Study examines risk factors of common diseases related to body weight
It has been widely reported that overweight and obesity are potential risk factors for metabolic disorders such as diabetes, high blood pressure and high cholesterol in the blood (hypercholesterolemia). On the other hand, there are reports of “sick slim people” who, despite their normal weight, have a similarly higher risk of cardiovascular diseases than obese people. Likewise, there seems to be the phenomenon of "healthy fats", which despite massive overweight do not develop metabolic disorders. A current study examined how metabolic risk factors are influenced by body weight and what actual risks for heart attack and stroke result from this.
Scientists from the German Institute for Nutritional Research (DIfE), Harvard University and the University Hospital Tübingen examined around 90,000 data records from a large US cohort study. The data all come from women. According to the analysis results, women who are severely overweight or obese have an increased risk of heart disease, even if they have a healthy metabolism. It was also shown that women of normal weight are at increased risk of having a heart attack or stroke if they have a metabolic disorder such as diabetes or high blood pressure. The results were recently published in the specialist journal "The Lancet Diabetes & Endocrinology".
Data was collected over 30 years
The research team led by Matthias Schulze and Nathalie Eckel from DIfE evaluated the data from a large US long-term study (Nurses' Health Study). The women were followed up medically for up to 30 years. The focus was on body weight, metabolic health and the occurrence of heart attacks or strokes. Women who did not have high blood pressure, diabetes or hypercholesterolemia were classified as metabolically healthy regardless of body weight.
Obesity as an independent risk factor
In the group of metabolically healthy women, it was found that subjects with overweight or obesity had an increased risk of cardiovascular diseases compared to normal weight subjects. The study also showed that as soon as a risk factor such as high blood pressure, diabetes or high cholesterol levels in the blood increased, the risk of heart attack and stroke increased regardless of body weight.
Diabetes and high blood pressure as the biggest risk factors
Over the course of 20 years, more than 80 percent of the metabolically healthy women who were overweight developed at least one of these risk factors. Around two thirds of women with normal weight also experienced at least one risk factor in the same period. According to the study results, diabetes and high blood pressure in particular are associated with a two to three times higher risk of heart attack and stroke.
There is no such thing as healthy obesity
"We observed that obese women were also at higher risk for cardiovascular diseases if they remained metabolically healthy for more than 10 or even 20 years," reports lead author Nathalie Eckel in a press release on the study results. Obesity thus represents a serious risk of disease, regardless of whether you have had no metabolic abnormalities for years. There is therefore still no clear evidence that a subgroup exists in people with obesity that is not at increased risk, said Eckel. The researchers emphasize that the results are consistent with a previous study that attempted to find an appropriate definition of healthy obesity.
Slim people should also be on guard
"We were also surprised that even among the metabolically healthy, normal-weight women, such a high proportion of either high blood pressure, diabetes or a fat metabolism disorder has developed over the course of 20 years," summarizes study director Matthias Schulze, who heads the Molecular Epidemiology Department at DIfE. Since these diseases significantly influence the risk of heart attack and stroke, it is important to maintain metabolic health in the long term through a healthy lifestyle and a healthy diet. This applies equally to normal-weight or overweight people. (vb)