Hybrid Closed-Loop Therapy in Adults With Type 1 Diabetes and Above-Target HbA1c: A Real-world Observational Study

OBJECTIVE

We explored longitudinal changes associated with switching to hybrid closed-loop (HCL) insulin delivery systems in adults with type 1 diabetes and elevated HbA1c levels despite the use of intermittently scanned continuous glucose monitoring (isCGM) and insulin pump therapy.

RESEARCH DESIGN AND METHODS

We undertook a pragmatic, preplanned observational study of participants included in the National Health Service England closed-loop pilot. Adults using isCGM and insulin pump across 31 diabetes centers in England with an HbA1c ≥8.5% who were willing to commence HCL therapy were included. Outcomes included change in HbA1c, sensor glucometrics, diabetes distress score, Gold score (hypoglycemia awareness), acute event rates, and user opinion of HCL.

RESULTS

In total, 570 HCL users were included (median age 40 [IQR 29-50] years, 67% female, and 85% White). Mean baseline HbA1c was 9.4 ± 0.9% (78.9 ± 9.1 mmol/mol) with a median follow-up of 5.1 (IQR 3.9-6.6) months. Of 520 users continuing HCL at follow-up, mean adjusted HbA1c reduced by 1.7% (95% CI 1.5, 1.8; P < 0.0001) (18.1 mmol/mol [95% CI 16.6, 19.6]; P < 0.0001). Time in range (70-180 mg/dL) increased from 34.2 to 61.9% (P < 0.001). Individuals with HbA1c of ≤58 mmol/mol rose from 0 to 39.4% (P < 0.0001), and those achieving ≥70% glucose time in range and <4% time below range increased from 0.8 to 28.2% (P < 0.0001). Almost all participants rated HCL therapy as having a positive impact on quality of life (94.7% [540 of 570]).

CONCLUSIONS

Use of HCL is associated with improvements in HbA1c, time in range, hypoglycemia, and diabetes-related distress and quality of life in people with type 1 diabetes in the real world.

Previous structured education attendance and the relationship with HbA1c and hypoglycaemia awareness in people living with type 1 diabetes mellitus using FreeStyle Libre: insights from the Association of British Clinical Diabetologists (ABCD) Nationwide Audit

Background: Dose Adjustment For Normal Eating (DAFNE) is the gold standard National Institute for Health and Care Excellence (NICE) recommended structured education programme that promotes self-management in people living with type 1 diabetes (T1D). We have recently shown that FreeStyle Libre (FSL) is associated with improved haemoglobin A1c (HbA1c) and hypoglycaemia awareness. Aims: To explore the effect of structured education including DAFNE on HbA1c and GOLD score when combined with FSL use. Methods: The ABCD national audit data on FSL users were used to conduct this prospective longitudinal study. The Stu- dent’s t test was used to compare the baseline and follow-up HbA1c and a change in the GOLD score for hypoglycaemia awareness. The baseline demographic and clinical characteristics of the study population were compared using ANOVA. Linear regression analysis identified predictors of change in HbA1c with FSL use. Results: The study consisted of 14,880 people living with insulin-dependent diabetes mellitus (IDDM), 97% of whom had T1D, of which 50% were female, with a mean±SD base- line HbA1c of 70±18 mmol/mol and baseline body mass index (BMI) of 25.3±6.2 kg/m2. Follow-up data for HbA1c were avail- able for 6,446 participants while data for GOLD score were available for 5,057 participants. The study population was divided into three groups: 6,701 people with no prior structured education (Group 1), 3,964 with other structured education (Group 2), and 4,215 had previously attended DAFNE structured education (Group 3). Groups 2 and 3 who had previously attended structured education had a lower initial HbA1c than those in Group 1 (p<0.0001). However, there was a significant but similar magnitude of the fall in HbA1c across all groups (−8.10 mmol/mol vs −6.61 mmol/mol vs −6.22 mmol/mol in Groups 1, 2 and 3, respectively), with p (ANOVA)=0.83. Similarly, the decline in GOLD score was comparable in Groups 1, 2 and 3 (−0.33 vs −0.30 vs −0.34, respectively), with p (ANOVA)=0.43. Linear regression analysis identified higher baseline HbA1c (β=0.585, p<0.0001), number of FSL scans over 14 days (β=−0.026, p=0.00135) and other structured education (β=−1.207, p=0.02483) as predictors of HbA1c reduction. Prior DAFNE training was not associated with improved HbA1c reduction in the linear regression model. Conclusions: FSL use was associated with improvements in HbA1c and GOLD score. Although DAFNE is an evidence- based intervention to improve outcomes in those with T1D, DAFNE attendance prior to commencing FSL did not influence HbA1c or GOLD score outcomes when compared with FSL use alone. Other structured education was identified as a predictor of HbA1c reduction when combined with FSL use.

