Haptoglobin polymorphism and diabetic nephropathy in Brazilian diabetic patients

Abstract

Diabetic nephropathy (DN) has an important impact on morbidity/mortality in diabetic patients. Genetic factors are probably involved in the development of this microvascular complication. Haptoglobin (Hp) is a genetically polymorphic glycoprotein that forms stable complexes with plasma-free hemoglobin (Hb) providing protection against heme-induced oxidative stress and kidney damage. The aim of the present study was to investigate the existence of association between the Hp genotypes and the presence of DN in Brazilian diabetic patients. The Hp genotypes of 265 patients, 95 type 1 diabetes mellitus (DM1) sufferers with at least 10 years of disease and 170 type 2 diabetes mellitus (DM2) sufferers with at least 5 years of disease were determined by allele-specific PCR; both groups included patients with and without DN. Hp allele and genotype frequencies were compared among the patient groups and between the patient groups and a control group of 142 healthy individuals. No association between Hp genotypes and DN could be demonstrated. Additionally, urinary albumin excretion values and the presence or absence of systemic arterial hypertension (SAH) were compared among the patient groups. Again, no significant correlations were found. The Hp polymorphism could not be associated with DN in the population studied here.

Haptoglobin Polymorphism as a Risk Factor for Chronic Kidney Disease: A Case-Control Study

“…Studies of Israeli, Irish and Egyptian subjects [7,9,10] indicated that the Hp2-2 genotype may confer susceptibility to diabetic nephropathy. However, there was no association between Hp genotype and diabetic nephropathy in studies of Japanese, North American and Brazilian subjects [11,12,13]. These contradictory results may be due to differences in the distribution of Hp alleles in different populations, linkage disequilibrium near the Hp locus [11] or study design and sample size, as well as baseline characteristics of enrolled patients.…”

“…Previous studies of Hp have investigated its impact on diabetic nephropathy [7,9,10,11,12,13], one of the common precursors to CKD; however, the relationship varies among different ethnic populations. Studies of Israeli, Irish and Egyptian subjects [7,9,10] indicated that the Hp2-2 genotype may confer susceptibility to diabetic nephropathy.…”

“…It has been reported that the Hp2-2 genotype is linked to susceptibility to diabetic vascular complications and certain neoplasms [5,6,7,8]. However, the association between Hp polymorphism and diabetic nephropathy remains conflicting among different ethnic populations [7,9,10,11,12,13]. …”

Genótipos de haptoglobina e hipertensão refratária em pacientes com diabete melito tipo 2

“…Obesity was defined as body mass index (BMI) 30 kg/m 2 28 . Diabetic retinopathy (DR) and diabetic nephropathy (DN) had been previously investigated in these patients 21,29 . Serum creatinine was measured by a modified Jaffé method, and the reference values for males and females were ≤1.20 mg/dL and ≤0.90 mg/dL, respectively 30 .…”

The Serum Protein Fractions in Thymoquinone Treated Rats

“…Ceruloplasmin that was synthesized primarily in the liver was accepted as an acute phase protein that shows a moderate response to conditions such as inflammation and tissue damage; as well as an antioxidant (Güngör et al, 2004). Haptoglobulin (Hp) induction provides protection against oxidative stress and kidney damage, creates a stable complex with free plasma hemoglobin, and is a genetic polyphormic glycoprotein (Wobeto et al, 2009;Blum et al, 2010). Plasma haptoglobin increases in acute infections, trauma, and nephrotic syndrome.…”