Racial/Ethnic Differences in Diabetes and Associated Risk Factors. New Mexico, 1999-2002 Diabetes is a disease characterized by. abnormalities in …

NEW MEXICO EPIDEMIOLOGY REPORT
Volume 2004, Number 7 September 17, 2004

Racial/Ethnic Differences in Diabetes and Associated Risk Factors New Mexico, 1999-2002
Heidi Krapfl, MS, Diabetes Epidemiologist Public Health Division, NM Department of Health Diabetes is a disease characterized by abnormalities in carbohydrate, protein, fat, and insulin metabolism Unlike reportable conditions, diabetes is not tracked on an individual basis Instead, the prevalence is determined indirectly At the state level, diagnosed diabetes is estimated by the Behavioral Risk Factor Surveillance System BRFSS The purpose of this report is to analyze the diabetes data from BRFSS by race/ethnicity and explore any differences Methods In order to obtain more precise estimates by race/ethnicity, 1999-2002 BRFSS data1 were aggregated The BRFSS is a Centers for Disease Control and Prevention CDC random-digitdialed telephone survey of the noninstitutionalized population aged 18 years Residents of New Mexico were first asked about doctor-diagnosed diabetes in this survey in 1988 A module was subsequently added to the survey to find out more about individuals with diabetes Currently there is one question about the
diagnosis of diabetes, and 12 questions on selfcare management practices and components of diabetes standards of care Elsewhere in the survey there are questions about risk factors for diabetes such as obesity and physical inactivity During this time period, the wording of some questions in the survey changed; when the meaning also changed, these questions and corresponding variables were not included in the final dataset Consistent with BRFSS guidelines, when denominators were smaller than 50, the confidence interval CI and estimate were not shown Results were also not shown if the CI spanned more than 15 percentage points Results Demographics According to the BRFSS, American Indians AI are the population most affected by diabetes in the state, with 105 of the adult population reporting a diagnosis of diabetes, followed by Hispanics HSP of any race 73 and nonHispanic Whites NHW 46 Because insulin resistance increases with age for all racial/ethnic groups, so does diabetes prevalence in general Figure 1 illustrates diabetes prevalence in New Mexico across age groups This trend was similar for NHW and HSP; however, for HSP, diabetes prevalence was higher for all age groups A trend
for AI could not be evaluated due to small sample sizes in the 65-74 and 75 age groups N22 and 17, respectively
160 140 120 100 80 60 40 20 00 Figure 1 Diabetes Prevalence by Age New Mexico, 1999-2002 146 94

121

18-44

45-64

65-74

Age in Years Source: BRFSS, NM Department of Health

The age at which an individual is diagnosed with diabetes also varies by race/ethnicity There is a significant difference between age at diagnosis between HSP and NHW and between AI and NHW p-values 0017 and 0000, respectively

New Mexico Epidemiology Report

September 17, 2004

AI and HSP both report a younger age at diagnosis than NHW The mean age at diagnosis for NHW, HSP, and AI is 505, 474, and 409 years, respectively Risk Factors Obesity has been linked to an increased risk of diabetes2 The standard index which is used to reflect weight status is the body mass index BMI and is calculated as weight in kilograms divided by height in meters squared Among adults, an individual with a BMI of less than 25 is classified as underweight or of normal weight this category will be referred to as normal At a BMI of 25 and greater but less than 30, the individual is classified as overweight; any
individual with a BMI of 30 or greater is classified as obese3 The average BMI among New Mexicans varies significantly between those who have diabetes and those who do not p 0000 People with diabetes are more overweight than individuals without diabetes This also holds true when stratified by race/ethnicity Figure 2 Although average BMI among people without diabetes varies significantly between NHW and HSP and between NHW and AI p0000 for both, this is not the case for people with diabetes Among those with diabetes, there is no statistically significant difference in average BMI between NHW and HSP p0764 or NHW and AI

p0262 Therefore, it appears that racial/ethnic differences in BMI vary with diabetes status To explore this relationship a multivariate analysis controlling for age was completed to determine the relative contributions of weight and race/ethnicity to diabetes The data in the Table indicate that both HSP and AI of any weight category are at higher risk odds ratio 1 of diabetes than NHW For HSP, as the weight category progresses to obese, the odds ratios ORs decrease, approaching the risk for NHW For AI, the ORs dont decrease until the obese category Apparently, by
the time an individual is obese, race/ethnicity is less important in increasing the risk of diabetes than it is for persons in lower weight categories That is, if an obese individual is AI or HSP, they still have an increased odds of diabetes compared to someone who is NHW But the relative increase is much smaller than seen for the overweight and normal categories Another risk factor for diabetes is physical inactivity When New Mexicans were asked if they had any leisure time physical activity in the past month, 759 said yes When stratified by diabetes status, there was a significant difference p0000 Among those with diabetes, 644 said they participated in any activity, whereas among those wit hout diabetes, 767

