American Diabetes Association Annual Scientific Sessions, San Antonio, 20-23 June 1992 S. Kumar Department of Medicine, Manchester Royal Infirmary, Manchester, UK

The 52nd Annual American Diabetes Association (ADA) meeting held in San Antonio, was attended by over 4000 delegates from all over the world. This year, over 710 abstracts were selected for presentation from over 1180 abstracts submitted. The format of this year’s meeting was different in that it included 19 symposia with only a few abstracts selected for oral presentation in the topical symposia: the remainder being presented as posters. This change in the format of the meeting highlighting poster presentations was intended to allow more detailed discussion of the work presented with the authors. Another new event introduced for the first time was the President’s poster session which included 75 posters on Complications: Molecular to Clinical displayed during a cheese and wine reception by the riverside. Also for the first time, poster reproductions were made available to all delegates by the side of each poster so that it was not necessary to make notes at the meeting itself, and thus delegates were able to take home copies of posters presented in the ring binder provided. The meeting started on Saturday 19 June 1992 with sessions sponsored by the various councils of the ADA, with 3 4 symposia running concurrently. Diabetic nephropathy was the theme of the symposium of the Council on Public Health. Dr J. Pugh (USA), speaking on the epidemiology of nephropathy, pointed out that in respect to diabetic nephropathy Type 1 and Type 2 diabetes are more alike than different and that Type 2 diabetes is responsible for more renal disease than Type 1. She also noted that susceptibility for nephropathy was greater in black and Hispanic ethnic groups in America, although preliminary data appeared to show that they were better survivors of this disease compared to white Americans. Professor R. DeFronzo (USA)gave an elegant, comprehensive overview of diabetic nephropathy in which he emphasized the high mortality in subjects with diabetic nephropathy due to heart disease and stressed the role of antihypertensive treatment. Professor G.C. Viberti (UK) gave an excellent overview of the pathogenesis of diabetic nephropathy: an area in which he has made many important original contributions. He Correspondence to: Dr 5. Kumar, Department of Medicine, Manchester Royal Infirmary, Oxford Road, Manchester, M13 9WL, UK.

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discussed the role of anti-hypertensivedrugs in preventing progression in those with microalbuminuria and pointed out that it is elevated blood pressure rather than ‘hypertension’ that should be treated in these often quite young patients. In the meeting of the Council of Epidemiology, the Kelly West lecture was delivered by Dr M. Harris (USA). She underlined the importance of identifying theestimated 6.3 million Americans with undiagnosed diabetes. As many as 21 Yo of Type 2 diabetic patients have retinopathy at the time of diagnosis. Extrapolating from data obtained from the Wisconsin retinopathy study, she estimated that the onset of Type 2 diabetes occurs about 7 years before the date of diagnosis, thus giving complications a running start to develop even before the patient is diagnosed as having diabetes. Stressing the importance of screening for diabetes especially in high-risk groups she recommended the use of the 2 hour oral glucose tolerance for identifying those with undiagnosed diabetes. Early intervention in the form of improved glycaemic control, treatment for other risk factors such as hypertension and dyslipidaemia at this stage may prevent or postpone the onset of complications. The symposium on ‘Lifestyle factors as risk factors for complications’ included papers on smoking, a relatively neglected area in diabetes. Dr E. Fischer (USA), speaking on smoking and weight gain, said that weight gain after stopping smoking is a real phenomenon, with 79 % gaining at least 5 Ibs (2.5 kg) after stopping smoking and in one study over 50 % of smokers said this was their main reason for not quitting. However, in the same study only 58 ‘30 of the subjects were advised to stop smoking by their physicians, and he suggested that they should spend more time advising their patients to stop smoking. Dr P. Sawicki (Germany), presented a paper on the effect of smoking on progression of nephropathy over 1 year. Progression of nephropathy, defined as an increase of over 20 % in urine albumin excretion rate, was compared in 96 Type 1 diabetic subjects which included a smoking and a non-smoking group matched for age, glycated haemoglobin, and blood pressure. Fifty-three percent of the smokers progressed, compared to 33 % of exsmokers and 11 % of non-smokers, the most important determinant being the number of cigarette pack years. 957 DIABETIC MEDICINE, 1992; 9: 957-959

