Diabetic polyneuropathy in the elderly

Diabetes in Europe: an update

Diabetes is among the leading causes of death in the IDF Europe Region (EUR), continues to increase in prevalence with diabetic macro- and microvascular complications resulting in increased disability and enormous healthcare costs. In 2013, the number of people with diabetes is estimated to be 56 million in EUR with an overall estimated prevalence of 8.5%. However, estimates of diabetes prevalence in 2013 vary widely in the 56 diverse countries in EUR from 2.4% in Moldova to 14.9% in Turkey. Trends in diabetes prevalence also vary between countries with stable prevalence since 2002 for many countries but a doubling of diabetes prevalence in Turkey. For 2035, a further increase of nearly 10 million people with diabetes is projected for the EUR. Prevalence of type 1 has also increased over the past 20 years in EUR and there was estimated to be 129,350 cases in children aged 0-14 years in 2013. Registries provide valid information on incidence of type 1 diabetes with more complete data available for children than for adults. There are large differences in distribution of risk factors for diabetes at the population level in EUR. Modifiable risk factors such as obesity, physical inactivity, smoking behaviour (including secondhand smoking), environmental pollutants, psychosocial factors and socioeconomic deprivation could be tackled to reduce the incidence of type 2 diabetes in Europe. In addition, diabetes management is a major challenge to health services in the European countries. Improved networking practices of health professionals and other stakeholders in combination with empowerment of people with diabetes and continuous quality monitoring need to be further developed in Europe.

Vascular factors predict polyneuropathy in a non-diabetic elderly population

We prospectively examined whether vascular factors are related to an increased incidence of Chronic Idiopathic Distal Symmetric Neuropathy (CI-DSN) in a non-diabetic elderly population. In 8 Italian municipalities, 2,512 men and women without both diabetes and CI-DSN at baseline are examined. Potential effect of vascular factors was estimated by regressing new onset CI-DSN on the occurrence of several vascular diseases and risk factors. Multivariate relative risks of CI-DSN were estimated by Cox proportional hazards models. After 3.8 (±2.4) years of follow-up, we documented 51 incident CI-DSN cases. At univariate analysis, age, comorbidity, waist circumference, leg length, peripheral artery disease, and coronary heart disease proved to increase the risk of developing CI-DSN. By multivariate analyses, only age (RR = 1.08; 95 % CI, 1.02-1.14), leg length (RR = 1.05; 95 % CI, 1.01-1.1) and peripheral artery disease (RR = 2.75; 95 % CI, 1.15-6.56) proved significant predictors of CI-DSN. Separate analyses by gender show that age is an independent predictor of CI-DSN both in men and in women, while PAD predicts the disease only in men, together with body height. Incidence of CI-DSN is higher in individuals carrying vascular conditions. In men, the presence at baseline of peripheral artery disease is associated with a threefold increase in the risk of developing CI-DSN. The incidence of neuropathy in non-diabetic individuals is associated with potentially modifiable vascular factors.

Reduced peripheral nerve function is related to lower hip BMD and calcaneal QUS in older white and black adults: the Health, Aging, and Body Composition Study

Bone tissue is innervated, and peripheral nerve function may impact BMD. Older black and white men and women (N = 2200) in the Health, Aging, and Body Composition Study with worse sensory and motor peripheral nerve function had lower hip BMD and calcaneal BUA independent of lean mass, strength, physical ability, and diabetes. Poor peripheral nerve function may directly affect bone.

INTRODUCTION

Bone tissue is innervated, yet little is known about the impact of nerve function on BMD. Poor peripheral nerve function may contribute to lower BMD and higher fracture risk, particularly in those with diabetic neuropathy.

MATERIALS AND METHODS

The Health, Aging, and Body Composition (Health ABC) Study included annual exams in white and black men and women 70-79 years of age recruited from Pittsburgh and Memphis. Nerve function in legs/feet was assessed by 1.4- and 10-g monofilament detection, vibration threshold, and peroneal motor nerve conduction velocity (NCV) and amplitude (CMAP). Total hip BMD, heel broadband ultrasound attenuation (BUA), and total fat and lean mass were measured 1 year later (QDR 4500A, Sahara QUS; Hologic).

