A Novel Diagnostic Test for End-Stage Sensory Failure Associated With Diabetic Foot Ulceration: Proof-of-Principle Study

Background:Diabetic foot ulceration (DFU) affects only a subgroup of patients with diabetic neuropathy, that is, those with pain-insensitivity due to end-stage sensory failure. Pain perception failure develops insidiously and remains asymptomatic until first DFU. As loss of pain perception is clinically significant, timely detection is mandatory.Objectives:A novel suprathreshold pinprick pain stimulus of 512 mN force made from optical glass-fiber was explored in a prospective cross-sectional diagnostic accuracy study to detect DFU-related end-stage sensory failure.Methods:A total of 116 participants were studied (25 healthy people, 22 patients with diabetes without relevant complications, 19 patients with previous painful foot or leg injuries, and 50 patients with previous or active painless DFU [reference standard]). Palmar and plantar surfaces were stimulated in a standardized fashion. At the feet, the second and third toe skinfolds and the middle of the plantar arch were stimulated. Participants scored stimulated pricking discomfort or pain intensity 0 to 10 on a numerical rating scale.Results:At hands, intensity was rated on average 5 (1-10) [median (range)] by 114/116 participants. Per foot, participants without DFU scored 5 (1-10), while those with DFU scored 0 (0-3) (P < .0001). At plantar toe skinfolds, the absence of pinprick pain perception detected DFU-associated sensory failure with an accuracy of 99.5% (sensitivity 99.5%, specificity 99.4%, positive likelihood ratio 248, and negative likelihood ratio 0.005).Conclusion:In this pilot study, nociceptive stimulation of a plantar toe skinfold with a 512 mN optical glass-fiber pinprick accurately identified DFU-associated end-stage sensory failure.     

Long-term safety, efficacy and side-effects of continuous subcutaneous insulin infusion treatment for Type 1 (insulin-dependent) diabetes mellitus: a one centre experience

Summary A follow-up study of 116 Type 1 (insulin-dependent) diabetic patients on long-term continuous subcutaneous insulin infusion was conducted after 4.5±0.2 years. The average HbA_1c-value of these patients decreased by 1% to 6.7±0.1% during this observation period. Typical side effects of continuous subcutaneous insulin infusion such as skin inflammation at the catheter insertion site occurred with similar frequency as has been reported previously by other authors. Diabetic ketoacidosis (0.14 per patient year) and disabling hypoglycaemia (0.1 per patient year, including 0.05 hypoglycaemic coma per patient-year) occurred at substantially lower rates than in other comparable studies with Type 1 diabetic patients at a similar degree of metabolic control. Subgroup evaluation suggested that a normal (<5.6%) HbA_1c-value at follow-up was associated with increased incidence of disabling hypoglycaemia, whereas poor metabolic control (HbA_1c>7.5%) was associated with increased rates of skin complications and hospital treatment for ketoacidosis. Thus, under the policies of this diabetes centre, continuous subcutaneous insulin infusion has proved to be beneficial to a large proportion of experienced adult Type 1 diabetic patients, who voluntarily had opted for, and continued with, this particular mode of insulin treatment.     

What may be gained from standard photocoagulation during early worsening of diabetic retinopathy? An observational study in type-1 diabetic patients after tightening of glycaemic control.

