Peripheral monocyte count is an independent predictor of all-cause mortality in type 2 diabetes with macro-vascular complications

The relationship between monocyte count and mortality seemed to be varied in different diseases, and it remains unclear in type 2 diabetes (T2D). We conducted a prospective study to investigate whether monocyte count predict all-cause mortality in patients with T2D. In this prospective study, a total of 1073 patients with T2D were enrolled at baseline and 880 patients completed the follow up. The median follow-up time was 47 months. At baseline, clinical characteristics including height, weight, waist circumference, blood pressure were recorded. Biochemical parameters including counts of white blood cells (WBCC), neutrophil (NC) and monocyte (MC), lipid profiles, glycated hemoglobin (HbA1c), serum creatinine were measured. Charlson comorbidity index (CCI) was calculated based on age and comorbidities. Participants were stratified into low, median, and high tertiles according to the baseline MC. Regression models were used to analyze the associations of peripheral MC and the all-cause mortality. Compared to the survived subjects, the baseline MC was significantly higher in patients who deceased during the follow-up (0.45 ± 0.16 vs 0.37 ± 0.15 × 10(9)/L, P = .003). In the multivariate Cox hazard models, subjects in higher MC tertile showed higher risks of all-cause mortality (low tertile as the reference, hazard ratio [HR] 95%CI 2.65 [0.84,8.31] and 3.73 [1.14,12.24] for middle and high MC tertile, respectively) after adjusted for gender, body mass index, CCI, duration of T2D, history of hypertension and metabolic syndrome, drugs, levels of high-sensitivity C-reactive protein, systolic blood pressure, HbA1c, WBCC, and NC. In T2D patients with macro-vascular complications at baseline, 1-SD increment of MC resulted in 1.92-fold higher risk of all-cause mortality. However, the relationship disappeared in subjects without macro-vascular complications at baseline (1.13 [0.72, 1.78], P = .591). Peripheral monocyte count is an independent predictor of all-cause mortality in T2D, especially for subjects with macro-vascular complications.