White blood cells count as an indicator to identify whether obesity leads to increased risk of type 2 diabetes

Abstract Aims Obesity promotes a variety of poor health outcomes, including type 2 diabetes (T2D). However, not all obese people are at an elevated risk of T2D. Obesity is closely linked to chronic inflammation. In addition, inflammation is an important contributor to T2D via the processes of insulin resistance and islet β-cell failure. Therefore, we hypothesize that white blood cells (WBC) count, a marker of subclinical inflammation, can be used as an indicator to identify whether or not obesity leads to increased risk of T2D. To investigate this hypothesis, we conducted a prospective cohort study in a general population. Methods A total of 47,678 subjects were followed up from 2007 to 2016. WBC count was determined by automated hematology analyzer. T2D and obesity were defined in accordance with the criteria of the World Health Organization. Adjusted Cox proportional hazards regression models were used to assess relationships between obese status, WBC count and the incidence of T2D. Results During the approximately ∼9-year follow-up period (median duration of follow-up: 3.48y), 1463 subjects developed T2D. In the final multivariate model, the hazard ratios (95% confidence interval) of T2D for obese participants with elevated WBC count, non-obese participants with elevated WBC count, and non-obese participants with low WBC count, when compared to obese participants with low WBC count were: 1.22(1.03–1.44), 1.37(1.12–1.66) and 0.99(0.83–1.20), respectively. Conclusions This study demonstrated that WBC count can be used as an indicator to identify whether or not obesity leads to increased risk of T2D.