J. Dolben

Non-mydriatic Polaroid photography in screening for diabetic retinopathy: evaluation in a clinical setting.

Because of fears that Polaroid colour prints produced with a non-mydriatic fundus camera may not detect important sight threatening lesions in diabetes a study was conducted comparing retinal images obtained on Polaroid prints taken in “field” conditions with those on 35 mm transparencies and fluorescein angiograms. Almost one in five (22/127) Polaroid prints could not be assessed owing to poor quality compared with 3 (2.4%) 35 mm transparencies and 2 (1.6%) fluorescein angiograms. The pick up rate of microaneurysms, haemorrhages, and hard and soft (cotton wool spots) exudates was equivalent for Polaroid prints and 35 mm transparencies of equivalent quality. In two cases with disc new vessels, however, these were not seen on the Polaroid prints. The widespread use of Polaroid colour prints obtained with a non-mydriatic camera without the necessary operative and interpretive skills further limits the usefulness of the technique.

Impact of initial treatment on renal function in newly-diagnosed type 2 (non-insulin-dependent) diabetes mellitus.

SummaryThe impact of improved glycaemic control on renal function in newly-presenting Type 2 (non-insulin-dependent) diabetic patients has not been adequately researched. Consequently, glomerular filtration rate and effective renal plasma flow and urinary albumin excretion rates were determined in 76 subjects (age (mean (SD)): 54 (9.5) years; 50 male) of an original cohort of 110 newly-presenting normotensive non-proteinuric Type 2 diabetic patients following 6 months treatment with diet alone (n=42) or with oral hypoglycaemic agents (n=34). Significant reductions were observed in (presentation vs 6 months): body mass index (p<0.01); fasting plasma glucose (p<0.001); glycated haemoglobin (HbA1) (p<0.001); systolic blood pressure (p<0.01); and diastolic blood pressure (p<0.001). Glomerular filtration rate declined from 117 (22) to 112 (21) ml·min−1 (p<0.01), with unchanged effective renal plasma flow (534 (123) vs 523 (113) ml·min−1) and filtration fraction (22.4 (3.0) vs 21.8 (3.4)%). Albumin excretion rate (median (range)) declined from 1.1 (0.1–34.7) to 0.5 (0.1–29.9) μg·min−1 (p<0.01). Changes in glomerular filtration rate (Δ values) were inversely correlated with presentation values (p<0.001), and positive relationships were observed with Δ effective renal plasma flow (p<0.01), and Δ glycated haemoglobin (p<0.05). Type 2 diabetic patients with glomerular filtration rate values at presentation over 120 ml·min−1 demonstrated significant reduction in glomerular filtration rate (n=31; p<0.001), whilst those with original values less than 120 ml·min−1 remained unchanged (n=45). Glomerular filtration rate, effective renal plasma flow and filtration fraction for the Type 2 diabetic patients remained elevated compared with age-controlled normal subjects (p<0.01-0.001). Albumin excretion rate at presentation and 6 months were positively correlated with fasting plasma glucose levels (p<0.05) but not renal haemodynamics. Thus, glomerular filtration rate and albumin excretion rate in newly-presenting Type 2 diabetic patients are influenced by metabolic control. Improved glycaemia for 6 months produces a reduction in glomerular filtration rate, mainly in the younger patients with values greater than 120 ml·min−1 at diagnosis of diabetes. Despite these changes, renal haemodynamic parameters remain elevated compared with age-matched normal subjects.

Dominant risk factors for retinopathy at clinical diagnosis in patients with type II diabetes mellitus

A study of 270 newly presenting, previously untreated, type II diabetic patents revealed that 38 patients (14%) had already developed diabetic retinopathy (DR). Among this group, 26 patients had lesions of background diabetic retinopathy and 12 patients already had maculopathy or preproliferative changes. The aim of this study was to determine the risk factors influencing susceptibility to retinopathy, and to provide an accurate predictive value for diabetic retinopathy from a detailed multiple regression analysis that involved 27 demographic variables and the metabolic and hormonal responses during a meal tolerance test (MTT) at presentation. Compared to the nonretinopaths, the retinopaths had higher fasting plasma glucose levels (FPG) (mean +/- SD) (13.9 +/- 3.1 versus 11.6 +/- 3.2 mmol/L, p < 0.001), lower body-mass index values (BMI) (26.1 +/- 3.8 versus 29.3 +/- 5.0 kg/m2, p < 0.001) and higher plasma urea concentrations (6.0 +/- 1.9 versus 5.3 +/- 1.2 mmol/L, p 0.05). In contrast, gender and levels of blood pressure and other lipid levels did not influence the prevalence of diabetic retinopathy. A multiple regression formula for the prediction of diabetic retinopathy was derived and then used to categorize patients into high-risk and low-risk groups. The retinopaths also had higher HbA1c (p < 0.001), higher plasma glucose are under curve (0-2 h, p < 0.001), lower plasma insulin area under curve (0-22 h, p < 0.001), lower C-peptide area under curve (0-2 h, p < 0.01). They were also leaner (p < 0.001) and older (p < 0.05). However, these variables did not feature significantly in the multiple regression formula. The retinopaths were found to have higher risk probability values (25.1 +/- 11.5 versus 13.1 +/- 10.4%, p < 0.001). In the high risk group, 81.6% of retinopaths were identified. In the low-risk group, 63.8% of nonretinopaths were found. The incidence of diabetic retinopathy in type II diabetic patients at clinical diagnosis was found to be highly related to the degree of hyperglycemia, body-mass index, and to a lesser extent, renal impairment.

