Diabetes prevalence, incidence, and complications among Alaska Natives, 1987

Diabetes Prevalence, Incidence, and Complications Among Alaska Natives, 1987

31.1/1000 in one coastal Indian group (5). This article updates the prevalence rate, including two additional years of observation, and provides incidence and complications data.

RESEARCH DESIGN AND METHODS— Details of methodology were described previously (5). In summary, the IHS computerized PCIS is searched annually for all inpatient and outpatient visits in Alaska with diabetesrelated ICD-9 codes; charts are reviewed, and those patients meeting WHO criteria OBJECTIVE— To provide descriptive epidemiological data on diabetes mellitus are entered into a computerized registry among Alaska Natives, including incidence, updated prevalence, and incidence rates maintained at the CDC Arctic Investigaof ESRD, LEA, MI, and stroke in the diabetic population. tions Program in Anchorage. The registry was established in 1985-1986, and RESEARCH DESIGN AND METHODS— In IHS and tribal contract hospitals baseline prevalence data for 1985 was and clinics throughout Alaska, Alaskan Indians, Eskimos, and Aleuts living in Alaska established previously (5). The PCIS data with documented diabetes mellitus were studied from 1986 to 1987. base is now searched for patients with renal failure, LEA, MI, stroke, retinopaRESULTS— The number of diabetic patients increased from 610 to 708, and the thy, or diabetic neuropathy; this listing is prevalence changed from 15.7 to 17.4/1000 (not a statistically significant increase). matched against the registry of diabetic Incidence rates per 10,000 diabetic person-yr for complications were 38 for ESRD, 69 patients. Additional sources of complicafor LEA, 92 for MI, and 92 for stroke. tions data include the Alaska Kidney Center (the only dialysis center in AlasCONCLUSIONS — The prevalence of diabetes mellitus increased during the pe- ka), the State of Alaska Diabetes Proriod of observation, but not to a statistically significant degree. Incidence rates for gram, and village health-care providers. All cases of ESRD, LEA, MI, and diabetes are lower than for the U.S. general population, but complications rates are stroke occurring in 1986 and 1987 were as high as those in other diabetic populations. confirmed by records review. Deaths were ascertained through state vital staiabetes once was thought to be rare WHO criteria for diabetes. As of Decem- tistics listings. Diabetes clinics, now held among Alaska's Eskimos, Indians, ber 1985, 610 Alaska Natives living in in all regions of the state, use the registry and Aleuts; studies conducted Alaska met WHO criteria for diabetes, and in turn provide a mechanism for from the 1950s to the early 1970s con- for an overall age- adjusted prevalence of verifying and updating registry informafirmed this impression (1-4). In 1986, a 15.7/1000. Prevalence varied fivefold tion, such as residence changes. Prevaproject was initiated to develop a registry within the Alaska Native population, lence and incidence rates for diabetes of all Alaska Native patients that met the from 5.8/1000 among Yupik Eskimos to were calculated by using IHS population estimates, and were age adjusted by the direct method to the 1980 U.S. populaF R O M THE DIABETES PROGRAM, ALASKA AREA NATIVE HEALTH SERVICE, AND THE ARCTIC INVESTIGATIONS tion (6).

CYNTHIA D. SCHRAER, MD LISA R. BULKOW, MS NEILJ. MURPHY, MD ANNE P. LANIER, MD, MPH

D

PROGRAM, CENTERS FOR DISEASE C O N T R O L , ANCHORAGE; AND M T . EDGECUMBE HOSPITAL, SOUTHEAST ALASKA REGIONAL HEALTH CORPORATION, SITKA, ALASKA. ADDRESS CORRESPONDENCE AND REPRINT REQUESTS T O CYNTHIA D . SCHRAER, MD, DIABETES PROGRAM COORDINATOR, ALASKA AREA NATIVE HEALTH SERVICE, 2 5 0 GAMBELL STREET, ANCHORAGE, A K 9 9 5 0 1 .

ESRD, END-STAGE RENAL DISEASE; L E A , LOWER-EXTREMITY AMPUTATION; MI, MYOCARDIAL INFARCTION; W H O ,

W O R L D HEALTH ORGANIZATION; I H S , INDIAN HEALTH SERVICE; P C I S , PATIENT CARE

INFORMATION SYSTEM; I C D - 9 ,

INTERNATIONAL CLASSIFICATION OF DISEASES, NINTH REVISION; C D C ,

CENTERS FOR DISEASE C O N T R O L ; TYPE II DIABETES, NON-INSULIN-DEPENDENT DIABETES MELLITUS.

