Association of Plasma β-amyloid 40 and 42 Concentration with Type 2 Diabetes Among Chinese Adults

We aimed to investigate the association of plasma β-amyloid (Aβ) 40 and Aβ42 with risk of type 2 diabetes. We performed a case-control study and a nested case-control study within a prospective cohort study. In the case-control study, we included 1063 newly diagnosed type 2 diabetes cases and 1063 controls matched by age and sex. In the nested case-control study, we included 121 incident type 2 diabetes cases and 242 matched controls. Plasma Aβ40 and Aβ42 concentrations were simultaneously measured with electrochemiluminescence immunoassay. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression with adjustment for age, sex, BMI, current smoking status, current drinking status, physical activity, family history of diabetes, and hypertension. In the case-control study, the multivariable-adjusted ORs of type 2 diabetes comparing the highest with the lowest quartile of plasma Aβ concentrations were 1.97 (95% CI: 1.46, 2.66) for plasma Aβ40 and 2.01 (95% CI: 1.50, 2.69) for plasma Aβ42. Each 30 ng/L increment of plasma Aβ40 was associated with 28% (95% CI: 15%, 43%) higher odds of type 2 diabetes, and each 5 ng/L increment of plasma Aβ42 was associated with 37% (95% CI: 21%, 55%) higher odds of type 2 diabetes. In the nested case-control study, the multivariable-adjusted ORs of type 2 diabetes for the highest versus the lowest quartile were 3.79 (95% CI: 1.81, 7.94) for plasma Aβ40 and 2.88 (95% CI: 1.44, 5.75) for plasma Aβ42. The multivariable-adjusted ORs of type 2 diabetes were 1.44 (95% CI: 1.18, 1.74) and 1.47 (95% CI: 1.15, 1.88) associated with each 30 ng/L increment in plasma Aβ40 and each 5 ng/L increment in plasma Aβ42, respectively. Our findings suggested positive associations of plasma Aβ40 and Aβ42 concentration with risk of type 2 diabetes. Further studies are warranted to elucidate the underlying mechanism and explore the potential roles of plasma Aβ in linking type 2 diabetes and Alzheimer’s disease. This work was funded by the National Key Research and Development Program of China, the Major International (Regional) Joint Research Project, and the National Natural Science Foundation of China.