LETTERSneed for early detection of undiagnosed therapy prevents the progression of not be allowed to delay the more wide-

spread provision of a service that is almostNIDDM in this particular population, diabetic microvascular complicationsin Japanese patients with non-insulin-despite mentioning that the ‘early detec- certainly widely desired and clinically jus-

tified.tion and treatment of complications’ is dependent diabetes mellitus: a ran-domized prospective 6-year study.an integral part of diabetes care. The early

T. Greenhalghdetection of diabetic complications would Diabetes Research and Clinical Prac-Department of Primary Care and Popu-surely be facilitated by the development tice 1995; 28: 103–117.lation Sciencesof a structured screening programme for 3. Davies MJ, Grenfell A, Day JL. ClinicalUCLMS/RFHSM,undiagnosed NIDDM as part of a strategy characteristics and follow-up of sub-London N19 5NFfor improving diabetes care for British jects with non-insulin-dependent dia-

betes mellitus diagnosed by screen-South Asians?Unlike IDDM, the benefits of early ing. Practical Diabetes International

1996; 13: 75–78.diagnosis and tight control of NIDDM Referencesand the later development of compli-cations have yet to be wholly established,

1. Alberti KGMM, Gries FA. Manage-although evidence is accumulating.2 Reply from T. Greenhalghment of non-insulin-dependent dia-However, the detection of British Southbetes mellitus in Europe: a concensusAsian people with previously undiagnosed

A discussion of the potential benefits and view. Diabetic Med 1988; 5: 275–NIDDM would identify a group at parti-likely cost-effectiveness of screening for 281.cularly high risk of developing coronarydiabetes in British South Asians was an 2. Hawthorne K. Accessibility and useheart disease in later years. Other riskimportant omission from my review. I of health care services by the Britishfactors for coronary heart disease haveagree that such a programme is theoreti- Asian community. Family Practicealso been shown to be present in patientscally justified even in the absence of firm 1994; 11: 453–459.with newly diagnosed NIDDM.3evidence of the effect of tight control onThe views of the British South Asiandisease-specific complications in Type 2population to a screening programme fordiabetes, since attention to modifiable Effect of Glycaemic Control and thediabetes (and other coronary heart diseasecardiovascular risk factors such as smok- Introduction of Insulin Therapy onrisk factors) are largely unknown. Knowl-ing and hypertension undoubtedly influ- Retinopathy in Non-insulin-dependentedge of these views may have importantences length and quality of life in this Diabetes Mellitusimplications for service development andgroup.1future interventions. Low uptakes by Brit-

My own ongoing research into the Henricsson et al. recently reported theirish South Asian women of breast andviews of British Bangladeshis with diabetes study of retinopathy in a cohort of 1378cervical cancer screening programmesand their relatives suggests that self screen- patients.1 In total, 1045 of their patientshave been reported, and some lessonsing for glycosuria is common. New dia- were treated with oral agents or dietcould be learnt from these programmesbetic patients frequently present as a alone, of whom 174 changed to insulinwhen considering the development of arequest to the GP to ‘please test my therapy during follow-up. The authorsscreening programme for diabetes.urine’, and a community-based screening used photography with Wisconsin scaleA research project being undertaken inprogramme for diabetes in Tower Hamlets grading and measured HbA1C during aBradford aims to assess the feasibility ofwould probably be well received (T. mean 3.1-year study period. They reportdeveloping a culturally sensitive screeningGreenhalgh and A.M. Chowdhury, unpub- that while insulin treatment at baselineprogramme for undiagnosed NIDDM andlished interviews). was not associated with any increase ofother coronary heart disease risk factors.

