Kathleen A. Jablonski

Haptoglobin Phenotype Is an Independent Risk Factor for Cardiovascular Disease in Individuals With Diabetes: The Strong Heart Study

OBJECTIVESnThe goal of this study was to determine if the haptoglobin phenotype was predictive of cardiovascular disease (CVD) in diabetic mellitus (DM).nnnBACKGROUNDnCardiovascular disease is the most frequent, severe, and costly complication of type 2 DM. There are clear geographic and ethnic differences in the risk of CVD among diabetic patients that cannot be fully explained by differences in conventional CVD risk factors. We have demonstrated that a functional allelic polymorphism in the haptoglobin gene acts as a major determinant of susceptibility for the development of diabetic microvascular complications.nnnMETHODSnWe sought to determine if this paradigm concerning the haptoglobin gene could be extended to CVD in DM. We tested this hypothesis in a case-control sample from the Strong Heart study, a population-based longitudinal study of CVD in American Indians. Haptoglobin phenotype was determined by polyacrylamide gel electrophoresis in 206 CVD cases and 206 matched controls age 45 to 74 years. Median follow-up was six years.nnnRESULTSnIn multivariate analyses controlling for conventional CVD risk factors, haptoglobin phenotype was a highly statistically significant, independent predictor of CVD in DM. The odds ratio of having CVD in DM with the haptoglobin 2-2 phenotype was 5.0 times greater than in DM with the haptoglobin 1-1 phenotype (p = 0.002). An intermediate risk of CVD was associated with the haptoglobin 2-1 phenotype.nnnCONCLUSIONSnThis study suggests that determination of haptoglobin phenotype may contribute to the algorithm used in CVD risk stratification, and in evaluation of new therapies to prevent CVD in the diabetic patient.

Percutaneous Fibrin Sheath Stripping versus Transcatheter Urokinase Infusion for Malfunctioning Wellpositioned Tunneled Central Venous Dialysis Catheters: A Prospective, Randomized Trial

PURPOSEnTo compare central dialysis catheter patency rates after stripping procedures with those after urokinase (UK) infusion.nnnMATERIALS AND METHODSnFifty-seven tunneled catheters with either (i) flow rates less than 250 mL/min and established baseline flow rates > or = 300 mL/min or (ii) flow rates 50 mL/min less than higher established baseline flows were prospectively randomized to undergo stripping procedures (n = 28) or UK infusion (n = 29) at 30,000 U/h via each port concurrently, for a total 250,000 U. Success and patency were determined by dialysis at normal flow rates (> or = 300 mL/min) or at the previously established higher baseline rate. Flow rates were monitored weekly. Primary patency ended with catheter malfunction or removal. Kaplan-Meier survival analysis was used to construct survival curves.nnnRESULTSnIn the stripping group, initial clinical success was 89% (25 of 28). The 15-, 30-, and 45-day primary patency rates were 75% (n = 20), 52% (n = 13), and 35% (n = 8), respectively. The median duration of additional function was 32 days (95% CI: 18-48 d). In the UK group, initial clinical success was 97% (28 of 29). The 15-, 30-, and 45-day primary patency rates were 86% (n = 21), 63% (n = 13), and 48% (n = 9), respectively. The median duration of additional patency was 42 days (95% CI: 22-153 d). The Wilcoxon test for equality detected no significant difference in the survival curves for the two treatment groups (P = .236).nnnCONCLUSIONnThere is no significant difference in time to primary patency between the two methods. Both allow temporary catheter salvage in most patients.

Effects of Isolated Post-challenge Hyperglycemia on Mortality in American Indians

