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

Endocrinol Diabetes Nutr (Engl Ed). 2019 Feb;66(2):99-107. doi: 10.1016/j.endinu.2018.07.008. Epub 2018 Oct 24.
[Article in English, Spanish]

Abstract

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.

Keywords: Diabetes mellitus tipo 2; Haptoglobin; Haptoglobina; Inflamación; Inflammation; Obesidad; Obesity; Polimorfismos; Polymorphisms; Type 2 diabetes mellitus.

MeSH terms

  • Adult
  • Aged
  • Alleles
  • Biomarkers
  • Blood Glucose / analysis
  • C-Reactive Protein / analysis
  • Case-Control Studies
  • Comorbidity
  • Cross-Sectional Studies
  • Cytokines / blood
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / epidemiology
  • Female
  • Genotype
  • Glycated Hemoglobin / analysis
  • Haptoglobins / analysis
  • Haptoglobins / genetics*
  • Humans
  • Hypertension / blood*
  • Hypertension / epidemiology
  • Inflammation / blood*
  • Inflammation / epidemiology
  • Male
  • Middle Aged
  • Obesity / blood*
  • Obesity / epidemiology
  • Polymorphism, Genetic
  • Waist Circumference
  • Waist-Hip Ratio

Substances

  • Biomarkers
  • Blood Glucose
  • Cytokines
  • Glycated Hemoglobin A
  • HP protein, human
  • Haptoglobins
  • C-Reactive Protein