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Irene M Stratton a Diabetes Trials
Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism,
University of Oxford, Radcliffe Infirmary, Oxford OX2 6HE, b Division of Public Health
and Primary Care, Institute of Health Sciences, University of Oxford,
Oxford OX3 7LF, c Oxford Centre for Diabetes,
Endocrinology and Metabolism, University of Oxford, Radcliffe Infirmary, d Royal Victoria
Hospital, Belfast BT12 6BA, e Diabetes Research Laboratories, Oxford Centre for
Diabetes, Endocrinology and Metabolism, University of Oxford, Radcliffe
Infirmary
Correspondence to: I M Stratton
irene.stratton{at}dtu.ox.ac.uk
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Abstract |
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Objective:
To determine the relation between exposure to glycaemia over time and the risk of macrovascular or microvascular complications in patients with type 2 diabetes.
The UK prospective diabetes study (UKPDS), a clinical trial of a
policy of intensive control of blood glucose after diagnosis of type 2 diabetes, which achieved a median haemoglobin A1c
(HbA1c) of 7.0% compared with 7.9% in those
allocated to conventional treatment over a median 10.0 years of follow
up, has shown a substantial reduction in the risk of microvascular
complications, with a reduction in the risk of myocardial infarction of
borderline significance.1 Complementary information for
estimates of the risk of complications at different levels of glycaemia
can be obtained from observational analyses of data during the study.
In patients with type 2 diabetes previous prospective studies have
shown an association between the degree of hyperglycaemia and increased
risk of microvascular complications,
2 3
sensory neuropathy,
3 4
myocardial infarction,
2 5 6
stroke,7 macrovascular mortality,8-10 and
all cause mortality.
9 11-14
Generally, these studies
measured glycaemia as being high or low or assessed glycaemia on a
single occasion, whereas repeated measurements of glycaemia over
several years would be more informative.
The existence of thresholds of glycaemia We evaluated the relation between exposure to glycaemia over time and
the development of macrovascular and microvascular complications and
compared this with the results of the UKPDS trial of a policy of
intensive control of blood glucose control.1
Participants recruited to the UKPDS
Participants in observational analysis
Table 1.
Design:
Prospective observational study.
Setting:
23 hospital based clinics in England,
Scotland, and Northern Ireland.
Participants:
4585 white, Asian Indian, and
Afro-Caribbean UKPDS patients, whether randomised or not to treatment,
were included in analyses of incidence; of these, 3642 were included in
analyses of relative risk.
Outcome measures:
Primary predefined aggregate
clinical outcomes: any end point or deaths related to diabetes and all
cause mortality. Secondary aggregate outcomes: myocardial infarction,
stroke, amputation (including death from peripheral vascular disease),
and microvascular disease (predominantly retinal
photo-coagulation). Single end points: non-fatal heart failure and
cataract extraction. Risk reduction associated with a 1% reduction in
updated mean HbA1c adjusted for possible
confounders at diagnosis of diabetes.
Results:
The incidence of clinical complications was significantly associated with glycaemia. Each 1% reduction in updated
mean HbA1c was associated with reductions in risk
of 21% for any end point related to diabetes (95% confidence interval 17% to 24%, P<0.0001), 21% for deaths related to diabetes (15% to
27%, P<0.0001), 14% for myocardial infarction (8% to 21%,
P<0.0001), and 37% for microvascular complications (33% to 41%,
P<0.0001). No threshold of risk was observed for any end point.
Conclusions:
In patients with type 2 diabetes the risk of diabetic complications was strongly associated with previous hyperglycaemia. Any reduction in HbA1c is likely
to reduce the risk of complications, with the lowest risk being in
those with HbA1c values in the normal range
(<6.0%).
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Introduction
Top
Abstract
Introduction
Methods
Results
Discussion
Summary
References
that is, concentrations above
which the risk of complications markedly increases
has not been
studied often in patients with type 2 diabetes. The relative risk for
myocardial infarction seems to increase with any increase in glycaemia
above the normal range,
15 16
whereas the risk for
microvascular disease is thought to occur only with more extreme concentrations of glycaemia.17-19 The diabetes control
and complications trial (DCCT) research group showed an association
between glycaemia and the progression of microvascular complications in
patients with type 1 diabetes for haemoglobin A1c
over the range of 6-11% after a mean of six years of follow
up.20 No specific thresholds of glycaemia were identified
above which patients were at greater risk of progression of
retinopathy, increased urinary albumin excretion, or
nephropathy.19-21 Nor has any threshold of fasting plasma
glucose concentration been identified for cardiovascular deaths.
