Int J Biol Sci 2009; 5(3):286. doi:10.7150/ijbs.5.286
Serum adipokine levels in the obese people
Gulhane School of Medicine, Department of Internal Medicine, Etlik 06018 Ankara, Turkey
Tasci I, Dogru T, Erdem G, Tapan S, Ercin CN, Sonmez A. Serum adipokine levels in the obese people. Int J Biol Sci 2009; 5(3):286. doi:10.7150/ijbs.5.286. Available from http://www.ijbs.com/v05p0286.htm
We read the article by Onat et al (1) on the association of serum adiponectin with obesity, hyperinsulinemia, lipoproteins, inflammatory markers and sex hormone binding globulin. In a relatively large population sample, they report some interesting results based mostly on statistical associations that, to our understanding, might not wholly represent the studied population itself.
As we know, other than the body fat content, degree of insulin sensitivity and age, there are some more major determinants of circulating adiponectin. First, we clearly know that not only the people with diabetes mellitus but also those with impaired glucose tolerance have lower adiponectin level compared to healthy controls (2). Second, increased blood pressure is a condition with decreased adiponectin concentration (3,4). Third, as the authors noticed in their model, medications for metabolic diseases such as diabetes, hypertension or dyslipidemia significantly alter blood level of adipokines (5-7).
The authors state in their paper that blood adiponectin has no association with antidiabetic, antihypertensive or hypolipidmic medications. However, no information was given about the fasting glucose level or glucose tolerance status of the other participants without documented diabetes most of whom were obese. Moreover, it appears that newly diagnosed or insufficiently treated diabetes or hypertension was categorized in the same group with established disease, which needs to be argued further. Therefore, it would be appreciated if the authors could present some more data adjusted for major confounders including fasting glucose, prediabetes and newly diagnosed or untreated diabetes and hypertension. This could provide the readers of the journal clearer information in relation to the link between adiposity, adipokines and insulin sensitivity.
1. Onat A, Hergenç G, Dursunoğlu D. et al. Relatively high levels of serum adiponectin in obese women, a potential indicator of anti-inflammatory dysfunction: relation to sex hormone-binding globulin. Int J Biol Sci. 2008;4:208-14
2. Behre CJ, Brohall G, Hulthe J, Fagerberg B. Serum adiponectin in a population sample of 64-year-old women in relation to glucose tolerance, family history of diabetes, autoimmunity, insulin sensitivity, C-peptide, and inflammation. Metabolism. 2006;55:188-94
3. Adamczak M, Wiecek A, Funahashi T, Chudek J, Kokot F, Matsuzawa Y. Decreased plasma adiponectin concentration in patients with essential hypertension. Am J Hypertens. 2003;16:72-5
4. Imatoh T, Miyazaki M, Momose Y. et al. Adiponectin levels associated with the development of hypertension: a prospective study. Hypertens Res. 2008;31:229-33
5. Hung YJ, Lin SH, Pei D. et al. Rosiglitazone improves insulin sensitivity in nonobese subjects with impaired glucose tolerance: the role of adiponectin and C-reactive protein. Metabolism. 2006;55:439-44
6. Swarbrick MM, Havel PJ. Physiological, pharmacological, and nutritional regulation of circulating adiponectin concentrations in humans. Metab Syndr Relat Disord. 2008;6:87-102
7. Tasci I, Erdem G, Ozgur G. et al. LDL-cholesterol lowering increases plasma apelin in isolated hypercholesterolemia. Atherosclerosis. 2008 [Epub ahead of print]
Correspondence to: Professor Ilker Tasci, itasciedu.tr