environmental Toxicology, 26, 93-102. https://doi.org/10.1002/tox.20533
[4]
Gorini, F., Sabatino, L., Gaggini, M., Chatzianagnostou, K. and Vassalle, C. (2021) Oxidative Stress Biomarkers in the Relationship between Type 2 Diabetes and Air Pollution. Antioxidants, 10, Article 1234. https://doi.org/10.3390/antiox10081234
[5]
Ribble, A., Hellmann, J., Conklin, D.J., Bhatnagar, A. and Haberzettl, P. (2023) Fine Particulate Matter (PM2.5)-Induced Pulmonary Oxidative Stress Contributes to Increases in Glucose Intolerance and Insulin Resistance in a Mouse Model of Circadian Dyssynchrony. Science of The Total Environment, 877, Article 162934. https://doi.org/10.1016/j.scitotenv.2023.162934
[6]
Alderete, T.L., Habre, R., Toledo-Corral, C.M., Berhane, K., Chen, Z., Lurmann, F.W., et al. (2017) Longitudinal Associations between Ambient Air Pollution with Insulin Sensitivity, β-Cell Function, and Adiposity in Los Angeles Latino Children. Diabetes, 66, 1789-1796. https://doi.org/10.2337/db16-1416
[7]
Lou, W., Zhang, M., Chen, Q., Bai, T., Hu, Y., Gao, F., et al. (2022) Molecular Mechanism of Benzo [a] Pyrene Regulating Lipid Metabolism via Aryl Hydrocarbon Receptor. Lipids in Health and Disease, 21, Article No. 13. https://doi.org/10.1186/s12944-022-01627-9
[8]
Dang, J., Yang, M., Zhang, X., Ruan, H., Qin, G., Fu, J., et al. (2018) Associations of Exposure to Air Pollution with Insulin Resistance: A Systematic Review and Meta-Analysis. International Journal of Environmental Research and Public Health, 15, Article 2593. https://doi.org/10.3390/ijerph15112593
[9]
Kodavanti, U.P. (2015) Air Pollution and Insulin Resistance: Do All Roads Lead to Rome? Diabetes, 64, 712-714. https://doi.org/10.2337/db14-1682
[10]
Gong, X., Wang, S., Wang, X., Zhong, S., Yuan, J., Zhong, Y., et al. (2024) Long-Term Exposure to Air Pollution and Risk of Insulin Resistance: A Systematic Review and Meta-Analysis. Ecotoxicology and Environmental Safety, 271, Article 115909. https://doi.org/10.1016/j.ecoenv.2023.115909
[11]
Vella, R.E., Pillon, N.J., Zarrouki, B., Croze, M.L., Koppe, L., Guichardant, M., et al. (2014) Ozone Exposure Triggers Insulin Resistance through Muscle C-Jun N-Terminal Kinase Activation. Diabetes, 64, 1011-1024. https://doi.org/10.2337/db13-1181
[12]
Halczuk, K., Kaźmierczak-Barańska, J., Karwowski, B.T., Karmańska, A. and Cieślak, M. (2023) Vitamin B12—Multifaceted in vivo Functions and in vitro Applications. Nutrients, 15, Article 2734. https://doi.org/10.3390/nu15122734
[13]
Cigerli, O., Parildar, H., Dogruk Unal, A., Tarcin, O., Kut, A., Eroglu, H., et al. (2016) Vitamin Deficiency and Insulin Resistance in Nondiabetic Obese Patients. Acta Endocrinologica (Bucharest), 12, 319-327. https://doi.org/10.4183/aeb.2016.319
[14]
Debnath, P.R., Debnath, D.K., Haque, A.F., Mohammuddunnobi, M. and Bhowmik, N.C. (2023) Role of Vitamin B12 Deficiency and Hyperhomocysteinemia in Diabetic Retinopathy. Mymensingh Medical Journal, 32, 459-462.
[15]
Zhu, J., Chen, C., Lu, L., Shikany, J.M., D’Alton, M.E. and Kahe, K. (2023) Folate, Vitamin B6, and Vitamin B12 Status in Association with Metabolic Syndrome Incidence. JAMA Network Open, 6, e2250621. https://doi.org/10.1001/jamanetworkopen.2022.50621
[16]
Amouzou, E.K., Chabi, N.W., Adjalla, C.E., Rodriguez-Guéant, R.M., Feillet, F., Villaume, C., et al. (2004) High Prevalence of Hyperhomocysteinemia Related to Folate Deficiency and the 677C→T Mutation of the Gene Encoding Methylenetetrahydrofolate Reductase in Coastal West Africa. The American Journal of Clinical Nutrition, 79, 619-624. https://doi.org/10.1093/ajcn/79.4.619
[17]
Avogbe, P.H. and Sanni, A. (2022) Hyperuricemia and Associated Cardiometabolic Factors: A Cross-Sectional Study on Taxi-Motorbike Drivers Working in Cotonou, Benin. Avicenna Journal of Medical Biochemistry, 10, 46-51. https://doi.org/10.34172/ajmb.2022.06
[18]
Joint Committee for Guideline Revision (2019) 2018 Chinese Guidelines for Prevention and Treatment of Hypertension—A Report of the Revision Committee of Chinese Guidelines for Prevention and Treatment of Hypertension. Journal of Geriatric Cardiology, 16, 182-241.
