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The Prevalence of Diabetic Retinopathy Among Adult Type 1 Diabetic Persons in the United States
Monique S. Roy, MD;
Ronald Klein, MD, MPH;
Benita J. O'Colmain, MPH;
Barbara E. K. Klein, MD, MPH;
Scot E. Moss, MA;
John H. Kempen, MD, PhD
Arch Ophthalmol. 2004;122:546-551.
ABSTRACT
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Objective To estimate the US prevalence of diabetic retinopathy (DR) among persons with type 1 diabetes mellitus (DM).
Methods Prevalence data from the New Jersey 725 and Wisconsin Epidemiologic Study of Diabetic Retinopathy were used to estimate the prevalence of DR by age, gender, and race among persons 18 years and older having type 1 DM diagnosed before age 30 years. Severity of DR was determined via masked grading of 7-field stereoscopic fundus photographs. Any DR was defined as retinopathy severity level of 14 or more; and vision-threatening retinopathy, as retinopathy severity level of 50 or more, the presence of clinically significant macular edema, or both. The estimates of the prevalence of DR among persons with type 1 DM were applied to the estimated number of persons with type 1 DM diagnosed before age 30 years in the 2000 US population to obtain prevalence estimates of DR due to type 1 DM in the general population.
Results Among 209 million Americans 18 years and older, an estimated 889 000 have type 1 DM diagnosed before age 30 years. Among persons with type 1 DM, the crude prevalences of DR of any level (74.9% vs 82.3% in black and white persons, respectively) and of vision-threatening retinopathy (30.0% vs 32.2%, respectively) are high. The prevalence of DR due to type 1 DM diagnosed before age 30 years in the general population 18 years and older is estimated at 767 000 persons having DR of any level (0.37%), and 376 000 persons having vision-threatening retinopathy (0.18%).
Conclusion Retinopathy due to type 1 DM is an important public health problem in the United States, affecting 1 per 300 persons 18 years and older, and 1 per 600 persons with advanced, vision-threatening retinopathy.
INTRODUCTION
Diabetic retinopathy (DR), the most common ocular complication of diabetes mellitus (DM), is the leading cause of new cases of legal blindness in Americans aged 20 through 74 years, despite the fact that visual loss due to DR may be preventable either through better glycemic control or photocoagulation treatments.1-4 For this article, the goal of the Eye Diseases Prevalence Research Group is to estimate the prevalence of DR in the United States specifically attributable to type 1 DM.5
The prevalence of DR among persons with type 1 DM has been previously reported in 2 large cohorts of patients: whites (the Wisconsin Epidemiologic Study of Diabetic Retinopathy [WESDR])6 and blacks (the New Jersey 725).7-8 The purpose of this article is (1) to estimate the prevalence of DR by age, gender, and race in persons with type 1 DM using data from those 2 studies, and (2) to estimate the prevalence of DR due to type 1 DM in the general population by applying the stratum-specific prevalence estimates of DR to the estimated number of persons with type 1 DM diagnosed before age 30 years derived from the National Health Interview Survey9 and the 2000 US Census.10
METHODS
INCLUSION OF STUDIES OF THE PREVALENCE OF DR
Data on patients aged 18 years and older from 2 cross-sectional prevalence studies, the New Jersey 725 and the WESDR, were used to estimate the prevalence of DR among persons with type 1 DM.6-8 Patients included in the New Jersey 725 were identified from among 39 710 African Americans, all of whom had a diagnosis of DM and were discharged between January 1, 1982, and December 31, 1996, from 31 hospitals located in 7 counties within a 20-mile radius of the New Jersey Medical School, Newark. Of 875 patients having type 1 DM whose condition had been diagnosed before the patient was 30 years old and who were receiving insulin therapy, 725 (83%) were enrolled in the study.7 In the WESDR, 996 younger-onset persons diagnosed as having DM before age 30 years who were taking insulin were identified from among 10 135 patients with DM who received primary care in an 11-county area in southern Wisconsin from 1979 to 1980.6 In both studies, DR was ascertained by masked grading of stereoscopic color fundus photographs of the 7 standard fields using the modified Airlie House classification of Diabetic Retinopathy and Early Treatment of Diabetic Retinopathy Study (ETDRS) severity scale.11-12
STANDARDIZATION BETWEEN STUDIES
DR Grading
For both the New Jersey 725 and the WESDR, color fundus photographs were graded for DR by the Wisconsin Fundus Photograph Reading Center, Madison. For each eye, the maximum grade in any of the 7 standard photographic fields was used to define the retinopathy level according to the ETDRS severity scale.12 Subsequently, the retinopathy level for a participant was determined, based on the worse eye. If the retinopathy severity could not be graded in 1 eye, the subject was considered to have a score equivalent to that in the gradable eye. Clinically significant macular edema (CSME) was defined as thickening of the retina with or without partial loss of retinal transparency at or within 500 µm of the center of the macula; or as hard exudates at or within 500 µm of the center of the macula associated with thickening of the adjacent retina; or as an area of retinal thickening 1 disc diameter (DD) or larger, any part of which was within 1 DD of the center of the macula.13 If macular edema could not be graded in an eye, the participant was assigned the score of the other eye.
