Trends in yield and effects of screening intervals during 17 years of a large UK community-based diabetic retinopathy screening programme

AIMS

To describe changes in risk profiles and yield in a screening programme and to investigate relationships between retinopathy prevalence, screening interval and risk factors.

METHODS

We analysed a population of predominantly Type 2 diabetic patients, managed in general practice, and screened between 1990 and 2006, with up to 17 years' follow-up and up to 14 screening episodes each. We investigated associations between referable or sight-threatening diabetic retinopathy (STDR), screening interval and frequency of repeated screening, whilst adjusting for age, duration and treatment of diabetes, hypertension treatment and period.

RESULTS

Of 63 622 screening episodes among 20 788 people, 16 094 (25%) identified any retinopathy, 3136 (4.9%) identified referable retinopathy and 384 (0.60%) identified STDR. The prevalence of screening-detected STDR decreased by 91%, from 1.7% in 1991-1993 to 0.16% in 2006. The prevalence of referable retinopathy increased from 2.0% in 1991-1993 to 6.7% in 1998-2001, then decreased to 4.7% in 2006. Compared with screening intervals of 12-18 months, screening intervals of 19-24 months were not associated with increased risk of referable retinopathy [adjusted odds ratio 0.93, 94% confidence interval (CI) 0.82-1.05], but screening intervals of more than 24 months were associated with increased risk (odds ratio 1.56, 95% CI 1.41-1.75). Screening intervals of < 12 months were associated with high risks of referable retinopathy and STDR.

CONCLUSIONS

Over time the risk of late diagnosis of STDR decreased, possibly attributable to earlier diagnosis of less severe retinopathy, decreasing risk factors and systematic screening. Screening intervals of up to 24 months should be considered for lower risk patients.

Development of a virtual reality training curriculum for laparoscopic cholecystectomy

Background

Training within a proficiency-based virtual reality (VR) curriculum may reduce errors during real surgical procedures. This study used a scientific methodology for development of a VR training curriculum for laparoscopic cholecystectomy.

Methods

Inexperienced (had performed fewer than ten laparoscopic cholecystectomies), intermediate (20–50) and experienced (more than 100) surgeons were recruited. Construct validity was defined as the ability to differentiate between the three levels of experience, based on simulator-derived metrics for nine basic skills, four procedural tasks and full laparoscopic cholecystectomy on a high-fidelity VR simulator. Inexperienced subjects performed ten repetitions for learning curve analysis. Proficiency measures were based on the performance of experienced surgeons.

Results

Thirty inexperienced, 11 intermediate and 16 experienced operators were recruited. Eight of nine basic skills and three of four procedural tasks were found to be construct valid. The full procedure revealed significant intergroup differences for time (1541, 673 and 816 s; P = 0·002), movements (1021, 595 and 638; P = 0·006) and path length (2038, 1235 and 1303 cm; P = 0·033). Learning curves plateaued between the second and ninth sessions.

Conclusion

This study shows that it is possible to define and develop a whole-procedure VR training curriculum for laparoscopic cholecystectomy using structured scientific methodology.

Peritoneal closure or non-closure at caesarean section

At caesarean section, the closure or non-closure of the parietal and/or the visceral peritoneum has short-term and long-term advantages and disadvantages. The majority of reports have compared double closure vs double non-closure, non-closure of the parietal, or non-closure of the visceral parietal, with special emphasis on operation time, febrile morbidity, and duration of hospital stay. The present study compares the three methods in 692 consecutive caesarean sections in a South African rural hospital, with special emphasis on wound sepsis, operation time and febrile morbidity. The prevalence of wound sepsis and febrile morbidity was 4.9% and 2.5%, respectively. The only significant difference between the three groups was that double closure resulted in the longest operation time.

