Corneal confocal microscopy identifies small nerve fibre damage in patients with hypertriglyceridemia

Abstract

Background: Hypertriglyceridemia has been identified as a risk factor for diabetic neuropathy.

Objective: Patients with hypertriglyceridemia underwent assessment of neuropathy and corneal confocal microscopy.

Methods: 24 patients with severe hypertriglyceridemia defined as a triglyceride level more than 5.5 mmol/L (485 mg/dL) with no history of diabetes and 19 age-matched controls underwent assessment of HbA1c, blood pressure, fasting lipid profile, neuropathy disability score (NDS) and corneal confocal microscopy (CCM).

Results: Patients with hypertriglyceridemia had a significantly higher NDS (P<0.001) and lower CNFD (no./mm²) (27.1 [25.0-29.9] Vs 35.9 [31.2-40.6], p<0.001), CNBD (no./mm²) (55.4±22.3 Vs 91.6±30.8, p<0.001), CNFL (mm/mm²) (19.2±4.3 Vs 26.7±4.4, p<0.001) and IWL (mm/mm²) (24.3±6.9 Vs 36.6±10.0, p<0.001) compared to control subjects. In subjects with hypertriglyceridemia serum triglyceride levels correlated with CNFD (rho= -0.473, p=0.002), CNBD (rho= -0.341, p=0.043), CNFL (rho= -0.446, p=0.006) and IWL (rho= -0.408, p=0.034), no correlation was found between triglycerides and CCM parameters in subjects without hypertriglyceridemia. Subjects with metabolic syndrome had a lower CNFD (32.3 [29.2-37.5] Vs 27.1 [20.8-30.2] no./mm², p=0.003), CNBD (20.1±6.0 Vs 23.9±5.3 no./mm², p=0.036), CNFL (57.7±26.9 Vs 79.2±32.6 mm/mm², p=0.037) and IWL (25.4±7.1 Vs 32.9±11.2 mm/mm², p=0.036) compared to subjects without metabolic syndrome.

Conclusion: Hypertriglyceridemia and metabolic syndrome are associated with small nerve fibre damage and clinical neuropathy. Elevated serum triglycerides may be a potential therapeutic target for the treatment of peripheral neuropathy.

Keywords: Corneal confocal microscopy; Metabolic Syndrome; Neuropathy; Small fibre neuropathy; Triglycerides.