Oral Presentation ANZOS-Breakthrough Discoveries Joint Annual Scientific Meeting 2018

Insights into type 2 diabetes susceptibility and resilience: TOFI_Asia study (#79)

Ivana R Sequeira 1 , Wilson Yip 1 , Louise WW Lu 1 , Lindsay Plank 2 , Rinki Murphy 3 , Kieren G Hollingsworth 4 , Jun Lu 5 , Sally D Poppitt 1 3
  1. Human Nutrition Unit, School of Biological Sciences, University of Auckland, Auckland, New Zealand
  2. Body Composition Unit, Department of Surgery, University of Auckland, Auckland, New Zealand
  3. Department of Medicine, University of Auckland, Auckland, New Zealand
  4. Newcastle Magnetic Resonance Centre, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
  5. Faculty of Health and Environmental Sciences, AUT, Auckland, New Zealand

Predicting rate of progression and identifying those most at risk of adverse metabolic health is difficult and often associated with environmental, lifestyle, and dietary factors. Importantly site of lipid deposition, including ectopic ‘overspill’ into key organs, increases metabolic risk. We investigated susceptibility to type 2 diabetes (T2D) in healthy and prediabetic Asian Chinese (N=209) and European Caucasian (N=156) adults resident in Auckland, enrolled in the TOFI_Asia Study; within the Peak Nutrition for Metabolic Health (PANaMAH) program, one of four priority research platforms in the New Zealand National Science Challenges (NSC).

Phenotypic characterisation of the 2 ethnicity cohorts, using anthropometry, body composition (dual energy X-ray absorptiometry, DXA) and blood biochemistry revealed that although of similar age and body mass index (BMI), Chinese (Mean±SEM, 42±1 yrs; 27.4±0.3 kg/m2) had significantly greater abdominal fat (42.0±0.6% vs 37.0±1.1%, p<0.01) than Caucasian (43±1 yrs; 26.9±0.4 kg/m2) with correspondingly higher fasting plasma glucose (FPG) concentrations (5.4±0.04 mmol/l vs 5.0±0.04 mmol/l, p<0.001) and glycated haemoglobin, HbA1c (36.0±0.3 mmol/mol vs 33.0±0.3 mmol/mol, p<0.05). In addition, pancreatic and liver fat were quantified, using magnetic resonance imaging (MRI) and spectroscopy (MRS), in a subset of 36 Chinese (41±2 yrs; 26.9±0.7 kg/m2) and 34 Caucasian (48±3 yrs; 28.0±0.7 kg/m2) women from the cohort. These overweight, younger Asian Chinese had significantly lower MRI-determined abdominal and subcutaneous fat (p<0.05) but pancreas (4.3±0.3%) and liver (11.0±1.7%) fat matched that, or tended to be higher than, Caucasian (pancreas: 4.1±0.3%; liver: 8.1±1.7%). Importantly, fat in pancreas (Chinese: R2=0.10, p=0.09; Caucasian: R2=0.28, p=0.001) and liver (Chinese: R2=0.12, p=0.04; Caucasian: R2=0.11, p=0.05) were positively correlated with FPG. The Thin on the Outside Fat on the Inside ‘TOFI’ profile observed in this Asian Chinese cohort, may contribute to their greater risk of poor metabolic health compared to Caucasian counterparts even in individuals of the same BMI and younger age.