The indicator test Neuropad in the assessment of small and overall nerve fibre dysfunction in patients with type 2 diabetes: a large multicentre study.

We examined the diagnostic utility of the indicator test Neuropad in the assessment of overall and small fibre dysfunction in 1,010 patients with type 2 diabetes mellitus (T2DM) (608 men, mean age 63.9 ± 10.3 years) from 5 diabetes clinics. Sudomotor function was diagnosed by the Neuropad® test. Overall and small nerve fibre dysfunction was diagnosed through clinical examination and symptoms. Patients were divided into Groups A (441 patients with sudomotor dysfunction) and B (569 patients without sudomotor dysfunction). The former were older (p<0.05) and had longer T2DM duration (p<0.05) than the latter. For overall nerve fibre dysfunction, abnormal Neuropad defined as patchy/blue had 94.9% sensitivity, 70.2% specificity and 98.1% negative predictive value (NPV), while for small fibre dysfunction the corresponding values were 85.6%, 71.2% and 93.3%. For overall nerve fibre dysfunction, abnormal Neuropad defined as blue had 64% sensitivity, 96% specificity and 91% NPV, while for small fibre dysfunction the corresponding values were 52%, 96% and 85%. The odds ratios (ORs) of Neuropad patchy/blue for overall and for small fibre dysfunction were 43.7 and 14.7, respectively. The ORs of Neuropad blue for overall and for small fibre dysfunction were 45.7 and 24.9, respectively. In conclusion, Neuropad patchy/blue response exhibited better diagnostic performance both for overall and small nerve fibre dysfunction. Its very high NPV renders it an excellent screening tool primarily to exclude neuropathy in T2DM.

Serum magnesium levels in non-diabetic offspring of patients with Type 2 diabetes mellitus.

A tendency for magnesium deficiency in patients with diabetes mellitus is well established, which probably results from glycosuria-related hypermagnesiuria, nutritional factors or hyperinsulinaemia. Hypomagnesaemia is probably a secondary event but it can also lead to insulin resistance itself. The offspring of patients with Type 2 diabetes mellitus (T2DM) are at increased risk of developing diabetes and several metabolic abnormalities of the disease. The aim of this study was to determine if serum total magnesium levels in healthy offspring of T2DM patients underwent alterations and their relationship to indicators of glucose homeostasis. The sample consisted of two groups: 30 healthy offspring with at least one diabetic parent, and 30 age-matched healthy subjects with no family history of T2DM. None of the participants was on a diet. The mean serum magnesium concentration was 1.070 +/- 0.059 mmol/l in offspring and 1.075 +/- 0.084 mmol/l in controls (p=0.66). There was no statistically significant correlation between serum magnesium levels and parameters of glucose homeostasis in offspring. Our results support the conclusion that total serum magnesium probably has no relationship with the main indicators of glucose homeostasis in offspring of T2DM patients and is not likely to be a fundamental risk factor for the development of insulin resistance.

Tumour necrosis factor-alpha levels in non-diabetic offspring of patients with type 2 diabetes mellitus.

Tumour necrosis factor-alpha (TNF-alpha) is considered to be involved in the insulin resistance of type 2 diabetes mellitus. The offspring of patients with type 2 diabetes mellitus are at increased risk of developing diabetes and several metabolic abnormalities, but the underlying defects responsible are not known. We studied serum TNF-alpha levels in 30 healthy non-diabetic offspring of type 2 diabetic parents (group A), and the relationship between TNF-alpha levels and variables associated with insulin resistance and diabetes. For comparison, 30 healthy offspring of non-diabetic parents (group B) were also studied. The median serum concentration of TNF-alpha was significantly higher in group A than in group B, 3.5 pg/ml compared with 2.0 pg/ml, respectively. The individuals of group A also had significantly elevated levels of glycosylated haemoglobin, fasting glucose, glucose 2 h after an oral glucose tolerance test and triglycerides. We conclude that serum TNF-alpha concentration is significantly elevated in non-diabetic offspring of type 2 diabetics and this may predict later impairment of insulin action in these individuals.