22 23
![]()
Methods
Top
Abstract
Introduction
Methods
Results
Discussion
Summary
References
Details are presented in the companion paper (UKPDS 36) published
in this issue (see page 412).
Of 5102 patients, 4585 white, Asian Indian, and Afro-Caribbean
patients who had haemoglobin A1c
(HbA1c) measured three months after the diagnosis of
diabetes were included in analyses of incidence rates. Of these, 3642 with complete data for potential confounders were included in analyses
of relative risk. Complete data were required for all participants
included in the multivariate observational analyses. For this reason
there are fewer (3642) participants in these analyses than in the
clinical trial, despite the inclusion of patients not randomised in the trial. Their characteristics are presented in table
1.
Participants in UKPDS blood glucose control study
After a three month dietary run-in period patients were stratified
on the basis of fasting plasma glucose concentration and body weight.
The 3867 patients who had fasting plasma glucose concentrations between
6.1 and 15.0 mmol/l and no symptoms of hyperglycaemia were randomised
to a policy of conventional glucose control, primarily with diet, or to
an intensive policy with sulphonylurea or
insulin.
1 24-26
The aim in the group allocated to
conventional control (n=1138) was to obtain fasting plasma glucose
concentration <15 mmol/l, but if concentrations rose to
15 mmol/l
or symptoms of hyperglycaemia developed patients were secondarily
randomised to non-intensive use of these pharmacological treatments,
with the aim of achieving fasting plasma glucose concentrations <15
mmol/l without symptoms. The aim in the group allocated to intensive
control (n=2729) was to achieve fasting plasma glucose concentration
<6 mmol/l, primarily with a single pharmacological treatment. Details
of treatments and their effect on glucose control have been published
elsewhere.1
Biochemical methods
Biochemical methods have been reported previously.27 Haemoglobin A1c was measured by high performance
liquid chromatography (Biorad Diamat automated glycosylated haemoglobin
analyser), the range for people without diabetes being 4.5% to
6.2%.
27 28
Baseline variables are quoted for
measurements after the initial dietary run-in period.
Glycaemic exposure
Exposure to glycaemia was measured firstly at baseline as
haemoglobin A1c concentration and secondly over time as an updated mean of annual measurements of haemoglobin A1c concentration, calculated for each individual
from baseline to each year of follow up. For example, at one year the
updated mean is the average of the baseline and one year values and at three years is the average of baseline, one year, two year, and three
year values.
Clinical complications
The clinical end points and their definitions are shown in the box
in the companion paper (UKPDS 36) published in this issue (see page 412).
Statistical analysis
Incidence rates by category of glycaemia
The unadjusted incidence rates were calculated by dividing the
number of people with a given complication by the person years of
follow up for the given complication within each category of updated
mean haemoglobin A1c concentration and reported
as events per 1000 years of follow up.29 The categories were defined (median values in parentheses) as: <6% (5.6%), 6-<7% (6.5%), 7-<8% (7.5%), 8-<9% (8.4%), 9-<10% (9.4%), and
10% (10.6%) over the range of updated mean haemoglobin
A1c of 4.6-11.2% (1st-99th centile). Follow up
time was calculated from the end of the initial period of dietary
treatment to the first occurrence of that complication or loss to
follow up, death from another cause, or to the end of the study on 30 September 1997 for those who did not have that complication. Hence,
follow up time is equivalent to duration of diabetes. For myocardial
infarction and stroke for participants who had a non-fatal followed by
a fatal event, the time to the first event was used. The rates were
therefore for single and not recurrent events. The median follow up
time for all cause mortality was 10.4 years.
Hazard ratio and risk reduction
To assess potential associations between updated mean haemoglobin
A1c and complications we used proportional
hazards regression (Cox) models. Potential confounding risk factors
included in all Cox models were sex, age, ethnic group, smoking
(current/ever/never) at time of diagnosis of diabetes, and baseline
high and low density lipoprotein cholesterol, triglyceride, presence of
albuminuria (> 50 mg/l measured in a single morning urine sample)
measured after three months' dietary treatment, and systolic blood
pressure represented by the mean of measures at two and nine months
after diagnosis. The hazard ratio was used to estimate the relative risk. At each event time, the updated mean haemoglobin
A1c value for individuals with an event was
compared with the updated value of those who had not had an event by
that time. The updated mean value was included as a time dependent
covariate to evaluate glucose exposure during follow
up.
