Haptoglobin polymorphism and association with complications in ghanaian type 2 diabetic patients

Haptoglobin Gene Polymorphism in Patients with Sickle Cell Anemia: Findings from a Nigerian Cohort Study

PURPOSE

To determine the various haptoglobin genotypes and their influence on the clinico-laboratory manifestations among young Nigerian sickle cell anemia (SCA) patients.

PATIENTS AND METHODS

A total of 101 SCA patients and 64 controls were studied. SCA was diagnosed by polymerase chain reaction (PCR). Haptoglobin genotype was determined by PCR followed by agarose gel electrophoresis. The patients' laboratory and clinical parameters were differentiated by haptoglobin genotypes.

RESULTS

The Hp1 and Hp2 alleles frequencies were 0.62 and 0.38 in the patients and 0.73 and 0.27 in the controls, respectively, and these did not differ significantly (p>0.05). The haptoglobin genotype distribution among the patients and controls were Hp1-1, 43 (42.6%); Hp2-1, 40 (39.6%); Hp2-2, 18 (17.8%) and Hp1-1, 35 (54.7%); Hp2-1, 24 (37.5%); Hp2-2, 5 (7.8%), respectively, with no difference between the two groups (P>0.05). No significant difference was found in the clinical events and laboratory parameters of the patients when partitioned according to the various haptoglobin genotypes (P> 0.05).

CONCLUSION

This study found that haptoglobin gene polymorphism does not have a significant influence on the clinico-laboratory manifestations among SCA patients.

Haptoglobin levels are influenced by Hp1-Hp2 polymorphism, obesity, inflammation, and hypertension in type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is an inflammatory condition associated to obesity and increased oxidative stress. Haptoglobin (Hp) is an acute phase reactant that scavenges extracorpuscular hemoglobin from circulation and prevents heme-iron oxidative damage.

OBJECTIVE

To assess the association between Hp levels and Hp1-Hp2 gene polymorphism and clinical and laboratory parameters in patients with T2DM.

METHODS

The study sample consisted of 102 T2DM patients and 62 controls. Hp plasma levels were measured using an ELISA assay, and Hp genotyping was performed using a specific two-step allelic polymerase chain reaction.

RESULTS

Hp levels were higher in T2DM patients as compared to controls (p=0.005). T2DM patients with high blood pressure had higher Hp levels than patients without this comorbidity (p=0.021). Obese T2DM patients had higher Hp levels as compared to obese controls (p=0.009) and to non-obese T2DM patients (p=0.003). The Hp1-Hp1 genotype was showed to be associated to T2DM according to additive (OR=3.038, 95% CI 1.127-8.192; p=0.036) and dominant model (OR=0.320, 95% CI 0.118-0.839; p=0.010), but Hp2 allele carriers contributed with higher Hp levels in T2DM as compared to controls. Waist circumference (p=0.002), BMI (p=0.001), and IL-6 (p=0.012), and hs-CRP (p=0.001) levels positively correlated with Hp levels in the T2DM group.

CONCLUSION

These results suggest that Hp levels are influenced by Hp1-Hp2 polymorphism, obesity, inflammatory status, and high blood pressure in T2DM.

The Association of Haptoglobin Gene Variants and Retinopathy in Type 2 Diabetic Patients: A Meta-Analysis

AIMS/INTRODUCTION

To collectively evaluate the association between haptoglobin (Hp) gene variants and diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (T2DM).

METHODS

A comprehensive literature review was performed for eligible studies. After inclusion and exclusion selection as well as quality assessment, those studies meeting quality standards were included. In this study, diabetic patients with retinopathy were selected as the case group and those ones without DR were treated as the control group. The recessive model, allele model, additive model, heterozygote model, and homozygote model were utilized to investigate the association of three Hp gene variants and DR. Subgroup analysis on different severity of DR including nonproliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR) was also conducted.

RESULTS

Six trials from different regions were finally included. A total of 1145 subjects containing 564 T2DM patients with retinopathy were included. The recessive model, allele model, additive model, and homozygote model results showed that Hp gene variants were not associated with DR, NPDR, and PDR. However, the heterozygote model indicated the association of Hp gene variants with DR.

CONCLUSIONS

No association was found between the Hp gene variants and PDR and NPDR. More studies are required to verify these findings.

Value of the combined examination of Cys-C and HbA1c for diagnosis of early renal injury in pediatric diabetes

The objective of the present study was to evaluate the combined application of measuring cystatin C (Cys-C) and hemoglobin A1c (HbA1c) levels for early renal injury in pediatric patients with type 2 diabetes. A total of 130 children with type 2 diabetes admitted to our hospital from May 2013 to July 2015 were selected. Patients were divided according to whether there was complication of renal injury. In group A (n=65), the patients had renal injury and in group B (n=65), the patients did not have renal injury. The levels of Cys-C and HbA1c in the two groups were examined. The results showed that the levels of Cys-C and HbA1c of patients in group A were significantly higher than those in group B (P<0.05), and the positive rate of the combined examination of Cys-C and HbA1c in group A was 92.3%, and was higher than that of the individual examinations of either Cys-C or HbA1c (P<0.05). The Spearman's correlation coefficient analysis was applied to group B and showed that Cys-C was positively correlated with HbA1c (r=0.842, P<0.05). From analysis of the receiver operating characteristic curves, the combined examination of Cys-C and HbA1c surpassed the individual examinations of Cys-C or HbA1c in sensitivity and specificity (P<0.05). In conclusion, the positive detection rate of early renal injury was significantly increased by the combined examination of Cys-C and HbA1c in pediatric patients with type 2 diabetes, which is beneficial for early identification and diagnosis of this diseases and is worthy of clinical application.

Haptoglobin polymorphism in individuals with type 2 diabetic microangiopathy

BACKGROUND

Haptoglobin is an acute phase protein with antioxidant and immunomodulatory properties. Gene polymorphism may be a risk factor for diabetic vascular disease in Iranian population.

AIMS

The study investigates the existence or not of an association between haptoglobin genotypes and prevalence of diabetic microangiopathy in individuals with type 2 diabetic microangiopathy.

MATERIALS AND METHODS

We included 206 type 2 diabetic patients (<5 years duration) categorized into two groups according to the presence or absence of diabetic microvascular complications. The cases of interest were diabetic neuropathy, retinopathy, and nephropathy identified during clinical and or laboratory examination. In addition, 114 age- and sex-matched individuals were selected to serve as a control group. Haptoglobin genotyping was done using an amplification gel electrophoresis.

RESULTS

The frequency of haptoglobin phenotype 2-1 in diabetic patients was 70/206 (33.9%) as compared with 54/114 (47.3%) in nondiabetics (P = 0.01). However, the frequency of haptoglobin phenotype 2-2 was greater in diabetics (126/114, 61.1%) than in those without diabetes (56/114, 49.1%; P = 0.02). Patients with diabetic microangiopathy; however, did not differ significantly between haptoglobin phenotype groups.

CONCLUSIONS

Haptoglobin phenotype 2-2 is considered to be a major susceptibility gene for type 2 diabetic patients. Moreover, haptoglobin phenotype 2-1may be good prognostic factors for the development of diabetes mellitus.