David M Nathan’s research while affiliated with Harvard Medical School and other places

Importance In 2013, the Trial to Assess Chelation Therapy (TACT) reported that in 1708 patients with stable coronary disease and prior myocardial infarction (MI), oral multivitamins and multiminerals (OMVMs), in a factorial design with edetate disodium (EDTA) chelation therapy, did not reduce cardiovascular events relative to placebo OMVMs, but active EDTA combined with active OMVMs was superior to placebo OMVM/placebo EDTA. Objective To compare OMVM vs placebo in terms of efficacy for reducing major adverse cardiovascular events in patients with diabetes and prior MI. Design, Setting, and Participants The TACT2 randomized, multicenter double-masked 2 × 2 factorial clinical trial took place across 88 sites in the US and Canada. Participants were 50 years or older, had diabetes, and had an MI 6 weeks ago or more. TACT2 participants were enrolled between September 2016 and December 2020. Data were collected between October 2016 and June 2023. Interventions Six caplets daily of a 28 component OMVM or matching OMVM placebo, and 40 weekly infusions of an EDTA-based chelation solution or matching placebo, in a 1:1:1:1 allocation ratio. Main Outcomes and Measures The primary end point was the composite of all-cause mortality, MI, stroke, coronary revascularization, or hospitalization for unstable angina. Results A total of 1000 participants were randomized (500 in the active OMVM group and 500 in the placebo group). The median (IQR) age was 67 (60-72) years, and 730 (73%) were male. Median (IQR) follow-up was 48 (34-58) months. The primary end point occurred in 175 participants (35%) in the active OMVM group and 175 (35%) in the placebo group (hazard ratio [HR], 0.99 [95% CI, 0.80-1.22]; P = .92). The 5-year event rate for the primary end point in the EDTA chelation + active OMVM group was 34.0%; in the EDTA chelation + placebo OMVM group, 35.7%; in the placebo infusion + active OMVM group, 36.0%; and in the placebo infusion + placebo OMVM group, 34.3%. The comparison of the active infusion + active OMVM with the placebo infusion + placebo OMVM was not significant (HR, 0.91 [95% CI, 0.67-1.23]; P = .54). Although nonsignificant, there was a numerically higher event rate of MI, stroke, mortality from cardiovascular causes in the active OMVM compared to placebo OMVM group. Conclusions and Relevance The results of this randomized clinical trial demonstrated that, for participants with chronic coronary disease, diabetes, and a previous MI, high-dose OMVM alone or in conjunction with EDTA-based chelation did not reduce cardiovascular events. Trial Registration ClinicalTrials.gov Identifier: NCT02733185

OBJECTIVE To determine whether the relationship between average glucose (AG) levels and hemoglobin A1c (HbA1c) differs across racial/ethnic groups. RESEARCH DESIGN AND METHODS We performed a prospective substudy of GRADE, a comparative effectiveness randomized trial conducted in 36 centers in the U.S. A total of 1,454 of the 5,047 participants in the GRADE cohort, including 534 non-Hispanic White (NHW), 389 non-Hispanic Black (NHB), and 327 Hispanic White patients and 204 patients of other racial/ethnic backgrounds, were included in the substudy. Continuous glucose monitoring (CGM) performed for 10 days was used to calculate AG10. Immediately after CGM, HbA1c and glycated albumin were measured. Fasting plasma glucose (FPG) and glucose area under the curve (AUC) were derived from a 75-g oral glucose tolerance test. RESULTS The relationship between AG10 and HbA1c was significantly different for NHB compared with NHW patients and those of other racial/ethnic groups. HbA1c levels were 0.2–0.6 percentage points higher in NHB than in NHW patients for AG10 levels from 100 to 250 mg/dL. For an HbA1c of 7%, AG10 was 11 mg/dL higher for NHW than for NHB patients. Similar findings were observed across races for relationships of FPG and AUC with HbA1c and for glucose measurements with glycated albumin levels. Differences in the relationship between AG10 and HbA1c across racial groups remained after adjustments for any demographic or other differences between racial/ethnic subgroups. CONCLUSIONS The relationship between several measures of glucose with HbA1c and glycated albumin consistently differed across races. These findings should be considered in setting treatment goals and diagnostic levels.

