Background Calpain-10(CAPN10)has been identified as a susceptibility gene in type 2 diabetes mellitus(T2DM)andinsulin resistance.The present study aimed to identify the effects of genetic variations in the CAPN10 gene on thedevelopment of type 2 diabetes and hypertension in northern Han Chinese population.Methods We performed a case-control study and genotyped single nucleotide polymorphism(SNP)-44,-43,-19 and-63 of CAPN10 gene in 1046 subjects from the northern China,including 493 patients with T2DM and hypertension and553 age- and gender-matched normal healthy controls.Results Univariate analysis showed that the four polymorphisms were not independently associated with T2DM andhypertension.However,the frequency distributions of SNP-44 allele C(allele 2)(17.89% vs 9.80%,P=0.0016)andgenotype CC(22)(4.21% vs 1.01%,P=0.0059)in obese patients(body mass index≥30 kg/m~2)were different from thosein non-obese patients.Logistic regression analyses revealed that carriers of the 1112/1221 diplotype had a significantlylower odds ratio for diabetes and hypertension(OR=0.399,95% CI,0.196-0.814,P=0.0115).The 1112/1121 diplotypeassociated with significantly increased risk of type 2 diabetes in Mexican-American was not associated with theincreased risk in Chinese.Conclusion These results suggested that CAPN10 gene variations might play roles in the risk of diabetes andhypertension in northern Han Chinese population. Background Calpain-10 (CAPN10) has been identified as a susceptibility gene in type 2 diabetes mellitus (T2DM) and insulin resistance. The present study aimed to identify the effects of genetic variations in the CAPN10 gene on the development of type 2 diabetes and hypertension in northern Han Chinese population. Methods We performed a case-control study and genotyped single nucleotide polymorphism (SNP) -44, -43, -19 and-63 of CAPN10 gene in 1046 subjects from the northern China, including 493 patients with T2DM and hypertension and 553 age- and gender-matched normal healthy controls. Results of univariate analysis showed that the four polymorphisms were not independently associated with T2DM and hypertensive. Despite, the frequency distributions of SNP-44 allele C (allele 2) (17.89% vs 9.80%, P = 0.0016) and the genotype CC (22) (4.21% vs 1.01%, P = 0.0059) in obese patients (body mass index≥30 kg / m ~ 2) were different from those in nonin- obese patients. Logistic regression analyzes revealed that carriers of the 1112/1221 dipl The pattern had a significantly lower odds ratio for diabetes and hypertension (OR = 0.399, 95% CI, 0.196-0.814, P = 0.0115). The 1112/1121 diplotypeassociated with significantly increased risk of type 2 diabetes in Mexican-American was not associated with the created risk in Chinese.Conclusion These results suggested that CAPN10 gene variations might play roles in the risk of diabetes and hypertensive in northern Han Chinese population.