Lean people who are metabolically unhealthy, but have normal weight, might be a 300 per cent greater chance of dying from Type 2 diabetes or cardiovascular disease, a research has claimed.
According to the Norbert Stefan, Professor at the University of Tubingen in Germany, it is a contrast to the small proportion of obese people who despite their body mass index (BMI) are metabolically healthy. And for this group, the risk of all-cause mortality is only 25 per cent higher than that of healthy lean people, Stefan added.
The research revealed that, among lean people, skinny lower legs may prove to be the strongest predictor of poor metabolic health while for obese people, abdominal fat levels and non-alcoholic fatty liver disease are strong predictors of cardiometabolic diseases such as Type 2 diabetes or cardiovascular disease.
In lean people, a gene-derived problem of storing fat in the lower limbs may be a crucial factor, placing them at an increased risk of cardiometabolic diseases, Stefan said.
The reserachers collected data from 981 subjects. After having defined metabolic health as having less than two risk parameters of the metabolic syndrome, they found that 18 per cent of their lean subjects were metabolically unhealthy.
Through magnetic resonance imaging and magnetic resonance spectroscopy, they found body fat mass, fat distribution and deposition of fat in the liver. Further, they also determined insulin sensitivity, insulin secretion, thickness of the carotid vessel wall and fitness.
Such unhealthy lean but normal BMI phenotype body shape also resembled people with certain rare diseases such as lipodystrophy in which the body is unable to sustain adequate fat reserves.The findings provide evidence for the existence of a “lipodystrophy-like phenotype in the general population”, the researchers noted.