Cardioprotective Effects of Pioglitazone in Type 2 Diabetes

Antidiabetic medications that improve glycemic control as well as cardiovascular outcomes will be the mainstay of treatment for type 2 diabetes moving forward. This article reviews the beneficial effects of the thiazolidinedione pioglitazone of ameliorating hyperglycemia and improving cardiovascular risk factors. While the newer sodium-glucose cotransporter 2 inhibitor and glucagon-like peptide 1 receptor agonist drug classes have confirmed cardiovascular benefits, pioglitazone also has been shown to reduce major adverse cardiovascular events, in both people with type 2 diabetes and nondiabetic subjects with insulin resistance. Adverse effects associated with pioglitazone can be mitigated by its use at a lower dose and in combination with antidiabetic agents from other drug classes.

Cardiovascular Disease and Type 2 Diabetes: Has the Dawn of a New Era Arrived?

Hyperglycemia is the major risk factor for microvascular complications in patients with type 2 diabetes (T2D). However, cardiovascular disease (CVD) is the principal cause of death, and lowering HbA1c has only a modest effect on reducing CVD risk and mortality. The recently published LEADER and SUSTAIN-6 trials demonstrate that, in T2D patients with high CVD risk, the glucagon-like peptide 1 receptor agonists liraglutide and semaglutide reduce the primary major adverse cardiac events (MACE) end point (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke) by 13% and 24%, respectively. The EMPA-REG OUTCOME, IRIS (subjects without diabetes), and PROactive (second principal end point) studies also demonstrated a significant reduction in cardiovascular events in T2D patients treated with empagliflozin and pioglitazone. However, the benefit of these four antidiabetes agents (liraglutide, semaglutide, empagliflozin, and pioglitazone) on the three individual MACE end points differed, suggesting that different underlying mechanisms were responsible for the reduction in cardiovascular events. Since liraglutide, semaglutide, pioglitazone, and empagliflozin similarly lower the plasma glucose concentration but appear to reduce CVD risk by different mechanisms, there emerges the intriguing possibility that, if used in combination, the effects of these antidiabetes agents may be additive or even multiplicative with regard to cardiovascular benefit.

Retinal vessel diameters and reactivity in diabetes mellitus and/or cardiovascular disease

Background

Retinal vessel calibre and vascular dilation/constriction in response to flicker light provocation may provide a measure distinguishing patients suffering from diabetes mellitus and/or cardiovascular disease.

Methods

One hundred and sixteen age and sex matched patients with diabetes mellitus (DM), cardiovascular disease (CVD) and both DM and CVD (DM + CVD) underwent systemic and intraocular pressure measurements. Retinal vessel calibres were assessed using a validated computer-based program to compute central retinal artery and vein equivalents (CRVE) from monochromatic retinal images. Vessel dilation and constriction responses to flicker light provocation were assessed by continuous retinal vessel diameter recordings. Plasma endothelial markers von Willebrand factor (vWf) and soluble E selectin (sEsel) were measured by ELISA.