RESULTS

Participants (N = 2200) were 48% men and 37% black. Poor nerve function (lower monofilament detection, higher vibration threshold, lower CMAP, lower NCV) was associated with 1.4-5.7% lower BUA and significant for all but NCV, adjusted for demographics, diabetes, body composition, and physical ability. Results were similar for adjusted hip BMD, with 1.0-2.9% lower BMD, significant for monofilament and CMAP testing. When considering the components of BMD, total hip area was 1.8-4.9% higher in those with the worst nerve function, although BMC showed little difference. Lower monofilament detection and CMAP were independently associated with lower heel BUA (p < 0.01), and monofilament detection was associated with lower hip BMD (p < 0.05) in regression additionally adjusted for lifestyle factors, bone-active medications, and diabetes-related complications.

CONCLUSIONS

Poor peripheral nerve function may directly related to lower BMD, likely through an increase in bone area in older adults, independent of lean mass, strength, physical ability, and diabetes. Whether those with impaired nerve function are at higher risk for fracture independent of falls needs to be studied.

Postprandial hyperglycaemia in type 2 diabetes: pathophysiological aspects, teleological notions and flags for clinical practice

Type 2 diabetes subjects carry an excess risk for micro- and macrovascular disease and a higher cardiovascular morbidity and mortality rate. The beneficial impact of tight glycaemic control-evidenced by the integrated marker of fasting glucose and postprandial glucose values, the HbA1c-for the prevention of microvascular complications is definitely confirmed. Over the past few years, several studies have identified postprandial hyperglycaemia as a better predictor of cardiovascular or even of all-cause mortality, as well as an independent risk factor for atherosclerosis. The continuous glucose monitoring could offer a rationale means for the detection of postprandial hyperglycaemia and ultimately for its effective management. Advances in technology keep a promise for a reliable, convenient and closer to the idea of the artificial endocrine pancreas glucose sensor. Subcutaneous glucose levels charted by one of the new sensors were found to be well correlated with venous glucose measurements. Intervention for a healthy lifestyle is frequently hampered by patients' poor compliance. The availability of diverse antidiabetic agents provides options for targeting the glycaemic goal and a choice more fitted to the particularized pathophysiology of each individual subject. Drugs targeting postprandial glycaemia may prove to represent the 'sine qua non' for the 'return' of postprandial glucose values at a 'non-deleterious' threshold, either as monotherapy for the early stages of the disease or as combination therapy later in the progression of diabetes.

Oral modified insulin (HIM2) in patients with type 1 diabetes mellitus: results from a phase I/II clinical trial

An effective, orally administered insulin product would be of substantial benefit in the treatment of patients with diabetes mellitus. This phase I/II clinical trial was the first to investigate the safety and effectiveness of a single oral dose of a modified human insulin in controlling postprandial plasma glucose levels in patients with type 1 diabetes mellitus who were receiving basal continuous subcutaneous insulin infusion (CSII) therapy. Fourteen patients with type 1 diabetes mellitus were evaluated in an open-label, 2-center, dose-escalation, nonrandomized study of oral hexyl-insulin monoconjugate 2 (HIM2). After an overnight fast and prior to receiving a standardized meal (50% carbohydrates, 30% fat, 20% proteins; 650 calories), the patients received either no additional insulin (day 1), or 0.5 to 1.0 mg/kg of HIM2 (day 2). All patients received a basal insulin regimen by CSII throughout the study. Blood samples were collected for determination of glucose and insulin levels for 240 minutes post-dose. The postprandial glucose excursion versus time curves showed clear reductions in glucose values after both HIM2 doses (day 2) relative to no treatment (day 1), although the differences in the reductions were not statistically significant. When the data for both HIM2 doses were pooled, a statistically significant effect of HIM2 on glucose excursion (as measured by AUCex(30-240)) was observed. Mean +/- SD values for AUCex(30-240) were 501.35 +/- 124.1 mg. h/dL after no treatment and 375.81 +/- 215.5 mg. h/dL after HIM2 (Wilcoxon signed-rank test, P =.042). The results of this study suggest that oral HIM2, when added to a basal insulin regimen, was safe and may prove effective in controlling postprandial hyperglycemia in patients with type 1 diabetes mellitus. Further clinical investigation is necessary.

