People with diabetes were three times as likely as those without it to develop life-threatening critical illness and die prematurely, shows a newly published study. But obese people who did not have diabetes had the same risk of death or organ failure as normal-weight people without the disease.
Being obese is a huge risk factor for type 2 diabetes. Nine out of 10 people with newly diagnosed type 2-diabetes are overweight or obese, according to the American Diabetes Association.
But most previous studies that have linked obesity to early death have not considered the independent impact of diabetes, researcher David M. Mannino, M.D., tells WebMD.
"What this paper shows pretty clearly is that diabetes is really the driving factor in early death from critical illness among people who are overweight or obese," Mannino says.
Mannino and colleagues from the University of Kentucky Chandler Hospital and Atlanta's Emory University School of Medicine analyzed data from 15,408 people. The study was conducted in the mid- to late 1980s, and the participants were between the ages of 44 and 66 at enrollment.
Obesity was measured by calculating body mass index (BMI), and hospital records were examined to determine if the participants experienced either acute organ failure (critical illness) or death from organ failure during the critical-illness hospitalization or within three years after the acute organ failure.
In the absence of diabetes, obese people in the study were not found to have an increased risk for either organ failure or early death. But obese study participants — those with BMIs over 30 — were four times as likely to have diabetes as those who were normal weight.
The study appears in today's issue of the journal Critical Care.
"Our results do not support the contention that obesity itself is a risk factor for increased mortality in patients with acute organ failure," the researchers wrote. "It brings up a new perspective on this still controversial subject of obesity, critical illness, and mortality."
The new findings are not likely to end the medical debate about whether obesity is a direct or indirect cause of early death.
The issue made headlines a year ago last spring, when CDC researchers reported that the risk of obesity-related death was much lower than had been previously believed.
Researchers also reported no increase in death risk among people who were overweight but not obese.