Pronounced cortisol response to acute psychosocial stress in type 2 diabetes patients with and without complications

It is increasingly recognized that psychological stress is linked with type 2 diabetes mellitus and its late complications. Thus, the aim of the current study was to investigate the psychophysiological response to acute psychosocial stress in patients with type 2 diabetes. In total, 53 type 2 diabetes patients with complications, 16 type 2 diabetes patients without complications, and 47 age and gender matched non-diabetic participants underwent the Trier Social Stress Test. Subjective as well as biological parameters (i.e., blood levels of cortisol, adrenocorticotropic hormone (ACTH), norepinephrine, methylglyoxal) were assessed repeatedly before and after stress induction. Data were analyzed by means of multilevel regression. Patients with type 2 diabetes showed an exaggerated cortisol response to acute stress as compared to age matched control participants (diabetes*T2 est. = 1.23, p < .001), while stress-induced alterations of ACTH and subjective parameters did not differ. Norepinephrine levels were lower among patients (diabetes est. = -4.36, p = .044) and tended to decrease earlier than in controls. The subjective reaction of type 2 diabetes patients with complications was stronger than that of patients without complications (complication*T2 est. = -1.83, p = .032), while their endocrine response to stress was similar. Stress had no effect on methylglyoxal level, and there were no group differences regarding methylglyoxal response. These results show that the cortisol reactivity of patients with type 2 diabetes to acute psychosocial stress is increased compared to a control group. Thus, alterations of the hypothalamus-pituitary-adrenal axis - especially regarding its dynamic regulation - are a plausible link between psychological stress and type 2 diabetes and its complications.

The role of serum methylglyoxal on diabetic peripheral and cardiovascular autonomic neuropathy: the ADDITION Denmark study

AIMS

Cardiovascular autonomic neuropathy and diabetic peripheral neuropathy are common diabetic complications and independent predictors of cardiovascular disease. The glucose metabolite methylglyoxal has been suggested to play a causal role in the pathogeneses of diabetic peripheral neuropathy and possibly diabetic cardiovascular autonomic neuropathy. The aim of this study was to investigate the cross-sectional association between serum methylglyoxal and diabetic peripheral neuropathy and cardiovascular autonomic neuropathy in a subset of patients in the ADDITION-Denmark study with short-term screen-detected Type 2 diabetes (duration ~ 5.8 years).

METHODS

The patients were well controlled with regard to HbA(1c), lipids and blood pressure. Cardiovascular autonomic neuropathy was assessed by measures of resting heart rate variability and cardiovascular autonomic reflex tests. Diabetic peripheral neuropathy was assessed by vibration detection threshold (n = 319), 10 g monofilament (n = 543) and the Michigan Neuropathy Screening Instrument questionnaire (n = 966). Painful diabetic neuropathy was assessed using the Brief Pain Inventory short form (n = 882).

RESULTS

No associations between methylglyoxal and cardiovascular autonomic reflex tests or any measures of diabetic peripheral neuropathy or painful diabetic neuropathy were observed. However, a positive association between methylglyoxal and several heart rate variability indices was observed, although these associations were not statistically significant when corrected for multiple testing.

CONCLUSION

Serum methylglyoxal is not associated with cardiovascular autonomic neuropathy, diabetic peripheral neuropathy or painful diabetic neuropathy in this cohort of well-treated patients with short-term diabetes.

[Fundus screening by medical technicians]

Ocular fundus photography allows detection of both ocular and systemic diseases. This study investigated the efficacy of a broad screening in a department of internal medicine using nonmydriatic digital fundus photography. For 8 weeks a medical technician was trained in using the camera as well as interpreting the photographs. The medical technician and an ophthalmologist evaluated the fundus photographs separately by using a self-developed questionnaire. The fundus camera was user-friendly and after several weeks of adjustment and practical application the medical technician was able to detect the majority of pathological fundus photographs. Out of 218 patients examined 148 (68%) were identified as pathological by the medical technician and 163 (75%) by the ophthalmologist (p = 0.0003). The medical technician missed 15 (7%) patients. Furthermore the diagnoses made by the medical technician were faulty. In summary an ophthalmological screening by a medical technician is feasible but the diagnosis still remains the responsibility of ophthalmologists. Such a compromise could facilitate the examination of a large number of patients and disclose previously unrecognized diseases.

Dynamic contrast-enhanced MRI for monitoring bisphosphonate therapy in Paget's disease of bone

PURPOSE

The purpose of this study was to evaluate changes in regional bone perfusion in Paget's disease (PD) following bisphosphonate therapy. We used dynamic contrast-enhanced MRI (DCE-MRI) for assessment of bone perfusion and compared MRI findings with alkaline phosphatase (AP) as a serum marker of bone turnover.

MATERIALS AND METHODS

We examined 20 patients (8 women, 12 men, 66 ± 11 years) with symptomatic PD of the axial skeleton. Patients were selected for infusion therapy with the bisphosphonate pamidronate. The most affected bone of lumbar spine or pelvis was examined by DCE-MRI prior to therapy and after a 6-month follow-up. The contrast uptake was evaluated using a two-compartment model with the parameters amplitude A and exchange rate constant K(ep). Color-coded parametric images were generated to visualize bone vascularization.

RESULTS

After a 6-month follow-up there was a significant decrease in alkaline phosphatase and in DCE-MRI parameters A and K(ep) (p < 0.0001). Patients without previous bisphosphonate treatment showed a significantly greater decrease in alkaline phosphatase and K(ep) (p < 0.001).