Results

Retinal vessel calibres were comparable across groups but CRVE correlated significantly with disease duration in DM patients (r = 0.57, p < 0.001). Patients suffering DM only exhibited reduced arterial vasomotion at rest and reduced arterial constriction following flicker light induced vessel dilation compared to patients with CVD and those suffering both CVD + DM (p = 0.030). Patients suffering from CVD + DM exhibited significant differences between each flicker cycle in regards to arterial maximum constriction (p = 0.006) and time needed to reach arterial maximum dilation (p = 0.004), whereas the other two groups did not show such inconsistencies between individual flicker cycles. vWf was raised in CVD + DM compared to the other two groups (p ≤ 0.02), whilst sEsel was raised in CVD + DM compared to DM alone (p = 0.044).

Conclusions

Dynamic retinal vascular calibres as obtained by continuous diameter measurements using flicker light provocation can reveal subtle differences between groups suffering from CVD with and without DM. This difference in reaction pattern and lack of arterial constriction in DM may provide a suitable marker to monitor progression.

Use of oral fluorescein angiography in the diagnosis of macular oedema within a diabetic retinopathy screening programme

AIMS

To assess if oral fluorescein angiography (OFA) is a suitable screening method to detect macular oedema in diabetic retinopathy.

METHODS

Eighty-four diabetic patients were included in the study. They were from a consecutive series of patients attending the diabetic eye-screening clinic, with retinopathy at the macula requiring ophthalmology assessment. All patients were subsequently examined in the eye hospital, by ophthalmologist slit lamp biomicroscopy assessment as the gold standard, followed by oral fluorescein angiography.

RESULTS

This study indicates a sensitivity of 92% and specificity of 81%. Only 4.8% of patients developed a minor reaction to oral fluorescein; 84.5% of images were of good quality.

CONCLUSIONS

Oral fluorescein angiography is an efficient and highly sensitive tool for the detection of macular oedema. It can be used as an adjunct in the diabetic screening service to identify patients with oedema within a disc diameter of the macula. Ultimately it will ensure that only necessary and smaller numbers of patients are referred to ophthalmologists.

What is the role of between meal snacks with intensive basal bolus regimens using preprandial lispro?

AIMS

Hypoglycaemia avoidance for patients on intensive insulin regimens requires the eating of snacks between meals. Insulin lispro with its shorter action profile may permit omitting such snacks.

METHODS

Ten Type 1 diabetes mellitus (DM) patients were rendered euglycaemic with a morning intravenous insulin infusion. Each was studied on six afternoons in random order, with previously determined equal doses of Humulin S (HS) injected at -30min, or lispro injected at 0 min before a standard lunch. The snack was either eaten mid-afternoon, combined with the lunch or omitted altogether.

RESULTS

Lispro and lunch with a snack combined at 0 min gave equal control to HS at -30 min and lunch at 0 min with a mid-afternoon snack. Lispro and lunch at 0 min with a mid-afternoon snack gave a lower early postprandial glucose. At 120 min glucose (mean mmol/l +/- SEM) were 7.4+/-0.8 vs. 7.0+/-1.0 (P = 1.0) and 3.9+/-0.5 (P = 0.045), respectively. The area under the insulin curve over the whole afternoon was similar for HS and lispro (13193.3+/-974.6 vs. 13193.6+/-809.9 mIU/min, P = 1.0) but with a greater peak for lispro than HS with lispro falling more rapidly. Despite significantly lower lispro levels after 180 min, intermediary metabolites concentrations were similar in all HS and lispro study days.

CONCLUSIONS

Lispro injected immediately before combined snack and lunch and with no subsequent snack achieves equivalent control to conventional regimens using HS -30 min before lunch and mid-afternoon snack. Lispro taken with traditional meal patterns without dose reduction risks early postprandial hypoglycaemia and late hyperglycaemia.

A 'fail-safe' screening programme for diabetic retinopathy

OBJECTIVE

To improve screening for diabetic retinopathy in a hospital diabetic clinic through the use of the audit process.