Acute unilateral cataract in a postpartum adolescent with poorly-controlled type 1 diabetes

Acute cataract is recognized as a rare complication in adolescents with type 1 diabetes mellitus and may be associated with rapid improvement in glycaemia in patients with newly diagnosed diabetes. Transient cataracts, which resolve following improved metabolic control, and irreversible cataracts requiring surgery have also previously been documented. Development or progression of retinopathy may complicate pregnancy in women with diabetes. To our knowledge, we present the first case report of an acute cataract developing postpartum in a woman with type 1 diabetes. This rare case serves to demonstrate a possible association between acute cataract and altered glycaemic control in pregnancy. Acute cataract should be considered in any woman with diabetes who develops sudden visual loss following pregnancy.

A case-control study on insulin resistance, metabolic co-variates & prediction score in non-alcoholic fatty liver disease

BACKGROUND & OBJECTIVE

Asian Indians have a high prevalence of insulin resistance and the metabolic syndrome. Currently, non-alcoholic fatty liver disease (NAFLD) is considered to be an integral part of the metabolic syndrome with insulin resistance as a central pathogenic factor. We studied anthropometric parameters, insulin resistance and metabolic co-variates in subjects with NAFLD as compared to those without NAFLD, and also developed a prediction score for NAFLD.

METHODS

Thirty nine subjects with NAFLD and 82 controls were selected for the study after ultrasonography of 121 consecutive apparently healthy subjects. Anthropometric profile [body mass index (BMI), waist circumference (WC) etc,], lipid profile, hepatic aminotransferases, fasting blood glucose (FBG), insulin were recorded and value of homeostasis model assessment of insulin resistance (HOMA-IR) was analysed. Step-wise logistic regression analysis and area under the receiver operator curve (aROC) were analysed to arrive at a prediction score.

RESULTS

Overall, prevalence of NAFLD was 32.2 per cent and prevalence of metabolic syndrome was seen in 41 per cent among cases and 19.5 per cent in controls (P<0.01). Subjects with NAFLD had significantly higher values of BMI, WC, hip circumference, FBG, fasting insulin, total cholesterol and serum triglycerides. Step-wise logistic regression analysis showed odds ratio (OR) and 95 per cent confidence interval (CI) for BMI [ 4.3 (1.6, 11.3)], FBG [5.5 (1.5, 19.8)] and fasting insulin [ 2.4 (1.0, 5.8)] as independent predictors of NAFLD. The prediction score for NAFLD was; 1 (fasting insulin) +1.6 (BMI) + 1.9 (FBG) (sensitivity of 84.6%, specificity of 51.2% and aROC 76%).

INTERPRETATION & CONCLUSION

In this study, presence of NAFLD indicated close relationship with multiple features of metabolic syndrome. The prediction score developed could be used as a screening tool to predict NAFLD among Asian Indians in north India.

Consensus statement for diagnosis of obesity, abdominal obesity and the metabolic syndrome for Asian Indians and recommendations for physical activity, medical and surgical management

Asian Indians exhibit unique features of obesity; excess body fat, abdominal adiposity, increased subcutaneous and intra-abdominal fat, and deposition of fat in ectopic sites (liver, muscle, etc.). Obesity is a major driver for the widely prevalent metabolic syndrome and type 2 diabetes mellitus (T2DM) in Asian Indians in India and those residing in other countries. Based on percentage body fat and morbidity data, limits of normal BMI are narrower and lower in Asian Indians than in white Caucasians. In this consensus statement, we present revised guidelines for diagnosis of obesity, abdominal obesity, the metabolic syndrome, physical activity, and drug therapy and bariatric surgery for obesity in Asian Indians after consultations with experts from various regions of India belonging to the following medical disciplines; internal medicine, metabolic diseases, endocrinology, nutrition, cardiology, exercise physiology, sports medicine and bariatric surgery, and representing reputed medical institutions, hospitals, government funded research institutions, and policy making bodies. It is estimated that by application of these guidelines, additional 10-15% of Indian population would be labeled as overweight/obese and would require appropriate management. Application of these guidelines on countrywide basis is also likely to have a deceleration effect on the escalating problem of T2DM and cardiovascular disease. These guidelines could be revised in future as appropriate, after another large and countrywide consensus process. Till that time, these should be used by clinicians, researchers and policymakers dealing with obesity and related diseases.

