Prevalence of diabetes/hyperglycemia and associated cardiovascular risk factors in blacks and whites: Chicago Heart Association Detection Project in Industry

Postchallenge plasma glucose excursions, carotid intima-media thickness, and risk factors for atherosclerosis in Chinese population with type 2 diabetes

AIMS

Isolated hyperglycemia is associated with atherosclerosis in individuals with type 2 diabetes, but the relationship between postchallenge glucose excursion and atherosclerosis is less clear. This study examines the relationships between postchallenge glucose spikes (PGS), carotid intima-media thickness (IMT), and traditional risk factors for atherosclerosis in individuals with type 2 diabetes.

METHODS

A total of 474 individuals with type 2 diabetes who were within the highest or lowest IMT distribution quartile were included. The Student's t-test, one-way analysis of variance (ANOVA), single variate and multivariate analyses were implemented to study the data. An additional healthy control group (n=896) was selected during routine health examination. They were Han nationality and unrelated to the diabetic patients.

RESULTS

(1) Compared with subjects of healthy control group, the subjects with type 2 diabetes had significantly higher levels of body mass index (BMI), waist-to-hip ratio (WHR), systolic blood pressure, triglyceride, total cholesterol, low density lipoprotein cholesterol (LDL-C), fasting plasma glucose (FPG), 120 min postchallenge glucose (PG120), hemoglobin A1c (HbA1c) and IMT (P < or = 0.01) and relatively lower levels of high density lipoprotein cholesterol (HDL-C) (P < or = 0.05). (2) According to the IMT which was measured by B-mode ultrasonography, the patients of type 2 diabetes could be divided into two subgroups: one was the subgroup of IMT > or = P(75) and another was the subgroup of IMT < or = P(25). Compared with subjects of IMT > or = P(25) subgroup, subjects being in the IMT > or = P(75) subgroup exhibited significantly increased age, WHR, diabetes duration, systolic blood pressure, total cholesterol, triglyceride, LDL-C, and significantly decreased HDL-C levels. And among all the plasma glucose variables, except for FPG and PG30, all the other variables (include PG60, PG120, PG180, PGS, HbA1C, under area curve of glucose) showed a significant increase in the IMT>/=P(75) subgroup. (3) A multivariate logistic regression analysis was performed to establish which were independently related with carotid IMT, and the results showed the PGS was identified as the strongest determinant of IMT from all the atherosclerosis risk factors. (4) PGS is significantly correlated to a variety of atherosclerosis risk factors.

CONCLUSIONS

This study identified several important associations between PGS and known risk factors for atherosclerosis and suggested that PGS is independently related to carotid IMT. Wide postchallenge glucose excursions may contribute to the development of atherosclerosis in individuals with type 2 diabetes, independent of other risk factors.

Simultaneous pancreas-kidney transplantation reduces excess mortality in type 1 diabetic patients with end-stage renal disease

BACKGROUND

Diabetic renal disease continues to be the most significant cause of end-stage renal disease (ESRD) in the United States. Renal transplantation improves diabetic ESRD patient survival; however, the diabetic state remains associated with poor patient survival. Simultaneous pancreas-kidney (SPK) transplantation can restore normoglycemia and thus may improve outcomes.

METHODS

We assessed the impact of SPK on age-range-matched type 1 diabetic patients who underwent renal transplantation at a single center. The observed/expected life span and annual mortality rates (AMRs) were used as measures of survival. A Cox proportional hazards analysis was used to analyze the impact of potential variables on mortality in SPK recipients.

RESULTS

SPK transplantation (N = 335) increased the observed/expected life span compared with diabetic cadaveric (DM-Cad, N = 147) and live-donor (DM-Live, N = 160) transplant recipients (P = 0.004) and significantly reduced the AMRs (SPK, 1. 5%; DM-Cad, 6.27%; DM-Live, 3.65%, P = 0.008, SPK vs. other DM). Moreover, the SPK observed/expected life span and AMR were not significantly different from that of age-range-matched nondiabetic transplant recipients (N = 492). The only variable that was significantly associated with patient survival was discharge serum creatinine (relative risk 1.16, P < or = 0.0154).

CONCLUSION

These data demonstrate that SPK improves the ability for type 1 diabetic patients to live more of their expected life span. This suggests that glycemic control, even as a late intervention in a diabetic patient's lifetime, may beneficially affect survival.

Diabetes mellitus, coronary heart disease incidence, and death from all causes in African American and European American women: The NHANES I epidemiologic follow-up study

Few data are available on risk for coronary heart disease in African American women with diabetes mellitus, a well-established coronary risk factor in European American women. This study tests the hypothesis that medical history of diabetes predicts coronary heart disease incidence in African American women in a national cohort. Participants in the NHANES I Epidemiologic Follow-up Study in this analysis were 1035 African American and 5732 European American women aged 25-74 years without a history of coronary heart disease. Average follow-up for survivors was 19 years (maximum 22 years). Risk of incident coronary heart disease by baseline diabetes status was estimated. Proportional hazards analyses for African American women aged 25-74 revealed significant associations of coronary heart disease risk with diabetes after adjusting for age (RR = 2.40; 95% CI, 1.58-3.64, P < 0.01). After adjusting for age, smoking, and low education, there was an elevated risk in diabetics age 25-74 (RR = 2. 34; 95% CI, 1.54-3.56, P < 0.01); this association did not differ significantly from that for European American women. Excess coronary incidence in African American compared to European American women aged 25-64 was statistically explained by controlling for diabetes history, age, education, and smoking but only partly explained by age and diabetes history. In African American women aged 25-74, diabetes was also associated with increased coronary heart disease, cardiovascular, and all-cause mortality. The population attributable risk of coronary heart disease incidence associated with a medical history of diabetes was 8.7% in African American women and 6.1% in European American women. Medical history of diabetes was a significant predictor of coronary heart disease incidence and mortality in African American women and explained some of the excess coronary incidence in younger African American compared to European American women.

