There is emerging evidence supporting a role of inflammation in the development and progression of diabetic sensorimotor polyneuropathy (DSPN) in patients with type 2 diabetes. We aimed to characterize inflammatory signatures associated with DSPN and/or type 2 diabetes using a multimarker approach. We measured 92 serum biomarkers including pro- and anti-inflammatory cytokines, chemokines, and growth factors (GF) using the Proseek Multiplex INF I assay (OLINK Proteomics) in 304 individuals with type 2 diabetes and polyneuropathy, defined by the Toronto Consensus Criteria (2011), from the PROPANE study (DSPN) as well as 158 individuals with type 2 diabetes without DSPN (T2D) and 354 individuals with normal glucose tolerance and without DSPN (CON) from the KORA F4 study (DSPN/T2D/CON [mean±SD]: age: 68±9/71±6/69±5 years; male: 76/59/41%; BMI: 30.8±5.3/30.8±4.4/26.9±3.7 kg/m²; diabetes duration: 13.5±9.6/7.6±5.8/- years; HbA1c: 7.4±1.3/6.6+1.0/5.5+0.3%). After adjustment for multiple testing and sex, age, BMI, and smoking, a biphasic pattern of serum levels (normalized protein expression values) with an increase in T2D and decrease in DSPN was observed for four GFs (e.g., transforming GF (TGF)-α: 4.51±0.51 vs. 4.63±0.56 vs. 3.91±0.51; vascular endothelial GF (VEGF): 10.9±0.5 vs. 11.0±0.5 vs. 10.8±0.6), two chemokines (e.g., C-C motif ligand 4 (CCL4): 8.18±0.57 vs. 8.4±0.6 vs. 7.93±0.68) and one cytokine (oncostatin M: 4.83±0.62 vs. 5.06±0.63 vs. 4.35±0.75). Compared to T2D, the levels of another 12 biomarkers were lower in DSPN (e.g., tumor necrosis factor (TNFSF)-14: 5.65±0.55 vs. 4.90±0.77; matrix metalloproteinase (MMP)-1: 14.4±0.7 vs. 14.1±0.9), while five were higher (e.g., CCL20: 5.2±1.1 vs. 5.79±1.23) (all P<0.00024).

In conclusion, deficits in growth factors promoting nerve regeneration/angiogenesis and a complex cross-talk between innate and adaptive immunity may contribute to the development of DSPN in type 2 diabetes.

Disclosure

G.J. Bönhof: None. A. Strom: None. W. Rathmann: Advisory Panel; Self; AstraZeneca. Research Support; Self; Novo Nordisk A/S. M. Heier: None. C. Meisinger: None. A. Peters: None. M. Roden: Speaker's Bureau; Self; Boehringer Ingelheim GmbH. Research Support; Self; Boehringer Ingelheim GmbH. Consultant; Self; Poxel SA. Research Support; Self; Danone Nutricia Early Life Nutrition, GlaxoSmithKline plc., Nutricia Advanced Medical Nutrition, Sanofi. B. Thorand: None. C. Herder: Other Relationship; Self; Sanofi, Eli Lilly and Company. D. Ziegler: None.

© 2018 by the American Diabetes Association.
2018
Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at http://www.diabetesjournals.org/content/license.