Screening for Diabetic Retinopathy

There is a need for greater educational emphasis, both at undergraduate and postgraduate level, on the detection of diabetic eye disease, in particular diabetic retinopathy. The early diagnosis of the sight‐threatening lesions of proliferative retinopathy and maculopathy is a prerequisite for the prevention or reduction of the visual loss and blindness associated with this diabetic complication. It is also essential that patients are aware that diabetes can result in visual loss due to diabetic retinopathy. Patients should understand that diabetic retinopathy may be present without ophthalmic or diabetic symptoms and that its incidence increases with duration of diabetes, poor diabetes control, and hypertension. They must also be aware that, if detected early, retinopathy can be treated successfully and vision preserved. Early detection depends on regular eye examination involving both visual acuity assessment and ophthalmoscopy through dilated pupils by experienced personnel. A comprehensive programme of screening followed by prompt and adequate treatment would made a significant contribution to eradicating diabetic retinopathy as a cause of blindness.

Cholesterol rich apo B containing lipoproteins and smoking are independently associated with macrovascular disease in normotensive NIDDM patients

A cross‐sectional study of macrovascular disease (MVD) and associated metabolic and other risk factors was conducted in 87 normotensive NIDDM patients. MVD was assessed by Rose questionnaire, 12 lead resting ECG, duplex scanning of carotid and peripheral vessels, and ankle:brachial systolic blood pressure ratio. Fasting serum total cholesterol, total triglycerides, LDL cholesterol, HDL cholesterol, apolipoproteins AI and B, lipoprotein (a), HbA1, plasma glucose, insulin, and C‐peptide responses to a carbohydrate rich meal, body mass index (BMI), waist‐hip ratio, urinary albumin excretion rate, blood pressure, smoking and family history were assessed as possible ‘risk factors’. Apolipoprotein:lipid ratios were calculated to estimate lipoprotein composition. Thirty‐six patients had demonstrable MVD. The presence of MVD was associated with higher total triglycerides (p < 0.05), BMI (p < 0.05), systolic blood pressure (p < 0.01), a lower apo B:non HDL cholesterol ratio (p < 0.001), and smoking (p < 0.005) but no other measures. Multiple regression analysis revealed smoking and a low apo B:non HDL cholesterol to be independently associated with MVD. The low apo B:non HDL cholesterol suggests a high cholesterol content of apo B containing lipoproteins. This lipoprotein abnormality is not a feature of NIDDM, but when present in these patients may be particularly atherogenic.

Nitrendipine once or twice daily in hypertensive non-insulin-dependent diabetes mellitus

Twenty (12 male, 8 female) hypertensive patients were recruited into the study; their mean (+/- SD) sitting blood pressure (BP) was 166 +/- 13/101 +/- 4 mm Hg, age 59.6 +/- 5.8 years, weight 83.4 +/- 14.2 kg, and glycosylated hemoglobin (HbA1) 9.9 +/- 2.6%. After a run-in period of 4 weeks, patients were randomized to receive nitrendipine once or twice daily, with 15 patients completing the 12-week study period. Prior to treatment with nitrendipine, the patients subsequently treated on a twice-daily regimen had a higher sitting systolic BP (SBP) of 173 +/- 15 mm Hg compared to the once-daily patient group at 159 +/- 7 mm Hg (p less than 0.05). There were no differences between the two treatment groups in weight or diabetes control. Once-daily nitrendipine effectively reduced the sitting SBP and diastolic BP (DBP), i.e., SBP fell from 159 +/- 7 to 147 +/- 12 mm Hg (p less than 0.05) and DBP fell from 100 +/- 4 to 86.3 +/- 8 mm Hg (p less than 0.001). Nonsignificant reductions in weight from 81.5 +/- 11.3 to 80.9 +/- 11.2 kg and HbA1 from 9.8 +/- 3.3 to 8.4 +/- 1.3% were also seen. Similarly, with twice-daily nitrendipine, a significant (p less than 0.01) fall in sitting systolic BP from 173 +/- 15 to 148 +/- 9 mm Hg and DBP 103 +/- 4 to 85 +/- 8 mm Hg was also achieved. Little or no change was observed in weight or glycemic control in this patient group.(ABSTRACT TRUNCATED AT 250 WORDS)