CONCLUSION

DCE-MRI shows a significant reduction in regional bone perfusion in PD following parenteral bisphosphonate treatment. Reduction in bone perfusion is greater in bisphosphonate-naïve patients than in those who had been previously treated.

Critical Evaluation of Mouse Models Used to Study Pain and Loss of Pain Perception in Diabetic Neuropathy

A number of studies have addressed diabetic neuropathy (DN) in transgenic and knock out mouse models to unravel the molecular mechanisms underlying metabolic pain and loss of pain perception. However, it is difficult to compare these studies with each other or even with human DN due to experimental differences including the type of diabetes, the background strain of the respective mouse model, the methods of diabetes induction and the duration of diabetes, animal age and gender. To receive useful information for DN from genetically modified mice, it is therefore mandatory to first define the appropriate model and – if necessary – to backcross transgenic strains into the respective background to allow a reliable (and at least in part translatable to human DN) interpretation of the results.

Prediction of immediate and long-term benefit after kyphoplasty of painful osteoporotic vertebral fractures by preoperative MRI

BACKGROUND

It is unclear if an MR-detectable bone marrow edema is a prerequisite for pain reduction and morphological correction by kyphoplasty. This comparative trial evaluates clinical and radiomorphological outcomes after kyphoplasty of painful osteoporotic vertebral fractures with and without preoperative MR-detectable bone marrow edema for 1 year of follow-up.

METHODS

Preoperative MR-images of 45 patients who received kyphoplasty for treatment of painful osteoporotic vertebral fractures were evaluated with regard to presence (n = 27) or absence (n = 18) of vertebral bone marrow edema. Pain scores (VAS 0-100) and radiomorphological measures (midline vertebral height, kyphosis angle) were analysed at baseline, postoperatively and after 12 months.

RESULTS

In the "bone edema" group, pain scores improved from 72.7 to 46.8 (postoperative) and 48.0 (12 months, P < 0.001, both). In the group without preoperative bone edema, pain score improved from 70.7 to 60.3 (postoperative, P = 0.013) and to 50.1 (12 months, P = 0.001). Pain scores of both groups were significantly different directly postoperative (P = 0.026), but not after 12 months (P = 0.714). Vertebral height restoration was slightly greater in the "bone edema" group (10.2% vs. 7.8%, P = 0.289). Correction of the kyphosis angle was greater in the "bone edema" group (P = 0.014) compared to the "no bone edema" group (P = 0.838).

CONCLUSION

A preoperative MR-detectable vertebral bone marrow edema predicts a better short-term outcome after kyphoplasty, but is not a prerequisite for long-term pain reduction in patients with old, chronically painful osteoporotic vertebral fractures.

Vertebroplasty and kyphoplasty - inefficient treatments for degenerative spine disease

Osteoporotic vertebral fractures and pathological vertebral lesions are frequent clinical situations causing severe back pain. The pharmacological treatment of the underlying disease and the analgetic treatment of the associated back pain usually do not rid the patient's back pain completely and are insufficient to prevent the fracture-weakened vertebral body from further fracturing with long term consequences for the biomechanical competence of the entire spine. In the last 10 years the minimal invasive treatment options vertebroplasty (VP) and balloon kyphoplasty (BK) have spread quickly because these procedures appeared to be promising treatments to stop the fracture and vertebral lesion associated back pain and to internally stabilize a fractured vertebral body. Numerous published reports on VP and BK appeared to support the notion of an immediate and lasting pain reduction after VP and BK in additon to a prevention of further fracturing of the treated vertebrae. The first three randomized controlled and partly blinded trials have been published this year. Two of these trials demonstrate that VP does not result in a better pain control than a sham operation whereas BK was shown to reduce back pain due to verterbal fractures for at least 12 months. Considering that more than 1.5 million people world-wide have been treated with VP and BK until now this work discusses the recent trials and suggests clinical and academic consequences on the basis of the most recent evidence.

The -174G>C IL-6 gene promoter polymorphism and diabetic microvascular complications

This study examined a possible association of the G>C polymorphism at nucleotide -174 in the promoter region of the interleukin-6 (IL-6) gene (rs1800795) with the prevalence of diabetic complications in 235 patients with type 1 and 498 patients with type 2 diabetes. Genotyping was performed using polymerase chain reaction (PCR) and subsequent cleavage by Nla III restriction endonuclease. Analyzing all diabetic patients together demonstrated that 301 patients (41.1%) carried the GG genotype, 114 (15.6%) the CC genotype, and 318 (43.3%) were heterozygous for the GC genotype. However, there was no correlation of any of the genotypes with the prevalence of diabetic nephropathy or diabetic neuropathy, but subjects with the CC genotype had a significantly higher prevalence of diabetic retinopathy compared to patients with the GC and GG genotype (p=0.016). This association was mainly lost when a logistic regression model was adjusted for diabetes duration (p=0.07). Consistently, a weak but not significant association of the polymorphism with diabetic retinopathy was observed when type 1 and type 2 diabetic patients were analyzed separately (patients with type 1 diabetes: p=0.12; patients with type 2 diabetes: p=0.09). Analogically, no association of the polymorphism was found for diabetic nephropathy or diabetic neuropathy in these groups. In conclusion these data suggest no major influence of the -174G>C variant in the promoter region of the IL-6 gene on the development of microvascular complications in patients with diabetes.