Eyes that could not be graded—because of opacities of the media, phthisis, or enucleation—were initially classified as "cannot grade." For such persons, review of all previous medical records was done subsequent to the study visit. When a history of panretinal photocoagulation for proliferative DR or pars plana vitrectomy for complications of proliferative DR was identified, then the retinopathy level was scored as 85. Persons who had an ETDRS grading of less than 50 at the time of examination and had previously received laser photocoagulation for proliferative DR, as documented by medical record review, were classified as grade 61.
For the purpose of this article, the severity scales were collapsed into the following categories based on the consensus of the Eye Diseases Prevalence Research Group:
- Mild nonproliferative DR (level 14 up to, but not including level 40)
- Moderate nonproliferative DR (level 40 up to, but not including level 50)
- Severe DR (level
 50, including severe nonproliferative and proliferative retinopathy)
Composite outcomes are defined as follows: (1) DR of any level, consisting of "mild," "moderate," or "severe" retinopathy, CSME, or any combination thereof; and, (2) vision-threatening DR (VTDR), consisting of severe retinopathy, CSME, or both.
The composite outcomes were used as the primary outcomes for this article, respectively, indicating (1) the presence of any level of DR and (2) a level of DR likely to result in vision loss in the absence of laser photocoagulation treatment.
Definitions
Included in both studies were patients with type 1 DM whose conditions were diagnosed and treated with insulin before the patients were 30 years old and who were receiving insulin therapy.6-8,14 In the New Jersey 725 study, African Americans who had the onset of DM before age 30 years but were not receiving insulin therapy were excluded.15 Age at onset of DM was taken as the age at which the diagnosis was first recorded by a physician on the patient's medical record or in a hospital medical record. Subjects' current age was defined as the age at the baseline examination. Race of the African Americans was determined from the hospital record and later confirmed by self-identification.
AGE-SPECIFIC PREVALENCE ESTIMATES FOR DR AMONG PERSONS WITH TYPE 1 DM
The age-, gender-, and race-specific prevalences of DR of any level and of VTDR among persons with type 1 DM are given for the following age categories: 18 through 39, 40 through 49, and 50 years and older. Prevalence for white and black persons was taken directly as reported in the WESDR and New Jersey 725 studies. Owing to lack of published data on the prevalence of DR due to type 1 DM for Hispanic persons and "other" race/ethnicity groups, the prevalence of DR in these populations was estimated using an unweighted average of the prevalence estimates for white and black persons. Since other race/ethnicity groups make up approximately 17% of the US population, these estimates were derived solely to provide some broad indication of the number of persons in these populations with DR due to type 1 DM.
PREVALENCE ESTIMATES FOR DR DUE TO TYPE 1 DM IN THE GENERAL POPULATION
To determine the number of individuals with DR due to type 1 DM in the US general population, an estimate of the total number of persons with type 1 DM diagnosed before age 30 years in each age-, gender-, and race-stratum was derived based on data from the National Health Interview Survey which gathers data from a nationally representative sample of civilian, noninstitutionalized persons residing in the United States.9 Persons answering yes to the questions "Have you ever been told by a doctor or health professional that you have diabetes or sugar diabetes" and "Are you now taking insulin" and also reporting age first diagnosed with DM as being younger than 30 years represented 0.38%, 0.48%, and 0.41% of the national population 18 years and older in 1999, 2000, and 2001, respectively. The average overall prevalence for these 3 years (4.25/1000) was used to extrapolate to the 2000 US population 18 years and older, arriving at an estimated 889 000 persons having type 1 DM diagnosed before age 30 years. The prevalence of DR among persons with type 1 DM was then applied to the estimates of the number of persons with type 1 DM in each age-, gender-, and race-specific stratum, resulting in stratum-specific estimates of the prevalence of DR (of any level and of VTDR) among persons with type 1 DM in the 2000 US population.