20 29 30
It was included as a categorical variable in
the categories of glycaemia listed above, with the lowest category
(<6%) as the reference category assigned a
hazard ratio of 1.0 and with the highest category
9%. (This is
reflected in the point estimates as shown in figures 3 and 4.) Separate models, with updated mean haemoglobin A1c as a
continuous variable, were used to determine reduction in risk
associated with a 1% reduction in haemoglobin
A1c (see regression lines in figures 3 and 4). We
evaluated the presence of thresholds by visual inspection. The 95%
confidence intervals were calculated on the basis of the floating
absolute risk.31 Log linear relations are reported by
convention.
1 32
The risk reduction associated with a
reduction of 1% updated mean haemoglobin A1c was
calculated as 100% minus the reciprocal of the hazard ratio expressed
as a percentage. The risk reduction from the continuous variable model
associated with a 1% reduction in observed haemoglobin
A1c was compared with the risk reduction seen in
the UKPDS intervention trial of an intensive versus a conventional
policy of blood glucose control, for which no adjustment for potential
confounders was required as they were balanced by
randomisation.1
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Results |
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The risk of each of the microvascular and macrovascular
complications of type 2 diabetes and cataract extraction was strongly associated with hyperglycaemia as measured by updated mean haemoglobin A1c. The incidence rates for any end point
related to diabetes, adjusted for age, sex, ethnic group, and duration
of diabetes, increased with each higher category of updated mean
haemoglobin A1c, with no evidence of a threshold
and with a threefold increase over the range of updated mean
haemoglobin A1c of <6% (median 5.6%) to
10% (median 10.6%) (figs 1 and 2). The unadjusted and adjusted
incidence rates are shown in table 2. Figure 2 shows the adjusted
incidence rates for myocardial infarction and microvascular end points.
The increase in the incidence rate for microvascular end points was
greater over the range of increasing glycaemia than was the increase in
the incidence rate for myocardial infarction. Thus at near normal
concentrations of updated mean haemoglobin A1c
the risk of myocardial infarction was twice to three times that of a
microvascular end point, whereas in the highest category of haemoglobin
A1c concentration (
10%) the risks were of the same order.
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The estimated hazard ratios associated with different categories of updated mean haemoglobin A1c concentration, relative to the lowest category, are shown as log linear plots in figures 3 and 4. Mortality related to diabetes and all cause mortality were both strongly associated with glycaemia (P<0.0001). The risk of each of the complications evaluated rose with increasing updated mean haemoglobin A1c concentration both before and after adjustment for baseline variables including age, sex, ethnic group, lipid concentrations, blood pressure, smoking, and albuminuria. The decrease in risk for each 1% reduction in updated mean haemoglobin A1c concentration is shown in table 3 and figures 3 and 4. The glycaemia associated reduction in risk for microvascular end points and for amputation or death from peripheral vascular disease was greater (by 37% and 43% per 1% reduction in haemoglobin A1c concentration, respectively, each P<0.0001) than it was for myocardial infarction, stroke, and heart failure (by 14% (P<0.0001), 12% (P=0.035), and 16% (P=0.021) per 1% haemoglobin A1c, respectively) (fig 4). In models that included a variable for conventional control of blood glucose or intensive control with either sulphonylurea or insulin, updated mean haemoglobin A1c remained associated with all complications, although for stroke and heart failure, where the numbers of events were lower than in the previous analyses, these were no longer significant. In these models, treatment of blood glucose per se had no association with any complication beyond that of mean updated haemoglobin A1c.
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There was no indication of a threshold for any complication below which
risk no longer decreased nor a level above which risk no longer
increased. The updated mean haemoglobin A1c
showed steeper relations than did baseline haemoglobin
A1c (table 3), and when both glycaemic variables
were included in a model for all complications of diabetes only updated
mean haemoglobin A1c reached significance (P<0.0001).
