Perirenal fat thickness and perirenal-to-subcutaneous fat ratio assessed by multislice CT are independently associated with type 2 diabetes mellitus: A retrospective cross-sectional study

Figures

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  Figure 1.. Schematic diagram of PRFT measurement. (A) Axial CT image at the level of the right renal vein, showing measurements of R1 (lateral) and R2 (posterior). (B) Axial CT image at the level of the left renal vein, showing measurements of L1 (lateral) and L2 (posterior). CT = computed tomography, PRFT = perirenal fat thickness.

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  Figure 2.. Schematic diagram of SAFT measurement at the umbilical level. The subcutaneous fat layer thickness was measured vertically on axial CT images at the umbilical level, and the mean value of bilateral measurements was calculated as SAFT. CT = computed tomography, SAFT = subcutaneous abdominal fat thickness.

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  Figure 3.. Comparison of general data and CT measurement indicators between the healthy control group (n = 90) and T2DM group (n = 85). (A) Age; (B) sex distribution; (C) BMI; (D) right mean PRFT; (E) left mean PRFT; (F) bilateral mean PRFT; (G) mean SAFT at the umbilical level; (H) PRFT/SAFT ratio. Box plots show median (P25–P75), and bar charts show mean ± standard deviation. Statistical test values are shown for each comparison. BMI = body mass index, CT = computed tomography, PRFT = perirenal fat thickness, PRFT/SAFT ratio = perirenal-to-subcutaneous fat ratio, SAFT = subcutaneous abdominal fat thickness, T2DM = type 2 diabetes mellitus.

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  Figure 4.. ROC curves of perirenal fat parameters for distinguishing T2DM patients from healthy controls. The PRFT/SAFT ratio showed optimal discriminative efficacy, with an AUC of 0.824 (95% CI = 0.762–0.886), an optimal cutoff value of 0.89, a sensitivity of 81.2%, and a specificity of 73.3%. AUC = area under the curve, CI = confidence interval, PRFT/SAFT ratio = perirenal-to-subcutaneous fat ratio, ROC = receiver operating characteristic, T2DM = type 2 diabetes mellitus.

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  Figure 5.. Logistic regression analysis results (model 1). (A) Forest plot showing OR values and 95% CI of each variable; (B) bar chart of regression coefficient B values. Bilateral mean PRFT was independently associated with T2DM status (P < .001); age, sex, BMI, and SAFT showed no statistical significance (ns). Model 2 (with PRFT/SAFT ratio instead of PRFT and SAFT) confirmed that the PRFT/SAFT ratio was independently associated with T2DM status (OR = 4.327, 95% CI = 2.156–8.684, P < .001). BMI = body mass index, CI = confidence interval, OR = odds ratio, PRFT = perirenal fat thickness, PRFT/SAFT ratio = perirenal-to-subcutaneous fat ratio, SAFT = subcutaneous abdominal fat thickness, T2DM = type 2 diabetes mellitus.