Abstract 554: Vitamin D in Chronic Kidney Disease is Not Associated with Insulin Resistance

Abstract

INTRODUCTION: Vitamin D deficiency is reported to be associated with Insulin Resistance (IR) in general population. Although the impaired homeostasis of vitamin D and IR are common conditions in chronic kidney disease (CKD), the underlying mechanisms of IR remain unclear and it is not known if vitamin D status is associated with IR in nondialyzed CKD patients. OBJECTIVE: To investigate if serum levels of 25 hidroxivitamin D [25(OH)D] are associated with IR in nondialyzed CKD patients. Methods: Cross-sectional study conducted in nondialyzed CKD outpatients under regular treatment, clinically stable, age≥18 years, estimated glomerular filtration rate (CKD-EPI) (eGFR)≤ 60 ml/min., not using vitamin D, corticosteroids and immunosuppressive drugs and without malignant diseases. Body adiposity: body mass index (BMI); total body adiposity by dual-energy X-ray absorptiometry-DXA; waist-to-height ratio (WheiR). Vitamin D was determined by analysing 25(OH)D by Passing-Bablok method; insulin by radioimmunoassay; Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). Results: Patients included in this study were 158 (men:55%/n=87) nondialyzed CKD patients presenting age=66±13years; eGFR=29±13ml/min.; BMI=26±5kg/m2 (54%/n=86 overweight/obese: BMI>25). Total body adiposity-DXA=34±9% and central body adiposity-WheiR=0.6±0.08. Patients were grouped according to HOMA-IR as: Group 1 (HOMA-IR<2.7; n=110) and Group 2 (HOMA-IR ≥2.7; n=48). VitD levels (ng/ml) were not different (p≥0.05) between Group 1 (27±9) and Group 2 (28±9). Participants were also stratified as: VitD-deficient (<20ng/ml; 25%/n=40) and VitD-no-deficient (≥20 ng/ml; 75%/n=118). VitD-deficient patients compared to VitD-no-deficient presented, respectively, similar values (p≥0.05) of HOMA-IR (median; interquartil interval: 1.7; 1-3 vs. 1.6; 1-3.4), insulin (7; 5-12 vs. 6; 5-13 μU/mL); glucose (105±28 vs. 109±62 mg/dl), glycosylated hemoglobin (GHb=6±1 vs. 6±2 %). No correlation (adjusted for confounders) was observed between VitD with HOMA-IR (r=0.01,p=0.87), insulin (r=0.02,p=0.8), glucose (r=-0.05,p=0.5) and GHb (r=-0.1,p=0.6). Conclusion: The present study suggests that serum levels of 25(OH)D are not associated with IR in nondialyzed CKD patients.