[19]
de Benoist, B. (2008) Conclusions of a WHO Technical Consultation on Folate and Vitamin B12 Deficiencies. Food and Nutrition Bulletin, 29, S238-S244. https://doi.org/10.1177/15648265080292s129
[20]
Allen, L.H. (2009) How Common Is Vitamin B-12 Deficiency? The American Journal of Clinical Nutrition, 89, 693S-696S. https://doi.org/10.3945/ajcn.2008.26947a
[21]
Lee, C., Liu, W. and Tsai, S. (2022) Development and Validation of an Insulin Resistance Model for a Population with Chronic Kidney Disease Using a Machine Learning Approach. Nutrients, 14, Article 2832. https://doi.org/10.3390/nu14142832
[22]
Kahn, S.E., Hull, R.L. and Utzschneider, K.M. (2006) Mechanisms Linking Obesity to Insulin Resistance and Type 2 Diabetes. Nature, 444, 840-846. https://doi.org/10.1038/nature05482
[23]
Barrio-Lopez, M.T., Bes-Rastrollo, M., Sayon-Orea, C., Garcia-Lopez, M., Fernandez-Montero, A., Gea, A., et al. (2013) Different Types of Alcoholic Beverages and Incidence of Metabolic Syndrome and Its Components in a Mediterranean Cohort. Clinical Nutrition, 32, 797-804. https://doi.org/10.1016/j.clnu.2012.12.002
[24]
Akahane, T., Namisaki, T., Kaji, K., Moriya, K., Kawaratani, H., Takaya, H., et al. (2020) Chronic Alcohol Consumption Is Inversely Associated with Insulin Resistance and Fatty Liver in Japanese Males. Nutrients, 12, Article 1036. https://doi.org/10.3390/nu12041036
[25]
Li, Z., Gueant-Rodriguez, R., Quilliot, D., Sirveaux, M., Meyre, D., Gueant, J., et al. (2018) Folate and Vitamin B12 Status Is Associated with Insulin Resistance and Metabolic Syndrome in Morbid Obesity. Clinical Nutrition, 37, 1700-1706. https://doi.org/10.1016/j.clnu.2017.07.008
[26]
Adaikalakoteswari, A., Finer, S., Voyias, P.D., McCarthy, C.M., Vatish, M., Moore, J., et al. (2015) Vitamin B12 Insufficiency Induces Cholesterol Biosynthesis by Limiting S-Adenosylmethionine and Modulating the Methylation of SREBF1 and LDLR Genes. Clinical Epigenetics, 7, Article No. 14. https://doi.org/10.1186/s13148-015-0046-8
[27]
Ulloque-Badaracco, J.R., Hernandez-Bustamante, E.A., Alarcon-Braga, E.A., Al-kassab-Córdova, A., Cabrera-Guzmán, J.C., Herrera-Añazco, P., et al. (2023) Vitamin B12, Folate, and Homocysteine in Metabolic Syndrome: A Systematic Review and Meta-analysis. Frontiers in Endocrinology, 14, Article 1221259. https://doi.org/10.3389/fendo.2023.1221259
[28]
Aparicio-Ugarriza, R., Palacios, G., Alder, M. and González-Gross, M. (2015) A Review of the Cut-Off Points for the Diagnosis of Vitamin B12 Deficiency in the General Population. Clinical Chemistry and Laboratory Medicine (CCLM), 53, 1149-1159. https://doi.org/10.1515/cclm-2014-0784
[29]
Aureli, A., Recupero, R., Mariani, M., Manco, M., Carlomagno, F., Bocchini, S., et al. (2023) Low Levels of Serum Total Vitamin B12 Are Associated with Worse Metabolic Phenotype in a Large Population of Children, Adolescents and Young Adults, from Underweight to Severe Obesity. International Journal of Molecular Sciences, 24, Article 16588. https://doi.org/10.3390/ijms242316588
[30]
Hannibal, L., Lysne, V., Bjørke-Monsen, A., Behringer, S., Grünert, S.C., Spiekerkoetter, U., et al. (2016) Biomarkers and Algorithms for the Diagnosis of Vitamin B12 Deficiency. Frontiers in Molecular Biosciences, 3, Article 27. https://doi.org/10.3389/fmolb.2016.00027