MEETING REPORT However, much larger studies need to be done to confirm these findings and as this study used a single measurement of urine albumin excretion (for which the biological variation is as high as 45 %!) as the main outcome measure, a change of over 20 % may not be significant. A truly outstanding programme concluded the scientific sessions for the afternoon of the first day. Two excellent lectures, the Presidential lecture given by the outgoing President of the ADA, Professor J.S. Skyler (USA), and the Banting lecture delivered by Professor G.F. Botazzo (UK), was followed by the President’s poster session including 75 posters on aspects of complications of diabetes, held by the riverside during a cheese and wine reception. In a lecture titled ‘Winds of change’ Professor Skyler drew attention to the ’storm brewing in terms of health-care reform’. The present health-care system in the USA lacks a chronic disease focus and he expressed concern over the way in which present policies allow the systematic exclusion of all those with diabetes from insurance cover and also for the fact that 35 million Americans do not have medical cover. At the same time, funding for research has not increased in America: only 3 % of the health budget is spent on research compared to 5-16% spent by most successful industries. He exhorted scientists and all those interested in science to become involved in the political process to ensure a stronger national commitment to science, and to ensure that the health care reforms are implemented. The highlight of the whole meeting was certainly the Banting lecture delivered by Professor Botazzo ‘and company’. In a unique and exciting presentation titled ‘The honey disease: a dialogue with Socrates’, Botazzo engaged Socrates (played by M. Costen, a medical student) in a learned discourse on the aetiopathogenesis of Type 1 diabetes, interspersed with fine music and slides of Greece during the breaks for ‘coffee’ or ‘rest’. Reversing traditional roles, Botazzo led Socrates and the audience through a closely reasoned argument on the aetiology of this ‘modern’ disease. Autoimmune diseases were described for the first time in the 19th century and this, he argued, was perhaps due to a change in the virulence of the virus responsible for initiating the autoimmune response involving both Class 1 and Class 2 major histocompatability antigens. This is also suggested by the presence of ’hot spots’ for Type 1 diabetes such as Finland and Sardinia, where he believed we have the best chance of finding the virus. The long latency period before the development of the disease suggests that this might be a ‘slow virus’ and in some ways analogous to HIV causing AIDS. Recent experiments by his group have suggested that the newly identified 37K antibody may be highly specific for those developing Type 1 diabetes. Dr S. Taylor (USA) delivered the Lilly Lecture, titled ‘Mechanisms of insulin resistance: lessons from patients with mutations of insulin-receptor gene’. Recent technological advances have made it possible to identify over 30 mutations in the insulin-receptor gene. He estimated 958

Dm the prevalence of mutations of the insulin-receptor gene in the general population to be as high as 1 in 1000, and in Type 2 diabetes it may be between 1 and 10 %. Thus high-risk categories may be identified and screened for specific defects, and those at risk for diabetes may be treated with diet and exercise. Diabetic patients may be treated with new specific drugs or by gene therapy, and in cases where the defect lies in the recycling of the insulin receptor, new low affinity insulin analogues may be effective in treating these patients. Thus, he hoped that new insights into the mehcanisms of insulin resistance in these conditions may lead to new preventative and therapeutic strategies. In the symposium on ‘Role of glucose in the complications of diabetes’ Dr E. Mathieson (Denmark) showed data from Denmark that demonstrated the pivotal role of poor metabolic control in the development of nephropathy. In their population, hypertension appeared to develop after the onset of proteinuria and did not appear to cluster in families as reported from other centres. Dr I. Barbosa (USA) showed that in Type 1 diabetic subjects undergoing renal transplantation, tight metabolic control can postpone the occurrence of the early signs of diabetic nephropathy characterized by mesangial expansion. In the symposium on ’Predicting and Preventing IDDM’ Dr R.J. Keller (USA) presented new data from their study of subjects at high risk for development of Type 1 diabetes. The subjects were first degree relatives of Type 1 diabetic patients and had normal oral glucose tolerance test, ICA titre >40 JDF units, and insulin response to intravenous GTT less than 1st centile. They were given insulin intravenously over a 5-day period every 9 months and subcutaneous low-dose insulin daily. Over a mean follow-up period of 2.7 years the treated group had a lower incidence of Type 1 diabetes and maintained normal growth and development. In their experience hypoglycaemia was rare and there was no significant change in lifestyle. They concluded that insulin treatment in such situations is safe and may prevent or postpone Type 1 diabetes. Dr E. Gale (UK) in an extremely clear presentation using ‘decision trees’ showed how currently available markers may be used to predict diabetes in different populations. In the presence of a family history of Type 1 diabetes, ICA positivity and loss of 1st phase insulin response is highly predictive of diabetes. However, in over 90% of cases there is no family history and, as predicted by Bayes theorem, the same markers have low specificity in the general population which has a lower prevalence of Type 1 diabetes as shown in the study of schoolchildren in Oxford. Thus different screening strategies are required to screen high-risk groups and the general population and he hoped that newer markers such as 64K and 37K antibodies will be more specific and will identify subjects who may benefit from specific interventions such as immunosuppression. A number of interesting posters were presented at this meeting. In a survey of over 2400 diabetic patients all over the USA, Dr M. Harris (USA) and colleagues showed MEETING REPORT