Consensus statement for diagnosis of obesity, abdominal obesity and the metabolic syndrome for Asian Indians and recommendations for physical activity, medical and surgical management

Asian Indians exhibit unique features of obesity; excess body fat, abdominal adiposity, increased subcutaneous and intra-abdominal fat, and deposition of fat in ectopic sites (liver, muscle, etc.). Obesity is a major driver for the widely prevalent metabolic syndrome and type 2 diabetes mellitus (T2DM) in Asian Indians in India and those residing in other countries. Based on percentage body fat and morbidity data, limits of normal BMI are narrower and lower in Asian Indians than in white Caucasians. In this consensus statement, we present revised guidelines for diagnosis of obesity, abdominal obesity, the metabolic syndrome, physical activity, and drug therapy and bariatric surgery for obesity in Asian Indians after consultations with experts from various regions of India belonging to the following medical disciplines; internal medicine, metabolic diseases, endocrinology, nutrition, cardiology, exercise physiology, sports medicine and bariatric surgery, and representing reputed medical institutions, hospitals, government funded research institutions, and policy making bodies. It is estimated that by application of these guidelines, additional 10-15% of Indian population would be labeled as overweight/obese and would require appropriate management. Application of these guidelines on countrywide basis is also likely to have a deceleration effect on the escalating problem of T2DM and cardiovascular disease. These guidelines could be revised in future as appropriate, after another large and countrywide consensus process. Till that time, these should be used by clinicians, researchers and policymakers dealing with obesity and related diseases.

Whole grains and health: perspective for Asian Indians

Grains are a part of human diet for about 10,000 years. Grains are the most important food source of Indian population, due to this carbohydrate consumption constitute approx. 60-70% of total food intake. Variety of grains are available in India, and different grains form staple diets of people in different part of the country. Whole grains are now recognized as an important source of fiber and other nutrients like trace minerals a vitamins. Grains have shown to have a role in prevention and reducing the risk of type 2 diabetes, coronary heart disease, cancer and obesity.

Distribution and cutoff points of fasting insulin in Asian Indian adolescents and their association with metabolic syndrome

AIM

To evaluate the levels and appropriate cutoff points of fasting insulin, and their association with the metabolic syndrome (MS) in Asian Indian adolescents.

METHODS

This cross-sectional, population based study included 948 (527 males & 421 females) adolescent subjects aged 14-19 years selected randomly from New Delhi, India. Cutoff points of fasting insulin were defined using Receiver Operating Characteristics curve analysis against overweight, abdominal obesity and high subscapular skinfold thickness. The MS was defined according to NCEP, ATP III and IDF criteria using age-, gender- and ethnicity-specific cutoff points.

RESULTS

Fasting insulin levels peaked at 16 y and reduced subsequently in both genders. The derived cutoff points for fasting insulin (pmol/L) were: 14-15 y- 128.5 and 164.8; 16-17 y- 126.1 and 152.8; 18-19 y- 121.2 and 162.4 in males and females, respectively. Prevalence of fasting hyperinsulinemia (39.1%) and MS (NCEP 2.2%, IDF 1.5%) was highest in age group 16-17 years.

CONCLUSION

The data from this first study describing the distribution and cutoff points of fasting insulin in Asian Indian adolescents may be helpful for detection of and application of primary prevention strategies for fasting hyperinsulinemia and the metabolic syndrome in this population.

The management of soft tissue sarcoma

SUMMARY

Soft tissue sarcomas are a rare group of mesenchymal tumours that display cardinal signs, which can raise suspicion to their diagnosis. Management in a sarcoma treatment centre by its multidisciplinary team has improved outcome. Good local disease control with limb salvage and adjuvant radiotherapy has considerably reduced the morbidity of previous limb amputation. By the early involvement of a plastic surgeon, tissue reconstruction is optimised and wound complications reduced. This article looks at the contemporary management of soft tissue sarcoma and, in particular, its relevance to the plastic surgeon today.

Plusoptix Vision Screener: the accuracy and repeatability of refractive measurements using a new autorefractor

BACKGROUND

The Plusoptix Vision Screener (PVS) is a new non-cycloplegic videoretinoscopy autorefractor. Refractive accuracy may affect its performance as a screening tool.

