Original Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Diabetes. Jul 15, 2012; 3(7): 135-141
Published online Jul 15, 2012. doi: 10.4239/wjd.v3.i7.135
Over expression of resistin in adipose tissue of the obese induces insulin resistance
Sadashiv, Sunita Tiwari, Bhola N Paul, Sandeep Kumar, Abhijit Chandra, S Dhananjai, Mahendra PS Negi
Sadashiv, Sunita Tiwari, S Dhananjai, Department of Physiology, CSM Medical University, Lucknow 226003, India
Bhola N Paul, Immunobiology Division, Indian Institute of Toxicological Research, Lucknow 226001, India
Sandeep Kumar, Department of Surgery, CSM Medical University, Lucknow 226003, India
Abhijit Chandra, Department of Gastroenterology, CSM Medical University, Lucknow 226003, India
Mahendra PS Negi, Institute for Data Computing and Training, Lucknow 226021, India
Author contributions: Sadashiv performed the experimental works and wrote the manuscript; Tiwari S designed the study and edited the manuscript; Paul BN provided analytical tools; Kumar S and Chandra A provided blood samples and adipose tissues; and Dhananjai S and Negi MPS helped in the statistical analysis.
Supported by Indian Council of Medical Research, New Delhi, India and Central Council Research in Yoga and Naturopathy, New Delhi, India, to Sadashiv and Tiwari S
Correspondence to: Dr. Sunita Tiwari, Professor, Head, Department of Physiology, CSM Medical University, Lucknow 226003, India. research.physiology@gmail.com
Telephone: +91-522-2257542 Fax: +91-522-2257539
Received: April 20, 2012
Revised: May 28, 2012
Accepted: June 10, 2012
Published online: July 15, 2012

AIM: To compare resistin mRNA expression in subcutaneous adipose tissue (SAT) and its correlation with insulin resistance (IR) in postmenopausal obese women.

METHODS: A total of 68 postmenopausal women (non obese = 34 and obese = 34) were enrolled for the study. The women of the two groups were age matched (49-70 years). Fasting blood samples were collected at admission and abdominal SAT was obtained during surgery for gall bladder stones or hysterectomy. Physical parameters [age, height, weight, body mass index (BMI)] were measured. Biochemical (plasma insulin and plasma glucose) parameters were estimated by enzymatic methods. RNA was isolated by the Trizol method. SAT resistin mRNA expression was done by real time- reverse transcription polymerase chain reaction (RT-PCR) by using Quanti Tect SYBR Green RT-PCR master mix. Data was analyzed using independent Student’s t test, correlation and simple linear regression analysis.

RESULTS: The mean weight (52.81 ± 8.04 kg vs 79.56 ± 9.91 kg; P < 0.001), BMI (20.23 ± 3.05 kg/m2vs 32.19 ± 4.86 kg/m2; P < 0.001), insulin (8.47 ± 3.24 μU/mL vs 14.67 ± 2.18 μU/mL; P < 0.001), glucose (97.44 ± 11.31 mg/dL vs 109.67 ± 8.02 mg/dL; P < 0.001) and homeostasis model assessment index (2.01 ± 0.73 vs 3.96 ± 0.61; P < 0.001) were significantly higher in postmenopausal obese women compared to postmenopausal non obese women. The mean serum resistin level was also significantly higher in postmenopausal obese women compared to postmenopausal non obese women (9.05 ± 5.15 vs 13.92 ± 6.32, P < 0.001). Furthermore, the mean SAT resistin mRNA expression was also significantly (0.023 ± 0.008 vs 0.036 ± 0.009; P < 0.001) higher and over expressed 1.62 fold (up-regulated) in postmenopausal obese women compared to postmenopausal non obese women. In postmenopausal obese women, the relative SAT resistin mRNA expression showed positive (direct) and significant correlation with BMI (r = 0.78, P < 0.001) and serum resistin (r = 0.76, P < 0.001). Furthermore, the SAT resistin mRNA expression in postmenopausal obese women also showed significant and direct association (r = 0.45, P < 0.01) with IR, while in postmenopausal non obese women it did not show any association (r = -0.04, P > 0.05).

CONCLUSION: Increased SAT resistin mRNA expression probably leads to inducing insulin resistance and thus may be associated with obesity-related disorders in postmenopausal obese women.

Keywords: Resistin, Subcutaneous adipose tissue, Insulin resistance, Obesity, Body mass index