(RxWiki News) Overweight and obesity are often associated with several different health problems later in life. But unhealthy people of normal weight could still be at risk.
A recent review of studies found that metabolically unhealthy people of normal weight, overweight people and obese people were all more at risk for death and heart disease than their healthy counterparts of each weight category.
The researchers concluded that there was long-term risk for health issues associated with increased weight regardless of metabolic health.
"Discuss healthy weight management with your doctor."
The lead author of this study was Ravi Retnakaran, MD, from the Leadership Sinai Centre for Diabetes at the Mount Sinai Hospital in Toronto, Ontario, Canada.
Dr. Retnakaran and colleagues reviewed eight past studies published between 1950 and June 5, 2013.
There were a total of 61,386 adult participants who were categorized as either normal weight, overweight or obese. In addition, the studies had to determine whether or not the participants were metabolically healthy or unhealthy in each category.
Metabolic health was based on the criteria for having metabolic syndrome — a group of conditions that happen together and increase the risk of heart disease, stroke and diabetes. These conditions include high blood pressure, high levels of blood sugar, large waist size because of excess fat and abnormal levels of cholesterol.
Each of the studies reported all-cause mortality (death due to any cause) or heart health events — both fatal and nonfatal. A total of 3,988 of these events occurred.
Between 11 percent and 51 percent of the participants had reported being current smokers at the time of the study.
A total of 6 percent of all the participants had metabolically unhealthy normal weight and 9 percent had metabolically healthy obesity.
Dr. Retnakaran and team found that the metabolically healthy obese participants had a 24 percent increased risk of all-cause mortality or heart disease over a period of 10 or more years compared to the metabolically healthy participants who were in the normal weight category.
The findings also showed that all the metabolically unhealthy participants in all three weight categories had similar risk increases compared to the healthy counterparts in their weight category.
Compared to the healthy, normal-weight participants, the metabolically unhealthy participants who were normal weight were found to have a 314 percent increased risk of death or heart disease.
The unhealthy overweight participants had a 217 percent increased risk of death or heart disease compared to their healthy counterparts.
For the unhealthy obese participants, the risk increased by 265 percent.
The findings also revealed that blood pressure, waist size and insulin resistance increased, and the level of good cholesterol decreased, for both metabolically healthy and unhealthy participants in all three weight categories as weight increased.
The obese participants — regardless of metabolic health — were still found to be at increased risk for negative health events long-term.
The researchers therefore concluded that being overweight or obese was unhealthy in the long run for all individuals.
The authors noted a few limitations of their review. First, most of the reviewed studies did not consider whether or not a participant used medication.
Second, the researchers of this review did not consider the risk difference between the different subgroups of obesity.
Third, the total risk associated with each weight category was based off of combined risk estimates that were not adjusted for outside factors in the original studies.
This study was published in the December edition of the Annals of Internal Medicine.
The Leadership Sinai Centre for Diabetes provided funding.