STATISTICAL TESTS
Tests for age-, gender-, and race-effects were conducted for DR of any level and for VTDR, as well as for mild, moderate, and severe DR, and for CSME. Gender differences were evaluated using the Mantel-Haenszel stratified-adjusted estimate of the relative risk with test inverted confidence limits. Similarly, racial differences were evaluated using the Mantel-Haenszel stratified-adjusted estimate of the relative risk adjusting for age and gender. The Cochran-Armitage test for trend and the Mantel-Haenszel  2 test for general association were used to evaluate age effects. Data analyses were conducted following approval by the institutional review board of the The Johns Hopkins School of Medicine, Baltimore, Md, and followed the principles of the Declaration of Helsinki.
RESULTS
Two studies contributed data on DR in persons with type 1 DM, of whom 594 were black (the New Jersey 725) and 790 were white (the WESDR). The original studies considered persons of all ages; in this study, only persons 18 years and older are included. Characteristics of the subjects with type 1 DM from the 2 studies are given in Table 1.
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Table 1. Studies Included in Estimates of Diabetic Retinopathy (DR) for Persons With Type I Diabetes Mellitus (DM)*
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PREVALENCE OF DR AMONG PERSONS WITH TYPE 1 DM
Among persons with type 1 DM, the crude prevalences of both DR of any level (74.9% among black and 82.3% among white persons) and VTDR (30.2% and 32.2%, respectively) were high, but similar in both racial groups. The prevalences of DR of any level and of VTDR increased significantly with age for both men and women (test for trend, P <.001, for both DR of any level and VTDR). However, the prevalence for men aged 50 years and older tended to level off or decrease, whereas the prevalence for women aged 50 years and older continued to increase, more so among black than among white women (Table 2). The prevalence of CSME increased significantly with age among white women (test for trend, P = .05), and even more so among black women (test for trend, P = .03), but not in either white (test for trend, P = .42) or black (test for trend, P = .78) men. After controlling for gender and race, tests of the association between age and DR of any level, VTDR, severe DR, and CSME were all statistically significant (2 test, P <.001 in each instance).
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Table 2. Estimated Prevalence of Diabetic Retinopathy (DR) in Persons With Type I Diabetes Mellitus by Age, Gender, and Race
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Gender differences in the prevalence of DR among persons with type 1 DM also were observed. After adjusting for age and race, women were more likely to have DR of any level than men (relative risk [RR] = 1.04; 95% confidence interval [CI], 0.99-1.10), mainly owing to a higher prevalence of mild DR (RR = 1.24; 95% CI, 1.09-1.42). However, men were more likely to have VTDR than women (RR = 1.17; 95% CI, 1.01-1.36), largely because of a higher prevalence of CSME among black men compared with black women (RR = 1.94; 95% CI, 1.20-3.12), and a higher prevalence of severe DR among white men compared with white women (RR = 1.24; 95% CI, 1.01-1.52). The prevalence of moderate DR (RR = 1.14; 95% CI, 0.86-1.53) was not significantly different for men compared with women.
After adjusting for age and gender, black persons with type 1 DM tended to have a lower prevalence of DR of any level than did white persons with type 1 DM (RR = 0.92; 95% CI, 0.87-0.97), but they had a similar prevalence of VTDR (RR = 0.99; 95% CI, 0.85-1.15). However, black persons with type 1 DM were more likely to have CSME than white persons with type 1 DM (RR = 1.43; 95% CI ,1.01-2.03). This difference was most pronounced for black men compared with white men (RR = 1.67; 95% CI, 1.05-2.63). The prevalences of mild, moderate, and severe DR were slightly higher among white than among black persons, but differences were not statistically significant.
