Modifiable Variables Are Major Risk Factors for Posttransplant Diabetes Mellitus in a Time-Dependent Manner in Kidney Transplant: An Observational Cohort Study

Abstract

Modifiable and nonmodifiable risk factors for developing posttransplant diabetes mellitus (PTDM) have already been established in kidney transplant setting and impact adversely both patient and allograft survival. We analysed 450 recipients of living and deceased donor kidney transplants using current immunosuppressive regimen in the modern era and verified PTDM prevalence and risk factors over three-year posttransplant. Tacrolimus (85%), prednisone (100%), and mycophenolate (53%) were the main immunosuppressive regimen. Sixty-one recipients (13.5%) developed PTDM and remained in this condition throughout the study, whereas 74 (16.5%) recipients developed altered fasting glucose over time. Univariate analyses demonstrated that recipient age (46.2 ± 1.3vs. 40.7 ± 0.6 years old, OR 1.04; P = 0.001) and pretransplant hyperglycaemia and BMI ≥ 25 kg/m² (32.8% vs. 21.6%, OR 0.54; P = 0.032 and 57.4% vs. 27.7%, OR 3.5; P < 0.0001, respectively) were the pretransplant variables associated with PTDM. Posttransplant transient hyperglycaemia (86.8%. 18.5%, OR 0.03; P = 0.0001), acute rejection (P = 0.021), calcium channel blockers (P = 0.014), TG/HDL (triglyceride/high-density lipoprotein cholesterol) ratio ≥ 3.5 at 1 year (P = 0.01) and at 3 years (P = 0.0001), and tacrolimus trough levels at months 1, 3, and 6 were equally predictors of PTDM. In multivariate analyses, pretransplant hyperglycaemia (P = 0.035), pretransplant BMI ≥ 25 kg/m² (P = 0.0001), posttransplant transient hyperglycaemia (P = 0.0001), and TG/HDL ratio ≥ 3.5 at 3-year posttransplant (P = 0.003) were associated with PTDM diagnosis and maintenance over time. Early identification of risk factors associated with increased insulin resistance and decreased insulin secretion, such as pretransplant hyperglycaemia and overweight, posttransplant transient hyperglycaemia, tacrolimus trough levels, and TG/HDL ratio may be useful for risk stratification of patients to determine appropriate strategies to reduce PTDM.

Figure 1

Kaplan-Meier curve showing the incidence of PTDM over time.

Figure 2

Tacrolimus (FK) trough level over time in months (m) in the PTDM (+) and PTDM (-) groups.

Figure 3

(a) Weight analysis over time in months (m) in the PTDM (+) and PTDM (-) groups. (b) Weight gain throughout the follow-up in comparison to the first month posttransplant in the PTDM (+) and PTDM (-) groups. PTDM (+) and PTDM (-) groups were not different, although both groups exhibited weight gain over time.