Importance In 2013, the Trial to Assess Chelation Therapy (TACT) reported that edetate disodium (EDTA)–based chelation significantly reduced cardiovascular disease (CVD) events by 18% in 1708 patients with a prior myocardial infarction (MI). Objective To replicate the finding of TACT in individuals with diabetes and previous MI. Design, Setting, and Participants A 2 × 2 factorial, double-masked, placebo-controlled, multicenter trial at 88 sites in the US and Canada, involving participants who were 50 years or older, had diabetes, and had experienced an MI at least 6 weeks before recruitment compared the effect of EDTA-based chelation vs placebo infusions on CVD events and compared the effect of high doses of oral multivitamins and minerals with oral placebo. This article reports on the chelation vs placebo infusion comparisons. Interventions Eligible participants were randomly assigned to 40 weekly infusions of an EDTA-based chelation solution or matching placebo and to twice daily oral, high-dose multivitamin and mineral supplements or matching placebo for 60 months. This article addresses the chelation study. Main Outcomes and Measures The primary end point was the composite of all-cause mortality, MI, stroke, coronary revascularization, or hospitalization for unstable angina. Median follow-up was 48 months. Primary comparisons were made from patients who received at least 1 assigned infusion. Results Of the 959 participants (median age, 67 years [IQR, 60-72 years]; 27% females; 78% White, 10% Black, and 20% Hispanic), 483 received at least 1 chelation infusion and 476 at least 1 placebo infusion. A primary end point event occurred in 172 participants (35.6%) in the chelation group and in 170 (35.7%) in the placebo group (adjusted hazard ratio [HR], 0.93; 95% CI, 0.76-1.16; P = .53). The 5-year primary event cumulative incidence rates were 45.8% for the chelation group and 46.5% for the placebo group. CV death, MI, or stroke events occurred in 89 participants (18.4%) in the chelation group and in 94 (19.7%) in the placebo group (adjusted HR, 0.89; 95% CI, 0.66-1.19). Death from any cause occurred in 84 participants (17.4%) in the chelation group and in 84 (17.6%) in the placebo group (adjusted HR, 0.96; 95% CI, 0.71-1.30). Chelation reduced median blood lead levels from 9.03 μg/L at baseline to 3.46 μg/L at infusion 40 ( P < .001). Corresponding levels in the placebo group were 9.3 μg/L and 8.7 μg/L, respectively. Conclusions and Relevance Despite effectively reducing blood lead levels, EDTA chelation was not effective in reducing cardiovascular events in stable patients with coronary artery disease who have diabetes and a history of MI. Trial Registration ClinicalTrials.gov Identifier: NCT02733185

Introduction The Look AHEAD randomized clinical trial reported that an 8-year intensive lifestyle intervention (ILI) compared with diabetes support and education (DSE) in adults aged 45–76 years with type 2 diabetes and overweight/obesity delayed kidney disease progression. Here, we report long-term post-intervention follow-up for the trial’s secondary outcome of kidney disease. Research design and methods We examined effects of ILI (n=2570) versus DSE (n=2575) on decline in estimated glomerular filtration rate (eGFR) to <45 mL/min/1.73 m² or need for kidney replacement therapy (KRT: dialysis or kidney transplant) during intervention and post-intervention follow-up (median 15.6 years overall). Results Incidence of eGFR <45 mL/min/1.73 m² was lower in ILI during the intervention (HR=0.80, 95% CI=0.66 to 0.98) but not post-intervention (HR=1.03, 0.86 to 1.23) or overall (HR=0.92, 0.80 to 1.04). There were no significant treatment group differences in KRT. In prespecified subgroup analyses, age×treatment interactions were significant over total follow-up: p=0.001 for eGFR <45 mL/min/1.73 m² and p=0.01 for KRT. The 2205 participants aged >60 years at baseline had benefit in both kidney outcomes during intervention and overall (HR=0.75, 0.62 to 0.90 for eGFR <45 mL/min/1.73 m²; HR=0.62, 0.43 to 0.91 for KRT). The absolute treatment effects were greater post-intervention: ILI reduced the rate of eGFR <45 mL/min/1.73 m² by 0.46 and 0.76 cases/100 person-years during and post-intervention, respectively; and reduced KRT by 0.15 and 0.21 cases/100 person-years. The younger participants experienced no such post-intervention benefits. Conclusions ILI reduced kidney disease progression during and following the active intervention in persons aged ≥60 years. ILI should be considered for reducing kidney disease incidence in older persons with type 2 diabetes.

