Excess fat, increased urinary albumin-to-creatinine ratio are predictors of heart failure hospitalization among patients with impaired glucose tolerance

April 29, 2013 – DTMI Director Rob Califf, MD, and researchers from the DCRI studied data from more than 9,000 patients enrolled in the NAVIGATOR trial.

Excess abdominal fat and an increased urinary albumin-to-creatinine ratio (UACR) are predictors of incident heart failure hospitalization in patients with impaired glucose tolerance (IGT), according to a study by DCRI and DTMI researchers.

The study’s results appear in the most recent issue of the journal Circulation: Heart Failure. The DCRI’s Yee Weng Wong, MBBS, Laine Thomas, PhD, Jie-Lena Sun, MS, and Adrian F. Hernandez, MD, MHS, were among the coauthors, and DTMI Director Rob Califf, MD, served as senior author of the study. Researchers from Australia, Canada, Great Britain, the Netherlands, and elsewhere in the United States also contributed to the study.

Patients with diabetes and IGT are already known to be at increased risk of heart failure. By identifying these patients as soon as possible and taking preventive measures, clinicians are able to reduce this risk. However, better models of risk prediction would allow clinicians to fine-tune their treatment strategies and avoid unnecessary procedures. In this study, the researchers attempted to characterize the risk of incident heart failure hospitalization and associated predictors among patients with diagnosed IGT and cardiovascular disease.

To construct their risk model, the researchers used patient data from the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial. That prospective, double-blinded, randomized trial enrolled 9,306 research participants aged 50 years or older with IGT and prior cardiovascular diseases or risk factors. Using statistical analysis tools, the researchers examined the relationships among baseline clinical factors and the outcome of incident heart failure hospitalization in patients without a history of heart failure.

The researchers found that increasing age, history of coronary heart disease, and atrial fibrillation or flutter were all predictors, a finding that comports with earlier research. They also identified two new risk factors: excess abdominal fat, as measured by waist circumference, and increased UACR. UACR is a measure of the protein albumin in a person’s urine. Excess albumin can be a sign of damage to the kidneys. The researchers suggested that increased UACR is somehow linked to the pathophysiology of heart failure, although the mechanism by which this occurs remains unclear.

These new risk factors, the researchers concluded, will allow clinicians to create more nuanced risk stratification models for patients with IGT, identify those who might benefit from risk factor modification, and potentially detect heart failure earlier. The findings will also allow researchers to identify patients at increased risk and study them to understand the mechanisms involved in the progression of IGT and insulin resistance to incident heart failure and then to develop novel therapies and treatment strategies.