The quality and relevance of peripheral neuropathy data on a diabetic clinical information system

Identification of potential plantar ulceration among diabetes patients using plantar soft tissue stiffness

This study investigates the relationship between plantar tissue stiffness and selected parameters, including age, diabetes mellitus (DM) duration, body mass index (BMI), and HbA_1c level. 70 diabetes patients with no foot problems were recruited. The plantar soft tissue at the 2nd sub-metatarsal head (MTH) pad was examined using the novel indentation system developed. The stiffness constant, K, was used to describe the tissue stiffness. The four factors (age, DM duration, BMI, and HbA_1c level) were plotted against the plantar tissue stiffness. The scatter plots revealed that a higher plantar tissue stiffness was usually associated with (1) BMI>25  kgm^-2, (2) HbA_1c score >10% (86 mmol/mol), and (3) DM duration >10 years. The three risk criteria were further evaluated using the binary classification test. The predictions were reported to be fairly accurate and reliable in detecting stiffened tissues. The study has successfully identified the strong association of BMI, HbA_1c, and DM duration with the plantar tissue properties. Special attention should be given to the high risk group with BMI>25 kgm^-2, HbA_1c score >10% (86 mmol/mol), and DM duration >10 years. The high diagnostic odds ratio attained suggests its potential usefulness in helping clinicians to diagnose diabetic foot more efficiently.

Incidence of and risk factors for diabetic retinopathy in diabetic clinic attenders

The incidence and risk factors for the development of diabetic retinopathy during a mean (SD) follow-up period of 4.6 (2.9) (range 1-12.4) years have been examined among 3424 patients (1878 males and 1546 females) with diabetes mellitus from three outpatient clinics at the University Hospital, Nottingham. The mean (SD) age of participants was 49.2 (17.9) years with a mean (SD) duration of diabetes of 7.3 (9.0) years at initial registration. Among the 3424 patients free of retinopathy at initial registration who attended the clinic at least twice in the period 1979-1992, the incidence of any retinopathy was 59.6 (57.8 male and 61.8 female) per 1000 person-years based on 15,571 person-years of follow-up. The incidence rate of retinopathy was 72% higher among insulin-treated than among non-insulin-treated noninsulin-dependent diabetes mellitus (NIDDM) clinic attenders. Using a Cox's Proportional Hazards Model for insulin-dependent diabetes (IDDM) and NIDDM (insulin and non-insulin-treated) diabetes separately, longer duration of diabetes, higher systolic blood pressure and poor metabolic control were significant independent predictors of retinopathy for all three groups. Never smoking was a significant independent predictor of retinopathy for the insulin-dependent diabetes groups. Lower body mass index, proteinuria and age were predictors of retinopathy only for non-insulin-treated NIDDM patients. Gender and creatinine had no significant independent association with retinopathy when other covariates were considered. These findings will help the identification of those patients at particular risk of retinopathy so that clinic time for screening of eyes can be appropriately focused.

Incidence of and risk factors for proliferative retinopathy and its association with blindness among diabetes clinic attenders

BACKGROUND

Proliferative diabetic retinopathy (PDR), a prevalent late-stage complication of diabetes, is associated with severe visual loss. The objectives of this report were to estimate the incidence of and risk factors for PDR using routinely collected data from a clinical information system at University Hospital Nottingham for insulin- and non-insulin-dependent (insulin-treated and non-insulin-treated) diabetes separately. We also attempted to assess the risk of blindness in these diabetes clinic attenders.

METHODS

During a mean (standard deviation (SD)) follow-up period of 5.1 (2.9) (range 0.5-12.4) years, 3482 diabetic patients (1915 male and 1567 female) from three outpatient clinics at University Hospital, Nottingham were examined. The mean (SD) age of the participants was 49.3 (17.9) years with a mean duration of diabetes of 7.1 (8.7) years at registration.

RESULTS

Among the 3482 patients who attended the clinic at least twice in the period 1979-1992, and who were free of PDR at registration, the overall incidence of PDR was 16.2 per 1000 person-years, based on 17,618 person-years of follow-up. The incidence rate of PDR was nearly three times as high among patients with non-proliferative diabetic retinopathy (NPDR) as in those without any retinopathy (42.1 vs. 15.0 per 1000 person-years). Based on a Cox's Proportional Hazards Model, significant independent predictors of PDR recorded at baseline were glycosylated haemoglobin (HbA1), systolic blood pressure, and longer duration of diabetes for patients without PDR or any retinopathy among insulin-dependent patients. Longer duration of diabetes was the only independent predictor of PDR for patients without PDR or any retinopathy in both insulin- and non-insulin-treated non-insulin-dependent patients. These clinic-based data clearly indicate the higher risk of PDR in non-insulin-dependent patients. Gender, age, BMI, creatinine, proteinuria and cigarette smoking, had no significant independent association with PDR when other covariates were considered in all groups. The risk of blindness was greater among those with PDR than those with NPDR in all three types of diabetes, but was substantial even for those without retinopathy.

