Small nerve fibre damage and cardiac autonomic dysfunction in patients with hypertriglyceridaemia

Background & objectives Hypertriglyceridaemia (HTG) is an independent risk factor for small fibre neuropathy in patients with type 1, type 2 diabetes, and obesity. This study assessed for evidence of small nerve fibre damage and cardiac autonomic dysfunction in individuals with HTG, without diabetes. Methods Participants with HTG (n=60) and age and sex-matched controls (n=31) underwent assessment of the lipid profile, neuropathic symptoms and disability, corneal confocal microscopy (CCM) and cardiac autonomic nerve function tests. Results Triglyceride (TG) concentration was significantly higher [6.0 (3.6–8.7) vs 1.1 (0.7–1.4) mmol/L, p < 0.001], and HDL-C [0.9 (0.7–1.2) vs 1.5 (1.3–1.8) mmol/L, p < 0.001) was lower in the HTG group. The Neuropathy Symptom Profile score [2 (0–5) vs 0, p < 0.001], Neuropathy Disability Score [2 (0–3) vs 0, p < 0.001] and vibration perception threshold [8.9 (5.5–10.5) vs 3.0 (2.0–4.0) volts, p < 0.001] were higher, whilst corneal nerve fibre density (CNFD) [28.9 (5.9) vs 35.1 (7.2) no./mm 2 , p < 0.001], corneal nerve branch density (CNBD) [50.0 (30.4–66.5) vs 76.1 (56.2–112.5) no./mm 2 , p < 0.001], corneal nerve fibre length (CNFL) [19.8 (4.8) vs 26.0 (6.2) mm/mm 2 , p < 0.001], deep breathing heart rate variability (DB–HRV) [18 (13–20) vs 25 (20–30) beats/min, p < 0.001], E−I ratio [1.13 (1.09–1.20) vs 1.25 (1.18–1.31), p < 0.001], valsalva ratio [1.29 (1.18–1.49) vs. 1.47 (1.28–1.59), p = 0.01] and 30–15 ratio [1.24 (1.16–1.36) vs. 1.40 (1.27–1.49), p = 0.002] were lower in the HTG group compared to controls. Serum TG concentration correlated negatively with CCM parameters and cardiac autonomic function tests. Conclusion HTG, independent of diabetes, is associated with signs and symptoms of neuropathy, small nerve fibre damage and cardiac autonomic dysfunction.