I believe the basis for this is small vessel disease/endothelial dysfunction. Exercise is certainly vital. Stick to a good exercise program; get the help of a physical therapist if possible. Absolutely get your lipids under control and make sure you do not have a glucose intolerance/insulin resistance issue. Up to 40 percent of all idiopathic (unexplained) cases of PN are ultimately tracked to a sugar issue. These sugar issues can fly under the radar. At least get a 2 hour glucose test after fasting. If you have an open-minded physician, have him or her review the niacin data, some of which shows that it has very favorable effects on axonal remyelination, endothelial dysfunction, etc. A couple studies that supposedly showed it was not effective for lipid modultion went contrary to 19 clinical trials involving tens of thousand of people across several decades and used niacin in an entirely wrong and deficient matter. Two researchers involved in those studies themselves refuted their own studies' negative niacin findings in a two part series that was published in a peer reviewed journal. A recent study that raised alarms about a single niacin associated factor that in isolation caused some inflammation proves nothing negative about niacin itself. You can isolate molecules from almost anything that in isolation and in high enough doses are toxic.