Table Risk of Diagnosed Diabetes by Weight Category and Race/Ethnicity New Mexico, 1999-2002 Normal Normal Overweight Overweight Obese Weight Weight OR CI OR Odds Confidence Ratio Interval OR CI Hispanic 28 19, 40 18 13, 24 15 American Indian NonHispanic White 49 13, 183 49 Reference 29, 83 Reference 16 Reference

Obese CI

12, 20 10, 28 Reference

Reference Reference

Source: BRFSS NM Department of Health

participated in any activity When race/ethnicity

New Mexico
Epidemiology Report

September 17, 2004

was taken into consideration, NHW with diabetes had a higher percentage of individuals who participated in any activity 703 than HSP 610, though this was not a significant difference The confidence interval was too wide to report results for American Indians Healthcare Practices The BRFSS does not ask questions about all diabetes standards of care; however, three practices were consistently asked about from 1999-2002: visits to a health professional for diabetes, foot checks by a health professional, and dilated eye exams Overall, 911 of people with diabetes see a health professional at least once per year for their diabetes; HSP have a higher percentage 928 than NHW 909, though this was not a significant difference The value for AI could not be reported due to CI width Due to neuropathy, persons with diabetes are at increased risk of foot ulcers as well as amputation Therefore annual foot checks of low-risk feet and more frequent checks of higher risk feet are essential AI with diabetes had the highest percentage 935 receiving a foot exam annually followed by HSP 726 and NHW 705; AI had a significantly p005 higher percent than NHW Another
standard of care for people with diabetes is a yearly dilated eye exam, which can detect retinopathy NHW 721 have a higher percentage than HSP 680; however this is not a significant difference The confidence interval was too wide to report the AI value Conclusions By aggregating four years of BRFSS data and looking at diabetes-related variables, some racial/ethnic differences could be identified Overall, HSP and AI face significant challenges with respect to diabetes They are diagnosed at an earlier age with diabetes and for HSP this translates into a higher diabetes prevalence at every age, compared to NHW If diabetes is poorly controlled in groups with a younger age at diagnosis, complications will also likely occur at a younger age Weight is also an important risk factor Obese individuals, regardless of race/ethnicity, are at high risk for diabetes

However, HSP and to a greater extent AI, are at risk for diabetes at lower BMIs, when compared to NHW On the other hand, with respect to physical activity and standards of care, diabetes diagnosis is more of a factor than race/ethnicity People with diabetes participated in less activity than do those without diabetes, but there were
no significant racial/ethnic differences For the standards of care examined, the only significant racial/ethnic difference was seen for foot checks, where AI had a higher percentage Although some conclusions can be made from the four-year BRFSS dataset, the sample size was still too small in many cases to make conclusions about AI with diabetes Oversampling could be undertaken to increase the sample size among AI with diabetes In addition, BRFSS likely underestimates the true prevalence of diabetes It is well known that weight management and physical activity are essential for diabetes management and prevention However, these factors also impact many other diseases Therefore, it becomes more important to shift away from a disease paradigm where each disease has its own prescription, almost all of which include good nutrition and regular activity The Department of Health is increasing the collaboration between programs addressing chronic disease prevention and control around physical activity and nutrition
References 1 Centers for Disease Control and Prevention CDC Behavioral Risk Factor Surveillance System Survey Data New Mexico Atlanta, Georgia: US Department of Health and Human
Services, Centers for Disease Control and Prevention, 1999-2002 2 Resnick H, Valsania P, Halter J, Lin X Relation of weight gain and weight loss on subsequent diabetes risk in overweight adults J Epidemiology Community Health 2000; 54: 596602 3 National Heart, Lung, and Blood Institute Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: The Evidence Report Washington, DC: Government Printing Office; 1998

Prsrt Std US Postage PAID Santa Fe, NM 390

Volume 2004, Number 7 Racial/Ethnic Differences in Diabetes and Associated Risk Factors, New Mexico 1999-2002

THE NEW MEXICO EPIDEMIOLOGY REPORT
C Mack Sewell, DrPH, MS, State Epidemiologist Ronald E Voorhees, MD, MPH, Deputy State Epidemiologist Michael G Landen, MD, MPH, Editor The New Mexico Epidemiology Report ISSN No 87504642 is published monthly, free of charge, by the Office of Epidemiology, Public Health Division, New Mexico Department of Health, 1190 St Francis Drive, PO Box 26110, Santa Fe, NM 87502 Toll-Free Reporting Number: 1-800-432-4404 24 Hour Emergency Number: 505 827-0006 or 505 984-7044

Figure 2 Average Body Mass Index and Diabetes Status by Race/Ethnicity, New
Mexico, 1999-2002
350 300 BMI m/kg2 250 200 150 100 50 00
Source:

302

255

300

266

285

274

Diabetes No diabetes

non Hispanic White BRFSS NM Department of Health

Hispanic

American Indian