Browsing by Author "Horton, Edward"

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    Circulating natriuretic peptide concentrations reflect changes in insulin sensitivity over time in the Diabetes Prevention Program
    (Springer, 2014-05) Walford, Geoffrey A.; Ma, Yong; Christophi, Costas A.; Goldberg, Ronald B.; Jarolim, Petr; Horton, Edward; Mather, Kieren J.; Barrett-Connor, Elizabeth; Davis, Jaclyn; Florez, Jose C.; Wang, Thomas J.; Department of Medicine, IU School of Medicine
    AIMS/HYPOTHESIS: We aimed to study the relationship between measures of adiposity, insulin sensitivity and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in the Diabetes Prevention Program (DPP). METHODS: The DPP is a completed clinical trial. Using stored samples from this resource, we measured BMI, waist circumference (WC), an insulin sensitivity index (ISI; [1/HOMA-IR]) and NT-proBNP at baseline and at 2 years of follow-up in participants randomised to placebo (n = 692), intensive lifestyle intervention (n = 832) or metformin (n = 887). RESULTS: At baseline, log NT-proBNP did not differ between treatment arms and was correlated with baseline log ISI (p < 0.0001) and WC (p = 0.0003) but not with BMI (p = 0.39). After 2 years of treatment, BMI decreased in the lifestyle and metformin groups (both p < 0.0001); WC decreased in all three groups (p < 0.05 for all); and log ISI increased in the lifestyle and metformin groups (both p < 0.001). The change in log NT-proBNP did not differ in the lifestyle or metformin group vs the placebo group (p > 0.05 for both). In regression models, the change in log NT-proBNP was positively associated with the change in log ISI (p < 0.005) in all three study groups after adjusting for changes in BMI and WC, but was not associated with the change in BMI or WC after adjusting for changes in log ISI. CONCLUSION/INTERPRETATION: Circulating NT-proBNP was associated with a measure of insulin sensitivity before and during preventive interventions for type 2 diabetes in the DPP. This relationship persisted after adjustment for measures of adiposity and was consistent regardless of whether a participant was treated with placebo, intensive lifestyle intervention or metformin.
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    Hepatic Fat in Participants With and Without Incident Diabetes in the Diabetes Prevention Program Outcome Study
    (The Endocrine Society, 2021) Goldberg, Ronald B.; Tripputi, Mark T.; Boyko, Edward J.; Budoff, Matthew; Chen, Zsu-Zsu; Clark, Jeanne M.; Dabelea, Dana M.; Edelstein, Sharon L.; Gerszten, Robert E.; Horton, Edward; Mather, Kieren J.; Perreault, Leigh; Temprosa, Marinella; Wallia, Amisha; Watson, Karol; Irfan, Zeb; Medicine, School of Medicine
    Context: There is little information about fatty liver in prediabetes as it transitions to early diabetes. Objective: This study is aimed at evaluating the prevalence and determinants of fatty liver in the Diabetes Prevention Program (DPP). Methods: We measured liver fat as liver attenuation (LA) in Hounsfield units (HU) in 1876 participants at ~14 years following randomization into the DPP, which tested the effects of lifestyle or metformin interventions versus standard care to prevent diabetes. LA was compared among intervention groups and in those with versus without diabetes, and associations with baseline and follow-up measurements of anthropometric and metabolic covariates were assessed. Results: There were no differences in liver fat between treatment groups at 14 years of follow-up. Participants with diabetes had lower LA (mean ± SD: 46 ± 16 vs 51 ± 14 HU; P < 0.001) and a greater prevalence of fatty liver (LA < 40 HU) (34% vs 17%; P < 0.001). Severity of metabolic abnormalities at the time of LA evaluation was associated with lower LA categories in a graded manner and more strongly in those with diabetes. Averaged annual fasting insulin (an index of insulin resistance [OR, 95% CI 1.76, 1.41-2.20]) waist circumference (1.63, 1.17-2.26), and triglyceride (1.42, 1.13-1.78), but not glucose, were independently associated with LA < 40 HU prevalence. Conclusion: Fatty liver is common in the early phases of diabetes development. The association of LA with insulin resistance, waist circumference, and triglyceride levels emphasizes the importance of these markers for hepatic steatosis in this population and that assessment of hepatic fat in early diabetes development is warranted.