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Discussion |
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This observational analysis shows highly significant associations between the development of each of the complications of diabetes, including mortality, across the wide range of exposure to glycaemia that occurs in patients with type 2 diabetes. This association remained after adjustment for other known risk factors, including age at diagnosis, sex, ethnic group, systolic blood pressure, lipid concentrations, smoking, and albuminuria. Each 1% reduction in haemoglobin A1c was associated with a 37% decrease in risk for microvascular complications and a 21% decrease in the risk of any end point or death related to diabetes. The association with glycaemia was less steep for stroke and heart failure, for which blood pressure is a major contributing factor. 32 34 35 In patients within the lowest category of updated mean haemoglobin A1c the incidence of myocardial infarction was higher than that of microvascular disease.5 These results suggest that, in these people, the effect of hyperglycaemia itself may account for at least part of the excess cardiovascular risk observed in diabetic compared with non-diabetic people beyond that explained by the conventional risk factors of dyslipidaemia, hypertension, and smoking.36 The rate of increase of relative risk for microvascular disease with hyperglycaemia was greater than that for myocardial infarction, which emphasises the crucial role of hyperglycaemia in the aetiology of small vessel disease and may explain the greater rate of microvascular complications seen in populations with less satisfactory control of glycaemia.
Relation to trial data
This observational analysis provides an estimate of the reduction
in risk that might be achieved by the therapeutic lowering of
haemoglobin A1c by 1.0%, but it is important to
realise that epidemiological associations cannot necessarily be
transferred to clinical practice. Tissue damage from previous
hyperglycaemia may not promptly be overcome, but the results are not
inconsistent with those achieved by the policy of intensive glucose
control in the clinical trial.1 This suggests that the
reduction in glycaemia obtained over a median 10 years of follow up of
the trial, comparing median haemoglobin A1c 7.0%
with 7.9%, provided much of the benefit that could be expected from
that degree of improved glycaemic control. Our results suggest that
intensive treatment with sulphonylurea or insulin does not have an
effect beyond that of lowering blood glucose concentration with respect to altering risk. The 16% risk reduction (P=0.052) in myocardial infarction in the clinical trial in the group allocated to a policy of
intensive blood glucose control (associated with a 0.9% difference in
haemoglobin A1c) was similar to the 14% risk
reduction seen in the epidemiological analysis, which was associated
with a 1% reduction in concentration of updated mean haemoglobin
A1c. The UKPDS clinical trial evaluated a policy
of intensive glucose control based primarily on single pharmacological
treatments to enable evaluation of the individual treatments. Now that
the UKPDS has shown that improved glucose control reduces the risk of
complications and that the treaments used are safe in clinical
practice, a larger reduction in haemoglobin A1c
might be achieved by the earlier use of combination treatments or by
the use of newer treatments, which could further reduce the risk of
myocardial infarction.
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What is already known on this topic
The risk of developing complications of diabetes increases with increasing concentrations of hyperglycaemia Reduction of hyperglycaemia in these individuals reduces the risk of complications What this study addsThere is a direct relation between the risk of complications of diabetes and glycaemia over time No threshold of glycaemia was observed for a substantive change in risk for any of the clinical outcomes examined The lower the glycaemia the lower the risk of complications The rate of increase of risk for microvascular disease with hyperglycaemia is greater than that for macrovascular disease |
Lack of thresholds
We observed no thresholds of glycaemia for any type of
complication of diabetes. This suggests that there is no specific
target value of haemoglobin A1c for which one
should aim but that the nearer to normal the haemoglobin A1c
concentration the better. In reality, it is difficult to
obtain and maintain near normal concentrations of haemoglobin
A1c in patients with type 2 diabetes,
particularly in those with a high concentration of haemoglobin
A1c at diagnosis of diabetes.37
Intensification of treatment by adding insulin to improve the
relatively modest reduction in glycaemia achieved with oral
hypoglycaemic treatments can be constrained by reluctance from patients
and providers because, in part, of side effects such as hypoglycaemia
or weight gain. These observational analyses, together with the results
of the clinical trial, however, indicate that any improvement in a
raised haemoglobin A1c concentration is likely to
reduce the risk of diabetic complications.
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Summary |
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Both the observational and clinical trial analyses of an intensive
glucose control policy suggest that even a modest reduction in
glycaemia has the potential to prevent deaths from complications related to diabetes as cardiovascular and cerebrovascular disease account for 50-60% of all mortality in this and other diabetic populations.
8 42-47
Individuals with very high
concentrations of glycaemia would be most likely to benefit from
reduction of glycaemia as they are particularly at risk from the
complications of type 2 diabetes, but the data suggest that any
improvement in glycaemic control across the diabetic range is likely to
reduce the risk of diabetic complications.
