Introduction Intergenerational “mismatch” has been suggested as being relevant to the emergent epidemic of diabetes in developing populations. Conversely, constrained growth conditions over generations may also increase susceptibility to diabetes. In a rapidly developing southern Chinese population, we tested whether maternal environment, proxied by maternal literacy, or family socio-economic position (SEP), proxied by paternal literacy, were associated with fasting blood glucose and diabetes. To assess if intergenerational mismatch contributed, we tested whether the associations were modified by life course SEP.

Methods In 19 818 older (≥50 years) adults from the Guangzhou Biobank Cohort Study (phases 2 and 3) examined in 2005–2008, we used multivariable censored and logistic regression to assess the associations of maternal and paternal literacy with fasting blood glucose and diabetes and whether these associations varied by sex, age or life course SEP.

Results Adjusted associations of maternal, but not paternal, literacy was negatively associated with fasting blood glucose (−0.07, 95% CI −0.13 to −0.02) and diabetes (0.92, 95% CI 0.83 to 1.02). These associations did not vary by sex, age or life course SEP.

Conclusions Better living conditions over generations may reduce the risk of diabetes, consistent with the high levels of diabetes in recently developed or developing populations.