Subtle morpho-functional kidney changes in type-2 diabetes mellitus patients: A duplex ultrasound assessment

Abstract

Objectives: Diabetes mellitus (DM) is a common endocrine disease with serious effects on multiple organs including the kidneys. This study aimed to investigate the subtle effects of type 2 DM (T2DM) on the kidneys.

Methods: This was a prospective case-control study conducted in the Radiology Department of University of Science and Technology Hospital (USTH) campus, Sana'a, Republic of Yemen, from 1 January 2020 to 31 November 2020. The renal length (RL), renal width (RW), resistive index (RI), and pulsatility index (PI) were prospectively measured in patients with T2DM and healthy controls. The results were compared using the independent samples t-test. Comparisons were likewise performed between patients with controlled DM and patients with uncontrolled DM.

Results: A total of hundred individuals, 50 diabetic patients and 50 controls, were enrolled in this study. Their mean age was 54 ± 7.88 years (range: 40-75 years). The RL, RI, and PI of both kidneys were significantly higher in T2DM than in the control group. Moreover, the RL, RI, PI and creatinine were slightly higher in patients with uncontrolled than in those with controlled DM.

Conclusion: T2DM has significant accentuating effects on the RL, RI and PI associated with low effective renal plasma flow, even before acute kidney injury or chronic kidney disease diagnosis, which may be attenuated by careful regulation of DM. Ultrasound Doppler is a highly valuable imaging modality for evaluating the subtle effects of T2DM on kidney dimensions and blood flow. The RI can be implemented as a tool for the early diagnosis of kidney disease and contribute to slowing the disease progression and preventing renal failure.

Keywords: Doppler dynamic measurements; Pulsatility index; Renal length; Renal resistive index; Subtle kidney changes.

Fig.1

Selected gray-scale ultrasonography longitudinal sections of both kidneys in a 45-year-old female diabetic patient referred for follow up ultrasound imaging that show normal renal measurements (length and width) of a) left kidney, and b) right kidney.

Fig.2

Selected spectral Doppler ultrasound images of the same 50-year-old female diabetic patient referred for follow up ultrasound imaging show Doppler measurement of RI (a) automatically, and (b) manually that was slightly higher than normal.

Fig.3

Selected spectral Doppler ultrasound images show Doppler RI of a) normal 52-year-old female individual with normal low resistance waveforms with RI=0.52, and b) diabetic 55-year-old female patient with RI=0.70 that is higher than normal.

Fig.4

Boxplot shows significant increase of both a) left and b) right kidney length of DM patients than that of control group. Boxplot shows significant increase of renal re sistive index (RI) of both c) left and d) right kidney of DM patients than that of control group. Boxplot shows significant increase of pulsatility index (PI) of both e) left and f) right kidney of DM patients than that of control group.