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Acknowledgments |
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The cooperation of the patients and many NHS and non-NHS staff at the centres is much appreciated. We thank Mr Dick Jelfs for the measurement of haemoglobin A1c. Details of participating centres can be found on the BMJ 's website.
Contributors: IMS selected the methodology, carried out the statistical analyses, coordinated the writing of the paper, and participated in the interpretation of results. AIA assisted with the writing of the paper and interpretation of results. HAWN, DRM, and DH participated in interpretation and revision of the paper. SEM managed the biochemical aspects and participated in interpretation and revision of the paper. CAC participated in preparation of the database and interpretation and revision of the paper. RCT and RRH were the principal investigators, planned and designed the study, and participated in interpretation and revision of the paper. RCT was also responsible for the initial draft of the paper. RRH is guarantor.
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Footnotes |
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Professor Turner died unexpectedly after completing work on this paper
Funding: The major grants for this study were from the UK Medical Research Council, the British Diabetic Association, the UK Department of Health, The National Eye Institute and The National Institute of Digestive, Diabetes and Kidney Disease in the National Institutes of Health, United States, The British Heart Foundation, Novo Nordisk, Bayer, Bristol-Myers Squibb, Hoechst, Lilly, Lipha, and Farmitalia Carlo Erba. Details of other funding companies and agencies, the supervising committees, and all participating staff can be found on the BMJ's website.
Competing interests: AIA has received fees for speaking from Bristol-Myers Squibb, SmithKline Beecham, and Pfizer. IMS has received support for attending conferences from Zeneca and Hoechst and fees for speaking from Hoechst. CAC has received support for attending conferences from Bristol-Myers Squibb, Novo Nordisk, and Pfizer and fees for speaking from Bristol-Myers Squibb and Novo Nordisk. DRM has received fees for speaking from Bristol-Myers Squibb, Novo Nordisk, SmithKline Beecham, and Lilly and research funding from Lilly. SEM has received support for attending conferences from Bayer and Novo Nordisk. RRH has received fees for consulting from Bayer, Boehringer Mannheim, Bristol-Myers Squibb, Hoechst, Lilly, Novo Nordisk, Pfizer, and SmithKline Beecham; support for attending conferences from Bayer, Bristol-Myers Squibb, Hoechst, Lilly, Lipha, Novo Nordisk, and SmithKline Beecham; and research funding from Bayer, Bristol-Myers Squibb, Lilly, Lipha, and Novo Nordisk.
Details of participating centres,
staff, and committees and additional funding agencies are on the BMJ's website.
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References |
|---|
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| 1. | UKPDS Group. Intensive blood glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). Lancet 1998; 352: 837-853[CrossRef][Medline]. |
| 2. | Klein R. Hyperglycemia and microvascular and macrovascular disease in diabetes. Diabetes Care 1995; 18: 258-268[Abstract]. |
| 3. | Pirart J. Diabetes mellitus and its degenerative complications: a prospective study of 4,400 patients observed between 1947 and 1973 (part 1). Diabetes Care 1978; 1: 168-188. |
| 4. | Adler AI, Boyko EJ, Ahroni AJ, Stensel V, Forsberg RC, Smith DG. Risk factors for diabetic peripheral sensory neuropathy. Results of the Seattle prospective diabetic foot study. Diabetes Care 1997; 20: 1162-1167[Abstract]. |
| 5. |
UKPDS Group.
Risk factors for coronary artery disease in non-insulin dependent diabetes (UKPDS 23).
BMJ
1998;
316:
823-828 |
| 6. | Kuusisto J, Mykkänen L, Pyörälä K, Laakso M. NIDDM and its metabolic control predict coronary heart disease in elderly subjects. Diabetes 1994; 43: 960-967[Abstract]. |
| 7. |
Lehto S, Ronnemaa T, Pyörälä K, Laakso M.
Predictors of stroke in middle-aged patients with non-insulin-dependent diabetes.