DESIGN

Comparison of an existing system of screening for diabetic retinopathy (a specialist optometrist using ophthalmoscopy alone) with a new system in which a specialist optometrist examined retinal Polaroid photographs taken through pharmacologically dilated pupils and combined this with ophthalmoscopy in all cases except when the photographs were perfect and definitely showed no retinopathy. In this new system, the optometrist could discuss cases of uncertainty with a diabetes physician while the patient was still in the clinic with eyes dilated.

SETTING

Inner city hospital diabetes clinic.

SUBJECTS

289 hospital diabetic clinic patients not already attending an ophthalmologist; a consecutive series of 144 such patients for the first audit, 145 for the repeat audit.

MAIN OUTCOME MEASURES

Assessment of each screening system against a gold standard. For the first audit this was agreement by two of four diabetes physicians, who combined examination of the photographs with the findings from dilated ophthalmoscopy, on the classification of the retinae of each patient, guided by standard European criteria. For the second audit, the gold standard was enhanced by discussing the photographs and findings of all patients with an independent ophthalmologist. For patients requiring referral, a second ophthalmologist also commented on the case.

RESULTS

The addition of retinal photography to universal pupil dilatation, and the availability of diabetes physician backup to discuss cases of uncertainty, greatly increased the optometrists' detection rate. Sensitivities for the first (ophthalmoscopy only) and second (ophthalmoscopy plus photography plus diabetologist back-up) audits were, respectively, 71.4% vs 100% for sight-threatening retinopathy, 33% vs 100% for retinopathy requiring six-month review, and 40.3% vs 97.2% for any retinopathy (p = 0.002).

CONCLUSIONS

Optometrists specialising in diabetic retinopathy using Polaroid retinal photography and ophthalmoscopy, both through dilated pupils, backed up by experienced diabetologists to discuss cases of uncertainty, could form the basis of a retinopathy screening service that accurately identifies and categorises retinopathy and does not miss sight-threatening cases.

Instant electronic imaging systems are superior to Polaroid at detecting sight-threatening diabetic retinopathy

Polaroid photography in diabetic retinopathy screening allows instant image availability to enhance the results of ophthalmoscopy. Retinal cameras are now being developed which use video/digital imaging techniques to produce an instant enlarged retinal image on a computer monitor screen. We aimed to compare one such electronic imaging system, attached to a Canon CR5 45NM, with standard Polaroid retinal photography. Two hundred and thirteen eyes from 107 diabetic patients were photographed through dilated pupils by both systems in random order and the images were analysed blind. Diabetic retinopathy was present in 58 eyes of which 55/58 (95%) were detected on the electronic image and only 49/58 (84%) on the Polaroid. Of 34 eyes requiring ophthalmologist referral according to standard European criteria, 34/34 (100%) were detected on the electronic image and only 24/34 (71%) on the Polaroid. Side by side comparisons showed electronic imaging to be superior to Polaroid at lesion detection. Using linear analogue scales, the patients assessed the electronic imaging photographic flash as less uncomfortable than the Polaroid equivalent (p < 0.0001). Other advantages of electronic imaging include: ready storage of the images with other patient clinical data on the diabetes computerized register/database; potential for image enhancement and analysis using image analysis software and electronic transfer of images to ophthalmologist or general practitioner. Electronic imaging systems represent a potential major advance for the improvement of diabetic retinopathy screening.

Impotence in diabetes

Impotence is more common in diabetic patients than in the normal population. This is due to the complications of diabetes, which damage the neurovascular bundle required for normal penile function. Minimally invasive methods of treatment have improved the outcome; however, the methods are still suboptimal. Recent advances in our understanding of the underlying mechanisms may lead to more non-invasive, targeted forms of treatment. (Trends Endocrinol Metab 1997;8:98-101). (c) 1997, Elsevier Science Inc.