AIMS

Study 1: To determine the intra- and interobserver variability of PVS measurements. Study 2: To compare PVS measurements with gold-standard manual cycloplegic retinoscopy (MCR).

METHODS

Study 1: PVS refraction of 103 children with mean (SD) age 5.5 (0.6) years by two observers. Study 2: PVS and MCR refraction of 126 children with mean (SD) age 5.5 (1.5) years, including 43 children with manifest strabismus >/=5 PD, comparing mean spherical equivalent (MSE) and Jackson cross cylinders J(0) and J(45).

RESULTS

Study 1: Repeatability coefficients (observer 1): MSE: 0.63 D, J(0): 0.24 D, J(45): 0.18 D; those of observer 2 were nearly identical. The mean difference (95% limits of agreement) between the two observers for MSE, J(0) and J(45) were, respectively, 0.03 (-0.62 to 0.68 D), -0.008 (-0.25 to 0.23 D) and 0.013 (-0.18 to 0.20) D. Study 2: MSE tended to be lower on PVS than MCR, with differences of up to 8.00 D. Less than 20% of values were within +/-0.50 D of each other. Agreement was better for J(0) and J(45). Strabismus was associated with an odds ratio of 3.7 (95% CI 1.3 to 10.5) of the PVS failing to obtain a reading.

CONCLUSIONS

The PVS may underestimate children's refractive error.

Pulmonary Absorption Enhancement of Salmon Calcitonin

The aim of this work was to develop formulations of calcitonin for pulmonary delivery to enhance the absorption and study the comparative pharmacodynamic behavior of developed formulations in rats. Formulations with different pH, absorption promoters of different classes and combination thereof at three concentration levels were prepared and instilled intratracheally in anesthetized rats. The absorption of calcitonin was measured by its hypocalcemic effect in blood collected at specific time points. The formulations having least concentration of absorption promoter with significant blood calcium reduction were selected out from three concentration levels of absorption promoters used. The relative pulmonary bioactivity of calcitonin in acetate buffer pH 6.0 and pH 3.9 was 21.0+/-1.5% and 53.9+/-2.8%, respectively, compared to subcutaneously administered calcitonin in equivalent dose. When sodium tauroglycocholate, dimethyl beta-cyclodextrin, chymostatin, and bacitracin were co-administered in acetate buffer pH 3.9 solution, the relative bioactivity of 139.1+/-7.3% was obtained. Only 72.0+/-2.7%, 79.2+/-3.9%, 83.0+/-2.1% and 87.0+/-3.9% were obtained, respectively, upon incorporation of these absorption promoters individually. It was concluded that absorption promoters in combination significantly increase the pulmonary bioactivity of calcitonin. These studies proves that calcitonin administered through the pulmonary route can yield higher systemic absorption for enhanced bioactivity.

In vitro performance of nano-heterogeneous dentin adhesive

Water is ubiquitous in the mouths of healthy individuals and routinely interferes with efforts to bond restorations to dental tissues. Our previous studies using tapping-mode atomic force microscopy (TMAFM) have shown that nanophase separation is a general feature of cross-linked polymethacrylates photocured in the presence of water. To explore the relationship between nanophase separation in dentin adhesives and their long-term mechanical properties, we evaluated model adhesives after 3 months of aqueous storage. The degree of contrast in the TMAFM phase image depended on the formulations used, ranging from 'not observable' to 'very strong'. Correspondingly, the mechanical properties of these model adhesives varied from 'minimal change' to 'significant depreciation'. The results support the hypothesis that a high degree of heterogeneity at the nano-scale is associated with poor mechanical durability in these model adhesives.