PURPOSEnTo assess the effects of isolated post-challenge hyperglycemia (IPH) on risk of cardiovascular disease (CVD), cancer, and all-cause mortality in American Indians using longitudinal data from the Strong Heart Study.nnnMETHODSnOf 4549 American Indian women and men aged 45 to 74 years participating in the Strong Heart Study, 4304 had fasting blood measurements or oral glucose tolerance test (OGTT) data to ascertain diabetes status. At baseline and follow-up, a personal interview was conducted, and physical examinations and laboratory tests were performed. Fasting blood samples were drawn for measurement of glucose, fibrinogen, insulin, lipids, lipoproteins, creatinine, and hemoglobin A1c (HbA1c). A 75-g OGTT was performed. Five diabetes categories were defined: (i) known diabetes, (ii) newly diagnosed diabetes (fasting glucose > or =126 mg/dL and no history of diabetes or diabetes medication; ADA-new diabetes), (iii) IPH, (iv) impaired fasting glucose (> or =110 - <126 mg/dL; IFG), and (v) normal fasting glucose (<110 mg/dL; NFG). Surveillance was initiated to determine CVD, cancer, and all-cause mortality over 9 years.nnnRESULTSnIPH had a worse CVD risk factor profile than NFG, but IPH was associated with a better CVD risk factor profile than known diabetes or ADA-new diabetes. At follow-up, individuals with IFG had no increased risk for CVD or all-cause mortality, whereas those with ADA-new or known diabetes had significantly increased risk (RR = 1.70 and 1.40 for ADA-new diabetes, and RR = 2.87 and 2.19 for known diabetes, respectively). Those with IPH had nonsignificant elevations in risk for CVD (RR = 1.54) and all-cause (RR = 1.27) mortality. Cancer mortality was not increased in those with IFG, IPH, ADA-new diabetes, or known diabetes compared to those with NFG.nnnCONCLUSIONSnAmong American Indians 45 to 74 years of age, IPH is associated with nonsignificant elevations in total and CVD mortality. The magnitude of mortality risk associated with IPH is intermediate between diabetes and IFG. Because those with IPH are at high risk for diabetes, American Indians with IPH should be targeted for diabetes prevention.

Accuracy of lipoprotein lipids and apoproteins in predicting coronary Heart disease in diabetic American Indians: The Strong Heart study

PURPOSEnTo evaluate the accuracy of lipoprotein lipids and apoproteins in predicting coronary heart disease (CHD) in diabetic American Indians.nnnMETHODSnThis study included 2099 diabetic participants of the Strong Heart Study, which is a longitudinal study of cardiovascular disease (CVD) and its risk factors in American Indians in Arizona, Oklahoma, and South and North Dakota. Diabetic participants with incident CHD (N = 126) were selected as the case group, and those without CHD or any cardiovascular events were the control group (N = 1732). Previous vascular events such as stroke were the sole exclusion criterion (N = 241). Baseline measurements of lipoprotein lipids and apoproteins were used to predict CHD diagnosed at the 4-year follow-up examination by using Receiver-Operating Characteristic (ROC) curve analysis.nnnRESULTSnThe ratio of high-density lipoprotein (HDL) to total cholesterol had the highest area under the ROC curve (0.69 +/- 0.02). The areas for the ratios of HDL to low-density lipoprotein (LDL) cholesterol (0.68 +/- 0.02), apo AI/B (0.66 +/- 0.02), and the single component of total cholesterol (0.64 +/- 0.03) and LDL cholesterol (0.63 +/- 0.05) were not significantly different from the area for HDL/total cholesterol. However, the areas for apo B (0.64 +/- 0.02), HDL cholesterol (0.62 +/- 0.03), triglycerides (0.58 +/- 0.03), and apo AI (0.57 +/- 0.05) were significantly lower than the area for HDL/total cholesterol. Logistic regression analysis indicates that only HDL and LDL cholesterol were significant independent lipoprotein lipid and apoprotein predictors for CHD. The other significant predictors in the model were study center, age, gender, and albuminuria. The ROC area for this model is 0.75.nnnCONCLUSIONSnHDL and LDL cholesterol were the most important independent predictors for incident CHD in diabetic American Indians. The ratios of HDL/total cholesterol, HDL/LDL cholesterol, and apo AI/B had higher accuracy for predicting CHD. Although the values for all lipoprotein lipids and apoproteins and their ratios were not large enough to definitely predict CHD, they can be used as screening tools for CHD in diabetic American Indians.

Effects of glycaemic control on cardiovascular disease in diabetic American Indians: the Strong Heart Study

Aimsu2003 Diabetes increases the risk of cardiovascular disease (CVD). Only part of this excess risk is explained by diabetes‐associated hypertension, obesity, and lipid disorders. Poor glycaemic control may help explain the residual CVD risk. The aim of this study was to determine whether variations in glycaemic control are associated with CVD risk in diabetic individuals.