"Natural family planning": effective birth control supported by the Catholic Church

During 20-22 September Manchester is to host the 1993 follow up to last year's "earth summit" in Rio de Janeiro. At that summit the threat posed by world overpopulation received considerable attention. Catholicism was perceived as opposed to birth control and therefore as a particular threat. This was based on the notion that the only method of birth control approved by the church--natural family planning--is unreliable, unacceptable, and ineffective. In the 20 years since E L Billings and colleagues first described the cervical mucus symptoms associated with ovulation natural family planning has incorporated these symptoms and advanced considerably. Ultrasonography shows that the symptoms identify ovulation precisely. According to the World Health Organisation, 93% of women everywhere can identify the symptoms, which distinguish adequately between the fertile and infertile phases of the menstrual cycle. Most pregnancies during trials of natural family planning occur after intercourse at times recognised by couples as fertile. Thus pregnancy rates have depended on the motivation of couples. Increasingly studies show that rates equivalent to those with other contraceptive methods are readily achieved in the developed and developing worlds. Indeed, a study of 19,843 poor women in India had a pregnancy rate approaching zero. Natural family planning is cheap, effective, without side effects, and may be particularly acceptable to the efficacious among people in areas of poverty.

Severe peripheral neuropathy and elevated plantar pressures causing foot ulceration in pituitary gigantism

We report two patients with treated pituitary gigantism and peripheral neuropathy, one of whom has chronic foot ulceration. Detailed neurophysiological assessment was performed on both patients. The patient with foot ulceration had clinical and neurophysiological evidence of severe neuropathy, whereas the patient without ulceration had only neurophysiological abnormalities. The sweating response to acetylcholine was markedly impaired in the feet of both patients, suggesting pedal autonomic denervation. Neither patient had evidence of diabetes mellitus and detailed investigation failed to reveal an alternative cause of peripheral neuropathy. Optical pedobarography revealed abnormally high pressure (> 10 kg/cm2) under the metatarsal heads of both patients, one such area coinciding with the area of ulceration. Thus in pituitary gigantism elevated plantar pressures may contribute to the development of foot ulceration when severe peripheral neuropathy is present. Furthermore, as in diabetes mellitus, impaired sweating may also increase the risk of ulceration as the resultant dry skin may develop fissures.

Psychometric assessment of diabetic impotence

In a study of 23 diabetic men complaining of impotence, completion of physical tests, self-report psychometric testing, a rating of marital intimacy, and a semi-structured interview revealed that, of ten patients found to be at risk of psychogenic impotence secondary to marital or psychiatric morbidity, five were thought to have adequate erectile response and to have a psychogenic component to their problem. This seems to show high sensitivity, if not specificity, of the self-report questionnaires.

Impotence in diabetes: aetiology, implications for treatment and preferred vacuum device

In an assessment of the contributions of autonomic neuropathy and vascular disease to the aetiology of male impotence in diabetes, evidence of autonomic neuropathy was identified in 23/39 (59%) individuals complaining of impotence. Thirteen of 26 men aged < 60 years tested with an intracorporeal injection of papaverine experienced little or no response and seven had tumescence but no rigidity. Radioisotope phallography demonstrated vascular disease in six of these seven, suggesting evidence of a vascular component in 19/26 (73%). Only one patient had non-organic impotence. Overall, evidence of vascular disease alone was demonstrated in 10/26 (38%), vascular disease plus autonomic neuropathy in 9/26 (35%), and autonomic neuropathy alone in 6/26 (23%). Many diabetic men complaining of impotence appear to have a significant vascular component which renders intracorporeal papaverine treatment ineffective. We compared the performance of a vacuum constriction-band (Erecaid) and condom-type (Synergist) device in 10 randomly selected men from this group. The devices, provided in random order for 5 months each, were assessed by questionnaire and interview of both the patient and partner. Two couples defaulted and another could use neither device. Although erectile capacity could be restored in the remainder, subsequent intercourse was only deemed satisfactory to both partners in five couples, who unanimously preferred the constriction-band device. In treatment with vacuum devices the constriction-band type seems to be the device of choice; the condom type should probably be reserved for those unable to use the constriction-band type.

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.