PREVALENCE OF DR DUE TO TYPE 1 DM IN THE UNITED STATES
The estimated prevalences of DR of any level and of VTDR in the general population are given in Table 3. In the United States an estimated 889 000 persons (0.43%) have type 1 DM diagnosed before age 30 years; of these, approximately 767 000 (86.4%) have DR of any level and 376 000 (42.1%) have VTDR. The estimated prevalences of DR of any level and VTDR in the general population are 0.37% and 0.18%, respectively.
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Table 3. Estimated Prevalence of Diabetic Retinopathy (DR) Due to Type I Diabetes Mellitus (DM) Diagnosed Before Age 30 Years in the US Population Aged 18 and Older by Age, Gender, and Race*
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COMMENT
The results of this analysis indicate that DR due to type 1 DM is common in the United States. Approximately 86% of persons with type 1 DM have DR of any level and 42% have VTDR. In the general population, DR due to type 1 DM is a major public health problem, with 1 per 300 adults (767 000) having DR of any level, and 1 per 600 adults (376 000) having VTDR. Additional persons would have DR due to older-onset type 1 DM diagnosed at or after age 30 years. However, because specific data on the prevalence of DR due to older-onset type 1 DM are unavailable from population-based surveys, it was impossible to obtain an overall estimate of the burden of DR because of type 1 DM. In this article, only estimates for persons with type 1 DM diagnosed before age 30 years are reported. An accompanying article provides estimates for the overall prevalence of DR in persons aged 40 years and older.5
The estimated population prevalences of DR of any level and of VTDR are highest in the 40- through 49-year and the 50-year-and-older age groups, most likely because older persons who had the onset of DM prior to age 30 years had a longer average duration of disease. The prevalence of DR in the general population declines thereafter, reflecting a decreasing prevalence of type 1 DM in older age groups (possibly due to early mortality among persons with type 1 DM).
White women with type 1 DM were more likely to have mild DR than white men, and white men had a higher prevalence of VTDR than white women, supporting a previous report of greater severity of DR among men compared with women in white persons with type 1 DM.16 Among black and white persons with type 1 DM, the prevalence of DR of any level increased significantly with age, reaching more than 95% in those aged 40 years and older. Among persons with type 1 DM, the prevalence of VTDR and of CSME did not increase uniformly with age across either gender or race. The prevalence of VTDR among black and white men with type 1 DM increased with age from the 18- through 39- to 40-through 49-year age group, but then declined for those aged 50 years and older. In contrast, the prevalence of VTDR among black women with type 1 DM increased significantly with age, and black women aged 50 years and older had a significantly higher risk of VTDR than white women of the same age. The greater severity of DR observed among black women in New Jersey was consistent with self-reported blindness registry data that indicated that nonwhite women were 3 times more likely to be blind from DR than any other race-gender subgroup.17
There were also differences between black and white persons with type 1 DM in that the frequency of CSME was much higher among black persons, particularly among black men. Among black men, the frequency of macular edema has been previously shown to be associated with the presence of renal disease, which itself is more prevalent among black (particularly men) than among white persons.18-20 In a clinic-based study, Arfken et al21 previously reported no significant differences in either the prevalence or severity of DR when comparing 58 African Americans with 142 white subjects with type 1 DM. In that study, however, there were no data regarding frequency of macular edema.
The strengths of the current article are that both the New Jersey 725 and WESDR had similar inclusion criteria (age at onset of DM <30 years was used) and used gold standard determinations of the outcomes (masked grading by the same reading center of retinal photographs of 7 standard fields using the ETDRS severity scale). Limitations include the fact that the studies were conducted about 15 years apart in different geographic locations. The older WESDR data may overestimate the current prevalence of DR of any level and VTDR because glycemic and blood pressure control have probably improved in the general population during the interval. These changes in clinical practice have probably decreased the incidence of DR but may also have improved survival, which would affect the prevalence of DR in opposite directions. Also, differences in the methods of obtaining population-based samples or other differences between study protocols could have given rise to apparent racial differences because neither study simultaneously evaluated both racial groups.