Objective Mid‐life cardiovascular risk factors are associated with later cognitive decline. Whether repetitive head injury among professional athletes impacts cardiovascular risk is unknown. We investigated associations between concussion burden and postcareer hypertension, high cholesterol, and diabetes among former professional American‐style football (ASF) players. Methods In a cross‐sectional study of 4080 professional ASF players conducted between January 2015 and March 2022, we used an mulitsymptom concussion symptom score (CSS) and the number of loss‐of‐consciousness (LOC) episodes as a single severe symptom to quantify football‐related concussion exposure. Primary outcomes were hypertension, dyslipidemia, and diabetes, defined by current or recommended prescription medication use. Results The prevalence of hypertension, high cholesterol, and diabetes among former players (52 ± 14 years of age) was 37%, 34%, and 9%. Concussion burden was significantly associated with hypertension (lowest vs. highest CSS quartile, odds ratio (OR) = 1.99; 95%CI: 1.33–2.98; p < 0.01) and high cholesterol (lowest vs. moderate CSS, OR = 1.46, 95%CI, 1.11–1.91; p < 0.01), but not diabetes. In fully adjusted models, the prevalence of multiple CVD was associated with CSS. These results were driven by younger former players (≤ 40 year of age) in which the odds of hypertension were over three times higher in those in the highest CSS quartile (OR = 3.29, 95%CI: 1.39–7.61; p = 0.01). Results were similar for LOC analyses. Interpretation Prior concussion burden is associated with postcareer atherogenic cardiovascular risk profiles among former professional American football players.

OBJECTIVE To examine the accuracy of different periods of continuous glucose monitoring (CGM), hemoglobin A1c (HbA1c), and their combination for estimating mean glycemia over 90 days (AG90). RESEARCH DESIGN AND METHODS We retrospectively studied 985 CGM periods of 90 days with <10% missing data from 315 adults (86% of whom had type 1 diabetes) with paired HbA1c measurements. The impact of mean red blood cell age as a proxy for nonglycemic effects on HbA1c was estimated using published theoretical models and in comparison with empirical data. Given the lack of a gold standard measurement for AG90, we applied correction methods to generate a reference (eAG90) that we used to assess accuracy for HbA1c and CGM. RESULTS Using 14 days of CGM at the end of the 90-day period resulted in a mean absolute error (95th percentile) of 14 (34) mg/dL when compared with eAG90. Nonglycemic effects on HbA1c led to a mean absolute error for average glucose calculated from HbA1c of 12 (29) mg/dL. Combining 14 days of CGM with HbA1c reduced the error to 10 (26) mg/dL. Mismatches between CGM and HbA1c >40 mg/dL occurred more than 5% of the time. CONCLUSIONS The accuracy of estimates of eAG90 from limited periods of CGM can be improved by averaging with an HbA1c-based estimate or extending the monitoring period beyond ∼26 days. Large mismatches between eAG90 estimated from CGM and HbA1c are not unusual and may persist due to stable nonglycemic factors.