Unawareness of hypoglycaemia and inadequate hypoglycaemic counterregulation: no causal relation with diabetic autonomic neuropathy

OBJECTIVE

To examine the traditional view that unawareness of hypoglycaemia and inadequate hypoglycaemic counterregulation in insulin dependent diabetes mellitus are manifestations of autonomic neuropathy.

DESIGN

Perspective assessment of unawareness of hypoglycaemia and detailed assessment of autonomic neuropathy in patients with insulin dependent diabetes according to the adequacy of their hypoglycaemic counterregulation.

SETTING

One routine diabetic unit in a university teaching hospital.

PATIENTS

23 Patients aged 21-52 with insulin dependent diabetes mellitus (seven with symptoms suggesting autonomic neuropathy, nine with a serious clinical problem with hypoglycaemia, and seven without symptoms of autonomic neuropathy and without problems with hypoglycaemia) and 10 controls with a similar age distribution, without a personal or family history of diabetes.

MAIN OUTCOME MEASURES

Presence of autonomic neuropathy as assessed with a test of the longest sympathetic fibres (acetylcholine sweatspot test), a pupil test, and a battery of seven cardiovascular autonomic function tests; adequacy of hypoglycaemic glucose counterregulation during a 40 mU/kg/h insulin infusion test; history of unawareness of hypoglycaemia; and response of plasma pancreatic polypeptide during hypoglycaemia, which depends on an intact and responding autonomic innervation of the pancreas.

RESULTS

There was little evidence of autonomic neuropathy in either the 12 diabetic patients with a history of unawareness of hypoglycaemia or the seven patients with inadequate hypoglycaemic counterregulation. By contrast, in all seven patients with clear evidence of autonomic neuropathy there was no history of unawareness of hypoglycaemia and in six out of seven there was adequate hypoglycaemic counterregulation. Unawareness of hypoglycaemia and inadequate hypoglycaemic counterregulation were significantly associated (p less than 0.01). The response of plasma pancreatic polypeptide in the diabetic patients with adequate counterregulation but without autonomic neuropathy was not significantly different from that of the controls (change in plasma pancreatic polypeptide 226.8 v 414 pmol/l). The patients with autonomic neuropathy had a negligible plasma pancreatic polypeptide response (3.7 pmol/l), but this response was also blunted in the patients with inadequate hypoglycaemic counterregulation (72.4 pmol/l) compared with that of the controls (p less than 0.05).

CONCLUSIONS

Unawareness of hypoglycaemia and inadequate glucose counterregulation during hypoglycaemia are related to each other but are not due to autonomic neuropathy. The blunted plasma pancreatic polypeptide responses of the patients with inadequate hypoglycaemic counterregulation may reflect diminished autonomic activity consequent upon reduced responsiveness of a central glucoregulatory centre, rather than classical autonomic neuropathy.

Autonomic denervation may be a prerequisite of diabetic neuropathic foot ulceration

Studies using visceral (cardiovascular) autonomic function testing have left doubt as to the importance of autonomic neuropathy in the development of diabetic neuropathic foot ulceration. A test for peripheral autonomic denervation has been developed (acetylcholine sweatspot test), dependent on intradermal acetylcholine causing secretion by innervated sweat glands, detected by starch/iodine discoloration. The response is photographed and quantified using a grid (normal score = 0 or 1; abnormal = 5 to 60). The sweatspot test was applied to the feet of 19 diabetic patients with a history of foot ulceration, 17 with neuropathic pain, 8 complaining of numbness, and to 15 diabetic control patients. The sweatspot test score of the foot ulcer patients (median 54) was very much greater than that of the other groups (pain group, 4, p less than 0.005; numbness group, 2, p less than 0.01; diabetic control group, 2, p less than 0.0001). All the patients with neuropathic foot ulceration had peripheral autonomic denervation. The results suggest that autonomic denervation in the feet is always present in patients with diabetic neuropathic foot ulceration. Tests of peripheral autonomic denervation such as the acetylcholine sweatspot test may be useful to identify patients at risk of neuropathic foot ulceration.