OBJECTIVE: To assess the outcome of laser photocoagulation treatment for rapidly progressing diabetic retinopathy, socalled early worsening, subsequent to a rapid improvement of glycemic control. For the purpose of this study, early worsening was defined as any incidence or progression of retinopathy that followed a reduction in HbA1c by > 2% within 6 months.MATERIAL AND METHODS: Retrospective observational study in type-1 diabetic patients in a university diabetes center.PATIENTS: 23 patients with early worsening were identfied during a 16-year period, with a mean age of 25 years, duration of diabetes of 12 years, and glycated hemoglobin HbA1c of 12.4%; retinopathy was absent or mild nonproliferative at baseline. Focal, and/or panretinal laser coagulation was performed according to standard ETDRS criteria. Retinal pathology and visual acuity was followed-up for 12-120 months.RESULTS: Improving metabolic control induced mild non-proliferative retinopathy without macular edema in 4 patients, which regressed without treatment. In 19 patients, symptomatic diabetic maculopathy developed with macular edema, resolving by focal coagulation in 3 patients. Of the remaining 16 patients, 14 developed proliferative retinopathy (7 of whom despite focal, grid or scatter coagulation pretreatment), and were treated by full panretinal coagulation. In 7 of the 14 patients with proliferative retinopathy, vitreous hemorrhages occurred requiring pars plana vitrectomy. Proteinuria, polyneuropathy, and impaired vision prior to laser treatment were indicative of poor prognosis. Visual acuity > 0.3 in at least one eye was preserved in 22 of the 23 patients.CONCLUSIONS: In patients with type-1 diabetes mellitus and early worsening of diabetic retinopathy, the benefit of standard laser photocoagulation was limited, and particularly in the presence of symptomatic macular edema.     

Effects of the glycaemic index of dietary carbohydrates on prandial glycaemia and insulin therapy in type I diabetes mellitus

Four carbohydrate diets with different glycaemic index were fed to 10 type I diabetic patients on continuous subcutaneous insulin infusion (CSII). Every diet consisted of 4 meals with identical carbohydrate content, being consumed during one day each at 8.00, 12.00, 16.00 and 18.00 h. CSII was conducted according to the patients' experiences, aiming at plasma glucose values between 70 and 160 mg/dl. From 8.00 to 20.00 h, plasma glucose was measured every 2 h. Plasma glucose profiles were near-normal with all of the diets; differences between the diets were statistically insignificant. The premeal insulin dosages, as delivered by the patients, varied significantly in relation to the time of the day, and to the premeal plasma glucose concentration. The patients varied their prandial insulin doses also in relation to the 4 diets, indicating that the glycaemic index was helpful for the prediction of their prandial insulin requirements. It is concluded that near-normoglycaemia can be achieved in type I diabetic subjects on CSII irrespective of the glycaemic index of their diet, if the prandial insulin requirements are met adequately.     

Effects on parameters of glucose homeostasis in healthy humans from ingestion of leguminous versus maize starches

Summary Background: Due to their lower glycaemic index, leguminous seeds affect human carbohydrate metabolism lesser than do cereals. Problems, however, could arise from side effects, e.g., increasing flatulence. Aim of the study and methods: In 26 healthy subjects, metabolic and symptomatic responses following acute ingestion of equivalent amounts of pure pea starch (NASTAR (Cosucra BV, Rosendaal/The Netherlands), crude yellow pea flour (CPC Deutschland, Germany), and modified and unmodified cornstarches (SNOWFLAKE and SIRONA, Cerestar/Germany) were assessed, i.e., plasma glucose, serum insulin, C-peptide, hydrogen exhalation, and flatulence. Results: Pure pea starch elicited less hyperglycaemia (minus 47 %), hyperinsulinaemia (minus 54 %), and C-peptide secretion (minus 37 %) as compared to cornstarch (p<0.05), while the responses to modified versus unmodified corn starch were similar (8 subjects, n.s.). Pure pea and corn starches were equally well tolerated, while flatulence and breath hydrogen concentration were increased only after the intake of crude pea flour. Maldigestion of pea flour was calculated to be around 10 % (reference lactulose). Conclusions: The well-known metabolic advantages of pea starch over cornstarch were confirmed. Tolerability of pure pea starch was excellent, but not of crude pea flour. Provided it has the same technical characteristics, pure pea starch as a “prebiotic” could replace cornstarch in industrial food production. Received: 15 January 1999, Accepted: 12 July 1999     

