J P Burke

Publications (7)60.22 Total impact

• Article: Elevated incidence of type 2 diabetes in San Antonio, Texas, compared with that of Mexico City, Mexico.

  J P Burke, K Williams, S M Haffner, C G Villalpando, M P Stern
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  ABSTRACT: To compare the incidence of type 2 diabetes between low-income Mexican-Americans residing in San Antonio, Texas, and low-income residents in Mexico City, Mexico. Using data from the San Antonio Heart Study and the Mexico City Diabetes Study, we compared the incidence of type 2 diabetes in 35- to 64-year-old low-income Mexican-American residents of San Antonio with similarly aged low-income residents of Mexico City. Because of the different follow-up times in the two studies, Poisson regression was used to compare the rates of diabetes. Potential risk factors for diabetes were also analyzed to determine whether they explained or contributed to a difference in incidence. The age- and sex-adjusted incidence of type 2 diabetes was significantly higher in San Antonio (RR 2.01) compared with Mexico City. This difference was seen primarily in the oldest age group (55-64 years of age) and remained statistically significant after adjusting for a number of diabetes risk factors, including demographic, anthropometric, and metabolic variables. Follow-up rates were similar in both cities. We conclude that there was a higher incidence of type 2 diabetes in San Antonio than in Mexico City, and that difference occurred primarily in individuals in the oldest age group. The potential mediating factors we examined did not account for this difference. Other factors, such as exercise and diet, which were not available for analysis in this study, in addition to a cohort effect, may have contributed to the difference in incidence of type 2 diabetes in the two cities. In addition, there was no evidence of a higher case fatality among diabetic individuals from Mexico City compared with San Antonio.
  Diabetes Care 10/2001; 24(9):1573-8. · 8.09 Impact Factor
• Article: Rising trend in obesity in Mexican Americans and non-Hispanic whites: is it due to cigarette smoking cessation?

  J P Burke, H P Hazuda, M P Stern
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  ABSTRACT: Several studies have examined the influence of smoking cessation on weight gain. However, to date no study has examined this association in Mexican Americans (MA). Using data collected from the San Antonio Heart Study, a population-based study of diabetes and cardiovascular disease, we examined the association between smoking cessation and weight gain in 1930 Mexican Americans and 1126 non-Hispanic whites (NHW). Smoking cessation was defined as self-reported smoking at baseline but not at follow-up. Although there was no significant ethnic difference in the prevalence of smoking at baseline (27.2% in MA and 25.4% in NHW, P = 0.309), a greater proportion of MA smoked at follow-up compared to NHW (19.7% vs 16.5%, P = 0.037). However, there was no significant ethnic difference in the percentage of individuals who stopped smoking during the follow-up period. A two-fold greater percentage of MA quitters than NHW quitters became overweight or obese, defined as a body mass index greater than or equal to 25 kg/m2 (7.4% vs 3.1%). However, this difference did not quite reach statistical significance (P = 0.072). Using linear regression to predict change in weight or body mass index from baseline to follow-up, smoking cessation was predictive of either weight gain or BMI gain in both ethnic groups. However, smoking status accounted for only 1.0% of the variance in these outcomes, and the estimated risk of becoming overweight or obese attributable to smoking cessation was only 7.4% in MA and 3.1% in NHW. We conclude that there is an ethnic difference in the influence of smoking cessation on weight gain in MA and NHW. However, in both ethnic groups this effect is quite small and makes only a slight contribution to the overall increase in prevalence of obesity in this population.
  International Journal of Obesity 01/2001; 24(12):1689-94. · 4.69 Impact Factor
• Article: Genetic basis of acanthosis nigricans in Mexican Americans and its association with phenotypes related to type 2 diabetes.