Acetylcholine sweatspot test for autonomic denervation

A test for autonomic denervation based on the local sweat response to 0.1 ml 1% acetylcholine administered intradermally, which depends on an intact local sympathetic supply, is described. Diabetic autonomic neuropathy affects the longest fibres first and thus the test was applied to the feet. After painting a standard site on the dorsum of the foot with iodine and starch, acetylcholine was injected intradermally in the centre. The normal response, visible to the eye, is a uniform distribution of dark spots of iodine discolouration at the sites of sweat production. In diabetic autonomic neuropathy this pattern is lost to a varying degree. In a photographic image magnified x 10, the spots were counted in sixty 2.5 cm squares in a grid centred on the injection site. 50 normal volunteers aged 18-69 were tested. No effect of age or sex was found. Five or more squares with less than 6 spots was the definition of abnormal. 24 diabetic men who complained of impotence were investigated with the sweatspot test, a pupil test, and cardiovascular autonomic function tests. 13 had abnormal sweatspot tests with scores up to sixty squares with less than 6 spots. In keeping with the increased length of the sympathetic fibres to the feet compared with those to the iris, there was a 30% false-negative rate for the pupil test if the sweatspot test is taken as standard. Agreement between the cardiovascular tests and the sweatspot test was seen in only 17 patients. The sweatspot test appears to be a more sensitive indicator of autonomic neuropathy than the commonly used cardiovascular tests.

The metabolic response to glucagon and glucagon-(1-21)-peptide in normal subjects and non insulin dependent diabetics

The metabolic effects of glucagon leading to hyperglycaemia are well recognised. However, the spasmolytic properties of glucagon have only relatively recently been utilised in clinical medicine. The marked hyperglycaemia accompanying the smooth muscle relaxant action of glucagon has led to the development of smaller peptides derived from glucagon which may retain the spasmolytic effects without the metabolic consequences. This study compares the metabolic and hormonal response to one such peptide, glucagon-(1-21)-peptide, with the parent peptide glucagon. The results demonstrate that glucagon-(1-21)-peptide has no metabolic effects comparable to glucagon. In normal subjects and non-insulin dependent diabetics, glucagon-(1-21)-peptide has no stimulatory effect on the pancreatic beta-cell.

Human, porcine and bovine ultralente insulin: subcutaneous administration in normal man

Six normal subjects received subcutaneous human, porcine, and bovine ultralente insulin (0.30 U/kg) and diluent (control) in randomized order. Plasma glucose, C-peptide, and insulin were measured for 32 h after injection. From 10 h onward human ultralente produced significantly lower plasma glucose levels (p less than 0.05-0.01) compared to bovine ultralente. Porcine ultralente produced an intermediate hypoglycaemic response up to 16 h and was similar to the bovine insulin from 24-32 h. Estimated exogenous insulin concentration was higher (p less than 0.05-0.001) following human ultralente compared to bovine ultralente between 2 and 22 h after injection. Up to 24 h the porcine preparation led to intermediate insulin levels, but becoming identical to bovine ultralente from 28-32 h. Peak mean exogenous insulin values for human, porcine, and bovine ultralente were 0.054, 0.044, and 0.023 nmol/l at 14, 16, and 18 h, respectively, reaching 0.022, 0.013, and 0.013 nmol/l at 32 h. The different pharmacokinetic behaviour of human and bovine ultralente insulin must be considered when initiating treatment with human ultralente or transferring patients from bovine to human ultralente.

