Sudden cardiac death may be linked to waist-to-hip ratio

One more reason to tell patients to watch the waistline this holiday season: Research indicates that higher waist-to-hip ratio may result in increased risk for sudden cardiac death (SCD).

These findings come out of data from the on-going Atherosclerosis Risk in Communities (ARIC) study and were published online recently in Heart. ARIC continues to follow four middle-age cohorts of individuals from four U.S. communities and current data represents 24 years of long-term observation.

SCD occurs in 300,000 individuals per year in the U.S. and is characterized by loss of heart function and blood flow. While some patients also may have coronary heart disease, this loss of function is unexpected and abrupt.

Research identified obesity as having a relationship to SCD, which this study confirmed. Selcuk Adabag, MD, of the cardiology division at the Veterans Affairs Medical Center in Minneapolis, and colleagues reviewed data from 14, 941 ARIC participants. They compared rates for SCD against measurements for body mass index (BMI), waist circumference and waist-to-hip ratio, all potential obesity indicators.

In nonsmokers, all three indicated some degree of risk for SCD. Of all measures, patients with high waist-to-hip ratio were twice as likely to have SCD compared to counterparts with normal waist-to-hip ratios. The doubled risk remained, even following adjustment for hypertension, diabetes, prevalent coronary heart disease, lipid levels, heart failure or left ventricular atrophy.

There was an incremental increase in risk for participants of 3 percent, 15 percent and 59 percent for BMI, waist circumference, and waist-to-hip ratio, respectively.

All findings related to nonsmokers specifically. Adabag et al found it difficult to characterize incidence for smokers as there were very few occurrences of SCD in the study population.

Adabag et al wrote, “The association between each of the three measures of obesity, namely BMI, WC [waist circumference] and WHR [waist-to-hip ratio], with SCD were continuous, indicating that the relationship exists across the continuum of the body size spectrum.” While they noted that some of the impact of BMI and WC were confounded by other traditional risk factors, this was not the case for waist-to-hip ratio.

“Only for WHR was there evidence of a direct association with SCD—even after adjusting for variables on the causal pathway, individuals in the top category of WHR had double the risk of mortality from SCD compared with those in the lowest WHR group,” they wrote.