Control of postprandial plasma glucose by an oral insulin product (HIM2) in patients with type 2 diabetes

OBJECTIVE

The objectives of this exploratory study were to assess the postprandial glucose-lowering effects and evaluate the safety and tolerability of single, escalating doses of an oral insulin product, hexyl-insulin monoconjugate 2 (HIM2), in patients with type 2 diabetes. Subcutaneous insulin and oral placebo were also administered for comparison.

RESEARCH DESIGN AND METHODS

Eighteen patients with type 2 diabetes were enrolled in this randomized, single-blind, placebo-controlled, three-way crossover, dose-escalation study. A single dose of each of the following study drugs was administered to each patient on 3 separate days: oral HIM2 (at one of three dose levels: 0.375, 0.5, or 1.0 mg/kg), subcutaneous regular insulin (8 units Humulin R), and oral placebo. At 30 min after dosing, patients ingested a standardized test meal (16 oz/720 calories of Boost Plus). Serial blood samples were collected for determination of plasma glucose and insulin concentrations during the 4-h postdose period.

RESULTS

The mean glucose area under the curve for 0 to 240 min (AUC(0-240)) values were lower following administration of 0.5 and 1.0 mg/kg HIM2 vs. placebo (1,097.1 vs. 1,196.9 and 801.1 vs. 992.1 mg x h(-1) x dl(-1), respectively). This difference was statistically significant at the 1.0-mg/kg HIM2 dose level. Insulin exposure, as measured by insulin AUC(0-240) values, for the 0.375-, 0.5-, and 1.0-mg/kg dose levels of HIM2 were 169.9, 193.1, and 230.8 micro U x h(-1) x ml(-1), respectively; insulin AUC(0-240) values for placebo were 165.8, 196.1, and 169.2 micro U x h(-1) x ml(-1), respectively. The mean glucose AUC(0-240) values were similar following administration of 0.5 and 1.0 mg/kg HIM2 vs. subcutaneous insulin (1,097.1 vs. 1,048.0 and 801.1 vs. 875.2 mg x h(-1) x dl(-1), respectively). For pooled data from the 0.5- and 1.0-mg/kg dose groups, the HIM2/subcutaneous insulin ratios for the 2-h postprandial glucose concentration (0.97, 95% CI 0.90-1.06), maximum postprandial glucose concentration (0.99, 95% CI 0.93-1.06), and glucose AUC(0-240) (0.98, 95% CI 0.9-1.06) were within 10% of unity, implying glucodynamic equivalence. Although HIM2 (0.5 and 1.0 mg/kg) and subcutaneous insulin (8 units) provided comparable control of postprandial plasma glucose concentrations, HIM2 resulted in peripheral insulin concentrations that were lower than subcutaneous insulin (mean insulin AUC(0-240) of 193.1 vs. 233.6 and 230.8 vs. 270.3 micro U x h(-1) x ml(-1), respectively).

CONCLUSIONS

Single, oral doses of HIM2 were safe and well tolerated. HIM2 (0.5 and 1.0 mg/kg) was more effective than placebo and as effective as subcutaneous regular insulin (8 units) at controlling postprandial glycemia with respect to the following parameters: 2-h postprandial glucose concentration, maximum glucose concentration, and glucose AUC(0-240). This occurred even though peripheral insulin concentrations were lower following the administration of HIM2 (0.5 and 1.0 mg/kg) than subcutaneous insulin. Thus, HIM2 therapy may control postprandial glycemia without causing peripheral hyperinsulinemia in patients with type 2 diabetes.