We aimed to evaluate the combined effects of type 2 diabetes risk variants on predicting deterioration of blood glucose and progression of beta cell function and insulin sensitivity in a 9 year prospective cohort from the Chinese population.

We constructed a weighted genetic risk score (GRS) model based on 40 variants associated with type 2 diabetes validated in an established cross-sectional Chinese population (n = 6,822). The weighted scores were categorised into tertiles to assess the predictive capacity for incidence of type 2 diabetes and impaired glucose regulation (IGR), as well as for changes in Stumvoll first- and second-phase insulin secretion indices and Gutt’s insulin sensitivity index (ISI) in a community-based 9 year prospective cohort (n = 2,495), including 2,192 individuals with normal glucose tolerance and 303 with IGR at baseline, through logistic, Cox and multiple linear regression tests.

Weighted GRS predicted the incidence of type 2 diabetes and IGR in logistic regression (OR 1.236, 95% CI 1.100, 1.389, p = 0.0004) as well as in the Cox model (HR 1.129, 95% CI 1.026, 1.242, p = 0.0128) after adjusting for age, sex, BMI, smoking and alcohol status at baseline. Moreover, we observed that weighted GRS was able to predict deterioration in beta cell function (β = −0.0480, p = 9.66 × 10⁻⁵ and β = −0.0303, p = 3.32 × 10⁻⁵ for first- and second-phase insulin secretion, respectively), but not insulin sensitivity (p = 0.3815), during the 9 year follow-up period.

The weighted GRS predicted blood glucose deterioration arising from change in beta cell function in the Chinese population. Individuals in the intermediate- or high-weighted GRS group exhibited progressive deterioration of beta cell function.