Possible new method to improve detection of diabetic retinopathy: Polaroid non-mydriatic retinal photography

Two retinal cameras (Canon CR2 45NM and CR3 45NM) have recently become available and are capable of producing an instant colour photography of a 45 degree field of retina, including the macula and optic disc, without dilatation of the pupils being necessary. The ability of each camera to detect diabetic retinopathy was compared with that of doctors in diabetic clinics using ophthalmoscopy during busy clinic hours. The CR3 was found to be considerably superior to the CR2 in terms of quality of photograph because it can use a smaller pupil. Overall, the detection rate of the camera was more than four times higher than that of ophthalmoscopy through undilated pupils and more than twice as high as that of ophthalmoscopy through dilated pupils. Lesions missed by ophthalmoscopy but detected by the camera included soft exudates and circinate rings of hard exudates, sometimes encroaching on the macula. Though various aspects of this system of screening for diabetic retinopathy, in particular its ability to detect new retinal vessels, have not yet been assessed, the system may prove beneficial in the detection and monitoring of diabetic retinopathy.

How soon after myocardial infarction should plasma lipid values be assessed?

Because acute myocardial infarction may affect plasma lipid concentrations it is commonly recommended that assessment of these concentrations should be delayed until about three months after the acute event. A study was therefore conducted of fasting plasma lipid concentrations in 58 patients with acute myocardial infarction. Measurements were made during their stay in hospital (days 1, 2, and 9) and three months later. Triglyceride concentrations remained unchanged throughout. Values of total cholesterol, low density lipoprotein, and high density lipoprotein all fell significantly between the first two days and day 9. Total cholesterol and low density lipoprotein also showed significant falls between days 1 and 2. Nevertheless, fasting plasma lipid concentrations showed no significant difference at any time during the first 48 hours from values measured three months later. After the infarction 26 patients changed to eating less fat or less energy, or both. More patients had hypercholesterolaemia in the first 48 hours than at three months. These results suggest that lipid state may be assessed as accurately, and possibly more accurately, during the first 48 hours after acute myocardial infarction than at three months.

Glycosylated serum albumin: an intermediate index of diabetic control

Glycosylated hemoglobin (HbA1) is widely used as an index of glycemic control in diabetic patients. However, due to the long survival time of erythrocytes (120 days), it remains elevated for several weeks after improved control. Other plasma proteins are similarly glycosylated, and as glycosylated serum albumin (GSA) has a shorter half-life (20 days), it should detect glycemic changes earlier. Fasting blood glucose (FBG), GSA, and HbA1 were measured weekly in newly diagnosed diabetic patients (N = 12) for 8 wk after beginning treatment. After 4 wk, a similar fall in FBG and GSA levels, i.e., 72% and 58% respectively, was observed. In contrast, HbA1 fell significantly less (P less than 0.01), by only 39% of its initial value. By 8 wk there was no significant difference between the percentage reduction in the three indices of control. Therefore, GSA provides the clinician with earlier objective evidence of the metabolic response to therapeutic intervention and can be regarded as an intermediate index of diabetic control.

Colonic release of 5-amino salicylic acid from an oral preparation in active ulcerative colitis

5-amino salicylic acid coated with acrylic based resin was given orally to eight patients with active ulcerative colitis. Abdominal X-rays confirmed that the preparation released its contents in the terminal ileum and proximal colon. Differences between individuals were marked; the plasma 'concentration-time profile' reflected variations in the time taken for tablets to reach the terminal ileum.

Normo-osmolar, nonketotic, hyponatremic diabetic syndrome associated with impaired renal function

A case is reported of a nonketotic woman with diabetes who presented with a blood glucose of 72.8 mmol/L (1310 mg/dl), plasma sodium of 92 mmol/L, normal osmolality, impaired renal function, and alert clinical state. Before the implication of the unusual nature of the metabolic disturbance was fully considered, the initial treatment was with a rapid infusion of saline. On consideration, however, it was postulated that as her hyperglycemia had developed, the expected osmotic diuresis was prevented by the impairment of her renal function. This had allowed compensatory hyponatremia to develop to maintain normal osmolality and protect the patient from coma. The high-dose saline infusion was stopped, and she was successfully treated with insulin and potassium but only minimal saline. The use of large quantities of saline in normo-osmolar, nonketotic, hyponatremic diabetic syndrome associated with impaired renal function and alert mental state is unnecessary and potentially dangerous.