Neonatal outcome after caesarean birth for fetal distress and/or meconium staining in a South African rural setting

The aim was to evaluate the effect of caesarean delivery on the neonatal outcome after labour with fetal distress and/or meconium staining (MS). We audited 199 caesarean sections performed for non-reassuring fetal condition (NRFC) and/or MS in a rural regional hospital. The 1 and 5 min Apgar scores were compared with those of 33 vaginal births after labour with MS. There were five neonates out of 232 (2.2%) with an Apgar score <7 at 5 min; one died early, neonatally. In the caesarean section group for NRFC, there were two fresh stillbirths and one early neonatal death, a perinatal mortality of 15.1/1,000 births. The 5 min Apgar score was not statistically significantly affected by the mode of delivery. Caesarean delivery does not improve the neonatal outcome when the amniotic fluid is meconium stained.

Comparison of definitions of the metabolic syndrome in adult Asian Indians

OBJECTIVE

The optimum definition of the metabolic syndrome (MS) is not known. We compared international definitions of MS [recently proposed modified definition of National Cholesterol Education Programme, Adult Treatment Panel III (NCEP, ATP III) and International Diabetes Federation (IDF)] with two proposed candidate definitions in adult Asian Indians.

DESIGN

Data from three previous cross-sectional studies carried out in North India were analyzed.

SUBJECTS

The study included 2050 adult (mean age: 40 +/- 18 years) Asian Indian subjects residing two metropolitan cities.

MEASUREMENTS

Candidate definitions of MS were proposed by modifying the NCEP, ATP III and IDF definitions by including the following modified variables into two combinations (MS-ATP1 and MS-IDF1); waist circumference cut-off points as >90 cm in males and >80 cm in females, body mass index (BMI) cut-off point as >23 kg/m2, impaired fasting glucose (IFG) cut-off point >100 mg/dl and waist circumference as an obligatory criterion.

RESULTS

Maximum overall and gender-specific prevalence of the MS (49.2% overall; 41.4% in males; 55.3% in females) was observed using the definition which included modified cut-off points of WC (non-obligatory), BMI, and IFG (>100 mg/dl) in addition to other defining parameters. Compared to other definitions this proposed candidate definition maximally detected presence of MS in subjects with IFG and T2DM [Percentage prevalence: 78.1% (73.0-82.7) and 91.1% (84.2-95.6)]. Even in subjects without abdominal obesity, a high prevalence of other abnormal defining parameters of the metabolic syndrome; hypertension (> or = 130 or > or = 85 mmHg), 35.7%; BMI >23 kg/m2, 15.3%; hypertriglyceridemia (>150 mg/dl), 20.2% and low levels of HDL-C (<40 in males; <50 mg/dl in females), 55% were seen. Further, 10.5% of subjects who did not have abdominal obesity had presence of at least 3 risk variables of the metabolic syndrome. These data indicate that by making abdominal obesity a mandatory criterion would lead to missing of some cases of the metabolic syndrome.

CONCLUSION

By including BMI and making waist circumference as a non-obligatory criterion, more cases of the metabolic syndrome is detected. For Asian Indians, making waist circumference as mandatory variable in the definition of the metabolic syndrome would lead to non-inclusion of nearly 11% cases who would otherwise be diagnosed as metabolic syndrome according to modified NCEP, ATP III definition.

Nano finite element modeling of the mechanical behavior of biocomposites using multi-scale (virtual internal bond) material models

It is evident that biocomposites, specifically mineralized Type-I collagen fibrils, have strong mechanical properties, such as a desirable combination of elastic modulus, fracture toughness, and fracture strength. The mineral Hydroxyapatite [Hap] by itself is stiffer, and it is not clear whether a collagen fiber by itself has a lower breaking strength than the mineralized fiber. Hence, the objective of this paper is to develop, outline, apply, and demonstrate issues involving a new nano explicit finite element based framework, by which the mechanical behavior of mineralized collagen fibrils and their constituents can be studied. A multi-scale virtual internal bond model is used to model the material behavior and failure of such biocomposites. In this research two models have been studied. The first model attempts to illustrate the hypothesis that materials are less sensitive to flaws at nanoscale and the second model studies the mechanical behavior of a nano sized dahlite mineral crystal commonly found in collagen fibril. Two important implementation characteristics have been introduced and illustrated, namely that scaled properties can be used at the micro and nano length scales along with scaled dimensions and secondly the loading time can be appropriately scaled without the loading becoming a dynamic loading.