The Future of Assessing Renal Function? - A Case Report Detailing Measurement of Renal Function in a NOF# Patient With LGMD

Introduction

LGMD populations have an increased fracture risk. LGMD populations also have a lower muscle mass and therefore abnormal serum creatinine levels, making it more difficult to assess renal function via conventional means, potentially leading to delays in care. Serum Cystatin-C, produced by all nucleated cells, is an alternative way to assess renal function in these patients.
Clinical Case

A 46-year-old woman with LGMD presented to hospital after a sudden fall from standing to the floor. X-ray imaging confirmed an extracapsular left NOF# and she was operated on the next day with a left Dynamic Hip Screw inserted. Her renal function was measured via serum creatinine as part of routine blood tests but was noted to be unmeasurable, making deciding the appropriate medical therapy for treating bone density more difficult. Serum Cystatin-C was tested to measure her renal function showing an eGFR Cystatin-C of 113 ml/min/1.73m2, however, this result was only received after discharge, delaying decisions for bone protection treatment.

Conclusion

This case illustrates both the increased fracture risks in and the unique challenges LGMD and other patients with abnormal muscle mass, such as geriatric and neuromuscular disorder populations face when accurately assessing renal function and appropriate medical therapy choices thereafter. Cystatin-C is produced by all nucleated cells, not just as a breakdown product of skeletal muscle cells, potentially making it a more accurate marker of renal function. An increased awareness, and use of, Cystatin-C could provide more appropriate and faster treatment choices for patients with abnormal serum creatinine, reducing delays in treatment.