Data examining the association between vitamin D and diabetic peripheral neuropathy are limited. This study investigated the serum levels of vitamin D, vitamin D-binding protein (VDBP), and vitamin D receptor (VDR) in diabetics in the Yozgat region of Turkey, and assessed their relationships with diabetic peripheral neuropathy. 69 diabetic patients and 49 age- and sex-matched control subjects were enrolled in this clinical prospective study. All the diabetics underwent conventional sensory and motor nerve conduction studies, and diabetic peripheral neuropathy was confirmed or ruled out according to the electromyography findings and Douleur Neuropathique 4 questions. Serum vitamin D, VDBP and VDR levels were measured using commercial enzyme-linked immunosorbent assay kits. The serum vitamin D levels (p = 0.001) were significantly lower, while the VDR levels (p = 0.003) were higher, in diabetics than in controls. The serum VDBP levels were similar in both groups (p > 0.05). The serum vitamin D levels were significantly lower in diabetics with diabetic peripheral neuropathy than in those without (p = 0.032), whereas the serum VDBP and VDR levels were similar in these two groups (p > 0.05). The lower serum vitamin D levels in diabetics, especially in those with peripheral neuropathy, may suggest a neurotrophic effect of vitamin D.

Fifty-eight patients with thyroid dysfunction were included, comparing 27 healthy subjects to evaluate the relationship between thyroid autoimmunity, thyroid functional status, and renal function. Regardless of clinical status, hypothyroidism was defined as T3-T4upper limit of normal, and hyperthyroidism was defined as T3-T4>normal limits and TSH <0.1 mcU/mL. In all participants, serum antithyroperoxidase level, serum antithyroglobulin level, creatinine clearance (CC), and urinary albumin excretion rate (UAER) in 24-h urine collections were measured. Of 85 persons, 41 patients ages 20 to 71 years (median; 44) had hypothyroidism, 17 patients ages 22 to 56 years (median; 32) had hyperthyroidism, and 27 subjects ages 20 to 67 years (median; 50) were normal. Regarding thyroid autoantibody positiveness, the positive group had a higher UAER than the negative group (30.2 mg/day, 20.8 mg/day, respectively; p=0.05). In hypothyroid patients, UAER was significantly higher than in hyperthyroid patients and control subjects (30.1 mg/day, 11.8 mg/day, 10.5 mg/day, respectively; p<0.001). In the hypothyroid population, with regard to UAER and CC, we could not find a significant difference between the thyroid autoantibody positive and negative groups. In view of CC, hypothyroid patients had significantly lower CC than the hyperthyroid group (79.0 mL/ min, 86.5 mL/min, respectively; p<0.01). A careful control of the renal function in thyroid diseases should be evaluated. Renal dysfunction seems to be secondary to hypothyroidism rather than thyroid autoimmunity.

No abstract

Evidence suggests that peripheral nerve injury occurs during the early stages of disease with mild glycemic dysregulation. Two proteins, neuron-specific enolase (NSE) and neurofilament light chain (NFL), have been examined previously as possible markers of neuronal damage in the pathophysiology of neuropathies. Herein, we aimed to determine the potential value of circulatory NSE and NFL mRNA levels in prediabetic patients and in those with peripheral neuropathy. This prospective clinical study included 45 prediabetic patients and 30 age- and sex-matched controls. All prediabetic patients were assessed with respect to diabetes-related microvascular complications, such as peripheral neuropathy, retinopathy and nephropathy. mRNA levels of NSE and NFL were determined in the blood by real-time polymerase chain reaction. NSE mRNA levels were similar between prediabetic and control groups (p > 0.05), whereas NFL mRNA levels were significantly higher in prediabetics than in controls (p < 0.001). NSE mRNA levels did not significantly differ between prediabetic patients with and without peripheral neuropathy (p > 0.05), while NFL mRNA levels were significantly higher in prediabetics with peripheral neuropathy than in those without (p = 0.038). According to correlation analysis, NFL mRNA levels were positively correlated with the Douleur Neuropathique 4 questionnaire score in prediabetic patients (r = 0.302, p = 0.044). This is the first study to suggest blood NFL mRNA as a surrogate marker for early prediction of prediabetic peripheral neuropathy, while NSE mRNA levels may be of no diagnostic value in prediabetic patients.

A total of 684 patients who had not been diagnosed with renal cyst but had undergone abdominal ultrasonography for various reasons were evaluated. Patients with and without renal cyst were classified into two groups and were compared in terms of hypertension (HT), hyperlipidemia (HL), diabetes mellitus (DM) and obesity (body mass index: > or = 30 kg/m2) prevalence. Although 94 patients (13.7%) were established with a renal cyst, 590 patients (86.3%) did not have a renal cyst. The mean age of the patients established with a simple renal cyst was 67.3 +/- 12.1 years (range: 28-82 years); 54 (57.4%) of them were women and 40 (42.6%) were men. Of the patients established with a simple renal cyst, 64 (68.1%) had HT, 40 (42.6%) had DM, 20 (21.3%) had HL, 42 (44.7%) were obese, 18 (19.1%) had nephrolithiasis, and 6 (6.4%) had urinary tract infection. Of the patients without a cyst, 272 (46.1%) had DM, 212 (35.9%) had HT, 122 (20.7%) had HL, and 96 (16.3%) were obese. HT and obesity were significantly higher in patients with a renal cyst when compared with those without a cyst. However, although HL incidence was higher in patients with a cyst, the difference was not significant statistically. HT, HL, and obesity are more prevalent in patients with a renal cyst when compared with patients without. Consequently, patients with a simple renal cyst should be evaluated and followed up in terms of atherosclerotic risk factors.