CONCLUSION

These data are of value in identifying those diabetes clinic attenders who may be most at risk.

Benchmark analysis on diabetics at high risk for lower extremity amputation

After the 1990 establishment of a multidisciplinary foot salvage clinic, 1346 diabetic patients, at high risk for the development of foot ulcers and eventual lower limb amputation, were followed for 4 years. Of the 224 high-risk patients admitted to the hospital, 74 amputations (5.5%) of all or part of a lower limb were performed. Patients undergoing amputation were younger, more severely ill, and required more frequent hospitalizations because of greater organ system involvement. They were also more likely to be institutionalized after discharge. Overall, patients with long-standing adult-onset diabetes, identified as at high risk for foot ulcer development, have a substantially increased risk for lower limb amputation, multiple organ system failure, hospitalization, and institutionalization than do diabetic patients as a whole. Clinical benchmarking facilitates the identification and reduction of unnecessary variations in patient care practices. Here, a formal benchmark analysis provides the current outcome expectations for amputation rates and co-morbidities in patients with diabetes who are classified as at high risk for lower extremity amputation. Management of these patients in a structured, multidisciplinary foot salvage clinic, augmentation of baseline services, and preliminary benchmark data may provide a standard for the measurement of therapeutic interventions that improve patient care.

Factors associated with impaired vibration perception in Mauritians with normal and abnormal glucose tolerance. Mauritius NCD Study Group

Vibration perception threshold (VPT) was measured in 1185 Indian, Creole, and Chinese men and women in Mauritius, where the current prevalence of diabetes mellitus in adults aged 25-74 years is estimated to be 13%. Vibration perception threshold was measured using a biothesiometer, at seven sites in the hand, wrist, foot, and ankle, during a population survey in 76% of 574 known diabetic patients (KDM), 79% of 525 newly diagnosed diabetic patients (NDM), 18% of 1121 subjects with impaired glucose tolerance (IGT), and in 127 normal subjects. The association of VPT with glucose tolerance and other risk factors was assessed in order to identify individuals most at risk of foot ulceration and to determine whether risk factors and normal levels for VPT in these ethnic groups were consistent with those reported for Caucasians. After adjusting for age and height, geometric mean VPT at six of seven sites increased significantly with worsening glucose tolerance and increasing duration of diabetes in both men and women, VPT also increased significantly with level of fasting plasma glucose in men, but not women. Smoking and alcohol consumption had no effect on VPT, and body-mass index (BMI) was positively associated only at some sites. Chinese subjects had lower VPTs than Indians or Creoles. In multiple linear regression models, age, male gender, duration of diabetes, ethnic group, and height (lower extremity sites) were significantly associated with VPT among diabetic subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Peripheral neuropathy as a presenting feature of type 2 diabetes: a case-controlled study

The characteristics and outcome of 68 newly diagnosed Type 2 diabetic patients who presented with clinically evident peripheral neuropathy were compared with matched controls who had no neuropathy at diagnosis. All subjects (34 male) whose median age was 68 (range 47-89) yr were identified from a computerized diabetes register and presented in 1982-1990. The groups were compared at diagnosis for haemoglobin A1, body mass index, blood pressure, smoking, and alcohol consumption, and for co-existent coronary and peripheral vascular disease. Mortality and morbidity were recorded to March 1991. Significantly more patients with neuropathy had co-existent peripheral vascular disease: 24(35%) compared to 6(9%) controls (p = 0.0021). Twenty (30%) of those with neuropathy and no controls had retinopathy at diagnosis, which was sight-threatening in 10. Seven (10%) with neuropathy but no controls presented with foot ulcers, one requiring limited amputation. Two more patients with neuropathy and one control subsequently developed foot ulcers resulting in one or more amputation in each group. Twenty-one (31%) of those with neuropathy and 14 (21%) controls died (p = 0.2109). In conclusion more diabetic patients with clinically evident peripheral neuropathy at diagnosis have peripheral vascular disease than matched patients without neuropathy. It is likely that macrovascular disease either exacerbates or causes the neuropathy in this group of patients. They are at high risk of developing foot ulceration and high priority should be given to foot care in planning their management.