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RESULTS— Table 1 summarizes the 1985 and 1987 prevalence rates among Alaska Natives overall and in the three major ethnic groups. Of the patients studied, >95% have type II diabetes. Over the 2-yr period, the overall prevalence rate increased from 15.7 to

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Diabetes and complications in Alaska Natives

Table 1—Diabetes prevalence among Alaska Natives, age adjusted to 1980 U.S. population

The ESRD incidence rate (38/10,000) appears to be higher than that of the U.S. diabetic population (all races) in 1987 (14/10,000) (Dr. J. Newman, CDC, un1987 1985 published observations), but lower than RATE No. OF RATE No. OF CHANGE OVER that of the IHS Aberdeen area in 1987 2 YR* (%) CASES ( N ) (PER 1000) (PER 1000) CASES ( N ) (61/10,000) (IHS program data). The stroke incidence rate (92/10,000) is 11 A L L ALASKA NATIVES 15.7 708 17.4 610 ALASKAN ESKIMO 8.8 216 16 179 10.2 roughly comparable with that of a mostly ALASKAN INDIAN 22.0 335 9 292 24.0 white diabetic population (101/10,000 ALASKAN ALEUT 27.2 157 139 5 28.6 in Rochester, MN, 1945-1969) (10). The diabetes prevalence for all races in the U.S. was 24.7/1000 in 1980 (7). The incidence rate for MI (92/10,000) is *None are statistically significant. much higher than the only other report of MI among diabetic Native Americans (16.8/10,000 in Southwestern Indians, 17.4/1000. However, none of the based on the registry, a dynamic data 1975-1978) (11). changes in Table 1 were found statisti- base, have inherent sources of error. In summary, diabetes is no cally significant, by the Mantel-Haenszel First, they are based on clinically recog- longer unusual among Alaska Natives. nized cases, not on comprehensive Both microvascular and macrovascular test adjusting for age. Age-adjusted annual incidence screening studies; second, a small num- complications occur at rates as high as rates were calculated for 1986-1987. ber of patients are diagnosed in the pri- those in other diabetic populations. For the 2-yr period, 55 Eskimos, 57 In- vate sector and their data may not be Whether diabetes will become as comdians, and 25 Aleuts were newly diag- included in the PCIS data base; and mon among Alaska Natives as it has in nosed with diabetes. The annual inci- third, death certificates sometimes are other Native American groups remains to dence rates per 10,000 were 15.7 for all filed late. However, the IHS is the only be seen. Alaska Natives, 13.0 for Eskimos, 18.3 health-care provider throughout much for Indians, and 18.6 for Aleuts. These of Alaska, and the number of Alaska Narates were lower than the 1980 U.S. all- tive individuals who used the system at Acknowledgments—We thank Anita Vogt least once from 1987 to 1989 was essen- for manuscript preparation and Alice Muller races incidence of 22.7/10,000 (8). The registry patients contributed tially equal to the census-based Alaska for data management. a total of 1299.5 diabetic person-yr of Native population estimate in 1989 (B. observation during 1986-1987. Inci- Boedeker, Alaska Native Health Service References dence rates per 10,000 diabetic per- Statistician, unpublished observations). 1. Scott EM, Griffith IV: Diabetes mellitus son-yr and numbers of cases of ESRD, Therefore, ascertainment of clinically in Eskimos. Metabolism 6:320-25, 1957 recognized cases is believed to be reasonLEA, MI, and stroke are shown in Table 2. Mouratoff GJ, Carroll NV, Scott EM: Diably complete. 2. Each of the four complications ocabetes mellitus in Eskimos. JAMA 199: curred in every ethnic group (Eskimo, The Alaska Native LEA incidence 107-12, 1967 Indian, and Aleut) in 1986-1987, with rate (69/10,000) is slightly higher than 3. Mouratoff GJ, Scott EM: Diabetes mellithe exception of amputation, which did the estimated rate for the U.S. diabetic tus in Eskimos after a decade. JAMA not occur among Eskimo diabetic pa- population in 1978 (59.7/10,000) (9) 226:1345-46, 1973 tients. and that of diabetic Navajo Indians in 4. Mouratoff GJ, Carroll NV, Scott EM: Di1985 (45/10,000) (IHS program data). abetes mellitus in Athabascan Indians in CONCLUSIONS— In general, higher Alaska. Diabetes 18:29-32, 1969 prevalence rates of diabetes occur in 5. Schraer CD, Lanier AP, Boyko EJ, population groups that have had the Gohdes D, Murphy NJ: Prevalence of diTable 2—Incidence of complications among longest contact with western life-styles Alaska Natives with diabetes, 1986-1987 abetes mellitus in Alaskan Eskimos, In(5). Historic data are scarce; however, a dians, and Aleuts. Diabetes Care 11:693comparison of current Eskimo rates with 700, 1988 ESRD LEA MI STROKE those documented in the past indicates a 6. Rothman KJ: Modern Epidemiology- Bospossible overall 10-fold increase in 30 yr CASES (N) 5 9 12 12 ton, MA, Little, Brown, 1986, p. 41-44 (1,5). INCIDENCE* 38 69 92 92 7. Harris MI, Hamman RF, Eds.: Diabetes in America. Washington, DC, U.S. Govt. Prevalence and incidence rates *Per 10,000 diabetic person-yr.

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diabetic cohort. Mayo Clin Proc 58:56Most RS, Sinnock P: The epidemiology of Printing Office, 1985, p. VI-4 (NIH publ. 58, 1983 lower extremity amputations in diabetic no. 85-1468) individuals. Diabetes Care 6:87-91, 1983 11. Sievers ML, Fisher JR: Increasing rate of 8. Harris MI, Hamman RF, Eds.: Diabetes in acute myocardial infarction in SouthAmerica. Washington, DC, U.S. Govt. 10. Roemholdt ME, Palumbo PJ, Whisnant western American Indians. Ariz Med 36: JP, Elveback LR: Transient ischemic atPrinting Office, 1985, p. IV-6 (NIH publ. 739-42, 1979 tack and stroke in a community-based no. 85-1468)

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