Diabetic neuropathy is one of microvascular complications of diabetes. Among many types of diabetic neuropathy small-fiber neuropathy is believed to be the earliest sign of nerve dysfunction. Albuminuria, the other microvascular complication, is common and precedes renal dysfunction in diabetes and the early detection of these two complications is important. In this study, we investigated whether the small-fiber nerve dysfunction would be prevalent in subjects with diabetes and albuminuria. If so, we could discover a common etiology of these two conditions. We enrolled adult type 2 diabetes (n = 311) and measured their feet electrochemical skin conductance (ESC) by SUDOSCAN, and albumin to creatinine ratio (ACR) using random urine samples. The subjects were categorized according to their albuminuria status: no albuminuria, newly detected albuminuria, and persistent albuminuria. We defined small-fiber neuropathy if the feet ESC levels were less than 60 uS. Mean ages of subjects were 57.9 years and 58.8% were male. Among them, 13.5% and 20.6% of subjects had newly detected and persistent albuminuria, respectively. Mean ESC levels were decreased in subjects with albuminuria than those without albuminuria. In addition, more subjects had small-fiber neuropathy in albuminuria groups than normal counterpart (47.6% vs. 56.3% vs. 26.8% in newly detected albuminuria, persistent albuminuria, and no albuminuria groups, respectively, P <0.001). Feet ESC levels were negatively correlated with ACR and it can detect the presence of albuminuria with 58.5% of sensitivity and 70.2% of specificity. The feet ESC levels were independently associated with albuminuria after adjusting for diabetes duration, HbA1c, systolic blood pressure, triglyceride, and LDL-cholesterol.
In conclusion, small-fiber neuropathy was more prevalent in diabetes with albuminuria compared to diabetes without albuminuria. The small-fiber neuropathy might be an independent risk factor for diabetic nephropathy.
T. Oh: None. S. Kang: None. S. Choi: None. H. Jang: None.