  J P Burke, R Duggirala, D E Hale, J Blangero, M P Stern
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  ABSTRACT: Acanthosis nigricans (AN) is a skin condition associated with hyperinsulinemia and insulin resistance and has been shown to be a risk factor for type 2 diabetes. The influence of genetic factors on AN and the basis of its association with type 2 diabetes and its risk factors are unknown. Using data from 397 participants from two Mexican American family studies, we investigated the heritability of AN and its genetic correlation with other diabetes risk factors. AN was examined as both a continuous trait and a dichotomous trait by means of a previously described validated scale. The results indicated that the heritability (h2) for AN, when examined as a continuous trait, was high (0.58+/-0.10) and statistically significant (P<0.001). The h2 for AN as a dichotomous trait was estimated to be moderate (0.23+/-0.05) and was also significant (P=0.018). The additive genetic correlations between AN (either as a continuous trait or a dichotomous trait) and type 2 diabetes and its risk factors, including body mass index and fasting insulin, were high or moderately high and statistically significant. The random environmental correlations, by contrast, were low and statistically insignificant. These data suggest that genes that influence AN have pleiotropic effects on diabetes and its risk factors.
  Human Genetics 06/2000; 106(5):467-72. · 5.07 Impact Factor
• Article: Insulin-resistant prediabetic subjects have more atherogenic risk factors than insulin-sensitive prediabetic subjects: implications for preventing coronary heart disease during the prediabetic state.

  S M Haffner, L Mykkänen, A Festa, J P Burke, M P Stern
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  ABSTRACT: Subjects who convert to type 2 diabetes mellitus have increased cardiovascular risk factors relative to nonconverters. However, it is not known whether these atherogenic changes in the prediabetic state are predominantly due to insulin resistance, decreased insulin secretion, or both. We examined this issue in the 7-year follow-up of the San Antonio Heart Study, in which 195 of 1734 subjects converted to type 2 diabetes. At baseline, converters had significantly higher body mass index, waist circumference, triglyceride concentration, and blood pressure and lower HDL cholesterol than nonconverters. Atherogenic changes in converters were markedly attenuated (and no longer significant) after adjustment for the homeostasis model assessment of insulin resistance (HOMA IR, a surrogate for insulin resistance); in contrast, the differences in risk factors between converters and nonconverters increased after adjustment for the ratio of early insulin increment to early glucose increment (DeltaI(30-0)/DeltaG(30-0)) during an oral glucose tolerance test (a surrogate for insulin secretion). We also compared converters who had a predominant insulin resistance (high HOMA IR and high DeltaI(30-0)/DeltaG(30-0)) (n=56) and converters who had a predominant decrease in insulin secretion (low HOMA IR and low DeltaI(30-0)/DeltaG(30-0)) (n=31) with nonconverters (n=1539). Only the converters who were insulin resistant had higher blood pressure and triglyceride levels and lower HDL cholesterol levels than nonconverters. Our data suggest that atherogenic changes in the prediabetic state are mainly seen in insulin-resistant subjects and that strategies to prevent type 2 diabetes might focus on insulin-sensitizing interventions rather than interventions that increase insulin secretion because of potential effects on cardiovascular risk.
  Circulation 04/2000; 101(9):975-80. · 14.74 Impact Factor
• Source

  Available from: diabetesjournals.org

  Article: A quantitative scale of acanthosis nigricans.

  J P Burke, D E Hale, H P Hazuda, M P Stern
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  ABSTRACT: To develop and validate a scale for acanthosis nigricans (AN). Subjects were participants from the San Antonio Family Diabetes Study and the San Antonio Family Heart Study. A total of 406 subjects were independently examined for AN by at least two observers. Five locations were examined: the neck, axilla, elbows, knuckles, and knees. Interobserver concordance and kappa statistics were calculated to determine replicability of the scale. Comparisons of diabetes-related risk factors by AN score were also calculated. Only the neck had consistently high kappa statistics, and thus, other locations were excluded from further analyses. Elevated AN was strongly associated with elevated fasting insulin and BMI in both diabetic and nondiabetic subjects. Elevated AN was also strongly associated with elevated fasting glucose, systolic blood pressure, and diastolic blood pressure, and with decreased HDL in nondiabetic subjects. In diabetic subjects, elevated AN was associated with elevated total cholesterol. We have developed a scale for AN that is easy to use, has high interobserver reliability in Mexican Americans, and correlates well with fasting insulin and BMI. This scale will permit longitudinal and cross-sectional evaluation of AN and will permit the evaluation of AN as a trait in genetic studies.
  Diabetes Care 11/1999; 22(10):1655-9. · 8.09 Impact Factor
• Source

  Available from: archinte.ama-assn.org

  Article: Rapid rise in the incidence of type 2 diabetes from 1987 to 1996: results from the San Antonio Heart Study.

