P38 An exploration of the adipose tissue overflow hypothesis between White British and Pakistani children: results from the born in bradford cohort study

Background

South Asian populations are known to be at an increased risk of non-communicable diseases, such as cardiovascular disease and diabetes. Both greater central adiposity and total higher adiposity for a given BMI compared to White peers may be related to differences. This study aims to explore the adipose tissue overflow hypothesis of Sniderman et. al, which proposes that, compared to White Europeans, South Asians have comparatively small, peripheral, superficial subcutaneous adipose tissue depots in children given the relative paucity of evidence to date.

Methods

Skinfold measurements from the subscapular, triceps and thighs were collected at 6–41 months from White British (N= 561) and Pakistani (N = 651) ethnic background infants from a subset of the Born in Bradford study, a multi-ethnic cohort based in the North of England. Linear spline models of skinfold growth for all three sites were developed, and results indicated best fitting knot placements were at 13 and 21 months for subscapular skinfolds, 11 and 23 months for triceps skinfolds, and 13 and 16 months for thigh skinfolds. Separate trajectories were created for each ethnic and sex group and models were adjusted for potential confounders such as birthweight, length of gestation and gestational diabetes.

Results

White British boys had lower skinfold values at six months than Pakistani boys for subscapular skinfolds (mean difference -0.16 mm (95% C.I.-0.24 to -0.08) whilst having higher triceps, 0.51 mm (95% C.I. 0.38 to 0.65) and thigh skinfolds (0.53 mm (95% C.I. 0.25 to 0.80). White British girls also had lower subscapular skinfolds (-0.50 mm (95% C.I.-0.57 to -0.40); and greater triceps compared with Pakistani girls (0.31 mm (95% C.I. 0.16 to 0.46)), but unlike in males, had lower thigh skinfolds (-0.81 mm (-1.13 to -0.50)) compared to Pakistani girls. The modelled trajectories of triceps and thigh skinfold showed higher mean values for White British children compared to Pakistani children of both sexes, from 7 months onwards, though the estimated magnitude of these ethnic differences was larger for triceps. In contrast mean subscapular skinfold trajectories tracked very similarly by sex group, and showed no consistent ethnic differences.

Conclusion

The results of our study provide some support for the adipose tissue overflow hypothesis in early life, with our findings showing South Asians on average having smaller fat compartments at the periphery and larger truncal deposits. Our findings require confirmation in larger cohorts, and further elucidation of the longer term cardiometabolic impacts of these early life adiposity site differences.