Relationship of obesity indices with clinical severity and nerve conduction studies in females presenting with median nerve compression neuropathy at the wrist.

ABSTRACT

Background: Carpal tunnel syndrome (CTS) is considered to be one of the most common peripheral nerve disorders with female preponderance which significantly reduces work efficacy and needs further research on its preventable factors, especially obesity. We studied the effects of obesity indices on Phalen's test duration and median nerve conduction study (NCS) parameters in patients presenting with CTS. Methods: We examined 229 female patients presenting with clinical features of CTS. Clinical examinations including Phalen's test, median NCSs, and body composition were evaluated. Obesity indices and electrophysiological parameters were compared. Results: There were significant associations of both body mass index (BMI) degrees and body fat percent (BF%) with clinical and NCS parameters with a linear relationship. BF% and BMI were strongly negatively correlated with Phalen's test duration (BF%; r = -0.334, BMI; r = -0.270 P = 0.001). On the other hand, BF% and BMI were positively correlated with median distal latency (BF%; r = 0.338, BMI; r = 0.372, P value = 0.001), M-latency (BF%; r = 0.264, BMI; r = 0.285, P = 0.001), median motor conduction velocity (MMCV) (BF%; r = 0.119, P = 0.072, BMI; r = 0.173, P = 0.009), median sensory conduction velocity (MSCV) (BF%; r = -0.195, P = 0.003, BMI; r = 0.327, P = 0.001), and sensory nerve action potential (SNAP amplitude) (BF%; r = -.239, BMI; r = -0.350, P = 0.001). Conclusions: Nerve conduction parameters are significantly affected by obesity degree defined by BMI and BF%. Therefore, combining BMI and BF% assessments gives more clinical information regarding CTS severity and management. The true predictive value of these indices needs to be elucidated further.