The relationship between circulating visfatin/nicotinamide phosphoribosyltransferase, obesity, inflammation and lipids profile in elderly population, determined by structural equation modeling

Abstract

Background: The available literature suggests that circulating visfatin/Nicotinamide Phosphoribosyltransferase (NAMPT) level variability in humans is related to obesity, insulin resistance, inflammation, and lipid profile. The aim of the study was to assess the relationship between circulating visfatin/NAMPT, obesity, insulin resistance, inflammation, and lipid profile in a large population-based, elderly cohort, applying structural equation modeling.

Materials and methods: The analysis included 2983 elderly participants of the PolSenior study with assessed total blood count, fasting concentrations of lipids, glucose, insulin, hs-CRP, interleukin-6, and visfatin/NAMPT (by ELISA), and calculated HOMA-IR.

Results: The circulating visfatin/NAMPT levels were higher in obese compared to normal weight subjects, in those with hs-CRP above 3 mg/L, with low serum HDL cholesterol, and in insulin resistant subjects. Based on results of the exploratory factor analysis, a baseline model of mutual relationship between four latent and measured variables was created and a final model was developed by maintaining only two significant categories. The important variables for ‘latent inflammation’ proved to be hs-CRP and IL-6 serum levels. In the case of ‘nutritional status’, important variables were BMI, waist circumference, and to a lesser extent insulin resistance. Additionally, the residual correlation between those two constructs was also statistically significant.

Conclusion: The structural equation modeling provided support for the existence of a link between nutritional status, inflammation and circulating visfatin/NAMPT level. This indicates that circulating visfatin/NAMPT can be considered as a novel surrogate marker of systemic inflammation associated with fat depot, especially visceral, in the elderly population.

Keywords:

• Elderly
• inflammation
• obesity
• visfatin/nicotinamide phosphoribosyltransferase

Disclosure statement

The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.

Funding

The PolSenior study was a publicly-funded project, [No. PBZ-MEIN-9/2/2006], Ministry of Science and Higher Education. Visfatin assessments were covered by grants from the Medical University of Silesia [KNW-1-050/P/2/0, KNW-092/K/3/0] and a grant from National Centre of Science [No DEC 2012/07/B/NZ5/02339].