Background
Diabetes mellitus type 2 (T2DM) is a metabolic disorder that is characterized by
high blood glucose in the context of insulin resistance and relative insulin
deficiency. Vaspin (visceral adipose tissue-derived serpin) is a member of the
broadly distributed serpin (a protein superfamily of serine protease inhibitors of
∼500 genes) and is identical to serpin A12. The upregulation of vaspin can
improve insulin resistance. Thus, identification of the protease inhibited by vaspin
may lead to the development of novel strategies in the treatment of diabetes and
insulin resistance. In patients with chronic kidney disease, the levels of vaspin
appear to increase mostly because of reduced renal metabolism of vaspin. Tumor
necrosis factor-α (TNF-α) is a cytokine involved in systemic inflammation. Its
increased production has been observed in adipose tissue, and it has been
implicated as a causative factor in obesity-associated insulin resistance, the
pathogenesis of T2DM, and the development of diabetic nephropathy (DN)
through several mechanisms. The association of T2DM patients (with and
without impaired renal function) with serum vaspin and TNF-α levels is not
clearly understood. This study aimed to evaluate the levels of vaspin and
tumor necrosis factor (TNF) in T2DM patients and compare their levels with
impairment in renal function in T2DM to determine whether circulating vaspin and
TNF could be a biomarker of DN.
Patients and methods
This case–control observational prospective study was conducted on 73 patients
with T2DM classified into two groups; group I included 20 T2DM patients with
reduced renal function, and group II included 53 T2DM patients with normal renal
function. The studied groups were recruited from the Diabetic Unit Outpatient Clinic,
Department of Internal Medicine, Sohag University Hospitals, from December 2014
to December 2015. T2DM was diagnosed according to the American Diabetes
Association Criteria. Totally, 12 age and sex matched apparently healthy
individuals who served as the control group (group III) were enrolled in the
study. The study was approved by the ethical committee of Faculty of Medicine,
Sohag University, and written informed consent was obtained from each
participant. All participants were subjected to thorough history taking, full clinical
examination, and anthropometric measurements, including weight, height, and
BMI. In addition, peripheral hemogram, random blood glucose evaluation, HbA1c
determination, liver function tests, kidney function tests, lipid profile, and serum
vaspin and serum TNF-α evaluation were carried out.
Results
In essence, significant correlations of vaspin and TNF were found with age of T2DM
patients, hypertension, BMI, and lipid profile, but not with HbA1c. Moreover, higher
levels of vaspin and TNF-α were significantly correlated with the degree of impaired
renal function in T2DM patients. Notably, multivariate linear regression shows that
BMI and age are negatively correlated with vaspin but not with TNF-α levels in
T2DM patient with more impaired renal function.
Conclusion
Strict monitoring of T2DM can reduce the morbidity and mortality rate and will also
improve the quality of life of diabetic patients. The association of renal insufficiency
due to diabetes mellitus with serum vaspin and TNF-α levels is not clearly
understood. However, vaspin may be beneficial as a positive biomarker for
prognostic marker for DN. Large studies are required to establish vaspin and TNF-α
efficacy and safety in T2DM
T2DM patients with impaired renal function and can be considered as a new