The British Diabetic Association retinopathy progression, change to insulinWe feel that such a screening programmerecently organized a ‘Living with Diabetes’ therapy had an increased relative risk ofwould benefit the substantial South Asianday in south London. The event was 2.0 for progression of retinopathy $ 3population living in Bradford (andaimed at a local population of around levels compared with other patients inelsewhere), and we will be working100 British Asians with diabetes but the study. However, the change of therapyclosely with members of this community,attracted nearer 500 people, some of to insulin is likely to have been motivatedas well as local health professionals,whom had travelled long distances by by poor glycaemic control. Thus thethroughout the research. Correspondencepublic transport. Screening for new dia- conclusion that change of therapy waswould be welcomed from individuals andbetes was not offered at this event, but the cause of deterioration of retinopathygroups with views or information on thisthe queue for retinal screening in known is unjustified. The cause may equallytopic or who are embarking on similardiabetic patients was so long that some have been the precedent to change,community-based research.patients waited several hours. They were namely the poor glycaemic control. This

is further suggested by the fact that thoseunwilling to risk losing their place inN.L. Jones1, D.R.R. Williams2

the queue by attending other talks and who moved to insulin had higher HbA1C1Clinical Epidemiology Research Unit,demonstrations (I. Griffin, British Diabetic during the study period (8.3 ± 1.1 %) thanNew Mill, Victoria Road, Saltaire, Shipley,Association, personal communication). those who remained on diet or oralWest Yorkshire BD18 3LD

Hawthorne has documented that the treatment (6.9 ± 1.3 %).2The Nuffield Institute for Health, 71–75‘poor uptake’ of screening programmes Retinal photography was carried outClarendon Road, Leeds LS2 9PLby minority ethnic groups is usually due every 2 years and annually thereafter once

established retinopathy was detected. Thisless to ‘cultural resistance’ than to patients’ignorance of available services, their invalidates the Cox proportional hazards

model, which requires specific dates ofincorrect assumption that they are ineli-Referencesgible, and administrative difficulties such events. Furthermore, the grading of the

photographs was carried out by those1. Greenhalgh PM. Diabetes in British as mis-spelt names and out-of-dateaddresses.2 Although continued researchSouth Asians: nature, nurture and who knew the treatment and clinical

details of the subjects. Their results areculture. Diabetic Med 1997; 14: into the most culturally acceptable formatfor a screening programme is to be10–18. therefore open to bias.

Patients who moved onto insulin had2. Ohkubo Y, et al. Intensive insulin applauded, political correctness should

709LETTERS

LETTERSworse retinopathy at entry than those who Table 1. Multivariate analysis of risk factors for progression of retinopathy $3 levelsremained on oral treatment or diet aloneand baseline retinopathy level is a risk Relative risk for 95% confidencefactor for progression. In addition, the progression $3 intervaltime in the study for those who progressed levels$ 3 levels was longer (3.8 years vs 2.9years for those with no progression) so Change of therapy/vs no change 1.42 1.2–1.8the duration of follow-up is unmatched. Any/no retinopathy at baseline 1.19 1.0–1.4

We feel that inappropriate conclusions Mean HbA1c above/below 7.8 % 1.75 1.4–2.1may have been drawn from these data.

n = 148, Total N = 1182I. M. Stratton and D. R. Matthews$3 levels (relative risk 2.3; 95 % confi- and prospective study would be required.University of Oxford, Nuffield Departmentdence interval 1.3–4.1). This study was carried out using histori-of Clinical Medicine, Diabetes Research

The analysis (Cox) of the risk of pro- cal data, and the photographs had beenLaboratories, Radcliffe Infirmary, Wood-gression $3 levels in patients with randomly allocated to different examiners.stock Road, Oxford OX2 6HEchanged treatment to insulin was reas- We do not suspect any systematic error,sessed using pre-insulin HbA1c values either in the grading of photographs or(individual values) instead of HbA1c values in the assessment of visual acuity.during the entire follow-up in the groupReferences We found an increased risk for pro-with changed therapy. Adjustments were, gression in this group of patients, but didas earlier, made for differences in age,1. Henricsson M, Nilsson A, Janzon L, not claim that the insulin treatment causedsex, and duration of diabetes. The riskGroop L. The effect of glycaemic the progression. Poor glycaemic contol,for progression in those who changedcontrol and the introduction of insulin change of therapy and retinopathy attreatment relative to all other patients intherapy on retinopathy in non-insulin- baseline were all related to progressionthe study was only moderately reduceddependent diabetes mellitus. Diabetic of retinopathy. We want to emphasizefrom 1.6 to 1.4 (95 % confidence intervalMed 1997; 14: 123–131. again our conclusions from the study,1.1–1.7). i.e. when aiming for normoglycaemia in

When HbA1c values (preinsulin values patients with NIDDM, careful ophthalmo-in the group of patients with change ofReply from M. Henricsson et al. logical supervision is recommended whentherapy) were categorized into two groups, treatment is intensified.