Stroke
1996;
27:
63-68 |
| 8. | Standl E, Balletshofer B, Dahl B, Weichenhain B, Stiegler H, Hormann A, et al. Predictors of 10-year macrovascular and overall mortality in patients with NIDDM: the Munich general practitioner project. Diabetologia 1996; 39: 1540-1545[CrossRef][Medline]. |
| 9. | Groeneveld Y, Petri H, Hermans J, Springer MP. Relationship between blood glucose level and mortality in type 2 diabetes mellitus: a systematic review. Diabet Med 1999; 116: 2-13. |
| 10. | Uusitupa MI, Niskanen LK, Siitonen O, Voutilainen E, Pyörälä K. Ten-year cardiovascular mortality in relation to risk factors and abnormalities in lipoprotein composition in type 2 (non-insulin-dependent) diabetic and non-diabetic subjects. Diabetologia 1993; 36: 1175-1184[CrossRef][Medline]. |
| 11. | Wei M, Gaskill SP, Haffner SM, Stern MP. Effects of diabetes and level of glycaemia on all-cause and cardiovascular mortality. Diabetes Care 1998; 21: 1167-1172[Abstract]. |
| 12. | Hanefeld M, Fischer S, Julius U, Schulze J, Schwanebeck U, Schmechel H, et al. Risk factors for myocardial infarction and death in newly detected NIDDM: the diabetes intervention study, 11-year follow-up. Diabetologia 1996; 39: 1577-1583[CrossRef][Medline]. |
| 13. |
Knuiman MW, Welborn TA, Whittall DE.
An analysis of excess mortality rates for persons with non-insulin-dependent diabetes mellitus in Western Australia using the Cox proportional hazards regression model.
Am J Epidemiol
1992;
135:
638-648 |
| 14. | Sasaki A, Uehara M, Horiuchi N, Hasegawa K. A long-term follow-up study of diabetic patients in Osaka, Japan: mortality and causes of death. Tohoku J Exp Med 1983; 141(suppl): 639-644. |
| 15. | Balkau B, Shipley M, Jarrett RJ, Pyorala K, Pyorala M, Forhan A, et al. High blood glucose concentration is a risk factor for mortality in middle-aged nondiabetic men. Diabetes Care 1998; 21: 360-367[Abstract]. |
| 16. | Fuller JH, Shipley MJ, Rose G, Jarrett RJ, Keen H. Mortality from coronary heart disease and stroke in relation to degree of glycaemia: the Whitehall study. BMJ 1983; 287: 867-870. |
| 17. | Jarrett RJ, Keen H. Hyperglycaemia and diabetes mellitus. Lancet 1976; ii: 1009-1012. |
| 18. | Pettitt DJ, Knowler WC, Lisse JR, Bennett PH. Development of retinopathy and proteinuria in relation to plasma glucose concentration in Pima Indians. Lancet 1980; ii: 1050-1052. |
| 19. |
Krolewski AS, Laffel LM, Krolewski M, Quinn M, Warram JH.
Glycosylated hemoglobin and the risk of microalbuminuria in patients with insulin-dependent diabetes mellitus.
N Engl J Med
1995;
332:
1251-1255 |
| 20. | DCCT Research Group. The absence of a glycemic threshold for the development of long-term complications: the perspective of the diabetes control and complications trial. Diabetes 1996; 45: 1289-1298[Abstract]. |
| 21. | Orchard T, Forrest K, Ellis D, Becker D. Cumulative glycemic exposure and microvascular complications in insulin-dependent diabetes mellitus. Arch Intern Med 1997; 157: 1851-1856[Abstract]. |
| 22. |
Balkau B, Bertrais S, Ducimitière P, Eschwège E.
Is there a glycemic threshold for mortality risk?
Diabetes Care
1999;
22:
696-699 |
| 23. |
Coutinho M, Gerstein HC, Wang Y, Yusuf S.
The relationship between glucose and incident cardiovascular events: a metaregression analysis of published data from 20 studies of 95,783 individuals followed for 12.4 years.
Diabetes Care
1999;
22:
233-240 |
| 24. | UKPDS Group. UK prospective diabetes study VIII: study design, progress and performance. Diabetologia 1991; 34: 877-890[CrossRef][Medline]. |
| 25. | Manley SE, Cull CA, Holman RR. Relation of fasting plasma glucose on patients with type 2 diabetes in UKPDS randomised to and treated with diet or oral agents. Diabetes 2000; 49(suppl 1): A180. |
| 26. | UKPDS Group. Effect of intensive blood-glucose control with metformin on complications in overweight patients with type 2 diabetes (UKPDS 34). Lancet 1998; 352: 854-865[CrossRef][Medline]. |
| 27. | UKPDS Group. UK prospective diabetes study XI: biochemical risk factors in type 2 diabetic patients at diagnosis compared with age-matched normal subjects. Diabet Med 1994; 11: 534-544[Medline]. |
| 28. |
Cull CA, Manley SE, Stratton IM, Neil HAW, Ross IS, Holman RR, et al.