Estimates of the prevalence of DR due to type 1 DM in the general population must also be interpreted with caution since only a general estimate of the prevalence of type 1 DM in the United States was available, thus, limiting the ability to accurately assess the total number of persons with type 1 DM for each age-, gender-, and race-specific stratum. Racial/ethnic differences as well as gender and age differences in the incidence of type 1 DM have been reported, but no reliable national data on the prevalence of type 1 DM in these populations are available.22 The estimates of the prevalence of DR due to type 1 DM for other races/ethnicities were based on extrapolation of the rates for white and black persons and, thus, may not accurately reflect the true prevalence in these populations. However, our results provide some measure of the burden of DR due to type 1 DM in the United States and may, thus, serve as a useful guide regarding public health policies and research priorities until more satisfactory data regarding the prevalence of type 1 DM in the United States by age, gender, and race/ethnicity and by the prevalence of DR due to type 1 DM in racial/ethnic groups other than blacks and whites become available.
In addition, there may be about 0.31% of the US population aged 30 through 74 years who have older-onset type 1 DM (onset at age 30 years) and an unknown number of adults identified with type 2 DM who slowly become insulin dependent.23 Our studies only evaluated DR in individuals having type 1 DM diagnosed before age 30 years. Thus, we are unable to accurately assess the nature and severity of DR in persons with older-onset type 1 DM. The omission of individuals with older-onset type 1 DM would lead to underestimates of DR due to type 1 DM in the general population. Therefore, the burden of DR due to type 1 DM in the general population may be as much as 2 times higher than the estimates provided here for DR due to younger-onset type 1 DM only.
CONCLUSIONS
In the United States, the prevalence of DR due to type 1 DM is high. An estimated 767 000 persons aged 18 years and older in the US general population have DR of any level, 1 per 300 adult persons. An estimated 376 000 persons in this age range have VTDR, 1 per 600 adult persons. The prevalence of DR is expected to increase substantially by 2020, driven by an increasing prevalence of DM over time with the aging of the US population, in combination with anticipated increases in the age-specific prevalence of DM. Because DR is a substantial public health problem, public and private policy efforts directed toward improving primary and secondary prevention programs are warranted.
AUTHOR INFORMATION
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Corresponding author and reprints: Monique S. Roy, MD, Department of Ophthalmology, University of Medicine and Dentistry of New Jersey–New Jersey Medical School, 90 Bergen St, Room 6164, Newark, NJ 07101-1709 (e-mail: Roymo{at}umdnj.edu).
Submitted for publication August 6, 2003; final revision received December 30, 2003; accepted December 30, 2003.
This study was supported by grants RO1 EY 09860 (Dr Roy), EY03083 (Drs Klein and Klein), and EY00386 (Dr Kempen) from the National Eye Institute, Bethesda, Md; and a Lew Wasserman Merit Award from Research to Prevent Blindness, New York, NY (Dr Roy).
From the Institute of Ophthalmology and Visual Science, the University of Medicine and Dentistry–New Jersey Medical School, Newark, (Dr Roy); Department of Ophthalmology and Visual Sciences, Madison, Wis (Drs R. Klein and B. E. K. Klein and Mr Moss); Department of Epidemiology and Biostatistics, School of Public Health and Health Services, Washington, DC (Ms O'Colmain); Macro International Inc, Calverton, Md (Ms O'Colmain); Department of Ophthalmology, The Johns Hopkins University School of Medicine (Dr Kempen), and Department of Epidemiology, Bloomberg School of Public Health, Baltimore, Md (Dr Kempen). The authors have no relevant financial interest in this article.
REFERENCES
1. American Academy of Ophthalmology. Preferred Practice Pattern: Diabetic Retinopathy 1998. San Francisco, Calif: American Academy of Ophthalmology; 1998.
2. Diabetic Retinopathy Research Group. Photocoagulation treatment of proliferative diabetic retinopathy: clinical application of diabetic retinopathy study (DRS) findings, DRS report number 8. Ophthalmology. 1981;88:583-600.
ISI
| PUBMED
3. Early Treatment Diabetic Retinopathy Study Research Group. Early photocoagulation for diabetic retinopathy: ETDRS report number 9. Ophthalmology. 1991;98(suppl):766-785.