Racial differences in risk factors for atherosclerosis. The ARIC Study. Atherosclerosis Risk in Communities

This paper describes black/white differences in risk factors for atherosclerosis in the large multicenter Atherosclerosis Risk in Communities (ARIC) Project sponsored by the National Heart, Lung, and Blood Institute. It is based on data collected at baseline in ARIC's four geographically distinct clinical centers. Participants were randomly selected (4264 black and 11,479 white men and women, ages forty-five to sixty-four years at entry). There were striking differences in obesity between black and white women, higher fasting glucose and greater prevalence of diabetes in blacks, and lower high-density lipoprotein values in white men. Not unexpectedly, blood pressure in black participants exceeded that in whites. Clustering of multiple risk factors was more common in the black population. Conversely, prevalence of no risk factors was greatest among whites. In conclusion, while African-Americans and Caucasians share much the same group of risk factors for atherosclerosis, there are clinically important racial differences in emphasis.

Diabetes mellitus, race, and socioeconomic status. A population-based study

To identify factors associated with diabetes mellitus and to determine whether racial differences in these factors, especially socioeconomic status, explain the high prevalence of diabetes among African-Americans, we performed a cross-sectional study using a population-based, representative sample from three US communities. The participants comprised 975 white and 418 African-American adults, aged 35 to 54 years. The main outcome variable was the presence of diabetes defined by either self-report or abnormal results on the oral glucose tolerance test (serum glucose level > 10.0 mmol/L (180 mg/dL) 1 hour after 50-g oral glucose dose). Compared to their white counterparts, African-American participants were more overweight, displayed greater central adiposity, and had lower socioeconomic status. Diabetes was over twice as prevalent among African-Americans (10.3%) as compared to whites (4.6%; odds ratio (OR) = 2.38; 95% confidence interval (95% CI): 1.50, 3.75; P = 0.0001). After adjustments for racial differences in age, socioeconomic status, overweight, and central adiposity, African-Americans remained over twice as likely to have diabetes compared to whites (OR = 2.35; 95% CI: 1.49, 3.73; P = 0.0003). The excess prevalence of diabetes in African-Americans was greatest in individuals of low socioeconomic status (OR = 4.09) and least among individuals of high socioeconomic status (OR = 1.90; P < 0.001 for trend). Racial differences in obesity and socioeconomic status do not appear to explain fully the higher prevalence of diabetes among African-Americans. African-American race seems to be a strong, independent risk factor for diabetes, especially among individuals of low socioeconomic status.

Duplex Doppler and spectral flow analysis of racial differences in cerebrovascular atherosclerosis

We compared carotid artery disease in 99 black and 106 white patients using duplex ultrasonography (B-mode imaging and Doppler spectral analysis). Blacks had significantly less stenosis of the extracranial internal carotid artery than whites. Among the risk factors investigated, hypertension alone, ischemic heart disease, diabetes mellitus, and smoking failed to explain the racial difference. Although carotid stenosis of greater than or equal to 40% correlated significantly with age in both races (p = 0.001 in whites and p = 0.005 in blacks), blacks had significantly less carotid stenosis of any degree even when age was taken into account. Multivariate analysis showed that race is a significant and independent risk factor for carotid stenosis (p less than 0.0001). Hypertension interacting with race was also significant. Our results require verification in population-based studies. Carotid duplex ultrasonography offers a noninvasive method for carrying out such studies.

Association of fasting insulin with blood pressure and lipids in young adults. The CARDIA study

The association of insulin with cardiovascular disease (CVD) may be mediated in part by the associations of insulin with CVD risk factors, particularly blood pressure and serum lipids. These associations were examined in 4576 black and white young adults in the CARDIA Study. Fasting insulin level was correlated in univariate analysis with systolic blood pressure (r = 0.16), diastolic blood pressure (r = 0.13), triglycerides (r = 0.27), total cholesterol (r = 0.10), high density lipoprotein (HDL) cholesterol (r = -0.25), and low density lipoprotein (LDL) cholesterol (r = 0.14), and with age, sex, race, glucose, body mass index, alcohol intake, cigarette use, physical activity, and treadmill duration (all p less than 0.0001). After adjustment for these covariates, insulin remained positively associated with blood pressure, triglycerides, total and LDL cholesterol, and apolipoprotein B and was negatively associated with HDL, HDL2 and HDL3 cholesterol, and apolipoprotein A-I in all four race-sex groups. Higher levels of fasting insulin are associated with unfavorable levels of CVD risk factors in young adults; these associations, though relatively small, can be expected to increase the risk of atherosclerosis. Demonstration of these relationships in a large, racially diverse, healthy population suggests that insulin may be an important intermediate risk factor for CVD in a broad segment of the U.S. population.