title: Small fibre dysfunction, microvascular complications and glycaemic control in type 1 diabetes: a case-control study.
abstract: OBJECTIVE
  The aim of this study was to determine the influence of microvascular disease on C-fibre function in patients with type 1 diabetes of moderate duration.
  
  
  METHODS
  The axon-reflex flare area induced on the dorsum of the foot by local skin heating to 47 °C was measured with a laser Doppler imager (LDI) in sex-, age- and height-matched groups with type 1 diabetes, with and without microvascular disease (MV+ and MV-, respectively) and in healthy controls (HC). Each group consisted of 24 individuals and all were free from clinical neuropathy (neuropathy disability score <3 and Toronto clinical neuropathy score <5).
  
  
  RESULTS
  LDI flare (LDIflare) was reduced in MV+ compared with HC (5.1 ± 1.8 vs 10.0 ± 3.1 cm², p < 0.0001) and MV- groups (9.9 ± 2.9 cm², p < 0.0001). MV- and HC groups did not differ. There was no difference in diabetes duration between MV- and MV+ groups (17.5 ± 5.7 and 20.1 ± 5.2 years, p = 0.21) nor current HbA(1c) (MV- 8.0 ± 1.2% [64 ± 10 mmol/mol]; MV+ 8.0 ± 0.9% [64 ± 9 mmol/mol], p = 0.53); neither variable correlated with flare size. In contrast, duration-averaged HbA(1c) was higher in the MV+ group (8.6 ± 0.9% [70 ± 9 mmol/mol] vs 7.6 ± 0.6% [60 ± 7 mmol/mol], p < 0.001) and correlated with LDIflare size (r = -0.50, p < 0.001). Triacylglycerols were higher in MV+ compared with MV- (1.23 ± 0.121 vs 0.93 ± 0.7 mmol/l, p = 0.04), but other metabolic variables did not differ between the groups.
  
  
  CONCLUSIONS
  We have shown that glycaemic burden and the presence of microvascular complications are associated with small fibre dysfunction in type 1 diabetes.
authors.affiliation: The Diabetes Research Centre, Ipswich Hospital NHS Trust, Heath Road, Ipswich, Suffolk IP4 5PD, UK.
authors.forename: P R J
authors.initials: PR
authors.lastname: Vas
authors.forename: A Q
authors.initials: AQ
authors.lastname: Green
authors.forename: G
authors.initials: G
authors.lastname: Rayman
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000150:complications*; D003925:Diabetic Angiopathies / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D042241:Early Diagnosis; D005260:Female; D005528:Foot; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D006943:Hyperglycemia / Q000517:prevention & control*; D015228:Hypertriglyceridemia / Q000150:complications; D008297:Male; D055806:Microvessels / Q000503:physiopathology*; D008875:Middle Aged; D009412:Nerve Fibers / Q000000981:diagnostic imaging / Q000473:pathology*; D010525:Peripheral Nerves / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012720:Severity of Illness Index; D012867:Skin / Q000294:innervation; D014463:Ultrasonography
chemical_list: D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human