OBJECTIVE: We examined whether adipocytokines might explain the ethnic differences in the relationship between obesity and insulin resistance among the three major ethnic groups in Singapore.
DESIGN AND PARTICIPANTS: This was a cross-sectional study of 101 Chinese, 82 Malays, and 81 South Asian men. Insulin sensitivity index (ISI) was measured using hyperinsulinemic euglycemic clamp. Visceral (VAT) and subcutaneous adipose tissue (SAT) volumes were quantified using magnetic resonance imaging.
MAIN OUTCOME MEASURES: Plasma total and high-molecular-weight adiponectin, leptin, visfatin, apelin, IL-6, fibroblast growth factor 21 (FGF21), retinol binding protein-4 (RBP 4), and resistin were measured using enzyme-linked immunoassays.
RESULTS: Principle component (PC) analysis on the adipocytokines identified three PCs, which explained 49.5% of the total variance. Adiponectin loaded negatively, and leptin and FGF21 loaded positively onto PC1. Visfatin, resistin, and apelin all loaded positively onto PC2. IL-6 loaded positively and RBP-4 negatively onto PC3. Only PC1 was negatively associated with ISI in all ethnic groups. In the path analysis, SAT and VAT were negatively associated with ISI in Chinese and Malays without significant mediatory role of PC1. In South Asians, the relationship between VAT and ISI was mediated partly through PC1, whereas the relationship between SAT and ISI was mediated mainly through PC1.
CONCLUSIONS: The relationships between abdominal obesity, adipocytokines and insulin sensitivity differ between ethnic groups. Adiponectin, leptin, and FGF21 play a mediating role in the relationship between abdominal adiposity and insulin resistance in South Asians, but not in Malays or Chinese.
AIM: The aim of this paper was to review the role of CMKLR-1 receptor and the potential therapeutic target in the management of chemerin induced type 2 diabetes mellitus and cancer.
PATHOPHYSIOLOGY: Increased chemerin secretion activates an inflammatory response. The inflammatory response will increase the oxidative stress in adipose tissue and consequently results in an insulin-resistant state. The occurrence of inflammation, oxidative stress and insulin resistance leads to the progression of cancers.
CONCLUSION: Chemerin is one of the markers that may involve in development of both cancer and insulin resistance. Chemokine like receptor- 1 (CMKLR-1) receptor that regulates chemerin levels exhibits a potential therapeutic target for insulin resistance, type 2 diabetes and cancer treatment.
METHODS: Fifty overweight/obese individuals aged 22-29 years were assigned to either no-exercise control (n=25) or HIIT (n=25) group. The HIIT group underwent a 12-week intervention, three days/week, with intensity of 65-80% of age-based maximum heart rate. Anthropometric measurements, homeostatic model of insulin resistance (HOMA-IR) and gene expression analysis were conducted at baseline and post intervention.
RESULTS: Significant time-by-group interactions (p<0.001) were found for body weight, BMI, waist circumference and body fat percentage. The HIIT group had lower body weight (2.3%, p<0.001), BMI (2.7%, p<0.001), waist circumference (2.4%, p<0.001) and body fat percentage (4.3%, p<0.001) post intervention. Compared to baseline, expressions of PGC-1∝ and AdipoR1 were increased by approximately three-fold (p=0.019) and two-fold (p=0.003) respectively, along with improved insulin sensitivity (33%, p=0.019) in the HIIT group.
CONCLUSION: Findings suggest that HIIT possibly improved insulin sensitivity through modulation of PGC-1∝ and AdipoR1. This study also showed that improved metabolic responses can occur despite modest reduction in body weight in overweight/obese individuals undergoing HIIT intervention.
OBJECTIVES: To determine the prevalence and characteristics of NAFLD in individuals with metabolically healthy obesity.
SETTING: A tertiary, academic, referral hospital.
METHODS: All patients who underwent bariatric surgery with intraoperative liver biopsy from 2008 to 2015 were identified. Patients with preoperative hypertension, dyslipidemia, or prediabetes/diabetes were excluded to identify a cohort of metabolically healthy obesity patients. Liver biopsy reports were reviewed to determine the prevalence of NAFLD.
RESULTS: A total of 270 patients (7.0% of the total bariatric surgery patients) met the strict inclusion criteria for metabolically healthy obesity. The average age was 38 ± 10 years and the average body mass index was 47 ± 7 kg/m2. Abnormal alanine aminotransferase (>45 U/L) and asparate aminotransferase levels (>40 U/L) were observed in 28 (10.4%) and 18 (6.7%) patients, respectively. A total of 96 (35.5%) patients had NAFLD with NALFD Activity Scores 0 to 2 (n = 61), 3 to 4 (n = 25), and 5 to 8 (n = 10). A total of 62 (23%) patients had lobular inflammation, 23 (8.5%) had hepatocyte ballooning, 22 (8.2%) had steatohepatitis, and 12 (4.4%) had liver fibrosis.
CONCLUSION: Even with the use of strict criteria to eliminate all patients with any metabolic problems, a significant proportion of metabolically healthy patients had unsuspected NAFLD. The need and clinical utility of routine screening of obese patients for fatty liver disease and the role of bariatric surgery in the management of NAFLD warrants further investigation.