Approach to maintaining comparability of biochemical data during long-term clinical trials.
Clin Chem
1997;
43:
1913-1918 |
| 29. | Breslow NE, Day NE. The design and analysis of cohort studies. Statistical methods in cancer research II. Oxford: Oxford University Press, 1987. |
| 30. | Agresti A. Categorical data analysis. New York: Wiley, 1990. |
| 31. | Easton DF, Peto J, Babiker AG. Floating absolute risk: an alternative to relative risk in survival and case-control analysis avoiding an arbitrary reference group. Stat Med 1991; 10: 1025-1035[Medline]. |
| 32. |
UKPDS Group.
Tight blood pressure control and risk of macrovascular and microvascular complications in type 2 diabetes (UKPDS 38).
BMJ
1998;
317:
703-713 |
| 33. | SAS. Version 6. Cary, North Carolina: SAS Institute, 1990. |
| 34. | MacMahon S, Peto R, Cutler J, Collins R, Sorlie P, Neaton J, et al. Blood pressure, stroke, and coronary heart disease. Part 1: prolonged differences in blood pressure: prospective observational studies corrected for the regression dilution bias. Lancet 1990; 335: 765-774[CrossRef][Medline]. |
| 35. |
Adler AI, Stratton IM, Neil HAW, Yudkin JS, Matthews DR, Cull CA, et al.
Association of systolic blood pressure with macrovascular and microvascular complications of type 2 diabetes (UKPDS 36): prospective observational study.
BMJ
2000;
321:
412-419 |
| 36. | Stamler J. Epidemiology, established major risk factors and the primary prevention of coronary heart disease. In: Parmley WW, Chatterjee K, eds. Cardiology. Philadelphia: JB Lippincott, 1987:1-41. |
| 37. |
UKPDS Group.
UK prospective diabetes study 24: relative efficacy of sulfonylurea, insulin and metformin therapy in newly diagnosed non-insulin dependent diabetes with primary diet failure followed for six years.
Ann Intern Med
1998;
128:
165-175 |
| 38. | American Diabetes Association. Report of the expert committee on the diagnosis and classification of diabetes mellitus. Diabetes Care 1998; 21(suppl 1): 5-19. |
| 39. | Franklin GF, Shetterly SM, Cohen JA, Baxter J, Hamman RF. Risk factors for distal symmetric neuropathy in NIDDM. The San Luis Valley diabetes study. Diabetes Care 1994:1172-7. |
| 40. | Harris M, Eastman R, Cowie C. Symptoms of sensory neuropathy in adults with NIDDM in the US population. Diabetes Care 1993; 16: 1446-1452[Abstract]. |
| 41. |
Adler AI, Boyko EJ, Ahroni JH, Smith DG.
Lower extremity amputation in diabetes mellitus: the independent effects of peripheral vascular disease, sensory neuropathy and foot ulcers.
Diabetes Care
1999;
22:
1029-1035 |
| 42. |
Adler AI, Matthews D, Holman RR, Turner RC.
Type 2 diabetes and death: causes, estimated life expectancy and mortality rates the UK prospective diabetes study.
Diabetes
1998;
47(suppl 1):
A71.
|
| 43. | Palumbo PJ, Elveback LR, Chu CP, Connolly DC, Kurland LT. Diabetes mellitus: incidence, prevalence, survivorship and causes of death in Rochester, Minnesota, 1945-1970. Diabetes 1976; 25: 566-573[Abstract]. |
| 44. | Panzram G. Mortality and survival in type 2 (non-insulin-dependent) diabetes mellitus. Diabetelogia 1987; 30: 123-131[CrossRef][Medline]. |
| 45. | Goodkin G. Mortality in diabetes. A 20 year mortality study. J Occup Med 1975; 17: 716-721[Medline]. |
| 46. | Wetterhall SF, Olson DR, DeStefano F, Stevenson JM, Ford ES, German RR, et al. Trends in diabetes and diabetic complications, 1980-1987. Diabetes Care 1992; 15: 960-967[Abstract]. |
| 47. | Stamler J, Vaccaro O, Neaton JD, Wentworth D. Diabetes, other risk factors, and 12 year cardiovascular mortality for men screened in the multiple risk factor intervention trial. Diabetes Care 1993; 16: 434-444[Abstract]. |
(Accepted 20 March 2000)