ISI
| PUBMED
4. The DCCT Research Group. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus. N Engl J Med. 1993;329:977-986.
FREE FULL TEXT
5. The Eye Diseases Prevalence Research Group. The prevalence of diabetic retinopathy among adults in the United States. Arch Ophthalmol. 2004;122:552–563.
FULL TEXT
|
ISI
| PUBMED
6. Klein R, Klein B, Moss S, Davis M, DeMets D. The Wisconsin Epidemiologic Study of Diabetic Retinopathy, II: prevalence and risk of diabetic retinopathy when age at diagnosis is less than 30 years. Arch Ophthalmol. 1984;102:520-526.
FREE FULL TEXT
7. Roy M. Diabetic retinopathy in African Americans with type 1 diabetes: the New Jersey 725, I: methodology, population, frequency of retinopathy and visual impairment. Arch Ophthalmol. 2000;118:97-104.
FREE FULL TEXT
8. Roy M. Diabetic retinopathy in African Americans with type 1 diabetes: the New Jersey 725, II: risk factors. Arch Ophthalmol. 2000;118:105-115.
FREE FULL TEXT
9. National Health Interview Survey (NHIS) Public Use Data Release for 1999;2000:2001. Available at: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Datasets/NHIS. Accessed on December 12, 2003.
10. US Census 2000 Population Tables. US Census 2000 Summary File 1 (SF 1) 100-Percent Data. Available at: http://factfinder.census.gov/servlet/DatasetMainPageServlet?_lang=en Accessed January 1, 2003.
11. Early Treatment Diabetic Retinopathy Study Research Group. Grading diabetic retinopathy from stereoscopic color fundus photographs: an extension of the modified Airlie House classification: ETDRS report number 10. Ophthalmology. 1991;98:786-806.
ISI
| PUBMED
12. Early Treatment Diabetic Retinopathy Study Research Group. Fundus photographic risk factors for progression of diabetic retinopathy: ETDRS report number 12. Ophthalmology. 1991;98:823-833.
ISI
| PUBMED
13. Early Treatment of Diabetic Retinopathy Study Research Group. Photocoagulation for diabetic macular edema: ETDRS report number 1. Arch Ophthalmol. 1985;103:1796-806.
FREE FULL TEXT
14. Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Report of the expert committee on the diagnosis and classification of diabetes mellitus. Diabetes Care. 1997;20:1183-1197.
ISI
| PUBMED
15. Winter W, McLaren N, Riley W, Clarke D, Kappy M, Spillar R. Maturity-onset diabetes of youth in Black Americans. N Engl J Med. 1987;316:285-291.
ABSTRACT
16. Bodansky H, Cudworth A, Drury P, et al. Risk factors associated with severe proliferative retinopathy in insulin-dependent diabetes mellitus. Diabetes Care. 1982;5:97-100.
ABSTRACT
17. Kahn HA, Moorhead HB. Statistics on Blindness in the Model Reporting Area, 1969-1970. Washington, DC: Department of Health and Human Services, Public Health Service, National Institutes of Health, National Eye Institute; 1973. NIH publication 73-427.
18. Klein R, Klein B, Moss S, Davis M, DeMets D. The Wisconsin Epidemiologic Study of Diabetic Retinopathy, V: proteinuria and retinopathy in a population of diabetic persons diagnosed prior to 30 years of age. In: Diabetic Renal-Retinal Syndrome. Vol 3. New York, NY: Grune & Stratton Inc; 1986:245-264.
19. Roy M, Klein R. Macular edema and retinal hard exudates in African-American with type 1 diabetes: the New Jersey 725. Arch Ophthalmol. 2001;119:251-259.
FREE FULL TEXT
20. Roy MS. Proteinuria in African Americans with type 1 diabetes. J Diabetes Complications. 2004;18:69-77.
FULL TEXT
|
ISI
| PUBMED
21. Arfken C, Salicrup A, Meuer S, et al. Retinopathy in African Americans and whites with insulin-dependent diabetes mellitus. Arch Intern Med. 1994 Nov 28;154(22):2597-602.
22. National Diabetes Data Group. Diabetes in America. 2nd ed. Bethesda, Md: National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases; 1995. NIH publication 95-1468.
23. Harris MI, Robbins DC. Prevalence of adult-onset IDDM in the US population. Diabetes Care. 1994;17:1337-1340.
ABSTRACT
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