(HealthDay News) – South Asians have lower total brown adipose tissue (BAT) volume than white Caucasians, according to a study published online Nov. 12 in The Lancet Diabetes & Endocrinology.
Leontine E.H. Bakker, MD, from the Leiden University Medical Center in the Netherlands, and colleagues assessed the volume and activity of BAT in 12 Dutch nationals with south Asian ancestry and 12 matched Caucasians, all healthy lean men, aged 18–28 years.
One Caucasian participant developed hyperventilation and was excluded from the assessments. The researchers found that south Asian participants did not differ in age or body mass index from Caucasians, but were shorter and lighter. South Asian participants had significantly lower thermoneutral resting energy expenditure than white Caucasians. Shiver temperature was 2 degrees Celsius higher for south Asians on cold exposure, while non-shivering thermogenesis was not increased in south Asians, but was increased by 20% in white Caucasians. There was no difference between the groups in maximum and mean standardized uptake volumes of 18F-fluorodeoxyglucose in BAT, but the total BAT volume was lower in south Asians than in Caucasians (188 vs. 287mL). In all assessable individuals, BAT volume correlated positively with resting energy expenditure.
“Lower resting energy expenditure, non-shivering thermogenesis, and BAT volumes in south Asian populations might underlie their high susceptibility to metabolic disturbances, such as obesity and type 2 diabetes,” the authors write.