title: Associations among Insulin Resistance, Triacylglycerol/High Density Lipoprotein (TAG/HDL ratio) and Thyroid hormone levels-A study on Type 2 diabetes mellitus in obese and overweight subjects.
abstract: OBJECTIVE
  Triacylglycerol/High density lipoprotein (TAG/HDL) ratio, a surrogate marker of LDL particle size (small dense) was included in our study to observe the link with insulin resistance and thyroid co-morbidity.
  
  
  METHODS
  Ninety three patients with T2DM of both genders were enrolled from a tertiary health care unit in Puducherry, during the latter half of 2015. The cardio-metabolic risk factors were assessed through body mass index (BMI), blood pressure, fasting blood glucose and lipid profile, glycated haemoglobin and homeostasis model assessment of insulin resistance (HOMA-IR). Serum free T4, T3 and TSH were also measured to evaluate the thyroid co-morbidity as a function of insulin resistance.
  
  
  RESULTS
  In addition to insulin resistance, results of our study were focussed on thyroid comorbidity. In overweight diabetic patients, the ROC curve analyses demonstrated that the best marker for insulin resistance was Triacylglycerol/High density lipoprotein (TAG/HDL), with the area under the ROC curve being 0.902. Thyroxine (T4) was less significant when compared to TAG/HDL with area under the ROC curve of 0.583. Triiodothyronine (T3) and T4 were more significant in obese group with areas under the curve being 0.842 and 0.816 respectively when compared against insulin resistance (cut-off value for HOMA-IR 2.69). The optimal cut-off points for overweight were: TAG≥101mg/dl; T4≥1.16ng/dl; TAG/HDL≥2.26 whereas for obese: TC≥163.5mg/dl; TAG≥141.5mg/dl; T3≥2.42pg/ml; T4≥0.96ng/ml.
  
  
  CONCLUSIONS
  In overweight type 2 diabetics, TAG/HDL ratio could be used as a reliable marker for insulin resistance with thyroid co-morbidity and T3, T4 were better objective markers in obese type 2 diabetics.
authors.affiliation: Department of Biochemistry, Mahatma Gandhi Medical College & Research Institute, Sri Balaji Vidyapeeth, Pondicherry 607403, India.
authors.forename: Rajendran
authors.initials: R
authors.lastname: Jayanthi
authors.affiliation: Department of Biochemistry, Mahatma Gandhi Medical College & Research Institute, Sri Balaji Vidyapeeth, Pondicherry 607403, India. Electronic address: raghavan.drvars2000@gmail.com.
authors.forename: Abu Raghavan
authors.initials: AR
authors.lastname: Srinivasan
authors.affiliation: Department of General Medicine, Mahatma Gandhi Medical College & Research Institute, Sri Balaji Vidyapeeth, India.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Hanifah
authors.affiliation: Department of Community Medicine, Mahatma Gandhi Medical College & Research, Institute Sri Balaji Vidyapeeth, India.
authors.forename: Anandraj Lokesh
authors.initials: AL
authors.lastname: Maran
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D050177:Overweight / Q000150:complications*; D011379:Prognosis; D012372:ROC Curve; D013963:Thyroid Hormones / Q000097:blood*; D014280:Triglycerides / Q000097:blood*
chemical_list: D015415:Biomarkers; D008076:Cholesterol, HDL; D013963:Thyroid Hormones; D014280:Triglycerides
keywords: Cardio metabolic factors; Obesity; Thyroid hormones; Type 2 diabetes