DT17 that among Type 1 diabetic patients 21 % had never tested their blood glucose and only 40% self-monitored their blood glucose at least once daily. Forty-seven percent of insulin-treated Type 2 diabetic patients never tested their blood glucose. Thus, a large proportion of insulin-treated diabetic patients in the USA were not selfmonitoring their blood glucose levels. Dr J. Manson (USA) and colleagues showed in a prospective study of 21 271 US male physicians that regular physical exercise is associated with reduced risk of diabetes even after adjusting for BMI, thus suggesting that this may be an effective strategy in preventing diabetes. Elevated blood pressure is being increasingly recognized as an important risk factor for diabetic complications. Professor R. Klein (USA) and colleagues presented data from the Wisconsin retinopathy study showing that elevated blood pressure is associated with the development of retinopathy. The presence of proteinuria at baseline predicts proliferative retinopathy. As many as 18 % of those admitted to hospital with diabetic ketoacidosis may not be markedly hyperglycaemic. In a study by Dr Burge and Dr Schade (USA) the mechanism of this euglycaemic ketoacidosis was investigated in 10 Type 1 diabetic subjects. Subjects were studied during 5 hours of insulin withdrawal both in the fed and in the fasting state. Subjects developed ketoacidosis without marked hyperglycaemia in the fasting state and this was related to higher production of NEFA and glycerol in the fasting state. Thus their work would suggest that fasting predisposesto the development of euglycaemic ketoacidosis. One of the problems encountered with nasal insulin is its poor bioavailability and several agents have been used to enhance absorption from the nasal mucosa. Dr Kowarski and colleagues (Baltimore) described a new formulation of nasal insulin using beta-glycyrrhetinic acid (a deriviative of liquorice) which is said to be pleasant tasting, anti-inflammatory, non-toxic, and a potent enhancer of nasal absorption of insulin. In a study


MEETING REPORT that included five Type 1 diabetic subjects this new preparation was well tolerated and was effective in controlling post-prandial hyperglycaemia. Indium-labelled white cell scan has been shown to be superior to X-rays or ordinary bone scans in diagnosing osteomyelitis. Dr L.G. Newman and colleagues (USA) showed that Indium-labelled leucocyte scans were superior even to MR scanning for diagnosing osteomyelitis. However, it is worth noting that although the sensitivity for this technique was 100 % in this study, the specificity was only 67 %. Thus it will still be extremely difficult to differentiate between early Charcot neuroarthropathy and osteomyelitis even using this technique. The location of this meeting in San Antonio ensured that this was also a socially pleasurable occasion. San Antonio must clearly be a popular location for scientific meetings as three large medical conferences were being held there at the same time. It was not difficult to see why! It is an unusual city with a unique blend of Mexican and Texan culture and apart from the excellent facilitites available for such conferences, San Antonio has many attractions including the famous Alamo, many wellknown museums, superb local ’Texan-Mexican’ cuisine, and the Paseo del rio (the riverwalk). The San Antonio Conference centre, the venue for this meeting, is located by the riverside and with many of the attractions nearby, I was surprised to find the majority of delegates in the Conference centre for most of the meeting! On the whole the quality of presentations, especially the lectures, at this meeting was very good. However, I did feel that the space allocated for the posters was not sufficient as the aisles were too narrow for the large number of attendees to move from poster to poster. Next year, the annual ADA meeting is to be held at an even more popular venue-Las Vegas! No doubt, following the success of this meeting, the organizers of next year’s meeting will anticipate a larger number of registrants and will arrange for a larger area for posters.


American Diabetes Association annual scientific sessions, San Antonio, 20-23 June 1992.

DT17 MEETING REPORT American Diabetes Association Annual Scientific Sessions, San Antonio, 20-23 June 1992 S. Kumar Department of Medicine, Manchest...
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