Early parasympathetic neuropathy associated with elevated fasting plasma C-peptide concentrations and late parasympathetic neuropathy with hyperglycaemia and other microvascular complications

Role of curcumin in the management of pathological pain

BACKGROUND

Pathological pain conditions can be triggered after peripheral nerve injury and/or inflammation. It is a major clinical problem that is poorly treated with available therapeutics. Curcumin is a phenolic compound derived from Curcuma longa, being widely used for its antioxidant, anti-inflammatory and immunomodulatory effects.

PURPOSE

This review systematically summarized updated information on the traditional uses of curcumin in order to explore antinociceptive effects in pathological pain and evaluate future therapeutic opportunities clinically. Moreover, some structure-activity relationships would greatly enrich the opportunity of finding new and promising lead compounds and promote the reasonable development of curcumin.

METHODS

PubMed were searched and the literature from the year 1976 to January 2018 was retrieved using keywords pain and curcumin.

RESULTS

This review systematically summarized updated information on the traditional uses, chemical constituents and bioactivities of curcumin, and highlights the recent development of the mechanisms of curcumin in the pathological pain by sciatic nerve injury, spinal cord injury, diabetic neuropathy, alcoholic neuropathy, chemotherapy induced peripheral neuroinflammtion, complete Freund's adjuvant (CFA) injection or carrageenan injection. Importantly, the clinical studies provide a compelling justification for its use as a dietary adjunct for pain relief. And we also present multiple approaches to improve bioavailability of curcumin for the treatment of pathological pain.

CONCLUSION

This review focuses on pre-clinical and clinical studies in the treatment of pathological pain. Although the mechanisms of pain mitigating effects are not very clear, there is compelling evidence proved that curcumin plays an essential role. However, further high-quality clinical studies should be undertaken to establish the clinical effectiveness of curcumin in patients suffering from pathological pain. Potential methods of increase the water solubility and bioavailability of curcumin still need to be studied. These approaches will help in establishing it as remedy for pathological pain.

Links between metabolic syndrome and cardiovascular autonomic dysfunction

BACKGROUND

Type 2 diabetes (T2D) might occur within metabolic syndrome (MbS). One of the complications of T2D is an impaired (imp) cardiovascular autonomic function (CAF).

AIMS

In subjects with T2D and age ≤ 55 years, the prevalence of impCAF and its relationship with BMI, waist, HbA(1c) values, MbS, hypertension, and family history of T2D and/or hypertension were analysed.

METHODS

180 subjects consecutively undergoing a day hospital for T2D were studied. The IDF criteria were used to diagnose MbS. To detect impCAF, 5 tests for the evaluation of CAF were performed with Cardionomic (Meteda, Italy). Univariate and multivariate analyses were performed.

RESULTS

The prevalence of impCAF and MbS were 33.9% and 67.8%, respectively. Among diabetics with impCAF, 86.9% had MbS. ImpCAF was significantly associated with MbS, overweight, and HbA(1c) > 7%. Both logistic (P = 0.0009) and Poisson (P = 0.0113) models showed a positive association between impCAF and MbS. The degree of ImpCAF showed a positive linear correlation with BMI and HbA(1c) values.

CONCLUSIONS

The study demonstrates that glycaemic control and overweight influence CAF and that T2D + MbS is more strongly associated with impCAF than isolated T2D. We suggest that MbS not only increases the cardiovascular risk of relatively young subjects with T2D but is also associated with impCAF.

C-peptide and chronic complications in patients with type-2 diabetes and the metabolic syndrome

INTRODUCTION

We investigated the relation between C-peptide levels and the prevalence of diabetic complications in patients with type 2 diabetes and the metabolic syndrome.

METHODS

This study includes all patients with diabetes and treated only with oral hypoglycemic agents who were admitted to our department in 2006. The chronic complications of diabetes (vascular disease, retinopathy, nephropathy, neuropathy) were evaluated.

RESULTS

The 77 patients with type 2 diabetes and treated only with oral hypoglycemic agents were divided in two groups, with and without the metabolic syndrome. The two groups did not differ in glycemic control, blood pressure levels, or duration of diabetes. CRP levels were higher in patients with the metabolic syndrome (p=0.03), and nephropathy was more common (70%, compared with 33%). Similar, C-peptide levels were higher in patients with the metabolic syndrome: 3.12+/-1.36 compared with 1.82+/-1.25 (p<0.001). In patients with the metabolic syndrome, C-peptide levels did not differ in patients with or without diabetic complications (3.01+/-1.16, compared with 3.96+/-2.55; p=0.51). Similarly, C-peptide levels in patients without the metabolic syndrome did not differ according to the presence of complications of diabetes (2.25+/-1.21 versus 1.36+/-1.16; p=0.07). However, C-peptide levels were higher in patients with diabetes and the metabolic syndrome who had either nephropathy or vascular disease, compared with those with those complications but without the metabolic syndrome (p=0.01). CRP levels did not correlate with C-peptide levels in any patient group.

DISCUSSION

Higher C-peptide levels were associated with metabolic syndrome in patients with type 2 diabetes and in diabetes patients who also had nephropathy and vascular disease.

Acute effects of C-peptide on gastric emptying in longstanding type 1 diabetes

Gastric emptying (GE) of a solid (100 g beef) and liquid (150 ml 10 % dextrose) meal was measured in eight patients with type 1 diabetes during intravenous infusion of C-peptide (6 pmol/kg/ min) or isotonic saline. C-peptide had no effect on either solid or liquid GE.