Laser Doppler flowmetry in the assessment of skin microcirculatory disorders in patients with diabetic polyneuropathy. Part 2

Diabetic polyneuropathy is one of the most common consequences of diabetes mellitus and is associated with the long-term damaging effects of hyperglycemia on the peripheral nervous system. The methods most commonly used in clinical practice for diagnosis are related to the assessment of sensitivity and complaints of the patient. However, these approaches are subjective. A number of clinical trials in this area have failed due to a lack of effective criteria for dynamic assessment of the severity of neuropathy (surrogate endpoints). Despite the active development of methods for diagnosing nerve fiber lesions, such as corneal confocal microscopy, skin biopsy and others, there remains a need for an objective and quantitative technique. Nerve damage and decreased microvascular reactivity are known to have a close pathogenetic relationship. The use of skin microcirculation measurement by laser Doppler flowmetry is considered in this area. This review describes functional tests for measuring skin microvascular reactivity, which are proposed for the diagnosis of nerve fiber lesions. The results obtained by different research collectives are variable, but most authors find reduced responses to heat exposure, orthostatic test, and acetylcholine and sodium nitroprusside iontophoresis in patients with diabetic polyneuropathy. Laser Doppler flowmetry is a prospective method for application in this field, so there is a need for further research, development of standardized analysis algorithms and investigation of combinations of different methods of hemodynamic assessment.