Abstract Aims/hypothesis Theaimofthisstudywastoassesstheextent to which insulin resistance and beta cell dysfunction account for differences in impaired fasting blood glucose (IFBG) levels in sub-Saharan African individuals living in different locations in Europe and Africa. We also aimed to identify determinants associated with insulin resistance and beta cell dysfunction among this population. Methods Data from the cross-sectional multicentre Research on Obesity and Diabetes among African Migrants (RODAM) studywereanalysed.ParticipantsincludedGhanaianindividuals without diabetes, aged 18–96 years old, who were residing in Amsterdam (n=1337), Berlin (n=502), London (n=961), urban Ghana (n=1309) and rural Ghana (n=970). Glucose and insulin were measured in fasting venous blood samples. Anthropometrics were assessed during a physical examination. Questionnaires were used to assess demographics, physical activity,smokingstatus,alcoholconsumptionandenergyintake. Insulin resistance and beta cell function were determined using homeostaticmodelling(HOMA-IR andHOMA-B,respectively). Logisticregressionanalysis was used to study the contribution of HOMA-IR and inverse HOMA-B (beta cell dysfunction) to geographical differences in IFBG (fasting glucose 5.6–6.9 mmol/l). Multivariate linear regression analysis was used to identify determinants associated with HOMA-IR and inverse HOMA-B.