  J P Burke, K Williams, S P Gaskill, H P Hazuda, S M Haffner, M P Stern
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  ABSTRACT: The prevalence of type 2 diabetes has increased in the early part of the 20th century, particularly in developing countries. There is now evidence that the prevalence also continues to increase in developed countries, including the United States. However, it is unknown whether this increase is due to a rise in the incidence of diabetes or to decreasing diabetic mortality or both. Participants in the San Antonio Heart Study, who were nondiabetic at baseline and who returned for a 7- to 8-year follow-up examination, were examined for secular trends in the incidence of type 2 diabetes. Risk factors for diabetes, such as obesity, were also examined. Patients were enrolled in the San Antonio Heart Study from 1979 to 1988 and 7- to 8-year incidence of diabetes was determined from 1987 to 1996. A significant secular trend in the 7- to 8-year incidence of type 2 diabetes was observed in Mexican Americans (5.7% for participants enrolled in 1979 to 15.7% for participants enrolled in 1988). In non-Hispanic whites, the incidence increased from 2.6% for participants enrolled in 1980 to 9.4% for participants enrolled in 1988 (P = .07) . After adjusting for age and sex, the secular trend remained significant in Mexican Americans and borderline significant in non-Hispanic whites. This indicates that between 1987 and 1996 the 7- to 8-year incidence of type 2 diabetes approximately tripled in both ethnic groups. The overall secular trend also remained significant after adjusting for additional risk factors for diabetes, such as obesity. A rising secular trend in obesity was also observed. There has been a significant increasing secular trend in the incidence of type 2 diabetes in Mexican Americans and a borderline significant trend in non-Hispanic whites participating in the San Antonio Heart Study. Unlike other cardiovascular risk factors such as lipid levels, cigarette smoking, and blood pressure, which are either declining or under progressively better medical management and control, and unlike cardiovascular mortality, which is also declining, obesity and type 2 diabetes are exhibiting increasing trends. Thus, obesity and diabetes could easily become the preeminent US public health problem.
  Archives of Internal Medicine 08/1999; 159(13):1450-6. · 11.46 Impact Factor
• Source

  Available from: diabetesjournals.org

  Article: Reversion from type 2 diabetes to nondiabetic status. Influence of the 1997 American Diabetes Association criteria.

  J P Burke, S M Haffner, S P Gaskill, K L Williams, M P Stern
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  ABSTRACT: To determine the incidence and the rate of reversion of type 2 diabetes to a nondiabetic status in the 7- to 8-year follow-up of the San Antonio Heart Study, and to determine the influence of the recent 1997 American Diabetes Association (ADA) criteria for diabetes on these rates. Individuals who revert have been problematic for those developing criteria for the diagnosis of type 2 diabetes. Few studies have addressed this issue using 1979 National Diabetes Data Group/1980 World Health Organization (WHO) criteria. We studied 3,682 Mexican-American and non-Hispanic white men and nonpregnant women who completed both the baseline and follow-up examination of the San Antonio Heart Study. Incidence and reversion rates were calculated using both the 1980 WHO and the 1997 ADA criteria. Risk factors for reversion were identified, and the best fitting model using multiple logistic regression was determined using both the 1980 WHO and the 1997 ADA criteria. Using the 1997 ADA criteria, the age-adjusted incidences of type 2 diabetes for Mexican-American men and women were 10.8 and 12.2%, respectively. For non-Hispanic white men and women, the age-adjusted incidence rates were 5.5 and 5.1%, respectively. Similar age-adjusted incidences were recorded using the 1980 WHO criteria. The reversion rate for individuals with type 2 diabetes was 11.5% using the 1980 WHO criteria and 12.5% using the 1997 ADA criteria. These rates were not significantly different. Numerous risk factors for reversion were identified. The best fitting model, after controlling for age, sex, and ethnicity, included baseline 2-h glucose level, baseline HDL cholesterol, and previous diagnosis of diabetes. The models were the same for both the 1980 WHO and the 1997 ADA criteria. There was no significant difference in the incidence or the reversion rates for diabetic subjects using either 1980 WHO or 1997 ADA criteria. In addition, the risk factors for reversion were very similar using either set of criteria. The revision of the ADA criteria did not have a significant influence on reversion in this study.
  Diabetes Care 09/1998; 21(8):1266-70. · 8.09 Impact Factor