Heat-shock protein 70 gene polymorphism is associated with the severity of diabetic foot ulcer and the outcome of surgical treatment

Abstract

Background: Foot ulcer is a significant cause of morbidity in diabetics. Genetic make-up can determine inflammatory and healing responses. This study examined the hypothesis that specific polymorphisms of the heat-shock protein 70 gene could predispose to the severity of diabetic foot ulceration. Methods: Some 106 consecutive diabetic patients (101 evaluable) with foot ulceration admitted to a tertiary care hospital were managed according to a standard protocol. DNA was extracted from venous blood and examined by polymerase chain reaction-restriction fragment length analysis for two specific polymorphisms: G1538A in the HSPA1B and C2437T in the HSPA1L gene. Results: HSPA1B genotyping showed that 70 patients were AG and 30 GG (one not amplified). The AG genotype was significantly associated with the severity of foot ulceration (Wagner grade) (P = 0.008, X² test), need for amputation (relative risk 2.02, 95 per cent confidence interval 1.02 to 4.01; P = 0.025) and median length of hospital stay (8 versus 5 days for GG; P = 0.043). HSPA1L genotypes (78 TT, 22 CT, one CC) did not show any significant association with these parameters. Conclusion: The HSPA1B genotype, was associated with the severity of diabetic foot ulceration, need for amputation and duration of hospitalization in these patients.