Association between HbA1c and peripheral neuropathy in a 10‐year follow‐up study of people with normal glucose tolerance, impaired glucose tolerance and Type 2 diabetes. Issue 12 (18th October 2017)

• Record Type: Journal Article
• Authors: Peterson, M.; Pingel, R.; Lagali, N.; Dahlin, L. B.; Rolandsson, O.
• Is Part Of: Diabetic medicine. Volume 34:Issue 12(2017)
• Page Start: 1756
• Page End: 1764
• Publication Date: 2017-10-18
• Subjects: Diabetes -- Periodicals; 616.462
• DOI: 10.1111/dme.13514
• Languages: English
• ISSNs: 0742-3071

Abstract

Abstract: Aims: To explore the association between HbA1c and sural nerve function in a group of people with normal glucose tolerance, impaired glucose tolerance or Type 2 diabetes. Methods: We conducted a 10‐year follow‐up study in 87 out of an original 119 participants. At study commencement (2004), 64 men and 55 women (mean age 61.1 years) with normal glucose tolerance ( n =39), impaired glucose tolerance ( n =29), or Type 2 diabetes ( n =51) were enrolled. At the 2014 follow‐up (men, n =46, women, n =41; mean age 71.1 years), 36, nine and 42 participants in the normal glucose tolerance, impaired glucose tolerance and Type 2 diabetes categories, respectively, were re‐tested. Biometric data and blood samples were collected, with an electrophysiological examination performed on both occasions. Results: At follow‐up, we measured the amplitude of the sural nerve in 74 of the 87 participants. The mean amplitude had decreased from 10.9 μV (2004) to 7.0 μV (2014; P <0.001). A 1% increase in HbA1c was associated with a ~1% average decrease in the amplitude of the sural nerve, irrespective of group classification. Crude and adjusted estimates ranged from –0.84 (95% CI –1.32, –0.37) to –1.25 (95% CI –2.31, –0.18). Although the mean conduction velocity of those measured at both occasions ( n =73) decreased from 47.6 m/s to 45.8 m/s ( P =0.009), any association with HbA1c level was weak. Results were robust with regard to potential confounders and missing data. Conclusions: Our data suggest an association between sural nerve amplitude and HbA1c at all levels of HbA1c . Decreased amplitude was more pronounced than was diminished conduction velocity, supporting the notion that axonal degeneration is an earlier and more prominent effect of hyperglycaemia than demyelination. What's new?: This is the first 10‐year follow‐up of the association between HbA1c and peripheral neuropathy in people with normal glucose tolerance, prediabetes and Type 2 diabetes. The results suggest an association between sural nerve amplitude and HbA1c at all levels of HbA1c and not only in those with diabetes.