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    Metabolic syndrome components and their response to lifestyle and metformin interventions are associated with differences in diabetes risk in persons with impaired glucose tolerance
    (Wiley Blackwell (Blackwell Publishing), 2014-04) Florez, Hermes; Temprosa, Marinella G.; Orchard, Trevor J.; Mather, Kieren J.; Marcovina, Santica M.; Barrett-Connor, Elizabeth; Horton, Edward; Saudek, Christopher; Pi-Sunyer, Xavier F.; Ratner, Robert E.; Goldberg, Ronald B.; Department of Medicine, IU School of Medicine
    AIMS: To determine the association of metabolic syndrome (MetS) and its components with diabetes risk in participants with impaired glucose tolerance (IGT), and whether intervention-related changes in MetS lead to differences in diabetes incidence. METHODS: We used the National Cholesterol Education Program/Adult Treatment Panel III (NCEP/ATP III) revised MetS definition at baseline and intervention-related changes of its components to predict incident diabetes using Cox models in 3234 Diabetes Prevention Program (DPP) participants with IGT over an average follow-up of 3.2 years. RESULTS: In an intention-to-treat analysis, the demographic-adjusted hazard ratios (95% confidence interval) for diabetes in those with MetS (vs. no MetS) at baseline were 1.7 (1.3-2.3), 1.7 (1.2-2.3) and 2.0 (1.3-3.0) for placebo, metformin and lifestyle groups, respectively. Higher levels of fasting plasma glucose and triglycerides at baseline were independently associated with increased risk of diabetes. Greater waist circumference (WC) was associated with higher risk in placebo and lifestyle groups, but not in the metformin group. In a multivariate model, favourable changes in WC (placebo and lifestyle) and high-density lipoprotein cholesterol (placebo and metformin) contributed to reduced diabetes risk. CONCLUSIONS: MetS and some of its components are associated with increased diabetes incidence in persons with IGT in a manner that differed according to DPP intervention. After hyperglycaemia, the most predictive factors for diabetes were baseline hypertriglyceridaemia and both baseline and lifestyle-associated changes in WC. Targeting these cardiometabolic risk factors may help to assess the benefits of interventions that reduce diabetes incidence.
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    Sex Differences in Diabetes Risk and the Effect of Intensive Lifestyle Modification in the Diabetes Prevention Program
    (2008-07) Perreault, Leigh; Ma, Yong; Dagogo-Jack, Sam; Horton, Edward; Marrero, David G.; Crandall, Jill; Barrett-Connor, Elizabeth
    OBJECTIVE—In participants of the Diabetes Prevention Program (DPP) randomized to intensive lifestyle modification (ILS), meeting ILS goals strongly correlated with prevention of diabetes in the group as a whole. Men met significantly more ILS goals than women but had a similar incidence of diabetes. Therefore, we explored sex differences in risk factors for diabetes and the effect of ILS on risk factors. RESEARCH DESIGN AND METHODS—Baseline risk factors for diabetes and percent change in risk factors over the first year in men versus women were compared using Wilcoxon's rank-sum tests. RESULTS—At baseline, men were older and had a larger waist circumference; higher fasting plasma glucose concentration, caloric intake, and blood pressure; and lower HDL cholesterol and corrected insulin response than women, who were less physically active and had a higher BMI (P < 0.01 for all comparisons). Over the first year of the DPP, no sex difference in risk factors for diabetes was observed for those who lost <3% body weight. Weight loss of 3–7% body weight yielded greater decreases in 2-h glucose (P < 0.01), insulin concentration (P < 0.04), and insulin resistance (P < 0.03) in men than in women. Weight loss of >7% body weight resulted in greater decreases in 2-h glucose (P < 0.01), triglyceride level (P < 0.01), and A1C (P < 0.03) in men than in women. CONCLUSIONS—Weight loss >3% body weight yielded greater reduction in risk factors for diabetes in men than in women. Despite the more favorable effects of ILS in men, baseline risk factors were more numerous in men and likely obscured any sex difference in incident diabetes.