Abstract: Objective To observe the effect of anti-tuberculosis drug isoniazid on nerve conduction velocity in patients with pulmonary tuberculosis complicated with diabetic peripheral neuropathy (DPN). 
Methods Patients admitted to our hospital were selected and grouped according to the case-control study. The patients were divided into simple initial treatment of non-drug-resistant pulmonary tuberculosis (TB) group (n=39), type 2 diabetic peripheral neuropathy (T2DPN) group (n=39), T2DPN combined with initial treatment of non-drug-resistant pulmonary tuberculosis (DPNTB) group (n=39). According to the specific conditions of patients, appropriate hypoglycemic regimens were given to patients, and the target blood glucose level was reached. All cases were newly diagnosed with secondary non-drug resistant pulmonary tuberculosis, and all received the first-line standardized intensive treatment regimen HRZE: Isoniazid (H) 0.3 g/time, once daily; Rifampicin (R) 0.45 g/time, once daily; Pyrazinamide (Z) 0.5 g/time, 3 times/day; Ethambutol (E) 0.75 g/time, once daily; They were all taken orally for 2 months. The sensory nerve conduction velocity of superficial peroneal nerve and sural nerve, and the motor nerve conduction velocity of deep peroneal nerve, superficial peroneal nerve, common peroneal nerve, tibial nerve and femoral nerve were compared among the three groups before and after treatment. 
Results After treatment, the sensory nerve conduction velocity of superficial peroneal nerve and sural nerve in the lower limbs of TB group and DPNTB group was significantly slower than that before treatment, and the sensory nerve conduction velocity of superficial peroneal nerve and sural nerve in DPNTB group was slower than that in TB group and DNP group, showing significant difference (P＜0.05). There was no significant change in motor nerve conduction velocity of deep peroneal nerve, superficial peroneal nerve, common peroneal nerve, tibial nerve and femoral nerve among the three groups before and after treatment (P＞0.05). 
Conclusion Isoniazid can cause sensory nerve conduction velocity to slow down in patients with pulmonary tuberculosis and DPN. especially in the lower limbs of pulmonary tuberculosis patients with DPN. Isoniazid had no significant effect on the motor nerves of the lower limbs. 

Key words: tuberculosis, pulmonary, diabetic neuropathies, neural conduction, isoniazid