Type 2 diabetes (T2D) mellitus has become the epidemic of the new millennium, with an estimated 382 million people affected worldwide as of 2013, and statistics projected towards 592 million by the year 2035. With the development of diabetes, complications have risen, with diabetic neuropathy becoming one of the most prevalent, affecting between 10–90% of those with the disease. Diabetic peripheral neuropathy (DPN) is difficult to detect in early stages of pathology, yet devastating once significant damage has taken place. Cardiac autonomic neuropathy (CAN), which is often silent, is associated with autonomic nervous system (ANS) dysfunction and increased risk for sudden death. Therefore, the purposes of this dissertation were early detection, assessment of quality of life (QOL) and disease intervention. Study I explored the effectiveness of the 128-Hz tuning fork, the 1-g and 10-g monofilaments, and the QOL-DN as tools for the early detection of DPN in overweight, obese and inactive (OOI), prediabetes (PD), and type 2 diabetes (T2D) individuals. Study II compared three QOL assessments: the QOL-DN, the PN-QOL-97 and the NeuroQOL-28, in OOI, PD and T2D individuals. Study III involved the execution of a double blinded, placebo controlled exploration of melatonin as a potential intervention for the improvement of ANS and sleep dysfunction in T2D.
The results of Study I suggest that the 1-g monofilament and QOL-DN measures correlate to NC-Stat DPN Check portable nerve conduction study (NCS) findings, that these measures function well for early detection purposes, and that the 128-Hz tuning fork is a useful screening tool in OOI, PD and T2D populations, despite lack of correlation to NCS measures. The results of Study II suggest that the QOL-DN and the NeuroQOl-28 QOL instruments significantly predict NCS results, indicating that these measures are useful for screening and accurately assessing neuropathy within our populations of interest. Study III results indicate that a 10 mg dose of melatonin taken 30 minutes prior to bedtime for four weeks has a positive effect on PSQI Subjective Sleep Quality, systolic blood pressure (SBP) in deep breathing and Valsalva maneuvers, and HRV SDNN measures in individuals with T2D