Zhiling Chan1, Cherlyn Ding1, Yu Chung Chooi1, John Choo1, Suresh Anand Sadananthan2, S Sasikala1, Amanda Chang1, Navin Michael2, Sambasivam Sendhil Velan2,3, Melvin K-S Leow1,4,5, Faidon Magkos1,6,7. 1. Clinical Nutrition Research Centre (CNRC), Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research (A*STAR), National University Health System, Singapore, Singapore. 2. Agency for Science, Technology and Research (A*STAR), Singapore Institute for Clinical Sciences (SICS), Singapore, Singapore. 3. Laboratory of Molecular Imaging, Singapore Bioimaging Consortium (SBIC), Agency for Science Technology and Research (A*STAR), Singapore, Singapore. 4. Department of Endocrinology, Tan Tock Seng Hospital, Singapore, Singapore. 5. Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore. 6. Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore, Singapore. 7. Department of Nutrition, Exercise and Sports, University of Copenhagen, Frederiksberg, Denmark.
Abstract
BACKGROUND: The importance of ectopic fat deposition and physical fitness in the pathogenesis of insulin resistance and beta cell dysfunction in subjects from the nonobese Asians is not known. MATERIALS AND METHODS: We conducted a cross-sectional study and measured insulin sensitivity (M value; 4-hour hyperinsulinaemic-euglycaemic clamp), insulin secretion rate (3-hour mixed meal tolerance test with oral minimal modelling), percent body fat, visceral adipose tissue, intramyocellular and intrahepatic lipid contents (magnetic resonance imaging and spectroscopy), cardiorespiratory fitness (VO2 max; graded exercise test) and habitual physical activity (short International Physical Activity Questionnaire) in 60 healthy nonobese Asian subjects (BMI = 21.9 ± 1.7 kg/m2 , age = 41.8 ± 13.4 years). RESULTS: M was inversely associated with percent body fat (r = -0.460, P < 0.001), visceral fat (r = -0.623, P < 0.001) and liver fat (r = -0.601, P < 0.001), whereas insulin secretion correlated positively with these adiposity indices (percent body fat: r = 0.303, P = 0.018; visceral fat: r = 0.409, P = 0.010; hepatic fat: r = 0.393, P = 0.002). VO2 max correlated negatively with insulin secretion rate (r = -0.420, P < 0.001) and positively with M (r = 0.658, P < 0.001). The amount of vigorous physical activity was positively associated with VO2 max (r = 0.682, P < 0.001). Multiple stepwise linear regression analyses indicated that VO2 max, age, and IHTG or VAT were independent determinants of insulin sensitivity and secretion (adjusted R2 = 69% and 33%, respectively, P < 0.001). CONCLUSIONS: Increased ectopic fat deposition is associated with reduced insulin sensitivity and increased insulin secretion in healthy nonobese Asians. Poor cardiorespiratory fitness, likely due to inadequate participation in vigorous exercise, is strongly related to suboptimal metabolic function. Interventions to encourage engagement in physical activity may thus be important for improving metabolic health in nonobese Asians.
BACKGROUND: The importance of ectopic fat deposition and physical fitness in the pathogenesis of insulin resistance and beta cell dysfunction in subjects from the nonobese Asians is not known. MATERIALS AND METHODS: We conducted a cross-sectional study and measured insulin sensitivity (M value; 4-hour hyperinsulinaemic-euglycaemic clamp), insulin secretion rate (3-hour mixed meal tolerance test with oral minimal modelling), percent body fat, visceral adipose tissue, intramyocellular and intrahepatic lipid contents (magnetic resonance imaging and spectroscopy), cardiorespiratory fitness (VO2 max; graded exercise test) and habitual physical activity (short International Physical Activity Questionnaire) in 60 healthy nonobese Asian subjects (BMI = 21.9 ± 1.7 kg/m2 , age = 41.8 ± 13.4 years). RESULTS: M was inversely associated with percent body fat (r = -0.460, P < 0.001), visceral fat (r = -0.623, P < 0.001) and liver fat (r = -0.601, P < 0.001), whereas insulin secretion correlated positively with these adiposity indices (percent body fat: r = 0.303, P = 0.018; visceral fat: r = 0.409, P = 0.010; hepatic fat: r = 0.393, P = 0.002). VO2 max correlated negatively with insulin secretion rate (r = -0.420, P < 0.001) and positively with M (r = 0.658, P < 0.001). The amount of vigorous physical activity was positively associated with VO2 max (r = 0.682, P < 0.001). Multiple stepwise linear regression analyses indicated that VO2 max, age, and IHTG or VAT were independent determinants of insulin sensitivity and secretion (adjusted R2 = 69% and 33%, respectively, P < 0.001). CONCLUSIONS: Increased ectopic fat deposition is associated with reduced insulin sensitivity and increased insulin secretion in healthy nonobese Asians. Poor cardiorespiratory fitness, likely due to inadequate participation in vigorous exercise, is strongly related to suboptimal metabolic function. Interventions to encourage engagement in physical activity may thus be important for improving metabolic health in nonobese Asians.
Authors: Nitin Kapoor; Stephen A Jiwanmall; Munaf B Nandyal; Dheeraj Kattula; Sandhiya Paravathareddy; Thomas V Paul; John Furler; Brian Oldenburg; Nihal Thomas Journal: Diabetes Metab Syndr Obes Date: 2020-09-16 Impact factor: 3.168
Authors: Angelo Sabag; Shelley E Keating; Kimberley L Way; Rachelle N Sultana; Sean M Lanting; Stephen M Twigg; Nathan A Johnson Journal: BMC Sports Sci Med Rehabil Date: 2021-04-16