We appreciate the concerns that patients HbA1c above and below 7.8 %, weobtained the results shown in Table 1who changed their treatment from oral

antihyperglycaemic agents to insulin in (adjusted for differences in age, sex, and M. Henricsson1, A. Nilsson2, L. Janzon3,fact represent a selected group of patients duration of diabetes). L. Groop4

with poor glycaemic control, and there- Multiplication of these risk factors yields Departments of 1Ophthalmology andfore the level of pre-insulin glycaemic a relative risk of 3.0 compared with all 2Internal Medicine, Helsingborg Hospital,control would be the most important other patients for progression $3 levels S-25187 Helsingborg, Swedenpredictor of progression of retinopathy. in patients with change to insulin therapy Departments of 3Community MedicineThis is partially true. However, and in having retinopathy at baseline and a pre- and 4Endocrinology, Lund University,addition, the introduction of insulin ther- insulin HbA1c value above 7.8 %. Malmo, Swedenapy seems to accelerate progression of Twenty-eight patients went blind or

developed moderate visual impairmentretinopathy based upon the following evi-dence. during the study period, predominantly

due to macular oedema. All of them hadIn the current study, when patientswith severe non-proliferative retinopathy retinopathy at entry to the study. Nine of

them changed treatment during follow-(NPDR) or proliferative retinopathy (PDR) Referencesat baseline were excluded from the study, up, and they had mild-moderate-severeNPDR at baseline. When adjusted forwe found that 50/167 (30 %) of patients

with changed treatment, 48/292 (16 %) differences in HbA1c (individual, and pre-1. Henricsson M, Nilsson A, Janzon L,of the insulin-treated, and 58/856 (7 %) insulin values in the group of patients

Groop L. The effect of glycaemicof patients treated with oral agents or diet who changed to insulin therapy), thecontrol and the introduction of insu-alone had progressed $3 levels in the relative risk for blindness/visual impair-lin therapy on retinopathy in non-retinopathy scale.1 ment was 2.2 (95 % confidence intervalinsulin-dependent diabetes mellitus.To examine the effect of glycaemic 1.4–3.4) in the group of patients withDiabetic Med 1997; 14: 123–131.control on progression of retinopathy, we change of therapy relative to all other

2. The Diabetes Control and Compli-used the average HbA1c during the study patients.cations Trial Research Group. Theperiod, which was also the most important It was not possible to examine therelationship of glycemic exposurepredictor of progression in the DCCT.2 association between progression of retino-(HbA1c) to the risk of developmentSince the follow-up time varied, we used pathy and a rapid improvement of glycae-and progression of retinopathy in thethe Cox proportional hazards model with mic control in the current study, sinceDiabetes Control and Complicationsthe event having occured the time point the follow-up time of the patients differedTrial. Diabetes 1995; 44: 968–983.when progression of retinopathy $3 levels considerably. However, in a previous

3. Henricsson M, Janzon L, Groopwas registered. case–control study, we found a relation-L. Progression of retinopathy afterWhen the relative risk was reanalysed ship between the degree of improvedchange of treatment from oral anti-using pre-insulin HbA1c values instead of glycaemic control and progression ofhyperglycemic agents to insulin inthe values from the entire follow-up in retinopathy.3 To discern between thepatients with non-insulin-dependentpatients with changed treatment, moder- effect of hyperglycaemia and that of rapiddiabetes mellitus. Diabetes Careate NPDR at baseline was still a significant improvement in glycaemic control on

progression of retinopathy, a randomizedrisk factor for progression of retinopathy 1995; 18: 1571–1576.

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