Bone Histomorphology May Be Unremarkable in Diabetes Mellitus

Abstract Background and Purpose:  Histomorphological studies on bone in human diabetes mellitus are scarce. The aim of this study was to observe the histomorphological appearance of bone in amputation specimens from feet of patients with diabetes mellitus. Material and Methods:  Routine histopathology reports on 45 amputation specimens were evaluated, provided the osteotomy was located in unaffected bone tissue. The bone morphology of regions affected with gangrene and/or osteomyelitis was considered, as well as the morphology at the dissection margin at a distance from the affected parts. The specimens were obtained from 43 diabetic patients, most of whom exhibiting the so-called neuroischemic diabetic foot with infection. The patients' age ranged from 50 to 92 years, duration of diabetes from 0 to 52 years; polyneuropathy was present in 36, peripheral ischemic vessel disease (PIVD) in 30, and renal failure in 24 of them, respectively. Results:  There were 22 clinical cases of osteomyelitis, 20 cases of gangrene (including three cases of necrosis without surrounding inflammation), and three cases of pressure ulcer, which were treated by amputation of 24 toes, and resection of 21 metatarsal bones, respectively. Histomorphology showed osteomyelitis (n = 29), bone necrosis (n = 1), myelofibrosis (n = 8), and normal bone (n = 7) at the affected sites, compared to normal bone (n = 26), myelofibrosis (n = 12), and osteoporosis (n = 7) at the osteotomy sites. In cases of clinical gangrene, bones were also affected by osteomyelitis, but less so than in cases of clinical osteomyelitis (8/18 vs. 22/22; p < 0.001). Bone tissue at the osteotomy sites was normal – with some myelofibrosis – in both conditions. Conclusion:  This pilot study shows that histomorphology of unaffected foot bone is mostly not abnormal in diabetic patients with neuropathy and PIVD. Further study is necessary to corroborate this preliminary evidence of absence of a “diabetic osteopathy” in the diabetic foot.      

Fundus polaroid screening for diabetic retinopathy. Is one print per patient enough?

The CR3-45 NM Canon nonmydriatic fundus camera detects relevant diabetic retinopathy with high sensitivity. To determine whether examination of one eye per patient would suffice for screening purposes, 473 pairs of standard 45 degree fundus Polaroid prints obtained with the Canon camera were assessed from 167 patients with and 306 without diabetic retinopathy. On the basis of considering only one eye per patient, absence of retinopathy would have been diagnosed in 336 patients, with 9% of the diagnoses false negative. One hundred thirty-seven of the 167 patients with retinopathy in at least one eye would have been diagnosed correctly by considering one eye per patient (sensitivity 82%, specificity 100%). Thus, a standard 45 degree fundus Polaroid print from one eye per patient may suffice for screening purposes if the picture is free from diabetic abnormalities. Otherwise, both eyes should be examined immediately, and the patient should be referred to an expert ophthalmologist who specializes in diabetic retinopathy for confirmation of the diagnosis and staging of diabetic retinopathy status.     

Foot dimensions of elderly people with and without diabetes mellitus - a data basis for shoe design

BACKGROUND: Injuries from footwear are common in elderly people, particularly in those with diabetes mellitus and polyneuropathy. A common cause is a mismatch between foot and shoe. OBJECTIVE: To assess the length and the breadth of the feet by an automatic measuring device in 568 patients with diabetic polyneuropathy and in 100 nondiabetic control subjects of the same mean age of 64 years. RESULTS: While the foot length in all cases matched well with the size of the normal footwear available on the market, more than two thirds of the feet were considerably broader than the normal footwear available. The foot breadth correlated variably with the foot length. Tables of foot dimensions for men and women are provided over the complete range of shoe sizes. CONCLUSIONS: This anthropometric data set on feet, which is the first conducted in elderly people, proves that most feet of elderly people with or without diabetic neuropathy do not fit ordinary casual footwear. Therefore, the construction of shoes according to the anthropometric data of elderly people is required in order to prevent foot injuries in this particular population.