The new paper was published in the journal JACC Heart Failure. It was the work of researchers associated with Harvard Medical School, Cedars Sinai Medical Center in Los Angeles and other hospitals and institutions.
The research is another ancillary study of the VITAL (Vitamin D and Omega-3 Trial). The researchers were looking to see what role T2D and race might have on the effects of omega-3 supplements on the incidence of HF hospitalization.
Heart failure—sometimes referred to as congestive heart failure—is a condition in which the heart muscle doesn't pump blood as well as it should. In these cases blood can back up and fluid can accumulate in the lungs, leading to shortness of breath.
The condition can be caused by coronary artery disease or high blood pressure. These can leave the heart too weak or too stiff to properly perform its function.
The researchers noted that prior studies have shown that 83% of patients diagnosed with heart failure will be hospitalized at least once, and 67% will be hospitalized two or more times. Mortality is high, and the costs of this care are high as well.
Big data set
The VITAL study provided participants with 2,000 IU of vitamin D and 460 mg of eicosapentaenoic acid [EPA] and 380 mg of docosahexaenoic acid [DHA]) a day, compared to placebo. The study ran from 2011 to 2017 and included more than 25,000 participants. The authors of the present study excluded 36 of those who had chronic heart failure at the time of enrollment in VITAL. About 1,700 of VITAL participants had been diagnosed with T2D.
After crunching the preexisting data, the researchers concluded that the omega-3s intervention had a positive effect on preventing hospitalization for heart failure among VITAL participants who had been diagnosed with T2D.
Within the window of the first follow up visit in VITAL, which averages about 5.3 years, 3.6% of the T2D group receiving the vitamin D-omega-3s intervention had been hospitalized for heart failure. That compared to 5.2% of the placebo group.
The researchers also saw a benefit of omega-3s on preventing recurrent heart failure hospitalizations among the T2D group. Interestingly, they did not find a protection against recurrent hospitalization among VITAL participants whose suffered form heart failure but who were not Type 2 diabetics. The Black subjects with T2D also enjoyed a protective effect from heart failure hospitalizations, but the researchers said this was true for Black participants without T2D, unlike the White members of the cohort.
Future study could unlock conundrum of differing outcomes
“Our data provide evidence in support of beneficial effects of marine omega-3 supplements on the incidence rate of both initial and recurrent HF hospitalization among participants with T2D. Our secondary finding of benefits of marine omega-3 supplements on HF risk among Black individuals merits further investigation,” the authors concluded.
“It’s a nice finding,” said William S. Harris, PhD, head of the Sioux Falls, SD-based Fatty Acid Research Institute, which itself has published a number of papers reexamining previously published data.
Harris said it could be a fruitful area of future research to parse out just what genetic factors might account for the differing outcomes for Black and White participants. There could a number of subtle factors at play, he said, given that most Black Americans have mixed race ancestry.
“This points the direction for a more focused study along these lines,” he said.
Source: JACC Heart Failure
Diabetes Mellitus, Race, and Effects of Omega-3 Fatty Acids on Incidence of Heart Failure Hospitalization
Authors: Djoussé L, et al.